Supplementary Material for: Post-Operative Shoulder Splint-Induced Palm Pressure Leading to Median and Ulnar Neuropathies: A Case Report

Introduction: Post-operative positioning devices, such as shoulder splints, are commonly used to support and stabilize the upper limb following surgery. However, improper placement and prolonged pressure from these devices can lead to iatrogenic nerve injuries. Case presentation: We present a case of severe axonal injury to the median and ulnar nerves at the proximal hand in a patient following shoulder surgery. This was attributed to palm pressure from a post-operative shoulder splint with a built-in palm stress ball designed to improve circulation and healing, along with impaired pain sensation from use of a pain pump. Electrodiagnostic (EDX) exam of the right upper extremity one year prior was normal. Post-operative EDX exam showed a decreased amplitude of right ulnar sensory amplitudes, decreased motor amplitudes of ulnar and median responses across the wrist, and associated evidence of axon damage on electromyography (EMG). These findings indicate the median and ulnar nerves at the proximal hand were affected. Conclusion: We hypothesize that the nerve injuries were due to prolonged pressure in the hand from strict compliance with the splint, the palmar stress ball, and impaired sensation due to a peri-procedural nerve block and post-operative pain pump. This case highlights the importance of optimizing post-operative positioning to prevent complications. It is imperative that patients are provided education regarding proper orthotic positioning, pressure relief, and the importance of frequent skin checks when prescribing a shoulder orthotic with a palm stress ball to reduce the risk of nerve injury.