ENDOSCOPIC CARPAL TUNNEL RELEASE AND CONGENITAL ANOMALIES OF THE MEDIAN NERVE

Effectiveness of an Endoscopic Recurrent Branch Release Procedure Combined with Standard Endoscopic Carpal Tunnel Release Surgery Compared to Standard Endoscopic Carpal Tunnel Release Surgery Alone: A Propensity Score-Matched Study

Background: The purpose of this study is to compare the effectiveness of endoscopic release of the recurrent branch from surrounding soft tissue in combination with standard endoscopic carpal tunnel release (ECTR) surgery to standard ECTR surgery alone in patients with established abductor pollicis brevis (APB) muscle weakness. Methods: Using propensity score matching, we compared the recovery rates of postoperative clinical symptoms in patients with idiopathic carpal tunnel syndrome in whom the preoperative Medical Research Council (MRC) scale of the APB muscle (MRC-APB) was zero (no contraction) and with undetectable distal motor latency (DML) of APB, to those who underwent standard ECTR surgery alone and those who underwent recurrent branch release in addition to standard ECTR. Results: Forty-nine hands in the recurrent branch release group and 49 hands in the standard ECTR surgery group were extracted. There were statistically significant differences in postoperative recovery rate from MRC-APB 0 to '4 or 5' at 30 months (OR: 2.42; 95% CI: 1.03-5.67; p = 0.04) and at final follow-up (OR: 2.64; 95% CI: 1.11-6.26; p = 0.03). There were statistically significant differences in postoperative recovery of MRC-APB scales at 24 months (p = 0.03), 30 months (p = 0.02) and at final follow-up (p = 0.02). There were statistically significant differences in postoperative recovery of DML (p = 0.04). Conclusions: Endoscopic release of the recurrent branch in combination with standard ECTR surgery showed better recovery rates in MRC-APB and DML recovery compared to standard ECTR surgery alone. Level of Evidence: Level III (Therapeutic).

Anomaly of flexor digitorum superficialis penetrating through the median nerve: case report

The median nerve displays frequent anatomic variation. Here, we report an unusual anatomic variation consisting of a penetrated median nerve and the tendon of the flexor digitorum superficialis to the index finger passing through it approximately 4 cm proximal to the wrist crease.

Dual-portal endoscopic release of the transverse ligament in carpal tunnel syndrome: results of 411 procedures with special reference to technique, efficacy, and complications

OBJECTIVE

Endoscopic release of carpal tunnel syndrome is still under debate. The main advantages of the technique are considered to be minor postoperative pain and a more rapid postoperative recovery. Disadvantages are thought to be the impossibility of a direct median nerve neurolysis and a higher surgical complication rate, including injury to the median nerve.

METHODS

The results of 411 consecutive endoscopic carpal tunnel procedures performed between March 1995 and September 2004 are presented. All patients were prospectively followed.

RESULTS

In the present series, a success rate of 98.05% was observed. There was no permanent morbidity and, in particular, there was no injury of the median nerve. In four (0.97%) patients, the preoperative symptoms did not improve. In two (0.49%) of these patients, an incomplete release of the carpal ligament occurred. In another four patients (0.97%), a switch to open surgery was required.

CONCLUSION

The present data prove that the endoscopic technique is a safe and reliable technique for carpal tunnel surgery. The data do not support the current discussion of a higher risk of median nerve injury with endoscopic carpal tunnel surgery. Thus, for our group, the endoscopic technique represents the therapy of choice for the primary idiopathic carpal tunnel syndrome.

Microsurgical dissection of the carpal tunnel with respect to neurovascular structures at risk during endoscopic carpal tunnel release

PURPOSE

The goal of this descriptive study was to investigate the anatomy of the carpal tunnel with respect to the related neurovascular structures, because a detailed knowledge of the complex anatomy of this region is essential to perform endoscopic carpal tunnel release.

