Comparison of the Results of Open Carpal Tunnel Release and KnifeLight Carpal Tunnel Release

Introduction: The study compares the results of open release of carpal tunnel syndrome with a release done with a proprietary instrument, the KnifeLight, which uses a minimal access approach.

Methods: A retrospective study was conducted on two groups of patients operated on by the same surgeon between January 1998 and August 2002. All cases presented with numbness of six months duration or more, and a positive Phalen's test. Open carpal tunnel release was done in the first group of 26 consecutive patients before the KnifeLight was introduced in January 2000. The KnifeLight technique was used in a second consecutive group of 49 patients. In two patients, the KnifeLight procedure was abandoned because the median nerve could not be safely separated from the transverse carpal ligament.

Results: The two groups were shown to be comparable with respect to clinical presentation and nerve conduction studies. There was no complication in both groups. However, no advantage could be demonstrated in the use of the KnifeLight procedure as compared to the open procedure in respect to improvement in pain, numbness or patient satisfaction. The study also showed that the severity of nerve conduction changes is not related to the severity of numbness. It is also not a good guide to the improvement of numbness and patient satisfaction after the operation.

Conclusion: The method was found to be acceptable to patients as an office procedure. The cost of doing either procedure is reduced when done as an office procedure, but there is a cost incurred in the use of the KnifeLight instrument.