Reverse shoulder arthroplasty megaprosthesis for surgical management of severe proximal humeral bone loss.

BACKGROUND: Shoulder arthroplasty in the setting of severe proximal humerus bone loss can be challenging. The purpose of this study was to evaluate the outcomes of a modular segmental megaprosthesis when implanted in a reverse configuration for complex primary arthroplasty, reconstruction at the time of oncologic resection, and revision shoulder arthroplasty. MATERIALS AND METHODS: A Joint Registry Database was queried to identify all shoulder arthroplasties performed at a single institution using the Comprehensive Segmental Revision System reverse shoulder arthroplasty (SRS-RSA; Zimmer Biomet). A retrospective review of electronic medical records and radiographs was performed to record demographic data, indication, outcomes, complications, and revision surgery. RESULTS: Between February 2012 and October 2022, a total of 76 consecutive SRS-RSAs were implanted. An analysis of patients with minimum 12-month follow-up yielded 53 patients with a mean follow-up of 4.1 ± 2.43 years. Surgical complication rate in this cohort was observed in 41.5% (22 of 53) of cases. Overall, the revision rate at final follow-up was 26.4% (14 of 53), with a significant difference between the primary and revision cohorts. The number of prior surgeries was a significant risk factor for revision surgery, with a hazard ratio of 1.789 (95% confidence interval 1.314-2.436, P < .001). When analyzing aseptic humeral loosening rates across study cohorts, a significant difference was found between the primary arthroplasty (0%, n = 0) and the revision arthroplasty cohorts (22.2%, n = 6) (P = .04). DISCUSSION: Reverse shoulder arthroplasty using a modular segmental megaprosthesis remains a reasonable salvage option for shoulder reconstruction in the setting of proximal humeral bone loss. Because of the substantial bone loss and soft tissue deficiencies typically present in these cases, surgeons should educate patients on the relatively high complication rate, particularly when used in the setting of a previous failed arthroplasty.

A review of the surgical management of distal humerus fractures and nonunions: From fixation to arthroplasty.

Distal humeral fractures in adults are challenging injuries. They often require surgical intervention in form of internal fixation or total elbow arthroplasty which is being increasingly used in physiologically elderly patients with comminuted fractures. Careful preoperative evaluation including type of fracture, quality of bone, pre-existing conditions and functional demand help in deciding optimal treatment. CT scans including 2D and 3D reconstructions are almost mandatory in proper planning of the surgical treatment. In most cases with a healthy physiologically young patient, ORIF is the treatment of choice. Biomechanical studies have shown that parallel plating resists rotational deformity to a greater degree than 90/90 plating allowing supracondylar union. Accurate realignment of articular fragments and compression at the supracondylar area is key to the success of the internal fixation. Main cause of failure of fixation is the nonunion or malunion in the supracondylar area. The principles described by O'Driscoll et al. allow for rigid fixation of the distal articular fragments and compression at the supracondylar level which is vital to healing and the prevention of hardware failure, and nonunion. Olecranon osteotomy improves the expodure of distal humeral articular surface but has its own share of problems and should be avoided if possible. Irritation of ulnar nerve is a common complication so it should be isolated, kept under vision throughout and if necessary, transposed anteiriorly. Nonunion or malunion of supracondylar fractures can be treated by revision ORIF or total elbow arthroplasty (TEA). Supracondylar shortening, bone grafting and contracture release are important elements of treatment of nonunions. In unreconstructable distal humerus fractures, where open reduction and internal fixation is not possible due to the small size of the fragments, severe comminution and/or poor bone quality, TEA is the treatment of choice. Triceps can be left intact as the excision of fractured fragments usually provide enough space to carry out the operation. Sometimes, the decision to perform TEA is only made after exposing the fracture so the surgeon should be comfortable in performing TEA if ORIF is not possible; and necessary instruments and implants should be available on the shelf. In spite of satisfactory outcome, overall complication rate after TEA remains high and makes surgical efficiency and technical competence of utmost importance.