Concurrent carpal tunnel syndrome and pronator syndrome: A retrospective study of 21 cases.

ABSTRACT

PURPOSE: Concurrent carpal tunnel syndrome and pronator syndrome are rarely considered and the proximal compression sites are easily overlooked. We retrospectively studied 21 concurrent cases in our series from 2009 to 2015 and report the results. PATIENTS AND METHODS: The typical symptoms were pain, tingling, and numbness of the radial 3½ digits. If paresthesia involved the thenar eminence and proximal forearm pain was noted in cases of carpal tunnel syndrome, carpal tunnel syndrome combined with pronator syndrome was considered. Additionally, nocturnal paresthesia symptoms are absent in pronator syndrome. Therefore, if nocturnal symptoms occurred in pronator syndrome, carpal tunnel syndrome was considered. We included concurrent carpal tunnel syndrome and pronator syndrome. We used arthroscopic release of the transverse carpal ligament and open decompression for the pronator teres in cases that underwent surgery for the first time. However, recurrent carpal tunnel cases were treated with the open carpal tunnel release and open pronator decompression procedure in our hospital. The two-point discrimination was used for evaluation of sensory deficit. The grip and pinch (thumb tip to index) strength were measured by dynamometry and pinch gauge respectively. RESULTS: We retrospectively reviewed 344 cases of sustained carpal tunnel syndrome or pronator syndrome from the medical records of our institution. Of the 344 cases, 322 involved carpal tunnel syndrome alone, 1 involved pronator syndrome alone, and 21 involved carpal tunnel syndrome combined with pronator syndrome. The 21 cases of carpal tunnel syndrome combined with pronator syndrome were included in our study. Among the total cases of carpal tunnel syndrome, 6% (21/343) had pronator syndrome. The patients included 3 men and 18 women with a mean age of 52 years (range 42-69 years). Electromyography (EMG) and nerve conduction studies were routinely performed. Postoperative evaluation showed that 15 out of 21 patients (71%) were completely relieved of pain and paresthesia and had no sensory deficit, satisfied strength improved (>85% of the opposite hand). Six patients (29%) had occasional paresthesia and pain, but no sensory deficit; grip and pinch strength deficit were recorded (<50% of the opposite hand). Six cases of these partially relieved patients had recurrent carpal tunnel syndrome but no one needed to perform tendon transfer for thenar muscle atrophy. CONCLUSION: It is important to consider the diagnosis of double crush syndrome of the median nerve, as carpal tunnel syndrome combined with pronator syndrome may impede treatment of the carpal tunnel syndrome.