(A) Dynamic extension splinting
(B) Injection of a corticosteroid
(C) Tendon transfers
(D) Interpositional nerve grafting
(E) Neurolysis

The correct response is Option C.

In patients with high radial nerve palsy, the primary goal is restoration of extension of the wrist, fingers, and thumb. If the nerve was intact at the time of the initial surgery and there is subsequently no return of function six months later, further improvement is unlikely, and tendon transfers are indicated at this time.

Transfer of the pronator teres to the extensor carpi radialis brevis is frequently performed to recover wrist extension. To regain finger extension, the flexor carpi radialis, flexor carpi ulnaris, or flexor digitorum superficialis of the long or ring fingers is transferred into the distal extensor digitorum communis tendons. Transfers to regain thumb extension include the palmaris longus or flexor carpi radialis to the extensor pollicis longus. Additionally, some surgeons advocate end-to-side tendon transfers.

The extensor carpi radialis brevis cannot be transferred to the extensor digitorum communis because it is also affected by the radial nerve palsy. Transfer of the flexor digitorum profundus tendon of the long finger is associated with significant loss of function at the donor site.

Splinting is not indicated in a patient who has persistent radial nerve palsy six months after the initial procedure.

Injection of a corticosteroid is inappropriate treatment of radial nerve palsy.

Because the nerve is shown to be intact, the presence of a neuroma in continuity may be inhibiting the reinnervation process. EMG should be performed to determine the potential for nerve grafting or neurolysis in this patient. However, most nerve grafting procedures in adults provide only limited improvement in motor and sensory functions six months after denervation.

References
1. Green DP. Radial nerve palsy. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;2:1481-1496.
2. Wheeler DR. Reconstruction for radial nerve palsy. In: Peimer CA, ed. Surgery of the Hand and Upper Extremity. New York, NY: McGraw-Hill, Inc; 1996:1363-1379.

A 23-year-old man sustained a complete laceration of the ulnar nerve at the level of the elbow four weeks ago when he was stabbed in the nondominant forearm with a knife. After surgical nerve preparation, a 2-cm gap is present. Which of the following is the most appropriate next step in management?

(A) Use of a vein conduit
(B) Tendon transfers
(C) Mobilization of the nerve 15 cm proximally and distally
(D) Sural nerve grafting
(E) Ulnar nerve transposition

The correct response is Option E.

In this 23-year-old man who has a 2-cm nerve gap after sustaining a clean laceration of the ulnar nerve at the elbow four weeks ago, the most appropriate next step in management is transposition of the ulnar nerve. Because transposition of this nerve at the elbow provides as much as 4 cm of length, it is recommended in this patient in whom primary coaptation cannot be performed because of nerve retraction.

Ulnar nerve transposition may yield as much as 3 cm of length when performed in the arm, 2 cm of length at the forearm, and 1 to 2 cm of length at the distal forearm and wrist. Transposition is also appropriate for repair of median and high radial nerve injuries.

Vein conduits should only be considered if direct repair and transposition are not options.

Tendon transfers alone do not restore sensory function, and are recommended for late reconstruction only when nerve repair is no longer an option.

Extensive mobilization of the ulnar nerve into the mid forearm may cause devascularization and injury to distal nerve branches and ultimately worsen functional outcome.

Sural nerve grafting may be considered if transposition of the ulnar nerve results in tension following nerve coaptation.

References
1. Strauch B. Use of nerve conduits in peripheral nerve repair. Hand Clin. 2000;16:123-130.
2. Trumble TE, McCallister WV. Repair of peripheral nerve defects in the upper extremity. Hand Clin. 2000;16:37-52.

In a patient with established Volkmann’s ischemic contracture, reconstruction via free transfer of the gracilis involves decompression of which of the following nerves?

(A) Anterior interosseous
(B) Median
(C) Posterior interosseous
(D) Radial
(E) Ulnar

The correct response is Option B.

