R&G CH40 Sternoclavicular Joint Injuries
What are some PE findings with posterior dislocation of SCJ?
-easily palpable sternum -venous congestion in the neck or UE -dry irritating cough and hoarseness -breathing difficulties, SOB, choking sensation -circulation to ipsilateral arm may be decreased (presence of pulses does not exclude vessel injury) -dysphagia or tight feeling in the throat -shock -PTX
What are the keys to the diagnosis of posterior SC dislocation?
-h/o violent injury -painful SCJ -dysphagia -dyspnea -deceased ROM of the UE -palpable step-off of the SCJ -positive "serendipity view" radiograph -posterior displacement seen on CT scan
What are some examples of posterior SC fractures and dislocations?
1. tracheal compression-trachea displaced by the posteriorly displaced medial aspect of the clavicle; key Sx = acute airway compromise, subacute dyspnea 2. PTX-pleural violation by the clavicle (high-energy trauma) 3. laceration of the great vessles-transection or compression of the great vessels (SVC, pulmonary artery, brachiocephalic vein) 4. esophageal perforation/rupture
Most posterior SC dislocations are successfully reduced closed if accomplished within what timeframe?
48 hours
On nonrated frontal radiographs, a difference in the relative craniocaudal positions of the medial clavicles of > what percent of the width of the heads of the clavicles suggests disclocation?
50%
What are the closed reduction methods of treatment for traumatic posterior dislocation?
ABduction traction technique Adduction traction technique
What is the treatment for traumatic posterior dislocation?
CT scan young adults with physeal fractures-nonoperative approach w/ closed reduction + anesthesia/narcotics/muscle relaxers
What is the best technique and method of choice to study problems of the SCJ and should be requested for both SCJ and medial half of B/L clavicles?
CT; showed signs of sclerosis, osteophytes, erosion, cysts, & joint narrowing
What is osteonecrosis of the medial clavicle?
Friedreich disease
What view has the patient supine with the xray tube 30 inches from the involved SCJ with the central ray bean directed tangential to the joint and parallel to opposite clavicle?
Heinig view
What view has the patient seated, leaning over the table with rib cage against the cassette, nape of flexed neck parallel (close) to the table, head supported on hands and the beam passes through the c-spine to project the SCJ onto the cassette?
Hobbs view
What is the most common cause of dislocation of the SCJ?
MVA (47%); 2nd = participation in sports (31%)
Can you reliably determine an anterior or posterior SCJ dislocation with clinical PE only?
No, need radiographic support
What typically manifests in postmenopausal years and can appear as a pseudosubluxation anteriorly?
OA
What is an inflammatory condition of the SCJ and medial ribs which results in new bone formation and even ankylosis of the SCJ?
SC hyperostosis; associated w/ Japanese ethnicity and dermatologic lesions on palms and plantar regions
What is likely the most frequently moved joint of the long bones in the body?
SCJ
Mild sprain =
all ligaments intact and joint is stable; may be local damage to capsule; joint may develop an effusion; no translation of clavicle or loss of congruity
Anatomically, it is essentially impossible for a direct force to produce what?
an anterior SC dislocation
What are the 2 methods used to classify SCJ subluxations and dislocations?
anatomic position of the injury and etiology of the problem
When dislocation of both ends of the clavicle occurs, the SC dislocation is usually where?
anterior
Which direction of SCJ dislocation is more common?
anterior
In the anatomic classification, what are the directions of displacement as they correlate with the anatomy?
anterior subluxation/dislocation: medial end of the clavicle is displaced anteriorly or anterosuperiorly to the anterior margin of the sternum posterior dislocation: medial end of the clavicle is displaced posteriorly or posterosuperiorly to the posterior margin of the sternum
What phsyeal injuries can be left alone w/o problem?
anterior; posterior should be reduced
Why does the SCJ have the distinction of having the least amount of bony stability of the major joints of the body?
b/c less than 1/2 of the medial clavicle articulates w/ the upper angle of the sternum
Why can lateral radiographs, although 90 degrees perpendicular to the AP/frontal films, cannot be interpreted for evidence of SC dislocation?
b/c of the density of the chest and overlap of the medial clavicles w/ the 1st rib and sternum
Where does the anterior jugular vein sit?
between the clavicle and the curtain of muscles
What does the "curtain" of muscles do?
blocks the view of vital structures
What is the most important structure in preventing upward displacement of the medial clavicle?
capsular ligament
Which ligament covers the anterosuperior and posterior aspects of the SCJ and may be the strongest ligament of the SCJ?
capsular ligament
What SCJ injuries are managed operatively?
chronic posterior dislocations acute, irreducible posterior dislocation possibly acute and chronic anterior dislocations (ORIF)
What is the first long bone of the body to ossify?
clavicle-5th IU week
What is the treatment for posterior physical injuries of the medial clavicle?
closed reduction for 23 y/o or less; shoulder held back in clavicular strap or figure-of-eight dressing for 3-4 wks
What is the treatment for anterior physical injuries of the medial clavicle?
