Surgical Approaches and Their Outcomes in the Treatment of Cubital Tunnel Syndrome

The main objective of this study was to compare the clinical outcome of participants treated by simple decompression (SD) of the ulnar nerve versus anterior subcutaneous transposition (AST). A prospective randomized controlled study was performed. Three hundred forty participants were referred to our institution between March 1999 and July 2002. One hundred fifty-two patients met the inclusion criteria and were randomized into two surgical groups: 75 were assigned to SD, and 77 were assigned to AST. Participants were followed for 1 year after surgery. The main outcome measure was clinical outcome 1 year after surgery. An excellent or good result was obtained in 49 of 75 participants who underwent SD and in 54 of 77 participants undergoing AST. The difference was not statistically significant. However, the complication rate was statistically lower in the SD group (9.6%) compared with the AST group (31.1%) (risk ratio, 0.32; 95% confidence interval, 0.14-0.69). Duration of symptoms, (sub)luxation of the ulnar nerve, and severity of the complaints did not influence outcome. Surgery for ulnar neuropathy at the elbow is effective. The outcomes of SD and AST are equivalent, except for the complication rate. Because the intervention is simpler and associated with fewer complications, SD is advised, even in the presence of (sub)luxation.

Cubital tunnel syndrome (CuTS) is the second most common peripheral nerve compression syndrome. In German-speaking countries, cubital tunnel syndrome is often referred to as sulcus ulnaris syndrome (retrocondylar groove syndrome). This term is anatomically incorrect, since the site of compression comprises not only the retrocondylar groove but the cubital tunnel, which consists of 3 parts: the retrocondylar groove, partially covered by the cubital tunnel retinaculum (lig. arcuatum or Osborne ligament), the humeroulnar arcade, and the deep flexor/pronator aponeurosis. According to Sunderland , cubital tunnel syndrome can be differentiated into a primary form (including anterior subluxation of the ulnar nerve and compression secondary to the presence of an anconeus epitrochlearis muscle) and a secondary form caused by deformation or other processes of the elbow joint. The clinical diagnosis is usually confirmed by nerve conduction studies. Recently, the use of ultrasound and MRI have become useful diagnostic tools by showing morphological changes in the nerve within the cubital tunnel. A differential diagnosis is essential in atypical cases, and should include such conditions as C8 radiculopathy, Pancoast tumor, and pressure palsy. Conservative treatment (avoiding exposure to external noxes and applying of night splints) may be considered in the early stages of cubital tunnel syndrome. When nonoperative treatment fails, or in patients who present with more advanced clinical findings, such as motor weakness, muscle atrophy, or fixed sensory changes, surgical treatment should be recommended. According to actual randomized controlled studies, the treatment of choice in primary cubital tunnel syndrome is simple in situ decompression, which has to be extended at least 5-6 cm distal to the medial epicondyle and can be performed by an open or endoscopic technique, both under local anesthesia. Simple decompression is also the therapy of choice in uncomplicated ulnar luxation and in most post-traumatic cases and other secondary forms. When the luxation is painful, or when the ulnar nerve actually "snaps" back and forth over the medial epicondyle of the humerus, subcutaneous anterior transposition may be performed. In cases of severe bone or tissue changes of the elbow (especially with cubitus valgus), the anterior transposition of the ulnar nerve may again be indicated. In cases of scarring, submuscular transposition may be preferred as it provides a healthy vascular bed for the nerve as well as soft tissue protection. Risks resulting from transposition include compromise in blood flow to the nerve as well as kinking of the nerve caused by insufficient proximal or distal mobilization. In these cases, revision surgery is necessary. Epicondylectomy is not common, at least in Germany. Recurrence of compression on the ulnar nerve at the elbow may occur. This review is based on the German Guideline "Diagnose und Therapie des Kubitaltunnelsyndroms" ( www.leitlinien.net ).