Presentation
Pain and functional limitation after total shoulder prosthesis implant.
Patient Data
Rx right shoulder
Postoperative check. Anteroposterior radiograph of a right shoulder after surgery showing a well-fixed humeral and glenoid component.
Rx right shoulder
Anteroposterior radiograph seven months after surgery showing medial subsidence of the cemented glenoid component and a cranial migration of the humeral head. Loose and dislocated polyethylene glenoid component. The component and its cement fixation has migrated anteriorly (arrow). The glenoid component is radiolucent and not visible on the radiograph, but cement can be seen around the three glenoid pegs, and a metallic marker embedded in the central peg can also be seen.
CT right shoulder
CT images demonstrates abnormal curvilinear lucency in axillary pouch of the joint (arrow). There are also signs of glenoiditis with bone fragments.
Case Discussion
Glenoid component loosening occurs more commonly than the humeral component and is one of the most frequent complications requiring revision surgery. Radiographic signs of loosening are progressive and extensive widening of interfaces between bone-cement, bone-prosthesis or cement prosthesis. Fragmentation or fracture of cement. Migration or subsidence of prosthetic components. Comparison with the initial baseline and early radiographs must be made. The failures of the prosthetic glenoid arthroplasty can be due to the glenoid or humeral prosthetic components, to the seat, to the fixation, to the failure of the glenoid bone and to the balanced management of the eccentric load (avoid "rocking horse effect").