Operative Techniques in Orthopaedic Surgery (4 Volume Set) 1st Edition

327. Wrist Denervation

Carlos Heras-Palou

DEFINITION

 Arthrosis of the wrist often presents with functional movement, but with substantial disability due to pain. The purpose of wrist denervation is to decrease pain by surgically dividing the nerves that transmit the afferent pain signal from the wrist.

ANATOMY

 The posterior interosseous nerve (PIN) is considered to be the most important nerve innervating the wrist joint.

 Other nerves involved are branches from the anterior interosseous nerve (AIN), the radial nerve, the dorsal branch of the ulnar nerve, the palmar branch of the median nerve, and recurrent intermetacarpal nerve branches.¹

PATHOGENESIS

 Common causative conditions include scaphoid nonunion advanced collapse, scapholunate advanced collapse, degeneration secondary to crystalline arthropathy, inflammatory arthritis, and trauma.

NATURAL HISTORY

 The natural history of wrist arthrosis is slow progression, but the correlation between radiologic staging and symptoms is sometimes poor.

PATIENT HISTORY AND PHYSICAL FINDINGS

 Patients with wrist arthrosis present with wrist pain, weakness of the grip, swelling, and stiffness.

 Often there is a sensation of grating during wrist movement, and occasionally clicking or clunking.

 Some patients report a history of wrist injury years previously, but many do not recall any wrist trauma.

 It is important to inquire about neurologic symptoms to identify any associated compressive neuropathy at the carpal tunnel, the canal of Guyon, or both.

 Examination of the wrist usually reveals dorsoradial swelling, loss of movement, weak grip strength secondary to pain, and crepitation.

Local Anesthetic Blocks

 Although controversial in the literature, selective injection of a local anesthetic can be used to predict the results of wrist denervation.

 Local anesthetic is injected about 1 cm ulnar and 3 cm proximal to the tubercle of Lister, delivering 1 mL Marcaine 0.5% around the PIN (FIG 1A). The needle is pushed forward through the interosseous membrane to deliver 1 cc of local anesthetic adjacent to the AIN.

 One cc Marcaine is then injected under the branches of the radial nerve (FIG 1B), under the dorsal cutaneous branch of the ulnar nerve (FIG 1C), under the palmar branch of the median nerve (FIG 1D), and finally between the base of the second and third metacarpals to block the recurrent intermetacarpal branches.

 The wrist is examined before the injections and again 20 minutes afterward. Baltimore Therapeutic Equipment is used where available.

 A decrease in pain rating by 90% and an increase in work output of more than 200% indicate a significant improvement.

 Patients with these results are considered good candidates for surgical denervation.

FIG 1 • One mL of 0.5% bupivacaine is injected to block the posterior and anterior interosseous nerves (A), the branches of the radial nerve (B), the branches of the dorsal cutaneous ulnar nerve (C), the palmar branch of the median nerve (D), and the branches of the intermetacarpal nerve. (Reprinted from Hunt T, Herlas-Palou C. Wrist denervation. In Chunk K. Operative Techniques: Hand and Wrist Surgery. Philadelphia: Elsevier, 2008:209–230.)

IMAGING AND OTHER DIAGNOSTIC STUDIES

 Posteroanterior and lateral radiographs of the wrist confirm the degenerative changes in the wrist joint.

 If there is any doubt about the degree of degeneration, an advanced imaging study (eg, MRI) or wrist arthroscopy can provide more precise information, but these are seldom required.

DIFFERENTIAL DIAGNOSIS

 Wrist denervation is a good option for patients with wrist pain secondary to degeneration. It is important to rule out other causes of pain, such as infection.

 Patients with frank wrist instability and patients with active inflammatory arthritis are unlikely to benefit from wrist denervation.

NONOPERATIVE MANAGEMENT

 For patients with wrist degeneration, conservative management, including anti-inflammatory drugs and splints, should be tried before considering surgery.

SURGICAL MANAGEMENT

 Wrist denervation is indicated in a patient with considerable pain due to wrist degeneration, recalcitrant to conservative measures.

 Alternatives to wrist denervation include open or arthroscopic wrist débridement, radial styloidectomy, partial carpal arthrodesis, proximal row carpectomy, and wrist arthrodesis. Some of these procedures can be combined with a denervation.

Positioning

 The patient is positioned supine with the affected arm on a hand table, under regional block, with a high arm tourniquet, and the procedure is carried out under loupe magnification.

Approach

 Standard denervation of the wrist is carried out through four incisions: dorsal, dorsal–ulnar, volar–radial, and dorsal, over the base of the metacarpals.

 A partial denervation is carried out through one dorsal incision.

