Complications of ulnar nerve decompression

1. Iatrogenic ulnar nerve subluxation can develop after simple in situ decompression at the cubital tunnel if the nerve is unstable preoperatively or if the medial intermuscular septum and Osborne's ligament are not adequately addressed.

True

In situ decompression preserves the nerve in the epicondylar groove. If the nerve is dynamically unstable preoperatively, postoperative anterior subluxation over the medial epicondyle can occur, producing recurrent symptoms and necessitating conversion to anterior transposition.

• Bartels RHMA, Verhagen WIM, van der Wilt GJ, Meulstee J, van Rossum LGM, Grotenhuis JA. Prospective randomized controlled study comparing simple decompression versus anterior subcutaneous transposition for idiopathic neuropathy of the ulnar nerve at the elbow: Part 1. Neurosurgery. 2005;56(3):522-530. PMID 15730578
• Macadam SA, Gandhi R, Bezuhly M, Lefaivre KA. Simple decompression versus anterior subcutaneous and submuscular transposition of the ulnar nerve for cubital tunnel syndrome: a meta-analysis. J Hand Surg Am. 2008;33(8):1314.e1-1314.e12. PMID 18929194

2. Persistent numbness after cubital tunnel decompression suggests incomplete release, a missed second site of compression, or pre-existing axonotmetic injury.

True

Persistent ulnar paraesthesia in the postoperative period is most often attributable to incomplete decompression — particularly missed proximal release at the arcade of Struthers or distal release at the deep flexor-pronator aponeurosis — to coexisting compression at Guyon's canal, or to severe baseline axonal loss with limited recovery potential.

• Mackinnon SE, Novak CB. Operative findings in reoperation of patients with cubital tunnel syndrome. Hand (N Y). 2007;2(3):137-143. PMID 18780075
• Rogers MR, Bergfield TG, Aulicino PL. The failed ulnar nerve transposition. Etiology and treatment. Clin Orthop Relat Res. 1991;(269):193-200. PMID 1864038

3. Persistent pain at the surgical site is uncommon following cubital tunnel decompression.

False

Postoperative pain — including incisional tenderness, scar pain, and medial antebrachial cutaneous nerve neuroma — is one of the most frequently reported complications of cubital tunnel surgery. Injury to branches of the medial antebrachial cutaneous nerve is reported in up to 30% of cases when the surgical incision is not designed to protect them.

• Lowe JB 3rd, Maggi SP, Mackinnon SE. The position of crossing branches of the medial antebrachial cutaneous nerve during cubital tunnel surgery in humans. Plast Reconstr Surg. 2004;114(3):692-696. PMID 15318047
• Sarris I, Göbel F, Gainer M, Vardakas DG, Vogt MT, Sotereanos DG. Medial brachial and antebrachial cutaneous nerve injuries: effect on outcome in revision cubital tunnel surgery. J Reconstr Microsurg. 2002;18(8):665-670. PMID 12524584

4. Perineural scar adhesion can restrict nerve gliding after decompression and produce recurrent symptoms despite anatomically adequate release.

True

Recurrent or persistent symptoms after cubital tunnel decompression are commonly attributed to perineural fibrosis tethering the nerve to the surrounding fascia or epicondylar bed. Revision surgery typically combines neurolysis, transposition into a vascularised soft-tissue bed, and protection of the medial antebrachial cutaneous nerve.

• Aleem AW, Krogue JD, Calfee RP. Outcomes of revision surgery for cubital tunnel syndrome. J Hand Surg Am. 2014;39(11):2141-2149. PMID 25169417
• Vogel RB, Nossaman BC, Rayan GM. Revision anterior submuscular transposition of the ulnar nerve for failed subcutaneous transposition. Br J Plast Surg. 2004;57(4):311-316. PMID 15145733

5. Revision surgery — typically involving neurolysis and anterior submuscular transposition — is indicated when initial in situ decompression or subcutaneous transposition fails to relieve symptoms and a remediable structural cause is identified.

True

Outcomes of revision cubital tunnel surgery are inferior to those of primary surgery. In carefully selected patients with identifiable persistent compression, perineural scar, or unstable nerve, neurolysis with submuscular transposition into a vascularised muscle bed achieves meaningful improvement in approximately two-thirds of cases.

• Aleem AW, Krogue JD, Calfee RP. Outcomes of revision surgery for cubital tunnel syndrome. J Hand Surg Am. 2014;39(11):2141-2149. PMID 25169417
• Gabel GT, Amadio PC. Reoperation for failed decompression of the ulnar nerve in the region of the elbow. J Bone Joint Surg Am. 1990;72(2):213-219. PMID 2303507