2009 Hand & Wrist Flashcards
What component (pulley) of the flexor tendon sheath is commonly involved in trigger finger? 1. A1 2. A2 3. A4 4. C1 5. C2
PREFERRED RESPONSE: 1 DISCUSSION: Although flexor tendons are occasionally seen to trigger anywhere within the fibroosseous tunnel, the most common location of mechanical mismatch is at the proximal opening, A1 pulley, of the tunnel. The pulleys are named by their configuration, either annular (A) or cruciate (C), and numbered by their location, beginning proximally. REFERENCE Froimson AL: Tenosynovitis and tennis elbow, in Green DP (ed): Operative Hand Surgery, ed 3. New York, NY, Churchill Livingstone, 1993, vol 2, pp 1992-1995.
The ulnar nerve innervates which of the following muscles in the hand and forearm? 1. Four lumbricals and abductor digiti minimi 2. Adductor pollicis and abductor digiti minimi 3. Extensor carpi ulnaris and flexor carpi ulnaris 4. Abductor digiti minimi and abductor pollicis brevis 5. Flexor pollicis brevis and opponens pollicis
PREFERRED RESPONSE: 2 DISCUSSION: The ulnar nerve innervates the abductor digiti minimi, adductor pollicis, flexor carpi ulnaris, the lumbricals to the small and ring fingers, and frequently a portion of the flexor pollicis brevis. The median nerve innervates the lumbricals to the index and long fingers, the flexor pollicis brevis, opponens pollicis, and the abductor pollicis brevis. The radial nerve innervates the extensor carpi ulnaris. REFERENCE Spinner M (ed): Kaplan’s Functional and Surgical Anatomy of the Hand, ed 3. Philadelphia, PA, JB Lippincott, 1984, pp 230-233.
Which of the following structures is typically spared in ulnar impaction syndrome? 1. Ulnar head 2. Lunate 3. Triquetrum 4. Triangular fibrocartilage 5. Pisiform
PREFERRED RESPONSE: 5 DISCUSSION: The bones of the ulnocarpal joint consist of the ulna, triquetrum, and lunate. The triangular fibrocartilage is interposed between the carpal bones and the ulnar head, and is typically the first structure to undergo degeneration. The interosseous ligament provides a continuation of the articular surface between the lunate and triquetrum, and also frequently shows early degeneration. Chondromalacia of the ulnar head, lunate, and occasionally the triquetrum is followed by cystic and sclerotic changes within these bones. The pisiform is not typically involved in this syndrome. REFERENCE Chun S, Palmer AK: The ulnar impaction syndrome: Follow-up of ulnar shortening osteotomy. J Hand Surg [Am] 1993;18:46-53.
Which of the following structures form the boundaries of the anatomic snuff box of the wrist? 1. Extensor pollicis longus tendon and abductor pollicis longus tendon 2. Abductor pollicis brevis tendon and abductor pollicis longus tendon 3. Extensor pollicis longus tendon and extensor pollicis brevis tendon 4. Radial artery and extensor pollicis longus tendon 5. Abductor pollicis longus tendon and extensor pollicis brevis tendon
PREFERRED RESPONSE: 3 DISCUSSION: In the first dorsal compartment, the extensor pollicis brevis tendon is ulnar to the abductor pollicis longus tendon. The anatomic snuff box of the wrist is bounded by the abductor pollicis longus and extensor pollicis brevis on its radial border and the extensor pollicis longus on its ulnar border. The distal half of the scaphoid and the tubercle of the trapezium form the floor. The radial artery and branches of the superficial radial nerve pass through this area. Branches of the lateral antebrachial cutaneous nerve, which is a branch of the musculocutaneous nerve, may also pass through this area. REFERENCE Spinner M (ed): Kaplan’s Functional and Surgical Anatomy of the Hand, ed 3. Philadelphia, PA, JB Lippincott, 1984, pp 359-371.
Management of a patient with an acute nail bed laceration should consist of 1. soaks and oral antibiotics. 2. volar splinting. 3. removal of the nail plate. 4. repair of the nail bed with 6-0 chromic suture. 5. reconstruction of the nail with split sterile matrix grafts.
