IS Hand / LE 2019

Which of the following techniques is most commonly used for reconstruction of a Blauth IIIB thumb hypoplasia in the United States? A. Great toe to thumb transfer B. Index pollicization C. Metacarpophalangeal (MCP) joint stabilization with opponensplasty D. Second toe to thumb transfer E. Toe wrap around transfer

B.

A 40-year-old man comes to the office because of an 8-month history of intermittent ischemic change to the right ring finger. The patient reports intermittent coolness, pallor, pain, and cold sensitivity. Angiogram demonstrates a tortuous ulnar artery at the wrist and faint radial digital artery runoff into the right ring finger. Digital brachial index (DBI) of the ring finger is 0.9. Which of the following is the most appropriate first step in management? A. Botulinum toxin type A injection B. Excision and vein grafting of the ulnar artery C. Ligation of the thrombosed ulnar artery segment D. Thrombectomy and heparin drip E. Trial of acetylsalicylic acid and nifedipine

E. This patient presents with hypothenar hammer syndrome. The gold standard for establishing the diagnosis is angiography. Aortic arch and upper extremity arteriography is the study of choice. In hypothenar hammer syndrome, the pathognomonic angiographic features can include tortuosity of the ulnar artery with a corkscrew appearance, aneurysm formation, occlusion of the ulnar artery segment overlying the hook of the hamate, occluded digital arteries in the ulnar artery distribution, and demonstration of intraluminal emboli at sites of digital obstruction. Treatment depends largely on the severity of the ischemia. The therapeutic strategy is controversial because there are limited studies on this problem. For most patients with milder or transient/intermittent symptoms, nonsurgical treatment will be sufficient, particularly in the setting of vasospasm with adequate collateral circulation. Conservative nonoperative care may include smoking cessation, avoidance of further trauma (may require change of occupation), padded protective gloves, cold avoidance, calcium channel blockers (nifedipine, diltiazem), antiplatelet agents or anticoagulation, local care of fingers with necrosis, and pentoxifylline to reduce blood viscosity. More severe symptoms (persistent ischemia, soft tissue loss/gangrene, ulnar nerve symptoms) or symptoms refractory to nonoperative management require consideration of surgical intervention. Surgical options in this setting include arterial ligation (assuming an intact radial/palmar arch), resection of thrombosed arterial segment or aneurysm with end-to-end anastomosis, or resection and vascular reconstruction with vein or artery graft. Some argue that best outcomes are seen in those treated with surgical resection and reconstruction. The benefits of surgical treatment include removal of the source of embolism, removal of the painful mass, relief of ulnar nerve compression, and creation of a local periarterial sympathectomy. As this patient has mild and intermittent symptoms without evidence of soft-tissue loss or gangrene or any evidence of ulnar nerve irritation, a trial medical management is indicated. Botulinum toxin type A is indicated for vasospasm secondary to Raynaud syndrome or disease and would not be part of the medical management algorithm.

A 50-year-old woman comes to the emergency department after sustaining an avulsion injury of the right ring finger proximal interphalangeal (PIP) joint. A photograph is shown. Examination shows the central slip is disrupted, and the inside of the PIP joint is visible through the dorsal wound. The patient is able to actively extend the PIP joint. Which of the following anatomical structures allows the patient to extend the PIP joint? A. Extrinsic extensor tendon B. Interosseous muscle tendon C. Lateral conjoined tendon D. Oblique retinacular ligament E. Sagittal band

The central slip of the extensor mechanism is the terminal direct extension of the extrinsic extensor tendon (extensor digitorum communis and extensor digiti quinti) and is the primary extensor of the proximal interphalangeal (PIP) joint. Injury to the central slip will normally produce flexion of the PIP joint due to unopposed action of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons and is called a boutonniere deformity. The intrinsic extensor mechanism, via the middle band of the interosseous muscles, also inserts on the dorsal base of the middle phalanx and causes extension of the PIP joint. In an open injury, the central slip may be injured without concurrent injury to the interosseous muscle tendon, allowing the patient to still actively extend the PIP joint even in the presence of a disruption of the central slip. The oblique retinacular ligament connects the flexor tendon sheath volarly to the terminal extensor tendon dorsally. When a patient sustains a laceration to the extensor mechanism over the body of the middle phalanx bone, the oblique retinacular ligament may prevent the occurrence of an extensor lag and a mallet deformity. The lateral conjoined tendon is formed by the lateral bands of the interosseous muscles and the lateral slips of the extrinsic extensor and produces extension of the distal interphalangeal (DIP) joint. The sagittal band keeps the extrinsic extensor tendon centralized over the dorsal metacarpophalangeal (MP) joint by connecting to the volar plate. Disruption of the sagittal band on one side of a finger would allow the extrinsic extensor tendon to dislocate and impair its ability to extend the MP joint.

Which of the following is the arterial supply of the flap for digital tip reconstruction shown (reverse homodigital island flap)? A. Distally based from the contralateral digital artery B. Dorsal perforating vessels C. Perineural perforating vessels D. Proximally based from the ipsilateral digital artery

A. A reverse homodigital island flap is shown. It is a distally based flap that is useful in the repair of fingertip injuries. Arterial inflow is based upon the contralateral digital artery in the crossing ladder vessels of the palmar digital arch that lie just dorsal to the volar plate at each joint. The flap requires sacrifice of the ipsilateral digital artery and care must be taken to preserve the digital nerve during elevation of the skin paddle. Typically, the donor site is grafted.

A 44-year-old woman comes to the office because of a 3-month history of a painful subungual area of bluish discoloration. The patient reports severe pain when localized pressure is applied to the area, and cold water testing elicits severe pain. Which of the following is the most likely diagnosis? A. Glomus tumor B. Hemangioma C. Hematoma D. Melanoma E. Pyogenic granuloma

A. Glomus tumors comprise approximately 1 to 5% of soft-tissue tumors of the hand. The majority are subungual. Presentation is typically a raised blue or pink nodule that can discolor or deform the nail. Love's pin test is performed by applying pressure to the area with a pinhead, causing exquisite pain. Diagnosis can be aided with plain film x-ray and MRI. Treatment includes complete surgical excision. Hematoma, hemangioma, and pyogenic granuloma would less likely present with point tenderness and positive cold water test.

A 17-year-old boy comes to the office because of ongoing pain of the right hand after he punched a wall 5 days ago. Physical examination demonstrates tenderness of the fifth carpometacarpal joint. Posteroanterior, oblique, and lateral x-ray studies taken at an urgent care facility were read as negative by the radiologist. Which of the following additional radiographic views is most likely to help confirm this patient's diagnosis? A. Anteroposterior with 30 degrees of pronation from full supination B. Carpal tunnel view with wrist in full extension C. Clenched fist lateral in neutral forearm position D. Lateral with 15 degrees of supination from neutral forearm position E. Posteroanterior with 45 degrees of supination from full pronation

A. Injuries to the fifth carpometacarpal joint, including subluxation, dislocation, and fracture-dislocation, are often missed with standard two-view and three-view hand images. Two views have been suggested to help detect this subtle injury: 1. Anteroposterior view with forearm pronated 30 degrees from full supination. This view shows more clearly the profile of the articulation between the hamate and fifth metacarpal base. (This is similar to the "reverse oblique" view, which is typically done in 45 degrees of pronation and might also be useful.) 2. Lateral with 30 degrees of pronation. This view is especially helpful for detecting subluxation of the metacarpal dorsally off of the hamate. In some cases, CT scan may be warranted if plain films are inconclusive.

A 42-year-old man presents with an open tibia fracture sustained during a motor vehicle collision 4 hours ago. Physical examination shows a 3-cm puncture wound at the fracture site, no dirt or debris in the wound, and no exposed bone. X-ray studies show a transverse fracture of the tibia and fibula without comminution. Which of the following is the appropriate initial antibiotic coverage? A. First generation cephalosporin B. First generation cephalosporin, aminoglycoside, and penicillin C. First generation cephalosporin and aminoglycoside D. Third generation cephalosporin E. Third generation cephalosporin, aminoglycoside, and penicillin

A. The Gustillo-Anderson classification system is used to grade open fractures based on the extent of bone and soft tissue injury, and the extent and nature of wound contamination. Aggressive debridement, administration of prophylactic antibiotics, application negative pressure dressing while the wound is open, and early definitive wound coverage (less than 5 days) reduces the infection risk. The open fracture described is a grade II injury and a first-generation cephalosporin alone provides appropriate antibiotic coverage. A concurrent vascular or neural injury or gross contamination could escalate this into a grade III injury, but there is no mention of these factors in the clinical scenario described.

