Failure of a Unipolar Radial Head Prosthesis Due to Component Dissociation

Midterm outcomes of a short-cemented bipolar radial head arthroplasty, in a cohort of 56 cases with minimum 2-years follow-up

BACKGROUND

Radial head prostheses are used in comminuted radial head fractures for elbow stabilisation when reduction and internal fixation is not possible. Several implant designs exist, but no large series exist about a short-cemented and bipolar implant.

HYPOTHESIS

The hypothesis was that this prosthesis design shows good clinical, functional, and radiological results, with acceptable rate of complications.

STUDY DESIGN

This retrospective study included the prostheses with bipolar design and short-cemented stem (Evolutive™), with a minimum 2-years follow-up.

MATERIALS AND METHODS

All prosthesis implanted in our Traumatology Center were included, with minimum 2-years follow-up. The evaluation consisted of a clinical and functional evaluation, associated with an independent radiographic assessment. All complications were listed, as long as rate and reasons for implant removal.

RESULTS

Fifty-six implants were studied with a mean follow-up of 64.9months (24 to 119). Fifty-three cases were acute injuries with 16% isolated radial head fractures and 76% complex elbow injury such as ulno-humeral, radio-ulnar or longitudinal forearm instability. Fifty (89%) implants were still in place at last follow-up. The main reason for implant removal was during arthrolysis procedure. Ranges of motion were: 126° in flexion, 9° of extension loss, 76° of pronation and 79° of supination. Mean Mayo Elbow Performance Index was 84.1 with 72% of excellent or good results, and the median quick-DASH was rated 18.2. Radiographic evaluation found 12% significant ulno-humeral arthtitis, 64% capitellar osteopenia and 12% loosening. We recorded 5% of implant-related complications.

DISCUSSION

The short-cemented stem bipolar radial head prosthesis presents clinical and functional results similar to other radial head prosthesis with low incidence of elbow arthritis, when treating both isolated radial head fracture or complexes elbow injury. This implant should therefore be valid for treating comminuted radial head fractures in all types of traumatological injuries.

LEVEL OF EVIDENCE

IV; Retrospective cohort study.

Primary cemented bipolar radial head prostheses for acute elbow injuries with comminuted radial head fractures: mid-term results of 37 patients

BACKGROUND

Radial head arthroplasty represents a widely accepted treatment for elbow injuries with non-reconstructible radial head fractures. The aim of this retrospective multicenter study was to assess mid-term results of patients with clearly defined elbow injuries including type III fractures of the radial head according to Mason's classification type III after primary arthroplasty using a cemented bipolar design.

MATERIALS AND METHODS

In 45 cases a primary cemented bipolar arthroplasty of the radial head was implanted for elbow injuries combined with an acute Mason type III radial head fracture. In all patients associated fractures were detected with preoperative CT scans and ligamentous injuries were evaluated and both were addressed intraoperatively based on a standardized algorithm. Patients with associated injuries other than coronoid fractures and collateral ligament tears were excluded from this study to obtain a more homogenous sample. Clinical and radiological assessment was performed on thirty-seven patients at an average of 5.6 years postoperatively.

RESULTS

DASH Score, functional rating index of Broberg and Morrey, Mayo Elbow Performance Score, and Mayo Modified Wrist Score confirmed good-to-excellent results in most of the patients. Compared to the unaffected arm range of motion and grip strength were slightly reduced. No elbow instability or loosening of the prosthesis, and minor degenerative changes were detected in a few cases.

CONCLUSION

Primary cemented bipolar arthroplasty for type III fractures according to Mason's classification in an elbow injury pattern only including associated coronoid fractures and/or ligamentous tears resulted in good-to-excellent mid-term results. These results suggest that primary bipolar radial head arthroplasty combined with distinct treatment of all associated injuries provides good functional outcomes concerning range of motion, elbow stability, and strength in this cohort. However, the associated injuries may influence clinical and radiological outcome and need to be detected, classified, and treated carefully.