NMS Q&A Family Medicine

148 NMS Q&A Family Medicine6. The answer is D. Fracture of the carpal navicular (alsocalled the scaphoid) occurs with falls onto an outstretchedhand, acutely showing tenderness in the “anatomic snuffbox,”which is that space between the extensor tendons ofthe thumb at the base of the metacarpal. Tenderness atthis locus is 90% sensitive for scaphoid fracture but only40% specific. Thus, diagnosis must be confirmed by x-raywith specific focus for the scaphoid bone. Regardless ofx-ray findings on the first few days, given the snuffboxand scaphoid tubercle tenderness, a short arm thumbspica should be applied and the patient brought back forreexamination and repeat x-ray in 2 weeks. Chronically,failure to diagnose may lead to aseptic necrosis andosteoarthritis. Missing this fracture has been the subjectof litigation for failure to diagnose.7. The answer is E. The ulnar deviation of the fifth digitis typical of a fifth metacarpal or “boxer’s” fracture. Thefact that there is skin break defines it as an open or “compound”fracture. The assumed human bite to which theskin break is ascribed defines the wound as infected, aswould a lower animal bite. Thus, the fracture should beimmobilized in good alignment, often by a hand surgeonand antibiotics prescribed to cover a human bite. Amoxicillin-clavulanate(Augmentin) is the first choice in nonpenicillinallergic patients.8. The answer is C. Passive inversion of the shoulderwhile the arm is forward, held in the horizontal by theexaminer – this is the Hawkins maneuver and when itcauses pain in the shoulder it signifies impingement syndrome.Pain of the impingement syndrome is also particularlyincreased by active abduction at the shoulder.Radiographs are usually normal, but MRI will reveal anyswollen tendon producing impingement and can identifytears in the rotator cuff. The pain of rotator cuff tendonitisusually has an insidious onset and is poorly localized– it is treated in the vast majority by physical therapy.Pain in the biceps proximal insertion is elicited by supinationagainst resistance and is called the Yergasonmaneuver. Tenderness also occurs in the proximal insertionin biceps tendonitis. Neither biceps nor elbow extensorstrength is an issue in impingement syndrome sinceabduction of the shoulder is involved. Thumb-fingerapposition tests the motor function of the median nerveas commonly done in probing for carpal tunnel syndrome.9. The answer is B. A right anterior glenohumeral dislocationis associated posterolateral humeral head fracture.The dislocation tends to occur anteriorly, and it is theanterior rim of the glenoid that may take off the posterolateralpart of the humeral head.10. The answer is C, AP views of both AC joints with thepatient holding 10-lb (4.5-kg) weights in each hand. Clinicallythe case seems to involve a grade III or IV sprain ofthe right AC joint (suggested by the high-riding rightclavicle). Hanging weights bring out the separationbetween the clavicle and acromion if the joint capsule istorn and comparison with the contralateral side is made.MRI or arthrogram could also show the capsule tears, butthey are more expensive and unnecessary in decidingtreatment. For this purpose, the right clavicle will be adequatelyviewed on the AC joint films.11. The answer is D. Tenosynovitis of the hand is a surgicalurgency calling for interruption and control of theinfection and surgical drainage and decompression whenindicated to save function of the affected digit. Cellulitisof the hand produces diffuse swelling of the whole hand;palmar space infection causes swelling of either the thenaror midpalmar space. Flexor tendon rupture, assuming noinfectious involvement, is not noted for the degree ofswelling found in the vignette and active flexion wouldnot be demonstrable at all. A stoving injury of the PIPjoint is caused by a blow to the end of an extended fingerwherein the impact is transmitted axially to the joint capsuleof, usually, the PIP joint. It produces fusiform swellingcentered on the joint itself, not the whole finger.12. The answer is B. Hand grip exercise would aggravatethe problem, which is a type of overuse syndrome,lateral epicondylitis. It is commonly called tennis elbow;lateral epicondylitis is caused in tennis by an amateurishtendency to stroke the backhand with the heavy tennisracquet as if it were a table tennis paddle. However, itmay develop through any repetitive supination or grippingaction (handgrip calls upon the wrist extensors tostabilize the wrist against flexion in doubling the fist aswell). The brachioradialis muscle attaching to the epicondyleoperates at a great mechanical disadvantage.Forearm splinting prevents the wrist extension and supination.A glucocorticoid mixed with a local anestheticinjected into the region of the epicondyle, but notdirectly into it, may give dramatic relief. Relief may belasting, provided the underlying mechanical cause isdealt with. Cold applications may give relief during theacute phase.13. The answer is C, laceration of the central slip of theextensor tendon. The configuration of the boutonnieredeformity is flexion of the PIP and extension of the DIPjoint. The DIP attachment of the extensor tendon is a convergenceof two lateral slips that course to the two sides ofthe PIP and thus are spared in an injury to the dorsal midlineof the proximal phalanx and the PIP joint. However,the central slip is involved by that injury. Activation of theextensor tendon apparatus without the functional presenceof the central slip allows the lateral strands of the tendonto slip sideways and relatively ventrally, allowing their