A 57-year-old woman comes to the office because of burning pain and stiffness of the right hand 8 weeks after closed treatment of a distal radius fracture. The patient reports that she has had difficulty sleeping and continues to have discomfort despite taking narcotics. On physical examination, the hand is shiny, swollen, and warm, and finger range of motion is decreased. There is hypersensitivity to light touch. X-ray studies show good alignment of the fracture. Electrodiagnostic testing shows no abnormalities. Bone scan shows increased periarticular uptake. Which of the following is the most appropriate diagnosis? A. Complex regional pain syndrome B. Factitious disorder C. Midpalmar space abscess D. Opioid addiction E. Pain catastrophizing

A. The most appropriate diagnosis is reflex sympathetic dystrophy, or complex regional pain syndrome (CRPS) type I. This patient exhibits symptoms consistent with CRPS, which is a form of severe neuropathic pain. The diagnosis of CRPS involves history, physical examination, and diagnostic testing. In addition to pain out of proportion, other features must be present. These can include changes in blood flow, altered temperature perceptions, sudomotor activity, edema, and pigmentation changes. Although no specific test is pathognomonic, triple-phase bone scans are helpful in adding credence to the diagnosis. First- and second-phase bone scans may show asymmetric flow and autonomic dysfunction, while the third phase demonstrates increased periarticular uptake in multiple joints of the affected extremity. CRPS is divided into two types. Type I occurs without identifiable nerve involvement (also known as reflex sympathetic dystrophy), and Type II has identifiable nerve involvement (causalgia). It is more common in smokers and in women. Pain in CRPS can be either sympathetically mediated or sympathetically independent. This condition is characterized by persistent pain, cold intolerance, autonomic dysfunction, and trophic changes. Patients may show swelling, stiffness, difficulty sleeping, and persistent pain out of proportion to the normal postoperative/post-injury course that may be incompletely relieved by narcotics. A variety of treatment modalities have been employed in addressing CRPS. These range from therapy modalities such as range of motion, stress loading, and desensitization to pharmacologic interventions with anticonvulsants or antidepressants. Stellate ganglion blocks or autonomic nerve blocks may be helpful in sympathetically mediated pain, and nerve stimulation (either transcutaneous or at the spinal cord level) can also be employed. Often multiple modalities are used concurrently and in sequence. Peripheral nerve decompression may be helpful in resolving symptoms related to CRPS type II.

An 11-year-old boy is brought to the office with an acute injury of the left small finger. A lateral x-ray study is shown (displaced fx at base of P2). Which of the following is the most appropriate description of this patient's injury? A. Displaced Salter Harris fracture of the middle phalanx B. Displaced Salter Harris fracture of the proximal phalanx C. Nondisplaced Salter Harris fracture of the distal phalanx D. Nondisplaced Salter Harris fracture of the middle phalanx E. Nondisplaced Salter Harris fracture of the proximal phalanx

A. This is a displaced growth plate fracture of the small finger middle phalanx. There is a 90% displacement of the metaphysis relative to epiphysis. Although there is no obvious involvement of the metaphysis and, thus, the injury could be interpreted as a Salter Harris I fracture, minor concurrent involvement of some portion of the metaphysis (making it technically a Salter Harris II fracture) cannot be excluded and is quite common. The proximal and distal phalanges of the small finger are not injured. Growth platesare in base of phalanges and thumb metacarpal. They are in head of all other metacarpals. The mnemonic "SALTER" may be used to recall Salter-Harris fracture types: Type I: S (Slipped). The fracture occurs through the cartilage of the growth plate (physis) with an incidence of 5-7%. Type II: A (Above). The fracture occurs above the physis, through the metaphysis. This is the most common type, occurring in 75% of patients. Type III: L (Lower). The fracture occurs below the physis into the epiphysis. This occurs in 7-10%. Type IV: TE (Through Everything). The fracture occurs through everything which includes the metaphysis, physis, and epiphysis. This type occurs in 10%. Type V: R (Rammed or crushed). The growth plate (physis) has been crushed. This occurs in <1%.

The Jones transfer for radial nerve palsy, specifically flexor carpi ulnaris to extensor digitorum communis III-V, is most likely to have which of the following significant disadvantages? A. Difficulty of dissection B. Inappropriate excursion of donor tendon C. Indirect line of pull requiring pulley creation D. Poor synergy E. Unacceptable postoperative rupture rate

B. Although the Jones transfers were practiced for years, there were significant disadvantages that led to them falling out of favor. Among the disadvantages are loss of flexor carpi ulnaris (FCU) as an important ulnar wrist stabilizer and weakness in flexion/ulnar deviation, which is a very important wrist motion. Additionally, the short excursion of FCU is inadequate to fully extend the fingers when transferred to extensor digitorum communis (EDC). Subsequent modifications to the Jones technique by Boyes and others found better alternatives to the use of FCU. Standard Boyes transfers are: PT to ECRL and ECRB FCR to EPL and ABL FDS-III to EDC (via interosseous membrane) FDS-IV to EPL and EIP (via interosseous membrane)

A 21-year-old man undergoes reconstruction with a free fibula flap. This procedure places the patient at risk for claw toe with loss of active flexion of the great toe. The muscle responsible for this functional loss is located in which of the following compartments in the lower leg? A. Anterior B. Deep posterior C. Lateral D. Superficial posterior

B. Claw toe or loss of active flexion of the great toe interphalangeal joint can result from harvest of the flexor hallucis longus for free fibula flaps. The flexor hallucis longus is present within the deep posterior compartment of the lower leg and should be resuspended to the interosseus membrane and posterior tibial muscles as needed to maintain proper tension. Physical therapy is initiated after adequate wound healing to maintain the mobility of the great toe and ankle. The deep posterior compartment musculature is composed of the tibialis posterior, the flexor digitorum longus, the flexor hallucis longus, and the popliteus. The superficial posterior compartment musculature is composed of the gastrocnemius, soleus, and plantaris. The anterior compartment musculature is composed of the tibialis anterior, the extensor digitorum longus, extensor hallucis longus, and the peroneus tertius. The lateral compartment musculature is composed of the peroneus longus and brevis muscles.

Congenital constriction band syndrome is responsible for which of the following percentages of all congenital upper limb defects? A. 6% B. 12% C. 18% D. 24% E. 30%

B. Constriction band syndrome and amniotic band sequence are the terms applied to a wide range of congenital anomalies, most typically limb and digital amputations and constriction rings which occur in association with fibrous bands. These classic syndromic birth defects represent disruptions and do not occur along the known lines of embryologic development. It has been proposed that the birth defects are caused by the action of the fibrous amniotic bands in association with a rupture of the amnion at early stage of pregnancy, which was later referred to as the "extrinsic theory." In this theory, low amniotic fluid level plays a major role in the development of constriction rings. This has become the more widely accepted theory. However, many cases are associated with birth defects not readily explained by the mechanism of fibrous strings entangling body parts and causing disruption of fetal structures. A subset of cases manifests with cleft lip and palate (CLP), congenital heart defect, and renal anomalies. There are also case reports of children presenting with polydactyly, supernumerary nipples, and skin tags suggesting a genetic origin. Based on a study on 419 upper limb defects and 171 lower limb defects occurring among 753,342 births in Finland during 1993 to 2005, constriction band syndrome comprises approximately 12% of all congenital upper limb defects and 14% of lower limb defects. Other skeletal and non-skeletal anomalies were present in 30% of the affected children, suggesting a possible genetic etiology.

A 23-year-old man who works in an office undergoes evaluation of the left nondominant wrist after sustaining an injury from a fall 2 days ago. CT scan shows a nondisplaced distal scaphoid tubercle fracture. Examination reveals no other abnormalities. Which of the following is the most appropriate next step in management? A. Autologous bone grafting and internal fixation plus immobilization for 3 to 6 months B. Cast immobilization for 6 to 8 weeks C. Compression screw fixation plus immobilization for 6 to 12 weeks D. Physical therapy for 6 weeks E. Observation until the wrist is nontender

B. Nondisplaced scaphoid fractures may not be apparent on plain radiographs and are better visualized on CT scan. Although the treatment options for nondisplaced scaphoid wrist fractures may include immobilization alone or surgical fixation, nondisplaced distal pole and tubercle fractures are felt to be more stable and can be treated with immobilization alone for 6 to 12 weeks. In addition, these fractures often have small fragments that are not as amenable to compression screw fixation. Observation and physical therapy allow mobilization of the wrist and are not recommended because of the potential for delayed healing or nonunion. Compression screw fixation is not generally necessary and is sometimes not possible for tubercle fractures, but it is a common treatment for scaphoid wrist fractures. Autologous bone grafting and internal fixation is generally reserved for scaphoid nonunions.

