Recurrent Carpal Tunnel Syndrome – Analysis of the Origin in 204 Cases and Comparison of Different Soft-Tissue Coverage for the Median Nerve

Carpal tunnel release (CTR) is regarded as a common and successful operative procedure in hand surgery. However, an increasing number of patients with complications have been referred to the authors' center in recent years.

The aim was to analyze the reasons for recurrent carpal tunnel syndrome (CTS) and to investigate the clinical and electrophysiologic results after different soft- tissue coverage of the median nerve.

In a comprehensive retrospective study patient charts were reviewed to delineate the intraoperative findings causing revision surgery. All patients who underwent flap coverage were invited to participate in a clinical examination and nerve conduction test (NCT). Pre- and postoperative NCT and clinical results of the two groups were statistically compared.

During a 26-month period between 2001 and 2003, 204 patients with recurrent CTS were surgically treated. In 108 cases, the transverse carpal ligament was incompletely released. In 17 patients, fibrous proliferation had formed around the nerve (in nine patients of this group, an intrafascicular neurolysis was performed). In 21 patients, no specific reason was found and in 12 patients, nerve lacerations were found. In 46 patients, symptoms were due to a nerve position directly in the scar. In 15 patients of this group, the median nerve was covered with a syonovial flap (SF) and in 11 patients with a hypothenar fat pad (HFP).

NCT demonstrated a significant improvement from pre- to postoperative states in both groups (values of distal motor latency, sensory- and motor nerve conduction velocity). Clinical outcome (DASH, grip strength, patient satisfaction, parasthesia, atrophia, nocturnal pain) appeared to be superior in the HFP group.

The great majority of revision surgery seems to be preventable by using a thorough operative technique based on an exact knowledge of the anatomy. Soft- tissue coverage is beneficial to prevent recurrent symptoms, if the nerve lies directly in the scar. In this study, coverage by an HFP produced superior clinical results, compared to cover with a SF.