Hybrid versus cemented implants for total hip replacement: a randomised feasibility study with embedded qualitative research

To evaluate the feasibility of a randomised controlled trial (RCT) comparing the clinical and cost-effectiveness of hybrid versus cemented implants for total hip replacement (THR). Two-arm pragmatic randomised feasibility trial with embedded qualitative semi-structured interviews. Performed at two NHS orthopaedic hospitals for the randomised feasibility trial; two further sites for qualitative interviews. 40 adults undergoing THR randomised to receive either cemented (cemented cup and stem) or hybrid (uncemented cup and cemented stem) THR. Qualitative study: 27 patients invited to participate in the trial; 16 consultant orthopaedic surgeons; 4 healthcare professionals involved in trial conduct. Primary outcomes: recruitment rate. Secondary outcomes related to feasibility and acceptability assessed using quantitative and qualitative methods. February- July 2021: 63 patients were screened and 40 (63%) randomised on a 1:1 allocation which was 100% of the adjusted recruitment target. Four participants were withdrawn due to surgery delays and five of 36 participants did not receive their allocated treatment. No adverse events of special interest and no serious adverse device effects were reported. Data completeness and follow-up were high. An indicative cost-utility analysis was performed, demonstrating feasibility for an RCT. Qualitative findings suggested that trial participation was acceptable to patients if they believed that their well-being would not be compromised. Surgeons’ recommendations regarding trial participation seemed influential. Surgeons seemed willing to recruit patients to the trial if they were in equipoise and perceived no detriment to patients’ outcomes following random allocation. This study has demonstrated that an RCT to evaluate the clinical and cost-effectiveness of hybrid vs cemented implants for THR is feasible and appears acceptable to patients where their surgeons support trial participation. It is important for surgeons to believe trial participation will not jeopardize patient outcomes to enable surgeons to support the trial. UK Clinical Study Registry ISRCTN11097021 date of registration 19/2/2021.