A 27-year-old woman comes to the office for evaluation of bilateral hand pain. The patient reports worsening pain when she retrieves items from the freezer and says that in the winter she experiences pain in her fingers unless she wears electric, heated gloves and on occasion her fingers will turn white and blue. Medical history includes no personal or family history of joint or skin problems. Physical examination shows the patient's fingers are warm, and wrist pulses are palpable. Which of the following is the most appropriate initial management of this patient's symptoms? A. Botulinum toxin type A injection B. Oral nifedipine C. Temperature biofeedback D. Thoracoscopic sympathectomy E. Topical nitroglycerin

B. Patients presenting with Raynaud syndrome fall into two classic categories: primary (traditionally referred to as Raynaud disease) and secondary (Raynaud phenomenon, associated with an underlying condition, most commonly involving an autoimmune process). In this woman presenting without an underlying etiology for her vasospastic symptoms, primary treatment should be directed at managing the vasospasm. Although a plethora of interventions have been tried, recent reviews show the calcium-channel blockers, such as nifedipine, to be the optimal first-line intervention. Temperature biofeedback has shown variable effect in multiple small trials, and, consequently, it is not recommended as a primary intervention for vasospasm. Topical nitrates can assist with vasodilation in the digits, making them an occasional adjunct treatment for symptoms not completely managed by calcium channel blockers. In isolation, topical nitrates have been ineffective for managing Raynaud syndrome. Multiple small trials have demonstrated successful relief of pain and digital ulcers in a mixed group of both primary and secondary Raynaud syndrome with injection of botulinum toxin around the digital vessels in the palm. The cost and risk of temporary paralysis to intrinsic muscles, however, renders this a second-line treatment for refractory pain or nonhealing ulcers. Treatment of digital vasospasm is still considered an "off-label" use of botulinum toxin and may not be covered by insurance. Surgical sympathectomy, either proximally through a thoracoscopic approach or peri-arterially in the wrist and hand, represents the most aggressive treatment and would typically be reserved for patients with nonhealing wounds or chronic ischemic changes. These procedures are gradually being supplanted by injection of botulinum toxin type A.

A 32-year-old man presents following a motor vehicle collision in which he sustained a dorsal perilunate dislocation of the nondominant left hand. He was treated with open reduction and internal fixation including ligament repair with suture anchors and Kirschner-wires two days after the injury. Which of the following is the expected long-term outcome for this patient? A. Chronic pain and grip strength less than 50% of the normal side B. Evidence of moderate post-traumatic arthritis and 80% of grip strength compared to the opposite side C. Normal x-ray appearance with greater than 80% of motion compared with the opposite side D. Normal x-ray appearance with poor wrist motion and poor grip strength E. Severe post-traumatic arthritis requiring total wrist fusion

B. Peri-lunate dislocations (PLD) and peri-lunate fracture dislocations (PLFD) are considered complex, high-energy injuries with potentially difficult recovery for many patients. In terms of outcomes research, long-term data are considered to be follow-up greater than 10 years. The long-term data are retrospective but consistent across many studies. The treatment of choice for PLD and PLFD is open reduction and internal fixation. Studies looking at closed reduction and casting or percutaneous pin fixation have shown inferior outcomes, and open treatment is recommend by most authors. All studies agree that there will be the presence of moderate or even severe post-traumatic arthritic changes on x-ray in most patients (50 to 100%), which can be various degrees of SLAC, SNAC, or avascular necrosis. However, the data also show that the presence of radiographic arthritis does not necessarily correlate with functional outcomes. On average, patients will achieve 65 to 70% of wrist flexion-extension arc and 80% grip strength compared with the unaffected side. Although some patients may develop severe complications of a PLD or PLFD such as advanced SLAC or SNAC or ulnar translation of the carpus, it is a rare finding. Most studies show outcomes in the good and fair range according to the Mayo wrist score and other outcome measures. Patients with the most severe arthritis usually do correspond to the worst symptoms and may require salvage procedures such as proximal row carpectomy or limited wrist fusion. Persistent, chronic pain is a rare finding with long-term outcomes of perilunate injuries. Pain with heavy activity only is the most commonly reported outcome, although many patients are largely pain free. Patients can have near normal looking x-rays after PLD or PLFD; however, this is rare. One would not expect >80% of wrist motion after an injury of this magnitude even with normal x-rays. Also, patients with minimal arthritic changes tend to show better functional outcomes.

When considering dislocations of the thumb carpometacarpal (CMC) joint, which of the following is most correct regarding which vector of dislocation would occur with injury to the stabilizing ligament? A. Dorsal intercarpal ligament and radial dislocation B. Dorsoradial ligament and dorsal dislocation C. Intermetacarpal ligament and ulnar dislocation D. Radiocarpal ligament and dorsal dislocation

B. The CMCJ is very important for hand function and plays a key role in pinch and grasp. The increased range of motion inherent to the thumb CMCJ is attributed to the anatomy of the joint. The biconcave saddle shaped articular surface of the CMCJ also provides some inherent stability. Motion allowed by the joint includes flexion, extension, adduction, abduction, circumduction. Stabilizing ligaments and joint capsule further reinforce the joint, thus thumb CMCJ dislocations are rare injuries. These injuries account for less than 1% of hand injuries. There are five major stabilizing ligaments to the CMCJ: anterior (volar) oblique, ulnar collateral, intermetacarpal, dorsoradial, and dorsal (posterior) oblique. These ligaments are critical stabilizers during motion. The volar oblique ligament and dorsoradial ligaments are considered to be the most important resistive forces in dislocation in cadaver studies. Reports of traumatic thumb CMCJ dislocation have been in a dorsal vector. The volar oblique ligament was originally thought to be the critical resistive ligament; however, recent literature has supported the dorsal complex (includes the dorsoradial and posterior oblique ligaments) are the most critical for restraint of the joint, thus are injured in dorsal dislocations. Timely recognition is important for these injuries as immediate reduction and casting or splinting for 4 to 6 weeks may be adequate to prevent recurrence. However, these injuries are often missed on radiologic examination or may be persistently unstable. Closed reduction and Kirschner wire fixation may be adequate for treatment in persistently unstable injuries. Some authors advocate for open reduction and ligament reconstruction. Delayed treatment especially beyond three weeks will likely require open reduction and ligament reconstruction. These injuries are often missed on x-ray examination as they can be subtle especially in the setting of more obvious trauma. Inadequate treatment puts these patients at increased risk for subsequent posttraumatic osteoarthritis given the joint malalignment. The radiocarpal and dorsal intercarpal ligaments are wrist stabilizer not thumb CMCJ stabilizers.

A 55-year-old woman is brought to the emergency department after sustaining mutilating injury to the hand during a motor vehicle collision. Examination shows the hand is unsalvageable. Disarticulation of the wrist is planned. Compared with transradial amputation, which of the following is the most likely benefit of this approach? A. Better accommodation of a myoelectric unit B. Better forearm pronation and supination C. Decreased risk of neuroma formation D. Decreased risk of prosthetic abandonment E. More stable soft-tissue envelope

B. The choice of wrist disarticulation compared with transradial amputation is a controversial one. The primary benefit of the wrist level disarticulation is preservation of the distal radioulnar joint and consequential improvement in forearm rotation. Preservation of the metaphyseal flare of the radius may aid in prosthetic fit; however, the additional length associated with functional units such as myoelectrics may result in a limb length discrepancy. The prominence of the distal radius and ulna may predispose to pressure-related wound issues associated with prosthetic wear. Patients with wrist level disarticulation are more likely to abandon their prosthesis compared with transradial amputees.

A 15-year-old boy is evaluated because of a 4-month history of a 2.5-cm, soft, well-circumscribed, tender dorsal mass of the right wrist. Examination shows the mass is well defined, does not transilluminate, and softens when the index and long finger are flexed. The image shown is obtained at the time of operative excision (muscle belly in dorsum of hand). Which of the following is the most likely diagnosis? A. Anomalous extensor indicis proprius insertion B. Extensor digitorum brevis manus C. Fibrosarcoma D. Giant cell tumor of tendon sheath E. Multilobulated ganglion cyst

B. The extensor digitorum brevis manus (EDBM) is a rare (2 to 3% incidence) anomalous muscle of the hand that may present similarly as a tender dorsal wrist mass distal to the radiocarpal joint about the distal edge of the extensor retinaculum. The clinical presentation can mimic a dorsal wrist ganglion cyst and many cases of EDBM were either initially misdiagnosed as or occurred concurrent with ganglion cyst. There are a number of clinical features that may aid in differentiating the anomalous EDBM from a dorsal ganglion. The pathologic EDBM more often presents in adults as pain and swelling following physical activity or manual labor. If bilateral, the dominant hand is more commonly symptomatic. Physical examination may show hardening of the mass with resisted index and long finger extension and softening with resting digital flexion as the muscle relaxes. Treatment is guided by symptom severity and patient preference and alternatives include rest and immobilization, surgical release of the fourth compartment alone, or fourth compartment release with complete muscle excision. Ganglion cyst does not appear solid and would transilluminate. Giant cell tumor of tendon sheath is a common tumor in the hand but rarely grows this large and is yellow, not red, in appearance. Anomalous insertion of the EIP is a rare source of dorsal wrist pain, but the mass seen here is not consistent with that diagnosis. Fibrosarcoma is a possibility but that tumor usually invades the skin, is irregular in form, and does not change in firmness with finger flexion and extension.