PREFERRED RESPONSE: 4 DISCUSSION: It is important to properly treat a nail bed injury acutely. As a rule, reconstruction does not provide the same results as proper early care. Using the proper suture (6-0 or 7-0 chromic) on a fine needle with magnification, 90% of patients should have good or better results. Reconstruction of the nail with split sterile matrix grafts or split germinal matrix grafts will improve nail appearance, but will most likely result in a permanent deformity. REFERENCES Manske PR (ed): Hand Surgery Update. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 289-293.
The recurrent motor branch of the median nerve innervates which of the following muscles? 1. Abductor pollicis brevis, first dorsal interosseous, opponens pollicis 2. Abductor pollicis brevis, flexor pollicis brevis, opponens pollicis 3. Adductor pollicis, first dorsal interosseous, opponens pollicis 4. Adductor pollicis, flexor pollicis brevis (deep and superficial heads) 5. Adductor pollicis, flexor pollicis brevis, opponens pollicis
PREFERRED RESPONSE: 2 DISCUSSION: The recurrent motor branch of the median nerve supplies the thenar muscles (abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis) that are primarily responsible for thumb opposition. The nerve can be injured in carpal tunnel release. A branch of the nerve also supplies the first lumbrical. The adductor pollicis and the interossei are supplied by the ulnar nerve. REFERENCES Last RJ: Anatomy: Regional and Applied, ed 6. London, England, Churchill Livingstone, 1978, p 109. Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, p 170.
A purulent flexor tenosynovitis of the thumb may communicate with the small finger flexor through which of the following structures? 1. Hypothenar space 2. Thenar space 3. Midpalmar space 4. Distal forearm (Parona space) 5. Lumbrical canal
PREFERRED RESPONSE: 4 DISCUSSION: Only the flexor sheaths of the thumb and small finger are continuous from the digit through the carpal canal and into the distal forearm. If one of the sheaths ruptures from synovitis, it may contaminate the other sheath through the Parona space in the distal forearm. This potential space lies superficial to the pronator quadratus and deep to the flexor tendons. REFERENCES Green DP, Hotchkiss RN, Pederson WC (eds): Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, pp 1044-1045. Burkhalter WE: Deep space infections. Hand Clin 1989;5:553-559.
Which of the following nerves travels with the deep palmar arch? 1. Recurrent motor branch of the median nerve 2. Medial branch of the median nerve 3. Lateral branch of the median nerve 4. Superficial branch of the ulnar nerve 5. Deep motor branch of the ulnar nerve
PREFERRED RESPONSE: 5 DISCUSSION: The ulnar nerve divides alongside the pisiform, and the deep branch supplies the three hypothenar muscles and crosses the palm with the deep palmar arch to supply the two ulnar lumbricals, all interossei, and finally the adductor pollicis. The superficial branch supplies the ulnar digital branches to the small and ring fingers. The median nerve branches are more superficial in the palm near the superficial palmar arch. REFERENCES Last RJ: Anatomy: Regional and Applied, ed 6. London, England, Churchill Livingstone, 1978, p 109. Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, pp 166-169.
Pacinian corpuscles are lamellated nerve endings that are responsible for providing the perception of 1. pain. 2. light touch. 3. pressure. 4. temperature. 5. vibration.
PREFERRED RESPONSE: 3 DISCUSSION: Pacinian corpuscles are nerve endings that provide the perception of pressure. REFERENCE Sunderland SS: Nerves and Nerve Injuries, ed 2. New York, NY, Churchill Livingstone, 1978, pp 343-347.
A positive Froment sign indicates weakness of which of the following muscles? 1. First dorsal interosseous 2. Adductor pollicis 3. Opponens pollicis 4. Flexor pollicis brevis 5. Abductor pollicis longus
PREFERRED RESPONSE: 2 DISCUSSION: Thumb adduction is powered by the adductor pollicis (ulnar nerve). Testing involves having the patient forcibly hold a piece of paper between the thumb and radial side of the index proximal phalanx. When this muscle is weak or nonfunctioning, the thumb interphalangeal joint flexes with this maneuver, resulting in a positive Froment sign. The paper is held by action of the thumb flexion (flexor pollicis longus and flexor pollicis brevis; median innervated). REFERENCE Burton RI: The Hand: Examination and Diagnosis. Chicago, IL, American Society for Surgery of the Hand, 1978, pp 26-27.
