Isolated Musculocutaneous Nerve Palsy after the Reverse Total Shoulder Arthroplasty

Abstract

Reverse total shoulder arthroplasty has been performed with promising results in rotator cuff tear arthropathy. However, the global complication of the reverse total shoulder arthroplasty is relatively higher than that of the conventional total shoulder arthroplasty. Neurologic complications after reverse total shoulder arthroplasty are rare but there are sometimes remaining sequelae. The cause of the neurologic complication is multifactorial, including arm traction, position and the design of the implant. Most cases of neurologic palsy following reverse total shoulder arthroplasty occur in the axillary nerve and the radial nerve. The authors report on a case of a 71-year-old man with isolated musculocutaneous nerve palsy after reveres total shoulder arthroplasty with related literature. Reverse total shoulder arthroplasty can produce good results in patients with an arthritic rotator cuff deficient shoulder. However, in a recent systemic review on reverse total shoulder arthroplasty, the global complication rate was reported relatively high as much as 24%.1) Neurologic complications following reverse total shoulder arthroplasty are rare but there are sometimes remaining sequelae. 1,2) Most cases of neurologic palsy after reverse total shoulder arthroplasty occur in the axillary nerve and the radial nerve.1) The author reported a case of a 71-year-old man with isolated musculocutaneous nerve (MCN) palsy after reveres total shoulder arthroplasty for rotator cuff tear arthropathy with related literature. Case ReportA 71-year-old man presented with a chief complaint of the right shoulder pain for 2 years. He reported no antecedent trauma or neurologic symptoms and his previous clinical history was unremarkable. Pain was exacerbated with attempted overhead activities. On physical examination, the active forward elevation of the right shoulder, the passive forward elevation, the internal rotation, and the external rotation at arm at side were 70°, 120°, buttock, and 30°, respectively. Preoperative radiographic demonstrated the cuff arthropathic change of the shoulder with Hamada grade 3, defined as erosion and so-called acetabulization of acromion with narrowing of the subacromial space to ≤5 mm (Fig. 1A).3) The pa tient was diagnosed with rotator cuff tear arthropathy. Despite conservative management for 3 months, the patient complained of sustained symptoms at the right shoulder and underwent re verse total shoulder arthroplasty.The procedure was performed in the beach-chair position under general anesthesia using a standard deltopectoral approach. A chronic and full-thickness subscapularis tear was observed during exposure. A thorough release of the tendon was done to reattach the subscapularis tendon to the lesser tuberosity without tension. Release at the subcoracoid space was done using a finger in order not to damage the brachial plexus.The bone preparation was performed using a routine method. Non-cemented humeral stem type reverse shoulder system (Biomet, Warsaw, IN, USA) was used (Fig. 1B). Final component...