A 24-year-old man presents with a Gustilo Type IIIB tibial fracture sustained during a motor vehicle collision. Reconstruction with an anterolateral thigh flap is planned. If technically feasible in this patient, how many venous anastomoses should be performed during reconstruction? A. One B. Two C. Three D. Four E. Five

B. There has been debate for many years about the optimal number of venous anastomoses. One school of thinking argues that fewer anastomoses allow for higher flow in each, while the other school argues that each additional anastomoses adds redundancy. Recent studies have shown a variable but significant decrease in venous thrombosis and an even higher reduction in flap complications when dual anastomoses are performed. Studies have not reliably evaluated more than two anastomosis. There are situations when two anastomoses are not technically feasible.

A 2-month-old infant is brought to the office for evaluation of bilateral complex syndactyly of the hands and feet. Which of the following is the most likely gene involved? A. Engrailed-1 (EN1) B. Fibroblast growth factor receptor-2 (FGFR2) C. LIM Homeobox transcription factor-1 beta (LMX1B) D. Sonic hedgehog (SHH) E. Wingless type (Wnt)

B. This patient presents with complex syndactyly of hands and feet consistent with Apert syndrome. This is an autosomal dominant condition that can be caused by mutation in the fibroblast growth factor receptor-2 gene. Which leads to no apoptosis Limb development is controlled by signaling pathways that are located within three different signaling centers. These govern the proximal-distal, anterior-posterior, and dorsal-ventral axes of limb development. Proximal to distal = AER, a thickened layer of ectoderm over the limb bud. Fibroblast growth factors secreted within the AER signal the underlying mesoderm to differentiate. Disruption of the AER results in truncation of the limb. Anterior-posterior (radioulnar) axis = zone of polarizing activity (ZPA). This is located in the posterior margin of the limb bud. The sonic hedgehog protein (SHH) acts to signal development of the limb into radial and ulnar aspects. Alterations in this pathway can result in mirror duplication. Dorsal-ventral limb development is signaled by the Wnt signaling pathway, which produces a transcription factor, LMX1B, that induces the development of dorsal structures. Deficiency in LMX1B has been associated with nail-patella syndrome. In the ventral portion of the limb, the Engrailed-1 gene product blocks the Wnt pathway, leading to ventralization. A variety of other transcription factors encoded by Hox and T-Box genes also govern limb and organ development, and alterations in these can give rise to various developmental differences.

A 35-year-old woman presents with a fixed adduction contracture of the first web space that has not improved with splinting and hand therapy for 4 months. Medical history includes a crush injury with complex laceration to the first web and dorsal hand and index finger five months ago. A photograph is shown (amputated IF tip, scattered scars on dorsum of hand, scar on base of thumb). Which of the following is the most appropriate plan for reconstruction of the first web space contracture in this patient? A. First dorsal metacarpal artery flap B. Flexor carpi ulnaris flap C. Posterior interosseous artery flap D. Thenar flap E. Split-thickness skin grafting

C. Contracture of the first web space may be secondary to cutaneous scarring, skin deficiency, fibrosis of the fascia and thenar muscles, or joint contractures. Mild contractures may be isolated to the skin; however, deeper structures are most likely involved as the contracture becomes more severe. It is important to understand the mechanism of injury, length of time the contracture has been present, and any prior treatments. Reconstruction of the first web space involves complete contracture release and resurfacing with adequate vascularized tissue. The dissection should be carried out palmarly and dorsally with release of the palmar fascia and adductor aponeurosis as needed. Intrinsic muscle and joint contractures should be addressed at this time, and a trapeziectomy may be needed to restore carpometacarpal (CMC) motion. This patient has a severe contracture that likely involves multiple structures given her history of deep lacerations and bony injury. This requires resurfacing with thin, pliable vascularized tissue. In this setting, the posterior interosseous artery (PIA) flap is the best choice. This flap is outside the zone of injury and provides an adequate amount of vascularized tissue for resurfacing of the web space. The PIA runs between the extensor carpi ulnaris and extensor digit quinti and forms an anastomosis with the anterior interosseous artery 2cm proximal to the distal radioulnar joint. Skin grafting alone, either split-thickness or full-thickness, should be avoided because of the inherent tendency for secondary contracture. Skin grafts may be combined with local flaps such as a 4-flap or 5-flap z-plasty in mild to moderate contractures. Tissue flaps from the dorsum of the hand such as the first dorsal metacarpal artery fasciocutaneous flap or dorsal hand transposition flap may be good options in some patients with small- to moderate-sized skin deficits. However, this patient sustained trauma to the dorsal hand with dorsal skin lacerations. This makes a random-pattern transposition flap unreliable. The defect in question is also too large to be completely resurfaced with a first dorsal metacarpal artery (FDMA) flap. The flexor carpi ulnaris flap is useful for elbow coverage as a turn-over flap but will not reach the hand.

A 27-year-old woman sustains a Grade IIIB degloving injury of the left lower extremity in a motor vehicle collision. Latissimus dorsi free flap placement is planned. Which of the following is the most likely outcome in this patient in terms of donor site morbidity? A. Decreased seroma formation but increased hematoma formation B. Inability to maintain sitting-up position when back is not supported C. Initial decreased shoulder range of motion that improves by one year D. Permanent loss of external rotation of the shoulder and inability to reach forward

C. Most studies that demonstrate shoulder weakness and loss of motion show that the loss of function is greatest in the early postoperative period and returns to baseline, or close to baseline, at 1 year or more after surgery. All studies comparing types of latissimus flaps demonstrate less morbidity with perforator or muscle-sparing flaps as compared to traditional or extended latissimus dorsi (LD) flaps. Lower functional morbidity is observed with more native muscle preserved as is other flaps. This assumes that the muscular branches of the motor nerve to the latissimus are spared. A recent meta-analysis does show higher functional impairment than expected after latissimus flap transfer. The number of patients who required a change in occupation was less than 10%. This was likely because of difficulty with activities such as ladder climbing, painting overhead, and sustained reach overhead. The function of the latissimus dorsi muscle is shoulder adduction, extension and internal rotation. Other muscles of the rotator cuff perform similar functions and will assist in compensation for the loss of the latissimus. Patients who do develop weakness report it in activities involving shoulder adduction and internal rotation. Paradoxically, limitations in range of motion are mostly in shoulder flexion and abduction possibly related to tight skin closure and internal scarring. Donor site seroma formation is particularly problematic, with published rates ranging from 3.9 to 79%.

A 47-year-old woman comes to the office after sustaining an injury to the left wrist after falling on her outstretched hand. Examination shows pain of the radial aspect of the left wrist and anatomical snuffbox. Scaphoid fracture is suspected. When obtaining posterior-anterior x-ray studies, which of the following is the optimal positioning of the wrist for evaluation of the entire scaphoid? A. Wrist in 20 degrees of radial deviation, 20 degrees of wrist extension B. Wrist in 20 degrees of radial deviation, 20 degrees of wrist flexion C. Wrist in 20 degrees of ulnar deviation, 20 degrees of wrist extension D. Wrist in 20 degrees of ulnar deviation, 20 degrees of wrist flexion E. Wrist in neutral radial/ulnar position, neutral flexion/extension

C. Scaphoid fractures are the most common carpal fracture and frequently occur after a fall onto an extended and radially deviated wrist. Initial workup often involves plain x-ray studies, which have a sensitivity of approximately 85%. The optimal position of the wrist when imaging scaphoid fractures includes ulnar deviation and wrist extension, which allows for evaluation of the long axis of the scaphoid. CT scan or MRI may be used as additional imaging if plain x-ray studies do not demonstrate a fracture, yet there is high clinical suspicion.