The vascularity of the digital flexor tendons is significantly richer in what cross-sectional region? 1. Volar ulnar quadrant 2. Volar radial quadrant 3. Peripheral one third 4. Dorsal one half 5. Center
PREFERRED RESPONSE: 4 DISCUSSION: The vascularity of the dorsal portion of the digital flexor tendons is considerably richer than the volar portion. The other regions are not preferentially more vascular. REFERENCES Hunter JM, Scheider LH, Makin EJ (eds): Tendon Surgery in the Hand. St Louis, MO, Mosby, 1987, pp 91-99. Gelberman RH, Khabie V, Cahill CJ: The revascularization on healing flexor tendons in the digital sheath: A vascular injection study in dogs. J Bone Joint Surg Am 1991;73:868-881.
In the first dorsal compartment of the wrist, what tendon most frequently contains multiple slips? 1. Extensor pollicis longus 2. Extensor pollicis brevis 3. Extensor carpi radialis longus 4. Extensor carpi radialis brevis 5. Abductor pollicis longus
PREFERRED RESPONSE: 5 DISCUSSION: The first extensor compartment of the wrist typically contains a single extensor pollicis brevis tendon and the abductor pollicis longus tendon that nearly always has multiple tendon slips. The extensor pollicis brevis tendon is frequently found to be separated from the slips of the abductor pollicis longus tendon by an intracompartmental septum. During surgery, this septum must be divided to complete the release of the compartment. REFERENCES Jackson WT, Viegas SF, Coon TM, Stimpson KD, Frogameni AD, Simpson JM: Anatomical variations in the first extensor compartment of the wrist: A clinical and anatomical study. J Bone Joint Surg Am 1986;68:923-926. Minamikawa Y, Peimer CA, Cox WL, Sherwin FS: DeQuervain’s syndrome: Surgical and anatomical studies of the fibroosseous canal. Orthopedics 1991;14:545-549.
An untreated mallet finger can progress into what type of deformity? 1. Boutonniere 2. Jersey finger 3. Swan-neck 4. Clinodactyly 5. Camptodactyly
PREFERRED RESPONSE: 3 DISCUSSION: The loss of the extensor insertion at the distal phalanx results in a mallet finger deformity that permits the extension mechanism to shift proximally, thereby increasing the extensor tone at the proximal interphalangeal (PIP) joint relative to the distal interphalangeal joint. If the volar plate of the PIP joint is lax, the joint will hyperextend as a secondary deformity. As the PIP joint hyperextends, the extensor mechanism will migrate dorsally to the axis of rotation of the PIP joint and a swan-neck deformity will result. REFERENCES Littler JW: The digital extensor-flexor system, in Converse JM (ed): Reconstructive Plastic Surgery. Philadelphia, PA, WB Saunders, 1977, vol 6, pp 3166-3214. Burton RI: Extensor tendon—late reconstruction, in Green DP (ed): Operative Hand Surgery. New York, NY, Churchill Livingstone, 1993, pp 1955-1988.
The strength of a repaired flexor tendon in the immediate postoperative period is most closely related to the 1. diameter of the suture used in the repair. 2. addition of a circumferential epitendinous stitch. 3. number of suture knots at the repair site. 4. number of suture strands that cross the repair site. 5. number of grasping loops on either side of the repair site.
PREFERRED RESPONSE: 4 DISCUSSION: Numerous in vitro studies have demonstrated that the strength of a flexor tendon repair is directly proportional to the number of core suture strands that cross the repair site. Four-strand repairs have twice the strength of two-strand repairs, and complex six-strand repairs are up to three times stronger. Repair strength has never been shown to be significantly affected by the diameter of the suture employed or by the addition of multiple grasping loops that have been shown to contribute to gap formation in one experimental model. The addition of a circumferential epitendinous stitch has been shown to increase the strength of the repair by 10% to 50%; therefore, it is recommended but is not considered essential. While most repairs rupture at the suture knot, the number of knots employed has not been shown to be a factor in the initial repair strength. REFERENCES Boyer MI, Strickland JW, Engles D, Sachar K, Leversedge FJ: Flexor tendon repair and rehabilitation: State of the art in 2002. Instr Course Lect 2003;52:137-161. Winters SC, Gelberman RH, Woo SL, Chan SS, Grewal R, Seiler JG III: The effects of multiple-strand suture methods on the strength and excursion of repaired intrasynovial flexor tendons: A biomechanical study in dogs. J Hand Surg [Am] 1998;23:97-104.
