Practical Plastic Surgery

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Figure 78.9. Fracture of the hamate bone. Hook fractures commonly occur in golfers, baseball players or construc-

Figure 78.8. Fifth metacarpal fracture, tion workers with a complaint of a dull commonly known as a boxer’s fracture. ache when gripping.

Figure 78.10. Fracture of the distal phalanx, or a mallet fracture. Distal phalanx fractures can occur due to avulsion of a bony fragment attached to the flexor or extensor tendon.

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A B

Figure 78.11. Dislocation of the lunate bone in the P-A (A) and lateral views (B). Note the normal position of the capitate bone with respect to the distal radius. In milder cases, the lunate can sublux dorsally after scapholunate ligament disruption (DISI) and will rarely sublux volarly after lunotriquetral ligament disruption (VISI).

Figure 78.12. Triquetrum fracture. Usually associated with other wrist fractures after a fall on an outstretched arm. This fracture is usually a dorsal cortex chip fracture best seen on a lateral view.

Figure 78.13. Avulsion fracture of the ulnar collateral ligament insertion at the base of the thumb, commonly referred to as a gamekeeper’s or skier’s thumb. If the fragment is widely displaced, a Stener lesion can result, requiring surgical intervention.

Figure 78.15. Late rheumatoid arthritis. There is marked MP joint destruction and narrowing. Weakening of the radial sagittal bands causes ulnar subluxation of the extensor mechanism and subsequent ulnar deviation of the MP joints.

Figure 78.16. Rheumatoid arthritis in the fingers. In contrast to osteoarthritis, the IP joints are narrowed with characteristic erosions.

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Figure 78.17. An illustration of several of the common clinical features of rheumatoid arthritis: symmetrical joint involvement, rheumatoid nodules, ulnar deviation of the MP joints, and swan neck deformity of the digits (IP hyperextension and DIP flexion).

Signs of ulnar nerve injury include flexor carpi ulnaris (FCU) paralysis, interosseous and thumb adduction loss with a weak “key pinch,” and FDP paralysis of the small and ring fingers. A long-standing injury can present with the classic “claw hand” deformity. In a low lesion of the ulnar nerve just above the wrist, there will be more clawing of the 4th and 5th fingers compared to a high lesion at the elbow. This is known as ulnar paradox and is due to the fact that in a high lesion the flexors will also be paralyzed.

Patients with a radial nerve injury will be unable to extend their wrist or fingers. This can occur following humeral shaft fractures. Injury to the radial nerve in the axilla will result in paralysis of the extensor carpi radialis longus (ECRL) and brevis (ECRB), triceps and brachioradialis muscles. These muscles will atrophy in long-standing nerve injury. Loss of ECRL and ECRB function leads to loss of wrist extension.

Muscle power is assessed on a scale of 0-5, with a score of 5 indicating full power

and a score of 0 being paralysis. 1 is given for just a flicker of muscle contraction, 2 79 for the ability to move with gravity eliminated, and 3 is the muscle strength neces-

sary to lift a joint against the force of gravity. A score of 4 is for muscle power between 3 and 5.

Flexor Tendon Evaluation

Separate evaluation of both FDP and FDS function is important. Division of the FDS without injury to the FDP will not be noticeable in the resting posture. The FDS is evaluated by immobilizing the surrounding fingers in extension and having the patient flex the finger at the PIP joint. FDS to the index finger is evaluated by having the patient perform a firm pulp-to-pulp pinch with the thumb. An injured FDS will cause pseudo mallet deformity of the distal phalanx (flexed DIP, extended PIP), whereas an intact FDS will result in a pseudo boutonniere deformity of the distal phalanx (extended DIP, flexed PIP). FDP is evaluated by immobilizing the PIP and IP joints and evaluating flexion of the isolated DIP joint.

The palmaris longus is present in 85-90% of patients. It courses over the hamate and is identified by having the patient forcibly oppose the thumb and little finger. This tendon is expendable and can be readily used for tendon grafting procedures.

Extensor Tendon Evaluation

Extension of each individual digit at each joint should be examined. It is important to remember that the juncturae tendinum located at the level of the MP joints connects the extensor tendons of extensor digitorum communis (EDC). Therefore, lacerations proximal to the juncturae may not impair digit extension due to the connection to the adjacent digits. Limitation of extension of the DIP joint of the finger is most often due to rupture of the insertion of the extensor tendon into the distal phalanx. This type of injury will produce a mallet finger deformity. If the extensor tendon is disrupted proximal to the PIP joint, a boutonniere deformity may be produced due to hyperextension of the DIP joint by the taught lateral slips.