A 55-year-old Caucasian man comes to the office for evaluation of a pigmented streak of the left thumb and index fingernails. Medical history includes a minor crush injury to the thumb one year ago that required no treatment. Examination shows a 4-mm-wide pigmented streak in both digits that extends from the eponychial fold to the tip of the sterile matrix. The patient reports that the pigmented areas have become darker over time. Which of the following clinical features is most consistent with a benign lesion? A. Age greater than 50 years B. Change in color over time C. Involvement of more than one digit D. Pigmentation involving the periungual skin E. Width greater than 3 mm

C. Subungual melanoma is a relatively rare melanoma subtype accounting for 0.7 to 3.5% of all melanomas. Because of the location, appearance, and unique anatomy of the nail unit, subungual melanomas are often diagnosed late in more advanced stages than typical cutaneous melanoma. There is disagreement as to whether subungual melanomas behave more aggressively than cutaneous melanomas of comparable depth. In addition, it can be difficult to distinguish subungual melanomas from benign melanonychia. Characteristics that are concerning for subungual melanoma are: age 50 to 70, longitudinal band greater than 3 mm or irregular border, change of lesion size or coloration, extension onto periungual skin (Hutchinson sign), personal or family history of melanoma, and single finger involvement. Benign melanonychia is more common in dark-skinned patients. The differential diagnosis of subungual pigmentation includes subungual hematoma, onychomycosis, and Addison disease among others. In this case, multiple digit involvement is the clue that the lesions are benign. All other characteristics could be consistent with malignant melanoma. If there is concern for subungual melanoma, a full-thickness biopsy of the pigmented area should be performed.

A 35-year-old man comes to the office for evaluation of a previous amputation of the dominant thumb. Medical history includes factor V Leiden mutation. The patient states that he does not want any microsurgical flap reconstruction. X-ray study shows amputation at the metacarpal base level. Which of the following reconstruction methods is most appropriate for the best aesthetic and functional outcome in this patient? A. Metacarpal distraction B. Osteoplastic reconstruction with iliac bone and radial forearm flap coverage C. Pollicization of the index finger D. Silicone prosthesis E. Web space deepening with Z-plasty

C. The thumb is considered to account for at least 40% of hand function. Essential characteristics to provide optimal function of the thumb include mobility, opposition, sensation, stability, strength, and normal shape. Metacarpal distraction can provide a strong, stable, and sensate thumb but is not very aesthetically pleasing as it will be larger than a normal thumb and lack a nail. Osteoplastic reconstruction and flap coverage provides a stable post but no mobility and poor sensation with the same visual concerns. Web space deepening with Z-plasty can provide a very functional stable thumb with more distal amputations but would not provide sufficient length in this patient. Silicone prostheses provide excellent cosmetic digits but are not functional. The most appropriate reconstruction in this patient without a toe transfer would be an index pollicization.

A 62-year-old woman presents because of a 6-month history of a painless mass near the nail fold of the left index finger. The patient reports that clear thick drainage leaks intermittently from the nail fold. She is concerned about the appearance of the nail. A photograph is shown. On evaluation of this patient, which of the following additional studies in her workup is most appropriate? A. Blood work B. Culture of a drainage specimen from the nail fold C. Diagnostic x-ray study of the finger D. Incisional biopsy of the mass E. MRI of the finger

C. This is a mucous cyst based on history and examination. Mucous cysts are cysts that arise from the distal interphalangeal joints. They are frequently associated with dorsal osteophytes secondary to osteoarthritis and x-ray studies are useful to establish the severity of osteophytes. X-ray views usually demonstrate osteophytes in proximity to the cyst. The cyst can decompress and clear viscous fluid can be seen. Pressure on the germinal matrix from an enlarging mucous cyst can cause nail grooving, which this patient demonstrates. These masses are benign and do not require treatment. Aspiration and corticosteroid injection can be considered for nonsurgical treatment. The osteophyte is thought to be an inciting cause of the mucous cyst in these patients and should be removed when surgically treating these patients hence the utility of x-rays in evaluation of the patient. The cyst and stalk are traditionally removed as well. MRI is unnecessary as clinical examination should be sufficient to establish the diagnosis. Blood work and culture would be unable to establish a diagnosis. Culture is sometimes necessary if there are signs of infection but there are no concerning signs or symptoms in this patient. Biopsy is helpful when clinical diagnosis is suspect, but unnecessary with this benign mass.

A 12-month-old male infant is brought to the office for evaluation of a small right thumb. Physical examination shows instability of the metacarpophalangeal joint and hypoplasia of the first web space. The carpometacarpal joint is stable. The patient has difficulty moving the thumb. Which of the following is the next best step in management? A. Free toe transfer B. Metacarpal lengthening C. Opponensplasty D. Pollicization E. Continued observation

C. This patient presents with a Blauth Grade 2 or 3A thumb hypoplasia. Surgical management is warranted and includes treatment of the absent or hypoplastic thenar musculature with opponensplasty; release of the first web space; and management of MCP instability. Pollicization is reserved for Blauth Grade 3B or more severe deficiencies. The distinction between a Blauth 3A and 3b hypoplastic thumb is determined by the stability of the CMC joint.

An 86-year-old farmer is brought to the emergency department because of a large dorsal wound of his nondominant left hand sustained when his hand was caught in a flail mower. After debridement is performed, examination shows normal volar structures, including nerve and tendon function, and loss of all dorsal skin and tendons. Medical history includes myocardial infarction 1 month ago. An x-ray study and photograph are shown (total crush injuries to index and middle metacarpals). Which of the following is the most appropriate method of reconstruction for this patient? A. Bilaminate neodermis (Integra) and skin grafting with delayed bone grafting B. External fixator and posterior interosseous artery flap C. Finger fillet flaps of index and middle finger D. Free anterior lateral thigh flap with secondary bone grafting E. Pedicle radial forearm flap with secondary bone grafting

C. When caring for patients with mangling hand injuries, it is imperative to consider all aspects of the patient's history and future goals. This patient would be at risk for cardiac complications if a longer procedure such as a free flap were chosen. The amount of bone loss in the index and middle metacarpals is also problematic and would most likely require multiple procedures. Just placing an external fixation and covering the wound with a local flap is also possible but will require several procedures. Bone grafting while receiving bilaminate neodermis (Integra) and skin grafts is not recommended because of the lack of subcutaneous tissue and poor blood supply. The most expeditious method of covering this patient's wounds in one procedure is finger fillet flaps of the injured digits. Finger fillet flaps can cover a large area for reconstruction as shown.

A 24-year-old man presents for reconstruction of an open tibial fracture. Examination of the middle third of the leg demonstrates circumferential loss of skin with exposure of the tibial fracture site. The patient's foot is pink and warm and the toes demonstrate 3-second capillary refill. Preoperative duplex ultrasound imaging shows that there is no flow of the peroneal and anterior tibial arteries distal to the injury site. Which of the following is the most appropriate Gustilo classification for this injury? A. I B. II C. IIIA D. IIIB E. IIIC

D. Although there are defined vascular injuries in this patient, this wound falls within the Gustilo IIIB category as there is an open fracture with soft tissue defect and a perfused foot through the posterior tibial artery. Gustilo IIIC injuries include a vascular injury requiring repair, which is not the case in this patient.

Myoelectric prostheses offer which of the following advantages over body-powered prostheses? A. Higher durability B. Lower cost C. Lower frequency of adjustment D. More complex motions performed E. Shorter training time

D. Body-powered prostheses have been shown to have advantages in durability, training time, frequency of adjustment, maintenance, and feedback; however, they could still benefit from improvements of control. Myoelectric prostheses have been shown to provide greater range of motion including more complex movements involving multiple joints moving at the same time. Currently, evidence is insufficient to conclude that either system provides a significant general advantage. Prosthetic selection should be based on a patient's individual needs and include personal preferences, prosthetic experience, and functional needs.

A 51-year-old woman is scheduled to undergo needle aponeurotomy for Dupuytren disease of the small finger. The addition of lipografting after needle aponeurotomy is most likely to decrease the rate and severity of recurrence in this patient by which of the following mechanisms? A. Decreasing the proximity of residual cord tissue to the skin B. Increasing the density of myofibroblast cell-to-cell contact C. Increasing the density of the residual cord tissue D. Inhibiting myofibroblast proliferation E. Providing stem cells to promote collagen production

D. Fat grafting (also called lipofilling) has shown promise as a means to improve outcomes after percutaneous needle aponeurotomy for Dupuytren disease. It is believed to work by several mechanisms: 1. Reducing the density of cell-to-cell myofibroblast contact 2. Inhibiting myofibroblast proliferation via adipose-derived stem cells 3. Acting as an interposed tissue graft 4. Providing passing over the cords to replace native subdermal fat displaced by the nodules and cords A randomized prospective trial by Kan and colleagues showed that aponeurotomy with lipofilling showed equivalent results at one year out from treatment with a much faster recovery compared with limited fasciectomy.