closed reduction for 25 y/o or less; shoulder held back in clavicular strap or figure-of-eight dressing for 3-4 wks; healing is prompt and remodeling will occur
What condition typically occurs in women of late child-bearing age and presents as a painful joint w/ sclerosis on xray?
condensing osteitis of the medial clavicle
What are the only complications that occur with anterior dislocation of the SCJ?
cosmetic bump or late degenerative changes
Which ligament is also called the rhomboid ligament, averages 1.3cm in length and thickness, has a twisted appearance, and whose fibers of the anterior and posterior components cross and allow for stability of the joint during rotation and elevation of the clavicle?
costoclavicular ligament
What are the operative methods of treatment for traumatic posterior dislocation?
delay in reduction of 48 h may make closed reduction impossible; require open reduction and acute repair of the soft tissues 1. direct repair of the anterior/posterior capsule, intraarticular disk ligament and costoclavicular ligament
What type of joint is the SCJ?
diarthrodial; only true articulation b/t UE and axial skeleton
Acute dislocation =
dislocated SCJ; capsular and intraarticular ligaments are ruptured; occasionallycostoclavicular ligaments are intact but stretched to allow dislocation of SCJ
Division of the capsular ligament results in what?
downward depression of the distal end of the clavicle
What forces tend to produce a SC joint dislocation?
either direct or indirect given its subjected to practically every motion
What is the last of the long bones in the body to appear and the last physis to close?
epiphysis at the medial end of the clavicle; ossifies at 18-20th year important b/c SC dislocations in adults are often injuries through the physeal plate
What do the posterior fibers of the costoclavicular ligament resist?
excessive downward rotation of the clavicle and medial displacement
What do the anterior fibers of the costoclavicular ligament resist?
excessive upward rotation of the clavicle and lateral displacement
What is the ROM of the SCJ?
freely movable; functions like a ball-and-socket; capable of 30-35 degrees of upward elevation, 35 degrees of combined forward and backward movement; 45-50 degrees of rotation
What special image is frequently obtained as a front line image and rarely obtained for evaluation of SCJ
frequently = serendipity view rarely = Heinig and Hobbs views (can be useful with high clinical suspicion prior to CT, esp in delayed presentation)
Infection may mimic trauma and should be especially be considered in what patients?
h/o IV drug abuse, immunocompromise, or indwelling subclavian catheters
Migration of pins or K-wires from operative fixation of SCJ have been found where?
heart, pulmonary artery, aorta, mediastinum, breast, subclavian vein/artery, lung
Recurrent dislocation =
if initial acute dislocation doesn't heal, mild to moderate forces may produce recurrence (rare)
What are the vital structures near the SCJ?
innominate artery, innominate vein, vagus nerve, phrenic nerve, internal jugular vein, trachea, esophagus also, arch of the aorta, SVC, RT pulmonary artery
Which ligament connects the superomedial aspects of the clavicle with the capsular ligaments and upper sternum and helps the capsular ligaments produce "shoulder poise" to hold up the shoulder?
interclavicular ligament
Which ligament is very dense, stretches to the SCJ from the synchondral junction of the 1st rib/sternum, divides the joint into 2 separate spaces and acts as a checkrein against MEDIAL displacement of the inner clavicle?
intraarticular disk ligament
What are the ligaments of the SCJ?
intraarticular disk ligament, costoclavicular ligament, interclavicular ligament, capsular ligament
If the shoulder is compressed and rolled backward, what type of dislocation results?
ipsilateral anterior dislocation
If the shoulder is compressed and rolled forward, what type of dislocation results?
ipsilateral posterior dislocation
What are complications accompanying unreduced posterior dislocations?
late TOS, late and significant vascular problems, respiratory compromise, DOE; also, edema and arm discoloration, effort thrombosis, and dysphagia
The anterosuperior fullness of the chest produced by the clavicle is more or less prominent and visible when compared with the normal side?
less prominent and visible; usual palpable medial clavicle is displaced posteriorly
What is the safe resection length of the SCJ (medial clavicle) that would result in honor minimal disruption of the costoclavicular ligament?
men = 1.0 cm women = 0.9 cm
What are the categories of etiologic classification of SCJ injuries?
mild sprain moderate sprain (subluxation) acute dislocation recurrent dislocation unreduced dislocation
Majority of injuries to the SCJ are managed how?
non-operatively
What is the treatment for traumatic anterior dislocation?
nonoperative closed reduction-narcotics/muscle relaxers, supine patient w/ shoulder pad b/t shoulder blades, gentle pressure over anteriorly displaced clavicle; figure-of-eight strap x 4-6 wks operative not recommended-complications too great
What is the treatment for traumatic anterior subluxation?
nonoperative ice x 12h, followed by heat x 24-48h; reduced by drawing the shoulders backward (can use a clavicle strap or sling and swathe for both anterior and posterior); protected x 4-6 wks
If arthrodesis is performed for habitual dislocation of the SCJ, what motion does it prevent?
