Disorders of the fingers & hands

Stenosing Tenosynovitis

aka "Trigger Finger" - Thickening of flexor retinaculum due to injury - Usually due to tendon nodule passing through constricted sheath at proximal flexor pulley (at MCP) S&S: Painful snapping of tendon on extension Eventually, finger locks in flexion RX: Immobilize, then stretching. NSAIDs, steroid injections; surgery for refractory cases - tend to reoccur until you operate

Treatment for Injury to Ulnar Collateral Ligament

aka Gamekeepers Thumb or "ski pole injury" Rx: partial tear requires splinting for 4-6 weeks Referral to a hand surgeon is prudent in most cases of suspected UCL injury (if its a full tear --> operation) UCL - ligament that is used to adduct the thumb (is on the ulnar side of the thumb). In injury thumb is pulled out & back Gamekeepers - raise birds, break the neck of the bird --> develop tears of the UCL

Gamekeepers Thumb

aka: "ski pole" injury Mechanism: hyperextension/hyperabduction of thumb MP joint w/ injury to the ulnar collateral ligament (UCL) - pain, tender in MP joint - weak pincer grasp - >45 degrees of abduction with MP flexed is complete tear (compare with uninjured thumb) Dx: X-ray: usually occurs w/ an avulsion Fx, stress views show laxity (looseness)

Sensory Innervation of the arm

• Axillary nerve = sensation to lateral aspect of shoulder • Musculocutaneous nerve = sensation to the extensor aspect (top) of the forearm

Hand Problems

• Boxer's fracture • Fight bites • Osteoarthritis • Dupuytren's contracture

Boxer's Fracture

• Fracture in 4th or 5th metacarpal neck, usually due to direct trauma to a clenched fist Exam: dorsum of hand swollen, bony tenderness is found over Fx tenderness or ecchymosis on the palmar bony surfaces (palm) is highly suggestive of fx • Obtain X-rays with AP, lateral & oblique views

Treatment for Jersey Finger

• Initial stabilization --> splint w/ the proximal interphalangeal (PIP) and DIP joints slightly flexed until evaluated by the surgeon. • Surgical repair is necessary!* (will not heel on its own b/c joints are not close to each other?)

Jersey Finger

• Results from rupture of the flexor digitorum profundus tendon (muscle from the arm that flexes the fingers) or from an avulsion fracture at the base of the DIP • Occurs when a flexed DIP joint is suddenly and forcefully hyperextended, leading to rupture of FDP tendon at insertion on distal phalanx • Inability to flex the DIP joint actively indicates a rupture of the FDP tendon** reach out to grab someone but all you can reach is their jersey - will not be able to flex the finger anymore

Jersey Finger vs. Boutonniere Deformity

• Rupture of the FDP (Jersey finger) will only limit DIP flexion. • PIP flexion and extension should be unaffected in a jersey finger. • This is an important distinction during examination.

Treatment for Mallet Finger

• Splinting to keep the DIP in full extension for 8 weeks; another 2 - 4 wks at night or longer for delayed treatment • no splint type is superior • Surgery might be needed for those that fail to improve after splinting

Intrinsic Muscles of the hand

"All for one, and one for all"

When to Refer (Hand Surgery)

1. Open fracture, neurovascular compromise 2. ANY first metacarpal (thumb) Fx 3. Unacceptable angulation or rotation (after you try to reduce) 4. Pts who require fine motor movement or grip strength (e.g., musicians, craftsman, seamstresses) 5. Patients who prefer less angulation for cosmetic reasons

Sensory Innervation of the hand

1. Ulnar nerve (when you hit your funny bone) 2. Median nerve 3. Radial nerve Dermatomes: C6: thumb C7: index and middle finger C8: pinky

Motor Innervation of the hand

1. Ulnar nerve innervates intrinsic and hypothenar muscles (palm on the ulnar side of the hand below the pinky) 2. Median nerve innervates flexors and thenars. 3. Radial nerve and branches innervate extensors

Finger and hand problems

• Subungual hematoma • Felon • Paronychia • Trigger finger • Fractures • Mallet finger • Boutonniere deformity • Jersey finger • Gamekeepers Thumb • Osteoarthritis • Boxer's fracture • Dupuytren's Contracture (palmar fasciitis)

Dupuytren's contracture

Etiology unknown - Fibrous contractures of the palmar fascia - Often hereditary and bilateral -Males >>> Females S&S: - Flexion contracture with adherence of overlying skin - Decreased ROM - Progresses ulnar to radial - (generally) distal to proximal (ascending) progression Diagnosis: Clinical

Bony Anatomy of the Hand

From Distal to proximal: 1.Distal Phalanges (DP) 2.Middle Phalanges (MD) - thumb does NOT have MD 3.Proximal Phalanges (PP) 4.Metacarpal bones (MC) - Sesamoid bone is in the thumb at the distal metacarpal 5.Carpal bones - go to the wrist joint (Ulna & Radius)