A 40-year-old man employed as a construction worker comes to the office because of a 3-month history of median nerve sensory distribution deficit. Diagnostic evaluation shows a mass located in the medial cord of the brachial plexus. Histology of the mass shows a malignant peripheral nerve sheath tumor. Metastasis is most likely found in which of the following organ systems? A. Brain B. Colon C. Liver D. Lung E. Spine

D. For malignant peripheral nerve sheath tumors, metastasis occurs in about 39% of patients, most commonly affecting the lung. Malignant peripheral nerve sheath tumors commonly present as a soft-tissue mass arising from a large peripheral nerve such as the sciatic nerve or brachial plexus. There is usually motor and sensory deficit of the affected nerve. Demographics for solitary neurofibromas are 30 to 55 years, and neurofibromatosis are 20 to 40 years. Malignant peripheral nerve sheath tumors are sarcomas. They originate from peripheral nerves or from the nerve sheath, such as Schwann cells, perineural cells, or fibroblasts. Wide surgical excision is the mainstay of treatment, including the affected nerve. Radiation therapy is an integral part of treatment. Chemotherapy is usually not used except in larger, higher grade tumors.

A 45-year-old man who is a cyclist comes to the office because of tingling of the left ring and small fingers. Normal sensibility dorsally is noted. Guyon canal release is planned. Which of the following structures is a border of the Guyon canal? A. Capitate B. Dorsal distal radio-ulnar ligament C. Lunate D. Pisohamate ligament E. Volar distal radio-ulnar ligament

D. Guyon canal, also known as ulnar canal and ulnar tunnel, allows passage of the ulna nerve and artery into the hand. It is a semi-rigid fibrosseous longitudinal tunnel, approximately 4 cm in length, beginning at the proximal edge of the transverse carpal ligament and ending at the hypothenar aponeurotic arch. The roof comprises the volar carpal ligament. The ulnar wall is the pisiform and pisohamate ligament. The radial wall is the hook of the hamate. The floor is the flexor retinaculum and hypothenar muscles. The volar and dorsal distal radio-ulnar ligaments are the thicker portions of the triangular fibrocartilage complex (TFCC) and do not contribute to Guyon canal. The capitate and lunate are part of the floor of the carpal tunnel and also do not contribute to Guyon canal.

A 54-year-old woman sustains an open fracture of the right ankle in a motorcycle collision. Flap coverage of the associated distal-third leg wound is planned. Which of the following is the most significant advantage of using a fasciocutaneous flap instead of a muscle flap? A. Better fill of dead space B. Higher flap survival rate C. Improved clearance of osteomyelitis D. Less donor site morbidity E. Quicker dissection

D. Muscle flaps were "workhorses" for lower extremity reconstruction for years, but harvest of muscle always leaves some donor site functional morbidity because of loss of the muscle function. Survival rates, speed of dissection, and treatment of osteomyelitis are not significantly different between the flap types. Muscle flaps tend to fill dead space easier than fasciocutaneous flaps.

An 18-year-old man presents for follow-up evaluation 8 weeks after he sustained a penetrating injury to the posterior medial right elbow and a complete transection of the ulnar nerve in the cubital tunnel. At this time, which of the following are the most likely Sunderland/Mackinnon injury grade and electromyogram/nerve conduction findings in this patient? Injury grade / sharp waves / fibrillations / motor amplitude A. Grade I / Absent / Present / Decreased B. Grade I / Present / Present / Normal C. Grade V / Absent / Absent / Normal D. Grade V / Present / Present / Decreased E. Grade VI / Present / Present / Normal

D. Nerve injuries are graded using the Sunderland/Mackinnon classification. Grade I injuries involve neurapraxia and are expected to recover completely; grades II to IV injuries involve increasing disruption of the perineurium and endoneurium (with expectation for a variable degree of spontaneous recovery); grade V injuries represent neurotmesis, or complete transection of the nerve. Grade VI injuries represent combined injuries in which more than one grade of injury exists within the same segment of damaged nerve. After a complete nerve transection and progression of Wallerian degeneration, patients develop fibrillations and sharp waves and progressive decrease in the compound motor action potential.

A 60-year-old woman with rheumatoid arthritis (RA) comes to the office because of the sudden inability to extend the right thumb. The patient reports no pain or swelling before the loss of extension. She notes her RA symptoms have been well controlled for over 10 years with low-dose prednisone and methotrexate. Physical examination shows strong flexion of the right thumb at the interphalangeal joint. The patient is unable to extend the thumb interphalangeal joint against resistance and is unable to lift the thumb off the tabletop when the palm is held flat. Full passive mobility of the thumb is noted. Rupture of which of the following tendons is most likely upon surgical exploration? A. Abductor pollicis brevis at the metacarpophalangeal joint B. Abductor pollicis longus at the carpometacarpal joint C. Extensor pollicis brevis at the metacarpophalangeal joint D. Extensor pollicis longus at the wrist E. Flexor pollicis longus near the scaphoid

D. One of the more common tendon ruptures in rheumatoid arthritis (RA) is the extensor pollicis longus (EPL) at the level of the wrist. Although spontaneous ruptures with no other known pathology occur, the most common etiologies for rupture center around mechanical or vascular changes in the EPL within the third extensor compartment as the tendon bends around Lister's tubercle. This appears to be related in part to the proximity of the tendon to an injury (in distal radius fractures) and to the "watershed" zone of perfusion of the EPL at Lister tubercle. In this patient with RA, the rupture is likely a combination of ischemia and direct inflammatory synovial infiltration of the tendon within the third compartment. Other tendon ruptures may occur in the setting of RA, the common ruptures being the extensor digitorum communis and extensor digiti minimi on the dorsal wrist and the flexor pollicis longus (Mannerfelt lesion) on the volar wrist. The presence of strong flexion of the thumb at the interphalangeal joint rules out flexor pollicis longus (FPL) rupture. Rupture of the extensor pollicis brevis (EPB) would not result in obvious loss of function as the motion would be compensated for by an intact EPL. Neither abductor rupture would result in loss of interphalangeal joint extension or retropulsion (lifting the thumb off the table with the palm held flat on the surface).

A 65-year-old woman comes to the office because she is unable to actively extend the left ring and small fingers. Medical history includes rheumatoid arthritis and no marked trauma. On physical examination, the ring and small fingers are held in 45 degrees of flexion with ulnar deviation at the metacarpophalangeal (MCP) joints. Mild swelling around the MCP joints of all fingers and a prominent ulnar head are noted. The patient is able to maintain extension when her fingers are passively extended. X-ray studies show moderate to severe wrist arthritis but minimal arthritic changes of the finger joints. Which of the following best explains the physical examination findings in this patient? A. Extensor tendon rupture of the ring and small fingers at the ulnar head B. Incomplete radial nerve palsy C. Severe ulnar neuropathy at the elbow D. Ulnar subluxation of the extensor mechanism at the MCP joint E. Volar subluxation of the MCP joint

D. Rheumatoid arthritis (RA) is an autoimmune inflammatory polyarthritis. Immune complex deposition results in inflammation and synovial hypertrophy, joint destruction, and weakening of the ligamentous support structures. This results in a predictable pattern of deformities seen in the hand and wrist related to the inflammatory synovitis. The wrist is the most commonly affected joint in the upper extremity in RA. Collapse of the carpal height on the radial aspect of the wrist from attenuation of the scapholunate ligament results in weakening of the ulnar collateral ligaments of the wrist, ulnar subluxation and supination of the carpus, and radial deviation of the metacarpals. Along with synovitis of the metacarpophalangeal (MCP) joints, this contributes to the characteristic ulnar drift of the fingers seen in RA. The loss of active finger extension in rheumatoid patients is because of one of three causes. Attenuation of the radial sagittal band of the MCP joint from inflammation and ulnarly directed forces from pinch and grip may result in ulnar subluxation of the extensor mechanism. The extensor tendons will slide into the valley between the metacarpal heads and the extensor tendon will place a flexion force on the MCP joint. In this case, passive extension of the fingers will centralize the extensor and the patient will be able to maintain the fingers actively in an extended position. This is the critical physical exam maneuver to diagnose this issue and the key to the patient in this question. Patients with synovitis of the distal radioulnar joint and dorsal subluxation of the ulnar head (caput ulna) may present with spontaneous rupture of the extensor tendons. This occurs in a predictable sequence beginning with the extensor digiti quinti and progressing radially across the hand. Intact junctura may make this difficult to diagnose initially, but these patients will not be able to extend the small finger with the adjacent digits flexed. These patients will not be able to actively maintain finger extension even if the fingers are passively extended. Finally, volar subluxation or dislocation of the MCP joints from synovitis can be a cause of ulnar drift and loss of digit extension. This may or may not be passively correctable. This can be distinguished easily from extensor tendon subluxation by x-ray evaluation of the hand. Joint malalignment is easily seen on standard x-rays but is not present in this patient. It is important to understand the cause of the deformity because the treatment for each is different. Radial neuropathy in RA is very rare and would not likely be isolated to extension of the ring and small fingers only. One would expect more global posterior interosseous nerve (PIN) palsy, which is not present in this case. Severe ulnar neuropathy would result in intrinsic weakness and possibly clawing of the ulnar digits. This would present with hyperextension of the MCP joints and flexion of the interphalangeal joints.

