Modern trunnion designs do not affect clinically significant patient-reported outcomes. Issue 6 (November 2020)

• Record Type: Journal Article
• Authors: Ihekweazu, Ugonna N; Lyman, Stephen; Chiu, Yu-fen; Vaynberg, Idelle; Westrich, Geoffrey
• Is Part Of: Hip international. Volume 30:Issue 6(2020)
• Page Start: 752
• Page End: 760
• Publication Date: 2020-11
• Subjects: Minimal clinically important change (MCIC) -- patient-reported outcomes -- total hip arthroplasty -- trunnion; Hip joint -- Pathophysiology -- Periodicals; Hip joint -- Diseases -- Periodicals; Hip joint -- Surgery -- Periodicals; 617.581005
• DOI: 10.1177/1120700019864317
• Languages: English
• ISSNs: 1120-7000

Abstract

Introduction: Trunnion geometry is known to vary between hip systems. Trunnionosis and the impact of trunnion design on total hip arthroplasty (THA) survival, has gained attention as a failure mechanism. We sought to report the differences in patient-reported outcome measures (PROMs) between the most commonly utilised modern THA trunnions. Methods: We reviewed primary unilateral THA patients from May 2007 to October 2011. The most frequently used stems were included. LEAS, HOOS subdomains, and SF-12 were obtained pre and post operatively while satisfaction was measured at 2 years after THA. Trunnions were grouped by taper geometry and manufacturer. The 2-year change in PROMs for each trunnion was compared to the pooled 2-year change in HOOS for all other trunnions. Results: 3950 THA patients were studied. 6 trunnion designs were evaluated from 5 manufacturers. The range in differences between the 2-year change in individual PROMs were as follows: HOOS pain (0.6–2.4), HOOS symptoms (0–3.8), HOOS ADL (0.4–4), and HOOS QOL (0.5–3.6). None of the differences in the 2-year change in PROMs reached a minimal clinically important change (MCIC), which we previously determined to be a minimum of 9 points for all HOOS domains. Conclusion: All of the trunnions designs utilised in our study cohort demonstrated excellent clinical results. Small differences were well below the known MCIC; and were not clinically relevant. The findings of this study should prompt further investigations into the long-term impact of trunnion design on clinical patient-reported outcomes.