The Results of Ulnar Nerve Decompression in Guyon's Canal Syndrome

Abstract

PURPOSE OF THE STUDY The aim of the study was to evaluate a group of patients treated for Guyon's canal syndrome with analysis of the cause for and outcome of surgery. MATERIAL AND METHODS The group comprised 13 patients operated on for compressive neuropathies of the ulnar nerve in the canal of Guyon in the period from 2007 to 2010. The clinical parameters evaluated were the adduction strength of the fifth digit, degree of interosseous primus muscle hypotrophy and degree of hypoesthesia in the area innervated by the ulnar nerve. EMG parameters included motor and sensory nerve conduction through Guyon's canal. Patients' subjective evaluations of the treatment outcomes were also recorded. The results were not compared with a control group. RESULTS Post-operative improvements in all clinical and EMG parameters were significant (p=0.02-0.003). All but one patient (90%) reported an improved subjective condition after surgery; on the other hand, pre-operative severe impairment of motor nerve conduction highly affected the post-operative motor function. Guyon's canal syndrome accounted for 0.8% of all compressive neuropathies of the upper extremity in our patients. DISCUSSION Ulnar nerve compression at the wrist is a relatively rare condition amongst the compressive neuropathies of the upper extremity, and literature data concerning this disease are very few. Although many causes of ulnar nerve compression at the wrist have been reported, only one of our patients had ganglion. We conclude that the majority of cases can be diagnosed as a neuritis due to chronic microtrauma produced by pressure of a hypertrophic palmar ligament. CONCLUSIONS Syndrome of Guyon's canal can easily be treated by surgery. As in other compression syndromes, the sooner a surgical decompression is performed, the better outcomes are achieved. © Česká společnost pro ortopedii a traumatologii 2006.