The development of locking plate technology has established a gold-standard for proximal humerus fracture fixation in the non-geriatric adult...
Reverse Shoulder Arthroplasty
Evolution of Reverse Shoulder Arthroplasty
The development of locking plate technology established a gold-standard for proximal humerus fracture fixation, however the treatment was still limited to an acceptable fracture reduction and relying on that bone to heal, making it not ideal in older patients. Another option is replacing the humeral head with a spherical metal implant and allowing the implant to articulate with the native concave glenoid fossa. In patients that also have ineffective rotator cuffs- either from longstanding tendinopathy or from an irreparable tuberosities- the solution is to revere the natural concave-convex relationship in the shoulder. A metal hemisphere is implanted on the scapular side while a concave implant is used on the humerus side, the deltoid muscle now has a longer fulcrum and greater mechanical advantage, eliminating the necessity for the rotator cuff muscles.
Stryker ReUnion® RSA Reverse Shoulder Arthoplasty system is designed for primary fractures or revision surgery. It has a fully convertible platform for the humeral stem, meaning components for their shoulder hemiarthroplasty, shoulder anatomic total arthroplasty and reverse shoulder arthroplasty can all interchangeably fit, making a conversion to a reverse total shoulder arthroplasty relatively easy if the rotator cuff fails on a primary hemiarthroplasty or total arthroplasty. The glenoid-sided component contains variable angle locking screws of up to 30 degrees as well a 3D printed porous metal backing to encourage bony ingrowth.