Felon

Infection of the closed pulp space of the distal phalanx. Secondary to puncture wound (usually Staph) S&S: Tender, taut, swelling of pad of distal phalanx. Erythema, can affect flexor sheath or DIP joint. Dx: clinical • Do NOT confuse w/ paronychia --> a soft tissue infection of proximal or lateral nail folds

Malrotation due to metacarpal Fracture

Lines will intersect at the wrists when you draw a straight line from your finger tips to the wrists (when wrist is clenched) The fifth finger does not go inward which is how you can detect a malrotation

Trigger Finger

Strap of connective tissue is the retinaculum that holds the tendon in place to the bone, must be a little loose so that the tendon can slide through when the finger is bent Nodule develops on the tendon with Stenosing Tenosynovitis, it will get stuck Or it will go under the retinaculum (flexors are strong) and get struck (extensors weaker cannot get it back under the reinaculum) (finger will pop open like its "triggering")

Osteoarthritis of Hand

Etiology: possibly repetitive stress or history of trauma Carpometacarpal (CMC) joint of thumb is the most commonly affected joint of the hand***** - Stiffness and pain, worse with activity, better with rest (better in the morning and gets worse at night) PE: look for signs of generalized OA - DIP: Heberden's nodes* - PIP: Bouchard's nodes* (but more common in RA) • X-rays: cortical sclerosis and/or osteophytes (abnormal outgrowths of bone) RX: NSAIDs, intermittent splinting, moist heat, steroid injections, hand therapy • arthroplasty (repair/replace the joint) or arthrodesis (fuse the joint) occasionally needed

Treatment for a Felon

Felon will not drain on its own w/o treatment when you drain it, MUST drain at the lateral side of the finger tip (never on the pulp (finger tip) b/c of tendon structures) - do NOT need to anesthesia a paronychia, can just make a small incision Rx: Early: po anti-staph antibiotics and moist heat: follow closely Late: Incision and drainage: under digital block anesthesia, followed by wound care & oral antibiotics

Fight Bites

Often in conjunction w/ boxer's fracture • Check for laceration ("fight bite") --> must be decontaminated aggressively to avoid joint infection Often present as puncture wounds. • Tetanus immunization Antibiotic prophylaxis: 1. Amoxicillin-clavulanate 875/125 bid x 5 d BEST 2. Doxycycline, trimethoprim-sulfa, cefuroxime, ciprofloxacin PLUS metronidazole or clindamycin as alternative treatments - Avoid cephalexin, dicloxacillin, erythromycin due to poor activity against Eikenella

Treatment for Dupuytren's contracture

Refer to orthopedist for fasciectomy; full ROM usually possible post-operatively. Collagenase clostridium histolyticum (Xiaflex) - a proteolytic enzyme that breaks down connective tissue, injected into the contracture (and allows fascia to relax)

Management of Boxer's Fractures

Ulnar gutter splint for minimally angulated fractures: 70-90 degrees of flexion at the MCP joint, slight flexion at the PIP and DIP joints, and mild wrist extension • RICE • Cast after swelling goes down, same position as splint

Mallet Finger

• Trauma to extensor tendon at the distal interphalangeal (DIP) joint or a bony avulsion of the distal phalanx • occurs when there is forced flexion of an extended finger • leads to a fixed flexion deformity or extensor lag at the DIP joint if the injury remains untreated (end up with a "Mallet Finger") i.e. like a finger jam when playing basketball - fingers are extended and a force causes flexion of the finger

Subungual Hematoma

• Typically trauma to fingertip, bleeding under nail plate (buildup of pressure) • Painful for several days • Usually resolves spontaneously Treatment: small "drill holes" in nailplate to relieve pressure and pain - coutary device can burn a hole in the nail (it will all grow out eventually)

boutonniere deformity

• results from tear to the central slip tendon on the dorsal (extensor) aspect of the PIP - occurs w/ forced flexion of the PIP joint during active extension or w/ volar dislocation of the PIP joint (lateral bands slip to sides)--> leading to central slip tendon rupture • Loss of the central slip (extensor) of the PIP + displaced lateral bands --> results in PIP flexion and DIP & metacarpophalangeal (MCP) hyperextension Treatment is splinting of the PIP in extension for 6 weeks lateral bands of the tendon slip off the top of the bone and sit laterally. Pulls the joint more into flexion when you try to extend it

Finger Fractures

• trauma • Simple fractures --> buddy taping or splinting. i.e. Tuft fracture (a fracture of the tip of the distal phalanyx). These are often accompanied by subungual hematomas (this is the only non-urgent open fracture) • Spiral and oblique fractures involve rotation or shortening and are unstable* --> should be referred • Comminuted fx, rotational fx, intra-articular fx, & displaced or angulated fx that do not stay reduced --> refer to hand surgeon Refer open fractures & tendon or nerve injuries