METHODS

Sixteen fresh-frozen cadaveric hands were used for the study. Dissection of the palmar aspect of the hand was performed by use of magnifying loupes, an operative microscope, and microsurgical instruments. All anatomic components were photographed, and dimensions were recorded by use of a micrometer. The distance from the radial aspect of the os pisiformis and the proximal and distal portals to the main structures that may be injured was measured. Topography of the transverse ligament and possible adhesions to the tendons and median nerve were also recorded.

RESULTS

The mean distance from the radial aspect of the os pisiformis to the radial border of Guyon's canal and the ulnar edge of the palmaris longus tendon was 10.3 mm (range, 9 to 12 mm) and 16.1 mm (range, 12 to 22 mm), respectively. The mean distance from the distal portal to the superficial palmar arch and the ulnar artery was 10.4 mm (range, 5 to 15 mm) and 7.6 mm (range, 4.5 to 9 mm), respectively. The mean distance from the distal edge of the transverse ligament to the thenar branch of the median nerve was 2.7 mm (range, 0 to 4.1 mm). The mean length of the transverse ligament was 31 mm (range, 25 to 34.5 mm). In 14 hands we also identified the palmaris longus tendon. In 11 hands we found adhesions between the transverse ligament and the sheath of the flexor tendons.

CONCLUSIONS

The palmaris longus can be used as a guide for the placement of the proximal portal. Staying at the ulnar side of the palmaris longus keeps the superficial palmar branch of the median nerve at a safe distance from the instruments. The "fat drop sign" is also a useful guide for the placement of the distal margin of the transverse carpal ligament, keeping the distal portal away from the superficial palmar arch. Synovial adhesions can usually cover the inferior surface of the transverse ligament, and they need to be removed for clear endoscopic identification of the transverse fibers before the ligament is cut.

CLINICAL RELEVANCE

Detailed knowledge of the complex anatomy of the carpal tunnel is essential to perform endoscopic carpal tunnel release.

Topographic localization of the motor branch of the median nerve

PURPOSE

To redefine the localization of the thenar branch (TB) of the median nerve in relation to the surface landmarks that are in routine use.

METHODS

The study was performed in 37 hands of 34 patients who had carpal tunnel release. All of the patients were women and the mean age was 50 years (range, 35-67 y). A radiologic marking technique was used to determine the localization of the TB, the middle finger radial side line, and Kaplan's cardinal line. The TB was marked by circumscribing with a soft radiopaque yarn and the surface landmark lines were shown by taping a K-wire to the hand for each line. An image-intensifier-printed image was obtained for each case and the distances between the markers of the TB and the wires were measured.

RESULTS

The TB had a mean ulnar offset of 12.6 mm (range, 4.0-19.7 mm) from the middle finger radial side line and was located 4.4 mm (range, 0-9.5 mm) proximal to the cardinal line.

CONCLUSIONS

During carpal tunnel release surgery the surgeon must pay more attention to the localization of the TB of the median nerve because it was found to be 12.6 mm more ulnar than the location described in the literature.

Novel surgical approach to the carpal tunnel: Cadaveric feasibility study

Carpal tunnel syndrome is the most common entrapment neuropathy dealt with by the clinician. Multiple techniques have been used to surgically treat this pathological condition and all of these approach the carpal tunnel from the palmar surface of the hand or wrist. We have developed a novel endoscopic approach to the carpal tunnel utilizing a dorsal approach that necessitates a good appreciation of the anatomy of this region. This approach was carried out in 10 hands. Through a single dorsal incision we were able to transect the flexor retinaculum in all specimens without obvious damage to neural or vascular tissues. The microscissors used in our study were found to be too delicate for transection of the flexor retinaculum thus another cutting tool should be considered. Our dorsal approach with visualization of the internal aspect of the flexor retinaculum may obviate many of the complications that are seen with the current techniques used to surgically treat carpal tunnel syndrome such as injury to the median nerve and its branches. Clinical trials are now necessary with prospective randomized studies that will determine which techniques are most efficacious and minimize complications most effectively.