Pre- and postoperative Guyon's canal pressure change in endoscopic carpal tunnel release: correlation with transient postoperative Guyon's canal syndrome

Feasibility and limitations of endoscopy in Guyon's canal

Introduction

This retrospective report summarizes observations from eight operations where the endoscopically assisted approach was used to explore Guyon's canal syndromes of idiopathic aetiology.

Aim

To evaluate the feasibility and limitations of endoscopic Guyon's canal release performed from a distal forearm incision.

Material and methods

Eight charts and video records of eight ulnar tunnel syndrome patients presenting concomitant idiopathic Guyon's canal syndromes were retrospectively reviewed. In all cases endoscopically assisted explorations in Guyon's canals with simultaneous cubital tunnel releases were performed.

Results

In all of the patients the multiple tight bands of the superficial volar carpal ligament forming the canal roof were divided. Some of these bands crossing the nerve in its direct vicinity could have been responsible for the constriction. We were also able to divide the proximal segment of the canal floor. We have observed, however, that the proximal to distal endoscopic dissection jeopardizes the motor branch of the ulnar nerve; therefore, it should not be used to release the pisohamate ligament, or the hypothenar fascia.

Conclusions

Although all of the patients showed improvement, we cannot recommend this method in its current form. We are of the opinion that safe endoscopic Guyon's canal operations may require a different approach.

Endoscopic carpal tunnel release

ECTR is an elegant minimally invasive operative treatment of CTS, providing a rapid rehabilitation without increasing the risk of complications. However, there is a significant learning curve and the cost of the operation is significantly higher than with conventional open technique. However, the faster rehabilitation and the probability of reducing sick leave may lead to ECTR being overall more cost-effective than open CTR.

Retrospective analysis of five-year and longer clinical and electrophysiological results of the world's first endoscopic management for carpal tunnel syndrome

We have analyzed postoperative long-term follow-up results of five years or more from idiopathic carpal tunnel syndrome patients that underwent our complete carpal canal release and decompression procedure that uses the Universal Subcutaneous Endoscope system. In this series, 203 hands were followed up both clinically and electrophysiologically. Final follow-up times were determined by the most recent electrophysiological measurements. Mean follow-up period was nine years. Tingling, pain (using a 3 gm needle) and touch (using a 2 gm von Frey hair) at all median nerve distribution areas recovered to normal in 92.9, 98.2, 95.2%, respectively. Abductor pollicis brevis muscle power improved from preoperative manual muscle testing of 0, 1, 2 to post-operative 4 or 5 in 82.6%. Mean detectable distal sensory latency improved from 4.3 (n = 130) to 3.1 msec (n = 200). Mean detectable distal motor latency improved from 6.2 (n = 189) to 4.1 msec (n = 200). Complication and recurrence rates were 0% and 0.5% respectively.

Carpal tunnel syndrome and ulnar neuropathy at the wrist: comorbid disease or not?

The aim of this study was to elucidate the possible association between carpal tunnel syndrome (CTS) and ulnar neuropathy at the wrist because of the contradictory results of previous studies. Thus, a retrospective case-control study was arranged with an electromyographic database including patients between 2003 and 2009. Patients were selected according to initial diagnosis and the examiner's criteria, and data were plotted by computer. One thousand nine hundred twenty-four patients were evaluated for CTS and 1,024 patients for diabetic CTS or diabetic polyneuropathy. CTS and ulnar neuropathy co-occurrence and CTS alone at the wrist was found in 54/404, 19/50, 20/27 patients, respectively. Logistic regression analysis revealed that having CTS was associated with a doubled risk of ulnar neuropathy at the wrist in both idiopathic CTS and diabetic CTS groups but not in diabetic polyneuropathy. Being male and of advanced age were other risk factors for ulnar neuropathy at the wrist. Correlation analysis (age and sex were controlled) revealed decreased but significant correlations between median and ulnar sensory amplitudes in CTS cases in all groups.

Deep palmar communications between the ulnar and median nerves

Innervation of the hand is supplied via the radial, median, and ulnar nerves. A common border of sensory distribution between the ulnar and median nerves is along the fourth digit. However, this sensory distribution may be affected by communication between these two nerves. Among the known communications between the median and ulnar nerves, the deep anastomotic branch in the hand is the least described and rarely illustrated in the literature. This study aims to provide data on the prevalence of a deep communicating branch via cadaveric dissection. We examined 50 hands taken from 25 adult cadavers. Communicating branches were found in 16% of the hands examined, with rami occurring bilaterally in two specimens. By describing the origin and pathway of this communicating branch, we hope to provide surgeons and clinicians with knowledge that may help avoid iatrogenic injuries.