TECHNIQUES

PARTIAL DENERVATION OF THE WRIST

  Excise a 1-cm segment of nerve.²,³

  Retract the fourth compartment extensor tendons radially and make a small window in the interosseous membrane.

  Excise a segment of AIN just deep to the interosseous membrane.

  Close the extensor retinaculum with absorbable suture and close the skin in a routine manner.

 Apply a soft dressing with or without a temporary splint.

  Partial denervation involves excision of the PIN with or without excision of the AIN just proximal to the radiocarpal joint.

  Make a 2-cm transverse dorsal incision 3 to 5 cm proximal to the wrist.

  Incise the fourth extensor compartment in a longitudinal direction and retract the extensor tendons ulnarward.

  Isolate the PIN on the radial floor of the fourth extensor compartment.

  The PIN travels with the posterior interosseous artery and veins.

FULL DENERVATION OF THE WRIST

  A full wrist denervation involves four separate incisions (TECH FIG 1).

  Make the same transverse incision described for a partial denervation 3 to 5 cm proximal to the wrist on the dorsal forearm.

 If a more distal incision is used, some articular branches from the PIN may not be completely eliminated.

  Excise the PIN (TECH FIG 2A) and branches of the AIN

  Make a 2to 3-cm dorsal–ulnar incision over the wrist at the level of the ulnar head.

(TECH FIG 2B) as discussed above.

TECH FIG 1 • The four incisions for a complete wrist denervation are marked on the skin. (Reprinted from Hunt T, Herlas-Palou C. Wrist denervation. In Chunk K. Operative Techniques: Hand and Wrist Surgery. Philadelphia: Elsevier, 2008:209–230.)

TECH FIG 2 • A. The posterior interosseous nerve is isolated on the radial floor of the fourth extensor compartment. B. A longitudinal incision in the interosseous membrane reveals the anterior interosseous nerve. (Reprinted from Hunt T, Herlas-Palou C. Wrist denervation. In Chunk K. Operative Techniques: Hand and Wrist Surgery. Philadelphia: Elsevier, 2008:209–230.)

  Dissect to the level of the extensor retinaculum.

  In the subcutaneous flap, isolate the dorsal branch of the ulnar nerve along with its small articular branches to the wrist joint (TECH FIG 3).

  Divide these small branches close to the point where they enter the extensor retinaculum.

  Eliminate sympathetic branches to the wrist by using finger dissection to develop planes deep to the vessel, deep to the palmar cutaneous branch of the median nerve, and deep to the radial sensory nerve.

  Make a 2to 3-cm volar–radial incision centered over the radial artery at the level of the wrist and distal forearm.

  Resect a portion of perivascular tissue from around the radial artery.

  Make a 2-cm transverse incision over the dorsal base of the second and third metacarpals.

  Dissect through the fascia to expose and resect the recurrent intermetacarpal branches (TECH FIG 4).

  Close in standard fashion.

  Apply a soft dressing with or without a temporary splint.

TECH FIG 3 • Through a dorsal–ulnar incision, a subcutaneous flap is raised containing the dorsal cutaneous branch of the ulnar nerve and its small branches, seen here heading toward the retinaculum. (Reprinted from Hunt T, Herlas-Palou C. Wrist denervation. In Chunk K. Operative Techniques: Hand and Wrist Surgery. Philadelphia: Elsevier, 2008:209–230.)

TECH FIG 4 • The recurrent intermetacarpal branch is exposed and resected between the bases of the second and third metacarpal. (Reprinted from Hunt T, Herlas-Palou C. Wrist denervation. In Chunk K. Operative Techniques: Hand and Wrist Surgery. Philadelphia: Elsevier, 2008:209–230.)

POSTOPERATIVE CARE

 Early range of motion is initiated but little formal therapy is required.

 A removable splint may be provided for comfort initially.

 Patients usually return to work 2 to 4 weeks after surgery.

OUTCOMES

 Wrist denervation is successful in providing pain relief in the long term in two thirds of patients.

 A partial wrist denervation seems to provide good results initially, but there is often deterioration after 12 months.

COMPLICATIONS

 Although there is a theoretical risk of causing a neuropathic Charcot joint, to our knowledge this has never been reported. This proves that a complete denervation of the wrist joint is never achieved.

 Neuroma formation has been reported in 2% of patients.

REFERENCES

1. Buck-Gramcko D. Denervation of the wrist joint. J Hand Surg Am 1977;2A:54–61.

2. Ferreres A, Suso S, Foucher G. Wrist denervation: surgical considerations. J Hand Surg Br 1995;20B:769–772.

3. Weinstein LP, Berger RA. Analgesic benefit, functional outcome, and patient satisfaction after partial wrist denervation. J Hand Surg Am 2002;27A:833–839.