Purpose: The aim of this study was to assess the clinical results of revision surgery due to persistent neurological disturbances after carpal tunnel release.
Patients and method: In a previous study we showed the reasons for persisting neurological symptoms after carpal tunnel release on the basis of the intraoperative findings in 200 patients who underwent revision surgery in the years 2001 - 2003. We classified them into four groups (1: incomplete release of the retinaculum flexorum, 2: traction neuropathy, 3: real recurrent carpal tunnel syndrome, and 4: nerve lesions). 122 of these patients have been investigated regarding the clinical results using two questionnaires in the year 2004. We used the DASH questionnaire as well as an additional self-assessment questionnaire asking about remaining symptoms of median nerve irritation and the subjective results of revision surgery. The completely filled-out forms were assigned to the four groups, analysed and the results compared with each other.
Results: Within group 1 (incomplete release), 78 % reported only one persistent neurological symptom, 89 % described a benefit from revision surgery and 84 % were satisfied with a median DASH score of 11. Within group 2 83 % complained about at least one persistent neurological problem and only 60 % reported on an improvement following revision surgery. The DASH score within group 2 averaged 30. 87 % of group 3 patients reported of an improvement following the revision operation (DASH score 24), whereas this was the case for only 55 % (DASH score 37) of group 4 patients.
Conclusion: The incomplete release of the flexor retinaculum is the most common reason for revision surgery. In most of these patients the clinical symptoms can be resolved with revision surgery leading to a very high satisfaction of the patients. A similarly high satisfaction can be expected following revision surgery of a true recurrent carpal tunnel syndrome although in most patients a significant degree of functional deficit will remain. Revision surgery due to fibrotic adhesions of the median nerve, leading to a traction neuropathy, or iatrogenic nerve lesions during the primary surgery will definitely lead to unsatisfactory overall results.