(iv) Reverse shoulder replacement

Arthritis of the glenohumeral joint in the presence of a deficient or poorly functioning rotator cuff is common and debilitating, particularly in the elderly population. Shoulder arthroplasty in this patient group has historically performed badly with poor function and limited pain relief. In an effort to combat the challenges faced when treating these patients, reverse polarity shoulder replacements were introduced, and the design of these implants has evolved over the last 30 years. The relative success of reverse shoulder replacements in these patients has led to their use for other indications including trauma and massive cuff tears without arthritis. In this review we present the biomechanical principles that underlie the design of the reverse shoulder replacement, and outline the evolution of the design in recent times. We also discuss surgical technique and review the clinical outcomes and complications associated with the procedure.