Since initiating endoprosthetic reconstruction following Tikhoff-Linberg procedure in 1999, several adjustments have been made to the implants used at USC to improve patient outcome. All implants were manufactured by Stryker Orthopaedics (formerly Howmedica-Osteotonics).
Model I: Polyethylene-lined constrained glenoid faces laterally.
Model II: Constrained glenoid faces more anteriorly, closer to the anatomic position.
Modular Type: Modular implies that the implant was designed to be made up of standardized units for easy assembly. Each implant could be customized to fit different patients using different components or modules. The original version of the humeral endoprosthesis consisted of 3 components, 1) Proximal humeral segment, 2) Intercalary segment, and 3) Intramedullary segment.
This version proved problematic due to dislocation of the humeral components, below left. This patient underwent a corrective procedure to fix the humeral components to each other, below middle and right.
Non-modular Type: The humeral prosthesis was modified to one piece to avoid the problem of dislocation of modular elements. This requires designing and manufacturing an individualized humeral implant for each patient.