DISCUSSION
Subcutaneous ulnar nerve transposition is an effective way to treat ulnar nerve compression at the cubital tunnel in appropriate patients. Many techniques have been described, including epineurial suture, fasciodermal sling, and using the medial intermuscular septum as a sling for the ulnar nerve.9,10,14,15 Eaton and colleagues14 described the creation of a 1 cm × 1 cm flap based on antebrachial fascial connected to the medial epicondyle. This flap is reflected medially and acts as a fasciodermal sling posterior to the transposed nerve at the medial epicondyle. This sling also acts like a septum to prevent posterior subluxation. Only subcutaneous fat is superficial to the nerve, in contrast to previous attempts at subcutaneous transposition. At an average of 18 months of follow-up, 14 patients showed improvement in their symptoms.14 Pribyl and Robinson,9 in 1998, described a procedure where a portion of the intermuscular septum is divided from a distance of 3 to 4 cm proximal to its insertion on the medial epicondyle; the portion is used as a sling and sutured to the fascia of the flexor/pronator mass or alternatively to the subcutaneous tissues. Tan and colleagues15 modified Pribyl and Robinson’s technique by creating a “V” sling with the intermuscular septum; this technique led to complete resolution of symptoms in 17 of 20 patients and improved the symptoms in the 3 remaining patients. Richmond and Southmayd10 reported excellent results in 83% of patients who had epineurium sutured to the fascia during subcutaneous transposition. However, each aforementioned technique has its own unique theoretical set of problems. The shortcoming of Eaton and colleagues’14 fasciodermal sling is the creation of a raw bed while creating the sling over the flexor-pronator fascia, which is prone to scarring. Moreover, given that the flexor-pronator fascia is incised, theoretically, the healing period is prolonged and the grip strength in the initial postoperative period decreases. Utilizing the medial intermuscular septum as a sling can create a narrow band, which creates sharp angles that limit nerve gliding. Suturing the epineurium to the fascia by using the technique of Richmond and Southmayd10 creates a construct that is resistant to tension-free gliding.
In this study, Osborne’s ligament was successfully used as a ligamentofascial or ligamentodermal sling in our subset of patients. We believe this is partially due to the large smooth gliding surface of Osborne’s ligament that helps to minimize sharp curves and allows for the ulnar nerve to glide tension free. This could be seen with other techniques as described previously. Furthermore, our technique is different because the flexor pronator fascia is not incised, which results in less soft tissue trauma and less pain generation; we suspect that the patients were able to have an early return to work and did not complain of decreased strength because the flexor pronator fascia was not disturbed. Our surveyed patients essentially had complete cessation of pain and were able to return to work in about 10 to 11 days. The patients reported that they felt subjectively “better” in approximately 4 weeks and reported no complications. Sensation was also subjectively “better” in all of the patients surveyed.
This study presents several limitations. The study was retrospective in nature and did not include randomization or a control group. In addition, there is a possibility of significant recall bias in the telephone survey that relies on patient recollection. Finally, the telephone survey is an invalidated outcome measure, and no formal statistical analysis was performed.
CONCLUSION
Subcutaneous ulnar nerve transposition using Osborne’s ligament as a ligamentofascial or ligamentodermal sling is a novel technique that creates a broad based, smooth-gliding sling for tension-free excursion of the ulnar nerve and showed success in our subset of patients.
This paper will be judged for the Resident Writer’s Award.