Determining Factors For Pseudoparalysis Post Massive Rotator Cuff Tear

Pseudoparalysis is defined as active shoulder flexion of less than 90 degrees without neurological deficits post massive rotator cuff tear (RCT). Loss of shoulder flexion hinders daily overhead reaching tasks decreasing quality of life. Integrity of the subscapularis has been identified as a potential contributor; however, the cause remains unclear, making treatment and prognosis difficult. Few studies compare the components of the International Society of Arthroscopy, Knee Surgery and Orthopeadic Sports Medicine (ISAKOS) RCT classification guidelines between those with and without pseudoparalysis. PURPOSE: To investigate RCT characteristics that may contribute to pseudoparalysis. METHODS: 2000 charts from 2010-2022 were reviewed. Inclusion criteria consisted of patients with a massive RCT, defined as full width full thickness tear in 2 or more tendons. Patient demographics, comorbidities, type of injury, and shoulder range of motion were recorded. MRI and physician reports were used to apply ISAKOS criteria of location, extension, pattern, fatty atrophy, and retraction to RCTs. Pseudoparalytic status was given to patients with less than 90 degrees of active humeral flexion. Logistic regressions were used to evaluate the odds of pseudoparalaysis in association with traumatic vs nontraumatic injury, number of tendons, and ISAKOS criteria. Odds ratios (OR) with 95% confidence intervals (95% CI) were reported. RESULTS: 83 patients were included, 32 had pseudoparalysis. There were no differences in the odds of pseudoparalaysis in relation to the mechanism of injury (OR: 2.60 (95% CI: 0.88, 7.66), p = 0.083), number of tendons involved (0.68 (95% CI: 0.29, 1.59), p = 0.376), or ISAKOS fatty infiltrate for any of the rotator cuff muscles such as supraspinatus (OR: 1.01 (95% CI. 0.64, 1.60), p = 0.962). CONCLUSION: Patients with pseudoparalysis post massive RCT did not have a defining metric or characteristic. Gathering more data may provide better insight into the contributors to pseudoparalysis and reduce the risk of type II error. The ambiguity of pseudoparalysis may warrant investigation via motion capture, electromyography, and scapular modeling to better understand the rotator cuff force coupling relationship and potential biomechanical and electrophysiological contribution to pseudoparalysis. Department of Orthopedic Surgery, Wake Forest University School of Medicine