Discovery Elbow System arthroplasty polyethylene bearing exchange: outcomes and experience.

BACKGROUND: The Discovery Elbow System (DES) utilizes a polyethylene bearing within the ulnar component. An exchange bearing requires preoperative freezing and implantation within 2 minutes of freezer removal to allow insertion. We report our outcomes and experience using this technique. METHODS: This was an analysis of a two-surgeon consecutive series of DES bearing exchange. Inclusion criteria included patients in which exchange was attempted with a minimum 1-year follow-up. Clinical and radiographic review was performed 1, 2, 3, 5, 8 and 10 years postoperative. Outcome measures included range of movement, Oxford Elbow Score (OES), Mayo Elbow Performance Score (MEPS), complications and requirement for revision surgery. RESULTS: Eleven DESs in 10 patients were included. Indications were bearing wear encountered during humeral component revision (n=5); bearing failure (n=4); and infection treated with debridement, antibiotics and implant retention (DAIR; n=2). Bearing exchange was conducted on the first attempt in 10 cases. One case required a second attempt. One patient developed infection postoperatively managed with two-stage revision. Mean follow-up of the bearing exchange DES was 3 years. No further surgery was required, with no infection recurrence in DAIR cases. Mean elbow flexion-extension and pronosupination arcs were 107° (±22°) and 140° (±26°). Mean OES was 36/48 (±12) and MEPS was 83/100 (±19). CONCLUSIONS: Our results support the use of DES bearing exchange in cases of bearing wear with well-fixed stems or acute infection. This series provides surgeons managing DES arthroplasty with management principles, successful and reproducible surgical techniques and expected clinical outcomes in performing DES polyethylene bearing exchange. Level of evidence: IV.

The Clavicular Hook Plate: Consequences in Three Cases.

The small fragment AO clavicular hook plate is indicated for certain fractures of the lateral end of clavicle and for symptomatic acromio-clavicular joint dislocations where there is rupture of the stabilizing ligaments. The complex anatomy and biomechanics of the acromio-clavicular joint can lead to complications that result in damage to the joint itself or acromial erosion. In addition, the rotator cuff complex is at risk of injury when inserting the plate. We report three cases where patients who underwent hook plate fixation subsequently required removal of the implant due to complications previously unreported in current literature.