In a patient with Volkmann’s ischemic contracture of the forearm, the median nerve is most likely compressed, and is thus most likely to require decompression, because it traverses the center of the scarred muscles. After muscle infarction occurs, peripheral nerves can become compressed within a constricting scar at a specific anatomic location. Because improvement in nerve function is related to the severity and duration of compression, early decompression is required to minimize further dysfunction. As a result, the median nerve should be decompressed as soon as the patient’s condition permits. In order to be successful, operative exploration is necessary at all points of compression.

In patients with compartment syndrome, high interstitial pressures are typically measured in the deepest compartments of the forearm, especially those compartments that lie adjacent to bone. The flexor digitorum profundus and flexor pollicis longus muscles are affected most often; in more severe cases, the flexor digitorum superficialis, flexor carpi radialis, and flexor carpi ulnaris are involved also. The median nerve often lies at the center of the a constricting scar in the forearm and is thus at risk for compression at the lacertus fibrosus, the two heads of the pronator teres, and the proximal arch of the flexor digitorum superficialis, as well as within the carpal tunnel.

The anterior interosseous nerve is a branch of the median nerve and thus is not involved in Volkmann’s ischemic contracture of the forearm. The posterior interosseous nerve and the radial nerve are rarely involved. The ulnar nerve is implicated less frequently than the median nerve and is often compressed at or just distal to the elbow.

References
1. Botte MJ, Keenan MA, Gelberman RH. Volkmann’s ischemic contracture of the upper extremity. Hand Clin. 1998;14:483-497.
2. Tsuge K. Management of established Volkmann’s contracture. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:592-603.

A 15-year-old girl has absence of sensation of the long finger and radial side of the ring finger 18 months after undergoing operative repair of a partial injury to the median nerve in the wrist. Sensation is normal in the thumb, index, and small fingers and in the ulnar side of the ring finger. An intraoperative photograph is shown above.

Which of the following is the most appropriate management?

(A) Internal neurolysis of the median nerve
(B) Excision of the neuroma only
(C) Excision of the neuroma and epineural repair
(D) Excision of the neuroma and sural nerve grafting
(E) Resection of the median nerve and epineural repair

The correct response is Option D.

In this patient who has a neuroma in-continuity, the most appropriate management is excision followed by sural nerve grafting. Neuroma in-continuity is often difficult to diagnose and treat. Serial clinical examination and electrodiagnostic testing are essential for diagnosis. Although operative exploration can improve hand function and result in a good outcome, the functional fascicles that lie adjacent to the neuroma are at risk for injury. Nerve conduction velocity studies should be performed intraoperatively to identify the nonfunctioning fascicles that lead into
and out of the neuroma. The surgeon should take great care during excision of the neuroma to avoid damaging the functional fascicles. Following excision, autogenous grafting with a donor nerve such as the sural nerve should be performed.

Internal neurolysis would not re-establish the continuity of the involved fascicles. Simple excision of the neuroma will result in recurrence. Excision and epineural repair would place excessive tension on the neurorrhaphy and potentially lead to the development of another neuroma. Resection of the median nerve is an excessive procedure that would eliminate the functional portion of the nerve.

References
1. Kline DG. Timing for exploration of nerve lesions and evaluation of neuroma-in-continuity. Clin Ortho. 1982;163:42.
2. MacKinnon SE, Glickman LT, Dagum A. A technique for the treatment of neuroma-in-continuity. J Reconstr Microsurg. 1992;8:379.

A 50-year-old man is undergoing evaluation because he has had weakness of grip in the right hand for the past two months that is affecting his golf swing. Physical examination shows limited abduction and adduction of the fingers of the right hand. He has difficulty crossing the fingers. Sensation is diminished over the volar aspect of the small finger and volar-ulnar aspect of the ring finger. Sensation is normal over the radial digits and dorsal aspect of the hand.

This patient most likely has an nerve lesion at which of the following sites?

(A) Arcade of Frohse
(B) Arcade of Struthers
(C) Guyon’s canal
(D) Origin of the flexor carpi ulnaris
(E) Vascular leash of Henry

The correct response is Option C.

