What happens to the elbow 15 years after a radial head prosthesis? A clinical and imaging long-term follow-up study.

BACKGROUND

Radial head arthroplasty (RHA) has increasingly become the standard treatment for nonreconstructable radial head fractures, especially in young active patients where long-lasting function restoration is of paramount importance. However, long-term evidence of the results over time is still scarce. The purpose of this study was to document the long-term outcomes of RHA for acute radial head fractures.

METHODS

Thirty-eight patients (mean age, 41.9 years) treated with RHA with at least 10 years of follow-up were included in this study for clinical and radiographic evaluation: 14 patients had isolated radial head fractures and 24 had associated lesions (17 terrible triads, 6 transulnar fracture-dislocations, 1 Monteggia fracture). The clinical outcomes were quantified through the Mayo Elbow Performance Score (MEPS), the Broberg-Morrey score (B&M), and the 12-Item Short Form Health Survey questionnaire. All patients were evaluated for range of motion (ROM), strength, complications, revision surgeries, and postoperative satisfaction. Radiographic findings at the final follow-up were assessed through plain anteroposterior and lateral radiographs.

RESULTS

At a mean follow-up of 14.5 years, the mean MEPS score was 96.4 (standard deviation [SD] 6.1). The mean B&M score was 93.0 (SD 7.7). The mean ROM in flexion-extension was 132° (SD 10.9) and 13° (SD 14.5), respectively, whereas the mean arc of motion in forearm rotation was 142° (pronation 76°, SD 21.0; supination 66°, SD 23.1). Three patients (7.9%) failed and underwent prosthesis explantation. The causes of prosthetic removal were 2 cases of elbow stiffness and 1 case of aseptic loosening. The presence of heterotopic ossifications was found in 9 patients (25.7%). Signs of moderate or severe elbow arthritis were observed in 14 patients (40%), 10 patients (28.6%) had radiographic evidence of stress shielding, and 16 patients (45%) presented various degrees of radiolucency areas around the stem. The press-fit implants showed higher rates of stress shielding compared with loose-fit implants (38.9% vs. 7.1%) and lower rates of radiolucency around the stem (28.6% vs. 71.4%). Survivorship rates for modular press-fit implants (Small Bone Innovation system) were 92.1% at 2 years, 5 years, and 14.5 years, whereas survivorship rates for modular loose-fit implants (Evolve; Wright Medical) were 100% at the final follow-up.

CONCLUSION

After 15 years, elbows treated with RHA presented signs of arthritis in the majority of patients. However, patients with RHA implanted within 4 weeks for nonreconstructable fractures of the radial head sustained a limited number of failures and, despite a relatively high rate of post-traumatic arthritis, obtained a good long-term clinical outcome.