normal elevation, depression, and rotation of the clavicle
Unreduced dislocation =
original dislocation is unrecognized, may be irreducible, or MD decides not to reduce it
What are 3 conditions associated with SCJ injuries and predominate in women?
osteitis, Friedreich disease, OA
ABduction traction technique
patient is supine w/ sandbag b/t 2 shoulders; traction is applied to the arm against countertraction in an ABducted and slightly extended position (in anterior dislocations, direct pressure over the medial end of the clavicle may reduce the joint; for posterior, you may need to manipulated the medial clavicle to dislodge the clavicle from behind the manubrium)
ADduction traction technique
patient is supine w/ sandbag b/t 2 shoulders; traction is applied to the arm in Adduction while a downward pressure is exerted on the shoulder (clavicle is levered over the first rib into its normal position)
What patients are predisposed to atraumatic anterior SCJ subluxation?
patients with generalized ligamentous laxity (Wynne-Davies signs)
Which SC dislocation causes more pain?
posterior
Significant concomitant injuries almost always occur in the setting of what type of SCJ injury?
posterior SC fractures and dislocations
What is the most important structure for preventing both anterior and posterior translation of the SCJ?
posterior SCJ capsule; anterior capsule is an important secondary stablizer
When a force is applied indirectly to the SCJ from the anterolateral or posterolateral aspects of the shoulder (MOST COMMON MOI for indirect trauma), the clavicle is typically pushed where?
posteriorly
When a force is applied directly to the anteromedial aspect of the clavicle, the clavicle is pushed where?
posteriorly behind the sternum and into the mediastinum
What is the treatment for traumatic anterior dislocation?
protect SCJ with figure-of-eight strap 2-6 wks; CT scan
What imaging is best to evaluate SC dislocation?
radiographs + CT
What is the recommended treatment course for degenerative changes noted in the SCJ?
resection of the medial end of the clavicle
Why might the distal NV exam reveal diminished sensation or weakness?
secondary to brachial plexus compression
What view has the patient lying on his back with tube tilted 40 degrees from vertical and centered directly on the sternum (40 degree cephalic tilt) and is the next best thing to having a cephalocaudal lateral view?
serendipity view
What is the post reduction care for SCJ relocations?
shoulders held back (figure-of-eight strap) x 4-6 weeks
Cutting the posterior capsule of the SCJ results in what?
significant increases in anterior translation
In regards to spontaneous subluxation or dislocation, atraumatic anterior dislocation is painful and associated with what?
snap or pop as arm is elevated overhead, another snap occurs when the arm is returned to patient's side
What condition usually occurs in the late teens and young adults, more often women?
spontaneous subluxation or dislocation; usually one joint more than b/l; h/o generalized ligamentous laxity of other joints, middle-aged women
How are B/L dislocations of the clavicle managed?
stabilization of the ACJ w/ operative fixation per type (III, IV, V and VI) and SCJ w/ nonoperative management (exception is unreduced posterior dislocation)
What is the basic function of the subclavius muscle?
stabilize the SCJ
When the clavicle is fractured with an SCJ disclocation, how should the clavicle be managed?
stabilized w/ internal fixation for posterior injuries and as appropriate for isolated clavicle fracture when dislocation is anterior
What is the "curtain" of muscles posterior to the SCJ and the inner 1/3 of the clavicle?
sternohyoid, sternothyroid, scaleni
Moderate sprain (subluxation) =
subluxation of SCJ (usually anterior); capsular ligaments, intraarticular disk and costoclavicular ligaments may be partially disrupted
What does the interclavicular ligament prevent?
superior displacement of the clavicle with shoulder adduction and depression; failure occurred at 53.7N
What can be helpful in distinguishing between SC dislocation and fracture, questionable anterior and posterior injuries of the SCJ and evaluate arthritic changes?
tomograms
A traumatic dislocation of the SCJ usually occurs only after what?
tremendous forces (direct or indirect) to the shoulder
T/F: CXR and possible CT scan w/ 3-D recon to completely evaluate an underlying congenital condition or pseudoarthrosis if the subluxation is rigid and unresponsive to nonoperative care.
true
T/F: Many so-called dislocations of the SCJ in adults are not dislocations but physical injuries that will heal w/o surgical intervention and the remodeling eliminates any bone deformity or displacement.
true
T/F: The SCJ ligamentous support structure is strong and one of the least commonly dislocated joints.
true
T/F: The articular surface of the clavicle is much larger than that o the sternum, and both are covered with hyaline cartilage.
true
The capsular ligament is the first line defense against what?
upward displacement of the inner clavicle caused by downward force on its distal end
While most chronic posterior SC fracture dislocations require open procedures, what is the singular exception to operative management?
young adults who may have no symptoms; can wait to see if the physical plate remodeling process removes the posteriorly displaced bone