In the early stage of carpal tunnel syndrome, Semmes-Weinstein monofilament testing is considered more sensitive than static two-point discrimination testing in assessing median nerve dysfunction because it measures the 1. innervation density of slowly adapting fibers. 2. innervation density of quickly adapting fibers. 3. threshold of quickly adapting fibers. 4. threshold of slowly adapting fibers. 5. conduction velocity of sensory fibers.
PREFERRED RESPONSE: 4 DISCUSSION: A threshold test measures the function of a single nerve fiber innervating a group of receptors, whereas an innervation density test measures numerous overlapping receptor fields. Therefore, threshold tests such as Semmes-Weinstein monofilament testing and vibration testing are more likely to show a gradual change in nerve function. Semmes-Weinstein monofilament testing reflects the function of slowly adapting touch fibers (Group-A beta), and vibration testing measures the quickly adapting fibers. Static and moving two-point discrimination testing both measure innervation density and are more a reflection of complex cortical organization. Therefore, they are most useful in assessing functional nerve regeneration after nerve repair. Conduction velocity is a useful measure of nerve dysfunction in compressive neuropathies but can be measured only with electrodiagnostic equipment. REFERENCES Gelberman RH: Operative Nerve Repair and Reconstruction. Philadelphia, PA, JB Lippincott, 1991, pp 158-162. MacKinnon SE, Dellon AL: Surgery of the Peripheral Nerve. New York, NY, Thieme, 1988, pp 217-219.
A 28-year-old woman has had progressive pain and loss of motion in her nondominant wrist for the past 6 months. Plain radiographs are shown in Figures 1A and 1B. Treatment should consist of 1. proximal row carpectomy. 2. total wrist arthrodesis. 3. lunate excision and silicone prosthesis replacement. 4. radial shortening osteotomy. 5. capitohamate fusion.
PREFERRED RESPONSE: 4 DISCUSSION: Based on the radiographic findings of lunate collapse without loss of carpal height nor a fixed carpal malalignment, the patient has stage IIIA Kienbock disease according to Lichtman’s classification. Although much controversy remains regarding optimal treatment for Kienbock disease, radial shortening osteotomy decreases the radiolunate load and has shown excellent clinical results in patients with stage III or IIIA disease who have a negative ulnar variance. Proximal row carpectomy and total wrist arthrodesis are both salvage procedures that are applicable in stage IIIB or IV disease. The use of a silicone lunate prosthesis is no longer advised because of a high rate of particulate synovitis. Capitohamate fusion alone has not been shown to unload the lunate, although it is sometimes combined with capitate shortening, which decreases the load across the radiolunate articulation. REFERENCES Quenzer DE, Dobyns JH, Linscheid RL, Trail IA, Vidal MA: Radial recession osteotomy for Kienbock’s disease. J Hand Surg [Am] 1997;22:386-395. Trumble T, Glisson RR, Seaber AV, Urbaniak JR: A biomechanical comparison of the methods for treating Kienbock’s disease. J Hand Surg [Am] 1986;11:88-93.
A 23-year-old man undergoes surgery for the condition shown in Figure 2. At surgery, a nerve is seen to be contused but in continuity. Postoperatively, the muscles at the elbow and below which this nerve innervates show no motor function. Which of the following muscles will first show recovery of function? 1. Flexor carpi ulnaris (FCU) 2. Extensor pollicis longus (EPL) 3. Brachioradialis (BR) 4. Extensor carpi radialis brevis (ECRB) 5. Flexor digitorum profundus (FDP) to the little finger
PREFERRED RESPONSE: 3 DISCUSSION: Distal humerus fractures (Holstein-Lewis injuries) are notorious for radial nerve palsies. The order of innervation/reinnervation is the BR, extensor carpi radialis longus, and ECRB, followed by the supinator and the thumb and digital extensors. Brachioradialis function can be elicited by having the patient flex the elbow against resistance and the muscle belly can be palpated firing on the anterior proximal forearm/elbow. The FCU and FDP to the little finger are innervated by the ulnar nerve. REFERENCES Jawa A, McCarty P, Doornberg J, Harris M, Ring D: Extra-articular distal-third diaphyseal fractures of the humerus: A comparison of functional bracing and plate fixation. J Bone Joint Surg Am 2006;88:2343-2347. Hoppenfeld S: Surgical Exposures in Orthopaedics: The Anatomic Approach, ed 2., Philadelphia, PA, 1994, JB Lippincott, p 73.