Evaluation of extensor pollicus longus (EPL) function is performed by asking the patient to place his palm flat on the table and to raise the thumb off of the table. Extension of the thumb alone is not an adequate test of EPL function since extensor pollicus brevis (EPB) and the intrinsic muscles of the thumb will contribute to its extension.

Intrinsic Hand Muscle Evaluation

The dorsal interossei are tested by asking the patient to abduct the fingers away from the middle finger, whereas the volar interossei are evaluated by adduction of the fingers towards to the middle finger. The lumbricals are tested by asking the patient to flex the fingers at the MP joints while the IP joints are held in extension.

Thumb Laxity

Instability of the MP joint of the thumb should be assessed. Laxity should be determined by abducting the thumb in both extension and flexion. Thumb laxity is normally greater in extension and should be compared between the two hands. Rupture of the ulnar collateral ligament (UCL) that connects the proximal phalanx of the thumb to the first metacarpal will result in excessive MP laxity. This injury is commonly seen in skiers, skateboarders, and anyone who falls on an extended thumb that is forcefully abducted. The acute injury is termed skier’s thumb, and the chronic

79 injury is referred to as gamekeeper’s thumb.

Vascular Exam

The color of the digits should be observed, and any pallor, hyperemia or cyanosis noted. Capillary refill greater than 2 seconds is not normal. Arterial inflow to the hand is determined by palpating the radial and ulnar artery pulses. The Allen test is performed using the thumb and fingers to compress the radial and ulnar arteries at the wrist. The patient exsanguinates the hand by making a fist several times and then opens the hand so that the fingers are in a relaxed and gently extended position. The examiner then releases pressure from over the ulnar artery. Capillary refill time in the hand is noted. A normal Allen test is refill in less than 5 seconds, and greater than 5 seconds indicates an abnormal Allen test.

Wrist Stability and Motion

Pronation and supination of the wrist are examined with the elbow flexed to 90° and held firmly to the sides in order to stop rotation of the shoulder. From this position, there is usually about 90° of pronation and 90° of supination. Flexion, extension, radial and ulnar deviation should all be compared between the two wrists simultaneously, and any discrepancies should be noted.

Volar and dorsal stability are determined by the examiner exerting axial traction while holding the patient’s forearm with one hand and the metacarpal heads with the other. Volar and dorsal displacement of the wrist in this position is minimal. If wrist laxity is present during volar pressure, midcarpal subluxation may be due to a flexion deformity of the first carpal row (the VISI deformity). If laxity is noted during dorsal pressure, a dorsal deformity (the DISI deformity) may be present.

Bony Landmarks

Patients will often present with focal pain in the hand or wrist. An understanding of the bony landmarks can help identify the structure that may be injured.

Volar Surface

The pisiform is located on the ulnar side of the palm just proximal to the palmar crease. Tenderness at the bony prominence should be assessed. The hook of hamate is 1-2 fingerbreadths towards the midline from the pisiform. The examiner places his thumb IP joint over the pisiform and directs his thumb towards the patient’s

index finger. The thumb pulp will rest over the hamate. The hook becomes more prominent with wrist flexion.

Dorsal Surface

The anatomic snuff box is located on the radial side of the wrist. Its radial border is EPB and abductor pollicus longus (APL; first dorsal compartment). The ulnar border is EPL (third dorsal compartment). This structure is important because the most commonly fractured carpal bone, the scaphoid, lies below the snuff box. The distal pole of the scaphoid can be palpated in the snuff box with the wrist in ulnar deviation. The scapholunate (SL) joint is the most common site of carpal dislocation. The examiner traces the third metacarpal proximally towards the wrist. The examiner’s finger falls into a depression overlying the SL joint. The lunate is the second most commonly fractured carpal bone. It lies just ulnar to the SL joint. It is palpated with the wrist in flexion during which it is the most prominent area on the dorsum of the wrist. Lister’s tubercle is an easily palpable prominence at the distal

radius that lines up with the third metacarpal. It is easier to palpate it during mild 79 wrist flexion. Recall that it separates the second and third compartments.