This patient has symptoms consistent with ulnar nerve compression, including weakness of the intrinsic muscles of the hand innervated by the ulnar nerve (which manifests as a loss of finger adduction and abduction) and evidence of muscle atrophy. There is also decreased sensation in the distribution of the ulnar nerve. The ulnar nerve is compressed most commonly in the region of the cubital tunnel; the second most common site of compression is at Guyon’s canal in the wrist. Sensation over the dorsoulnar hand, which is supplied by the dorsal branches from the ulnar nerve arising proximal to Guyon’s canal, is tested to determine the location of compression. If sensation is altered dorsally, the lesion lies proximal to the distal forearm, and is most likely to involve the cubital tunnel. However, if sensation in the dorsoulnar hand is normal, the lesion lies distal to the distal forearm, and most likely involves Guyon’s canal, as in this patient.

Other, less common sites of compression of the ulnar nerve include the arcade of Struthers, which is a thin aponeurotic band extending from medial head of the triceps to the medial intermuscular septum, located approximately 8 cm proximal to the medial epicondyle, and occasionally the origin of the flexor carpi ulnaris. The arcade of Frohse and vascular leash of Henry are potential sites of compression of the radial nerve.

When compressed, peripheral nerves typically cause pain and specific nerve deficits of sensation and strength. Some sensory branches divide from the nerve proximal to the wrist or at the level of the carpal canal. The dorsal sensory branch of the ulnar nerve divides approximately 6 cm proximal to the wrist. The motor branches of the median and ulnar nerves can be separated into extrinsic and intrinsic function.

Reference
1. Eversmann WW Jr. Entrapment and compression neuropathies. In: Green DP, ed. Operative Hand Surgery. 3rd ed. New York, NY: Churchill Livingstone, Inc; 1982:1341-1385.

A 27-year-old woman has intense, burning pain in the right arm 10 days after sustaining a fracture of the right radius. Conservative treatment of the pain with oral administration of narcotic agents has not been effective. At the time of injury, a long arm cast was applied in the emergency department.

Which of the following is the most appropriate diagnostic test?

(A) Three-view radiographs of the wrist
(B) Stellate ganglion block
(C) Thermography of the upper extremity
(D) Triple-phase bone scan
(E) MRI of the wrist

The correct response is Option A.

This patient has symptoms consistent with complex regional pain syndrome type I, or reflex sympathetic dystrophy (RSD), a complex alteration of the pain response following trauma. In contrast, patients with complex regional pain syndrome type II, or causalgia, have posttraumatic pain resulting from an identifiable nerve injury. While its exact cause is unknown, RSD is characterized by pain, stiffness, limited function, atrophic changes, and vasomotor instability. Early diagnosis and treatment are essential for optimal functional outcome; the surgeon must also differentiate RSD from other, treatable conditions.

Although fractures of the distal radius are a common precipitating factor for RSD, the pain may actually be caused by fracture nonunion or an excessively tight cast. Therefore, appropriate initial management involves removing the cast and obtaining three-view radiographs of the wrist to determine the adequacy of fracture reduction. This should be performed before any of the other diagnostic tests listed.

Stellate ganglion blocks are used in the treatment of RSD and can be performed diagnostically, but simple radiographs should be obtained first. Thermography has been advocated for diagnosis of this condition but has low sensitivity and specificity. Triple-phase bone scans are important for evaluation and have a relatively high specificity for diagnosis, but should not be performed initially. MRI is ineffective in diagnosis and management of RSD.

References
1. Amadio PC, MacKinnon SE, Merritt WH, et al. Reflex sympathetic dystrophy syndrome: consensus report of an ad hoc committee of the American Association of Hand Surgery on the definition of reflex sympathetic dystrophy syndrome. Plast Reconstr Surg. 1991;87:371.
2. Koman LA, Poehing GG, Smith BP, et al. RSD after wrist injury. In: Levin LS, ed. Problems in Plastic and Reconstructive Surgery: The Wrist. Philadelphia, Pa: JB Lippincott; 1992:300-321.