Distal Mononeuropathy Before and After Arthroscopic Rotator Cuff Repair: A Prospective Investigation

Purpose The purpose of this study was to characterize the occurrence of distal mononeuropathy (DMN) in patients before and after arthroscopic rotator cuff repair (RCR) as well as resolution of the symptoms. Methods One hundred one patients over the age of 18 undergoing arthroscopic RCR +/− concurrent procedures completed a questionnaire regarding the presence of a symptomatic DMN. Patients with history of diabetic neuropathy, cervical radiculopathy, brachial plexopathy, or Spurling sign were excluded. All patients underwent physical examination to determine the characteristics and location of symptoms. Postoperatively, patients underwent repeat examination at 2, 6, and 12 weeks. Results Preoperatively, 19% (19/101) of RCR patients described DMN symptoms (9 median nerve symptoms, 5 ulnar nerve symptoms, 4 nonspecific symptoms, one with both ulnar and median nerve symptoms). Ninety percent (17/19) patients with preoperative DMN symptoms described resolution within the final 12 weeks of follow-up. A portion of previously asymptomatic RCR patients (12/82) developed new DMN symptoms (6 nonspecific symptoms, 3 ulnar nerve symptoms, 2 median nerve symptoms, one radial sensory nerve symptoms) postoperatively, with 92% (11/12) having resolution by the final 12-week follow-up. At the final 12 weeks, 3 RCR patients had DMN symptoms with 2 of those 3 patients having their symptoms existing preoperatively. Conclusions This study supports the hypothesis that DMN can be a preexisting finding in patients undergoing arthroscopic RCR. Similarly, it is common for patients undergoing arthroscopic RCR to develop new DMN symptoms following their procedure. Regardless, there is good evidence to show that a large majority of both groups of patients will go on to have resolution of their symptoms. Level of Evidence Level IV, prospective case series.