A 26-year-old man comes to the office 4 weeks after injuring his left shoulder while snowboarding. Physical examination shows limited abduction and forward flexion of the shoulder to 30 degrees. No additional abnormalities are noted. From which of the following areas of the brachial plexus does the affected nerve most likely arise? A. Lateral cord B. Lower trunk C. Medial cord D. Posterior cord

D. The axillary nerve (ventral rami of C5 and C6) arises from the posterior cord of the brachial plexus, giving off muscular branches to teres minor and deltoid. It also innervates the shoulder joint and the skin over the deltoid. Its close proximity to the inferior shoulder capsule as it courses on the anteroinferior border of the subscapularis and then through the quadrangular space, puts it at risk for injury. The axillary nerve is most commonly injured during orthopedic surgeries such as shoulder arthroscopy, and open reduction and internal fixation (ORIF) of the proximal humerus, in which case, it is most commonly the result of closed traction injury. It can also be seen in the setting of an anterior glenohumeral joint dislocation or proximal humerus fracture, or as the result of a direct blow to the superior aspect of the shoulder. The majority of nerve injuries are temporary neurapraxias, which typically resolve within 6 to 12 months of injury; however, permanent nerve deficit can occur, requiring surgical intervention in the form of decompression, or reconstruction with nerve graft or nerve transfer from the radial nerve. The lateral cord receives contribution from C5, C6, and C7 roots, and contributes to the musculocutaneous and median nerves. The medial cord receives contribution from C8 and T1 roots, and contributes to the median and ulnar nerves. There are no superior or anterior cords within the brachial plexus.

A 36-year-old man comes to the office because of a 2-week history of pain of the right wrist after a fall on his outstretched hand. X-ray studies are shown (SL interval widening and SL angle approx 80). If this injury is left untreated, which of the following joint surfaces is most likely to develop arthritis first? A. Capitolunate B. Lunotriquetral C. Radiolunate D. Radioscaphoid E. Scaphocapitate

D. The most likely joint surface to develop arthritis is the radioscaphoid joint. This patient shows evidence of scapholunate ligament tear. There is evidence of widening of the scapholunate interval and increase in the scapholunate angle. The scapholunate angle is calculated by measuring the angle between a line drawn perpendicular to the distal surface of the lunate and along the axis of the scaphoid on the lateral view. The normal scapholunate angle varies from 30 to 60 degrees. A tear in the scapholunate ligament results in volar flexion of the scaphoid bone and dorsiflexion of the lunate, with a resultant increase in the angle. If a scapholunate ligament tear is left untreated, a degenerative pattern of changes result. This is known as scapholunate advanced collapse (SLAC) wrist. Over time there is separation of the scaphoid and lunate bones and descent of the capitate into the intervening space. With scapholunate ligament tears, arthritis occurs in a predictable sequence. This initially begins in the radioscaphoid joint, followed by the scaphocapitate joint and the capitolunate joint. The radiolunate joint is typically spared until advanced stages. The lunotriquetral ligament is intact and arthritis does not occur in this area with SLAC wrist.

A 30-year-old man with a history of radius and ulna midshaft fractures underwent fasciotomies for acute compartment syndrome of the nondominant left volar forearm with immediate return of normal perfusion 4 months ago. He is now pain-free with normal sensation but has persistent stiffness and weakness of the fingers, despite appropriate splinting and physiotherapy. His compartments are soft, and there are no joint contractures. He has full motion and normal strength, except the fingers and thumb can fully extend only with the wrist flexed, and finger and thumb flexion have MRC grade 4/5 strength. Which of the following is the most appropriate next step in management? A. Dynamic splinting B. Flexor tendon transfers C. Intrinsic releases D. Selective muscle origin slide E. Strengthening physiotherapy

D. The patient is presenting with evidence of Volkmann ischemic contracture of his deep volar forearm compartment musculature, specifically flexor digitorum profundus and flexor pollicis longus. Flexor digitorum superficialis could be minimally involved, but the wrist flexors are spared. Mild median nerve involvement with full recovery and sparing of the ulnar nerve would support this diagnosis. The patient has already undergone appropriate physiotherapy. With persistent findings at 4 months, the most appropriate treatment is surgical exploration, debridement of necrotic muscle, with either selective muscle origin slide or tendon lengthening of preserved but contracted muscle. Although continued dynamic physiotherapy could potentially provide further improvement in this patient's muscle tightness, strengthening physiotherapy will not address the problem adequately. Dynamic splinting could complement physiotherapy and be helpful but has likely provided most of its benefit in the 4 months after initial surgery. Intrinsic releases would be indicated in intrinsic muscle contractures; however, this patient has involvement of the extrinsic flexors, not the intrinsic muscles. Finally, flexor tendon transfers would be indicated for more severe cases of Volkmann contractures, where there is no muscle function remaining. This patient's examination suggests adequate muscle function remains.

A 45-year-old woman who underwent Achilles tendon repair through a posterior midline incision 3 weeks ago develops a postoperative wound infection and subsequent skin necrosis. Physical examination shows a 3 x 3-cm wound directly overlying the Achilles tendon in the absence of peritenon. A fasciocutaneous propeller flap from the medial leg is designed to cover this defect. The septal perforators to this flap run between which of the following structures? A. Flexor hallucis longus and gastrocnemius B. Gastrocnemius and soleus C. Peroneus longus and peroneus brevis D. Soleus and flexor digitorum longus E. Tibialis anterior and extensor digitorum longus

D. This defect may be reconstructed with a posterior tibial artery perforator propeller flap. These vessels emerge between the flexor digitorum longus and the soleus muscle. In one anatomic study, there were three clusters of perforators: 4 to 9 cm, 13 to 18 cm, and 21 to 26 cm from the intermalleolar line. The peroneal artery perforators often arise through the posterior peroneal septum, and the anterior tibial artery perforators are often found between the extensor digitorum longus and the peroneus longus or between the tibialis anterior and the extensor digitorum longus.

A 50-year-old woman comes to the emergency department because of a stab wound to the right forearm. A photograph is shown (transverse laceration across dorsum of forearm). She is taken to the operating room and general anesthesia is administered. Which of the following is the most appropriate examination, in this intubated patient, to assess for tendinous injuries to the fingers? A. Passively extend the fingers B. Passively extend the wrist C. Passively flex the fingers D. Passively flex the wrist E. Place hand in cold water

D. This patient has sustained a dorsal mid forearm laceration. Common injuries within this location include injuries to the musculotendinous units of the extensors to the wrist, fingers, and thumb. Additionally, the radial sensory nerve and dorsal branch of the ulnar nerve could be injured depending on the location and vector of the object that caused the injury. Passive flexion as demonstrated in the photograph demonstrates the effect of tenodesis. With passive wrist flexion, intact digital extensors should be put under tension and bring the metacarpophalangeal joints into extension. However, in this patient the long and ring fingers do not extend with wrist flexion. In an uninjured hand, when the wrist is passively flexed the fingers and thumb will extend. With wrist extension, the fingers are brought into flexion and the thumb is brought toward the small finger. Bringing the wrist into extension would help with a volar wound as it would help establish injuries to digital flexors. Putting the hand in cold water is a better test for sensory nerve injury as loss of wrinkling will be demonstrated. Passive flexion or extension of the fingers will not reliably demonstrate which specific tendons are injured in this patient.

A 23-year-old man is brought to the emergency department because of a laceration of all extensor tendons at Zone VII of the right upper extremity. Which of the following tendons has the most distal muscle belly when attempting to reappose the tendon ends? A. Extensor carpi radialis longus B. Extensor carpi ulnaris C. Extensor digitorum communis to long finger D. Extensor indicis proprius E. Extensor pollicis longus

D. Zone 7 extensor tendon injuries are those over the dorsal wrist. The extensor indicis proprius tendon typically has the most distal muscle belly and this fact can frequently be used to uniquely identify this tendon.

A 52-year-old man presents for evaluation of a claw deformity of the right ring and small fingers. Medical history includes an unrepaired low ulnar nerve injury sustained 30 years ago. Which of the following is the most likely pathophysiology of this patient's deformity? A. Unbalanced abductor digit minimi muscle B. Unbalanced median and ulnar innervated intrinsic muscles C. Weak thenar muscles D. Weak ulnar innervated extrinsic flexor muscles E. Weak ulnar innervated intrinsic muscles

E. Clawing after ulnar nerve injury includes hyperextension of the metacarpophalangeal (MCP) joints and flexion of the interphalangeal (IP) joints. The pathophysiology includes paralysis of the interossei and third and fourth lumbricals. Unopposed long extensors cause the metacarpophalangeal joints to fall into extension while the long flexors pull the proximal interphalangeal joints into flexion. This posture is the classical 'claw hand.'

