Hemiarthroplasty of the elbow: the effect of implant size on kinematics and stability

Elbow Hemiarthroplasty for the Treatment of Distal Humerus Fractures

Distal humerus hemiarthroplasty is a good surgical option for nonreconstructable intraarticular distal humerus fractures in selected lower-demand patients. The lifetime activity restrictions have not been determined, but are likely less than a total elbow arthroplasty. From a technical standpoint, distal humeral prostheses should be implanted at the correct depth and rotation. The collateral ligaments, condyles, and epicondyles should be preserved and/or repaired to maintain joint stability. Short- to midterm retrospective studies have shown promising results.

Elbow hemiarthroplasty for the management of distal humeral fractures: current technique, indications and results

There has been a growing recent interest in the use of elbow hemiarthroplasty for the treatment of distal humeral trauma in select patients. However, the current available evidence regarding outcome after elbow hemiarthroplasty is limited to case series and biomechanical data. Consequently, the procedure remains unfamiliar to many surgeons. The aim of the present review is to outline the evidence regarding elbow hemiarthroplasty and to use this, along with the author's experience, to better describe the indications, surgical technique and outcomes after this procedure.

Hemiarthroplasty of the elbow: the effect of implant size on joint congruency

BACKGROUND

Distal humeral hemiarthroplasty is a treatment option for elbow joint disease that predominantly affects the distal humerus, including distal humerus fractures, nonunions, and avascular necrosis. The effect of hemiarthroplasty implants on joint contact has not been reported. The purpose of this in vitro study was to quantify the effects of hemiarthroplasty and implant size on ulnohumeral joint congruency.

METHODS

Five fresh frozen cadaveric upper extremities were mounted to a custom elbow testing system. Active and passive motion were performed in dependent, horizontal, varus, and valgus positions. A registration and interbone distance algorithm was used to quantify ulnohumeral joint congruency throughout elbow flexion.

RESULTS

The optimally sized hemiarthroplasty implant demonstrated the greatest joint congruency with the ulna, followed by the oversized implant, then the undersized implant. Joint congruency was greater during active vs. passive flexion, indicating that the elbow joint is more reduced in active flexion than in passive flexion.

CONCLUSION

This study demonstrates that undersized distal humeral hemiarthroplasty implants have the lowest joint congruency compared with an optimally sized or oversized implant.