Important Provocative tests

Tinel’s sign is a useful test for neuropathy. If percussion at the site of nerve entrapment produces tingling along the course of the nerve or in the digits supplied by the nerve, the test is positive. At the wrist, the volar carpal ligament can be percussed to test for median nerve neuropathy (carpal tunnel syndrome). The test has a low sensitivity (50-70%), but a high specificity (94%).

Phalen’s test is used to provoke median nerve compression. It is performed by having the patient hold both wrists in flexion for a minute by opposing the dorsum of the two hands. If this reproduces the symptoms, the test is positive. It has a sensitivity of 70-80% and a specificity of 80%. The more rapidly the symptoms are produced, the higher the specificity of the test.

Finkelstein’s test is used to test for tenosynovitis of the first dorsal extensor compartment (de Quervain’s disease). The wrist is braced in ulnar deviation while the thumb is passively adducted and flexed. A positive test produces pain at the base of thumb. There may also be point tenderness over the radial styloid.

The grind test is used to assess for arthritis of the carpometacarpal (CMC) joint of the thumb, a common condition that produces pain similar to de Quervain’s tenosynovitis. The examiner exerts axial pressure on the thumb and grinds it against the first metacarpal against the trapezium. A positive test produces pain. In addition, plain radiographs will show arthritic changes—a finding that will be absent in de Quervain’s disease.

The scaphoid shift, or Watson test, is used to test for SL instability or scaphoid fracture, although it has a low sensitivity and specificity. The examiner’s fingers are placed dorsally on the distal radius, while the thumb is placed firmly on the scaphoid tubercle (on the volar surface). The other hand holds the metacarpals, and the wrist is deviated ulnarly which places the scaphoid in extension. As the wrist is moved in radial deviation, the scaphoid is blocked from flexing by the examiner’s thumb. If the SL ligament is injured, the scaphoid will move dorsally under the posterior margin of the radius inducing pain when it touches the examiners fingers. When pressure on the scaphoid is removed, the scaphoid goes back into position with a thunk or clunk. The test should be performed on the uninjured wrist for comparison.

The screwdriver test is used to examine the triangular fibrocartilage complex (TFCC). The examiner shakes the patient’s hand and performs alternating supination and pronation of the wrist (i.e., screwing and unscrewing motion). This motion will usually cause ulnar-sided pain at the wrist if a TFCC injury is present. Decreased range of motion may also be apparent.

Pearls and Pitfalls

–Any patient with an acute injury should be asked the following questions:

•When did the injury occur?

•What was the mechanism of injury?

•What was the position of the hand and/or fingers during the injury?

•Was the environment clean or dirty?

•Have any medications been administered by the ER staff such as a local anesthetic?

•Is there a history of prior injury?

•What is the tetanus status?

79– Palpation for specific tender spots is often the most painful part of the physical assessment and should therefore be reserved for the end of the exam.

–A patient complaining of chronic hand or wrist pain should be asked to demonstrate the movements that most accurately replicate the pain.

–In order to avoid missing an important finding on the initial physical exam, it is useful to follow an examination routine such as:

•Observation

•Vascular: Radial and ulnar artery, capillary refill, skin color

•Sensory: Median, ulnar and radial nerves

•Motor: Median, ulnar and radial nerves

•Flexor tendons

•Extensor tendons

•Intrinsic hand muscles

•Wrist stability and range of motion

•Palpation of bony landmarks

•Provocative tests

Suggested Reading

1.Corley Jr FG. Examination and assessment of injuries and problems affecting the elbow, wrist, and hand. Emerg Med Clin North Am 1984; 2(2):295-312.

2.Daniels IInd JM, Zook EG, Lynch JM. Hand and wrist injuries: Part I. Nonemergent evaluation. Am Fam Physician 2004; 69(8):1941-8.

3.Daniels IInd JM, Zook EG, Lynch JM. Hand and wrist injuries: Part II. Emergent evaluation. Am Fam Physician 2004; 69(8):1949-56.

4.Kuschner SH, Ebramzadeh E, Johnson D et al. Tinel’s sign and Phalen’s test in carpal tunnel syndrome. Orthopedics 1992; 15:1297-1302.

5.Skvarilova B, Plevkova A. Ranges of joint motion of the adult hand. Acta Chir Plast 1996; 38(2):67-71.

6.Waylett-Rendall J. Sensibility evaluation and rehabilitation. Orthop Clin North Am 1988; 19(1):43-56.