Which of the following is the greatest predictive risk factor for birth brachial plexus injury? A. Cesarean delivery B. Forceps delivery C. Macrosomia D. Multiple gestation E. Shoulder dystocia

E. In multivariate analysis, shoulder dystocia has overwhelmingly been found to be the risk factor most predictive of (most associated with) birth brachial plexus injury. The epidemiological study by Foad showed a 100 times greater risk; another study by DeFrancesco showed an odds ratio of 113.2. While conferring a smaller risk, macrosomia and forceps delivery are far weaker predictive factors, with increases in risk of 14-fold and 9-fold, respectively. Multiple gestation and cesarean delivery are actually protective factors against birth brachial plexus injury.

A 59-year-old man with type 2 diabetes mellitus comes to the office because he has had swelling, pain, and decreased function of the right small finger after he injured it slightly 2 weeks ago. The patient reports similar symptoms of the right thumb, although it sustained no inciting injury. Examination of both digits shows signs and symptoms of pyogenic flexor tenosynovitis. In addition to washing out the respective tendon sheaths, exploration of which of the following additional sites is necessary? A. First web space B. Flexor carpi radialis tendon sheath C. Hypothenar compartment D. Ring finger flexor tendon sheath E. Space of Parona

E. Infectious flexor tenosynovitis can spread from the tendon sheath of the fifth digit to the flexor tendon sheath of the thumb by way of the space of Parona: the potential space in the volar wrist, deep to the flexor tendons but superficial to the pronator quadratus muscle. In this area, the proximal extent of the tendon sheaths of both the small finger and the thumb are in close proximity. This has been termed the "horseshoe abscess" of the upper extremity.

A 71-year-old woman elects to undergo surgery for basal thumb osteoarthritis. In addition to carpal tunnel syndrome and presence of pathology at the scaphotrapeziotrapezoid (STT) joint, assessment for which of the following additional concomitant conditions is most appropriate during the operative planning for this patient? A. Lunotriquetral dissociation B. Radioscaphoid arthritis C. Scapholunate dissociation D. Thumb interphalangeal arthritis E. Thumb metacarpophalangeal hyperextension

E. Operative planning for surgical treatment of basal thumb osteoarthritis requires not only careful history, physical examination, and radiographic examination of the basal thumb joint, but also the scaphotrapeziotrapezoid (STT) joint, the carpal tunnel, and the thumb metacarpophalangeal (MP) joint. Persistent arthritic symptoms following treatment of the basal thumb joint are often due to unrecognized STT arthritis, and many patients will have carpal tunnel syndrome concomitant with basal thumb arthritis; thus, it is important to evaluate for these pathologies to avoid persistent symptoms following surgery. The MP joint must be evaluated for collapse, or hyperextension, particularly with pinch prior to operative treatment. Failure to correct MP hyperextension, particularly that beyond 30 degrees, may lead to persistent pain and progressive collapse of the thumb. The scapholunate, lunotriquetral, thumb interphalangeal, and radioscaphoid joints are not associated with basal thumb arthritis or its treatment.

An 8-year-old girl is brought to the office because of severe, worsening pain as well as finger swelling and numbness three days after she underwent cast placement for a fracture of the left forearm. After removal of the cast, her pain continues and is worsened by passive wrist motion. Which of the following is the most appropriate next step in assessment of this patient's condition? A. Angiography B. CT scan C. Duplex ultrasound D. Electromyography E. Manometry

E. The most appropriate next test is manometry. The patient is exhibiting signs of compartment syndrome after swelling due to fracture under a tight restrictive cast. Signs and symptoms of compartment syndrome include pain with passive stretch, increased pressure on palpation, paresthesia, paralysis, pallor, and pulselessness. Early recognition and treatment are necessary to prevent permanent damage. The pressure within the muscles increases, preventing blood flow to the area and capillary exchange of nutrients. Fasciotomy is recommended if compartment pressure exceeds 30 mmHg, or if the difference between intracompartmental pressure and diastolic blood pressure is less than 30 mmHg. Without treatment, ischemic necrosis to the muscles can result, leading to Volkmann ischemic contracture and causing permanent disability. Scarring and shortening of the muscles can occur, with resultant contracted intrinsic minus appearance of the hand. Compartment pressures can be measured by handheld manometer (Stryker pen), or needle manometer method (Whitesides) with an arterial line setup. Operative fasciotomy is indicated to release the compartment pressures and prevent tissue loss and muscle necrosis in cases of compartment syndrome. Loss of pulse typically occurs later in the spectrum of findings.

A 67-year-old man comes to the office because of nerve deficit of the left lower extremity which occurred after undergoing a femoral-distal bypass 5 days ago. Physical examination shows numbness of the plantar surface of the foot and weakness in plantarflexion. Which of the following nerves is most likely injured in this patient? A. Femoral B. Obturator C. Peroneal D. Sural E. Tibial

E. This patient appears to demonstrate symptoms of a tibial nerve injury. The tibial nerve is a branch of the sciatic nerve. It travels through the popliteal fossa and gives off branches to gastrocnemius, soleus, plantaris, and popliteus muscles. The tibial nerve travels in proximity to the posterior tibial artery. In the leg, it gives off branches to the flexor digitorum longus, tibialis posterior, and flexor hallucis longus. Distally in the foot, it branches to give rise to the medial and lateral plantar nerves, which provide sensation to the plantar surface of the foot. Injury to the tibial nerve results in deficits of plantarflexion, as well as anesthesia to the plantar surface of the foot. The femoral nerve innervates muscles of the anterior thigh, including the quadriceps group, iliacus, and sartorius. Injury to the femoral nerve results in weakness of leg extension. The obturator nerve provides innervation to the medial thigh muscles (adductor group), including adductor brevis, longus, and magnus, as well as the gracilis and obturator externus. The cutaneous branch provides sensation of the medial thigh. Injury to the obturator nerve results in weakness in thigh adduction, and sensory deficits in the medial thigh. The peroneal nerve is divided into superficial and deep branches at the area of the fibular neck. The superficial peroneal nerve supplies the lateral compartment of the leg, giving motor branches to peroneus longus and brevis, as well as sensory contributions to the lateral aspect of the leg. Injury to the superficial peroneal nerve results in anesthesia of the lateral aspect of the leg and weakness in eversion and plantarflexion of the foot. The deep peroneal nerve travels in the anterior compartment of the leg, and gives branches to the tibialis anterior, extensor hallucis longus, and extensor digitorum longus and brevis, as well as peroneus tertius. The sensory distribution of the deep peroneal nerve is in the area of the first web space. Injury to the deep peroneal nerve causes weakness in dorsiflexion of the foot. The sural nerve travels on the posterior aspect of the leg between the lateral malleolus and calcaneus. It provides sensation to the lateral aspect of the foot, and does not have a motor component. It is commonly sampled in nerve biopsy and used as a source of nerve graft. Injury or sacrifice of the sural nerve would result in numbness of the lateral foot.

A 24-year-old man is scheduled to undergo reconstruction for avascular necrosis of the proximal pole of the scaphoid with a free osteochondral bone flap. Which of the following arteries is the most commonly encountered vascular pedicle for the medial femoral condyle free bone flap? A. Anterior tibial recurrent B. Descending genicular C. Popliteal D. Saphenous E. Superficial femoral

The medial femoral condyle free bone (corticocancellous) flap has been shown to be an excellent option for treatment of complicated degenerative bone pathology in the wrist, particularly scaphoid avascular necrosis. The Mayo group has also shown improved outcomes for scaphoid nonunion with humpback deformity compared with pedicled flaps from the distal radius. The same group has shown more consistent presence of supply from the medial superior genicular artery, which can be used in cases where the descending genicular artery is insufficient, although the pedicle length of the medial superior genicular artery is generally shorter. More recent anatomic analysis has shown this vessel can supply flaps up to 11 cm in length. The (superficial) femoral and popliteal arteries are larger, regional vessels, with the superficial femoral artery being the immediate source vessel for the descending genicular artery. The popliteal artery is the source vessel for the medial superior genicular artery. The anterior tibial recurrent artery is distal and lateral, lying over the lateral aspect of the tibial plateau, and does not supply the medial femoral condyle. The saphenous artery has been described as a branch of the superficial femoral supplying the skin paddle overlying the medial femoral condyle but does not supply the bone.