A Twist in the Shoulder Tale: Proximal Humerus Fracture Following Trapezius Transfer - A Case Report.

INTRODUCTION: Proximal humerus fractures constitute approximately 4-6% of all fractures, commonly affecting the elderly due to low-energy trauma and osteoporotic bones. Two-part surgical neck fractures are the most frequent subtype. In younger individuals, high-energy trauma is a usual cause. However, a proximal humerus fracture in a patient with a history of trapezius muscle transfer for brachial plexus injury is an extremely rare clinical scenario, with limited literature available on its management and rehabilitation.

CASE REPORT: A 30-year-old right-hand-dominant male presented with acute pain and swelling in the right upper arm following a non-traumatic event during aggressive physiotherapy. He had a history of brachial plexus injury managed by double Oberlin nerve transfer and later a trapezius transfer due to poor shoulder function. Two months into post-operative rehabilitation, he sustained a surgical neck humeral fracture. Open reduction and internal fixation with a dynamic compression plate and subpectoral biceps tenodesis were performed. A structured post-operative rehabilitation protocol resulted in a functional recovery with 90° of shoulder abduction at 1-year follow-up.

CONCLUSION: Peri-implant fractures following trapezius transfer are rare and demand careful surgical and rehabilitation planning. This case highlights the importance of cautious, supervised, and graded physiotherapy to prevent such complications and optimize outcomes.