Long-term outcome and survival rate of monopolar radial head replacement

Abstract

The purposes of this study were 1) to report functional outcomes, 2) to assess complications, revisions and survival rate, and 3) to assess differences in functional outcomes between removed and retained RHAs, early and delayed treatment, and type of RHA used at long-term follow-up after monopolar RHA for unreconstructible radial head fractures or their sequelae. Seventy-eight patients (mean age 59.2 years) that were at least six years postoperatively following monopolar RHA between 1994 and 2010 for unreconstructible RHFs or their sequelae and were included. The Mayo Elbow Performance Score (MEPS), Quick Disability of the Arm, Shoulder and Hand (QuickDASH) score, the Visual Analog Scale (VAS), postoperative satisfaction (1-6, 6=highly unsatisfied), range of motion, complications and revisions were assessed. Radiographic findings were reported. Kaplan-Meier survival analysis was performed. Subgroups (RHA type, early vs. delayed surgery, RHA removed vs. retained) were compared. At a median clinical follow-up of 9.5 years (range: 6.0-28.4), median MEPS was 80.0 (IQR:60.0-97.5), median QuickDASH was 22.0 (IQR:4.6-42.6), median VAS was 1 (IQR:0-4), median postoperative satisfaction was 2 (IQR:1-3), and median arc of extension/flexion was 110° (IQR:80°-130°). Radiographic follow-up was available for 48 patients at a median of 7.0 years (range: 2.0-15.0). Heterotopic ossifications were seen in 14 (29.2%), moderate to severe capitellar osteopenia/abrasion in 3 (6.1%), moderate to severe ulnohumeral degeneration in 3 (6.1%) and periprosthetic radiolucencies in 17 (35.4%) patients. Twenty-nine patients (37.2%) had complications and 20 patients (25.6%) underwent RHA exchange or removal. Kaplan-Meier analysis with failure defined as RHA exchange or removal demonstrated survival of 75.1% (95% CI 63.7-83.3) at 18 years. The highest annual failure rate was observed in the first year in which the RHAs of seven patients (9%) were exchanged or removed. No significant differences were detected between type of RHA in MEPS (Mathys: 82.5 (75.0-100) vs. Evolve: 80.0 (60.0-95.0); P=.341) and QuickDASH (Mathys: 12.5 (0-34.4) vs. Evolve: 26.7 (6.9-46.2); P=.112). Early surgery (≤3weeks) yielded significantly superior MEPS (80.0 (70.0-100.0) vs. 52.5 (30.0-83.8); P=.014) and QuickDASH (18.6 (1.5-32.6) vs. 46.2 (31.5-75.6); P=.002) compared to delayed surgery (>3weeks). Patients with retained RHAs had significantly better MEPS (80.0 (67.5-100) vs. 70.0 (32.5-82.5); P=.016) and QuickDASH (18.1 (1.7-31.9) vs. (49.1 (22.1-73.8); P=.007) compared to patients with removed RHAs. Long-term outcomes for RHA are satisfactory; however, there is a high complication and revision rate, resulting in implant survival of 75.1% at 18 years with the highest annual failure rate observed in the first postoperative year. Level III; Retrospective Cohort Comparison; Treatment Study.