Clinical effectiveness of a modified muscle sparing posterior technique compared with a standard lateral approach in hip hemiarthroplasty for displaced intracapsular fractures (HemiSPAIRE): a multicenter, parallel-group, randomized controlled trial.

Objectives: Assess the effect of a modified muscle sparing posterior approach; SPAIRE (Save Piriformis and Internus, Repairing Externus), in hip hemiarthroplasty for displaced intracapsular fractures on postoperative mobility and function compared with a standard lateral approach. Design: Pragmatic, superiority, multicenter, parallel-group, randomized controlled trial (with internal pilot). Participants, ward staff, and research staff conducting postoperative assessments were blinded to allocation. A CTU allocated treatments centrally using computer-generated lists. Setting: Six hospitals in Southwest England, recruiting November 25, 2019-April 25, 2022. Participants: 244 adults (≥60 years) requiring hip hemiarthroplasty (122 allocated to each approach). 90 and 85 participants allocated to SPAIRE and lateral, respectively, had primary outcome data within the prespecified data collection window. Interventions: Surgery using SPAIRE or standard lateral approach. Follow-up 3 days and 120 days postoperation. Main outcome measure: Oxford Hip Score (OHS), via telephone at 120 days. Secondary outcomes: function and mobility (3 days), pain (3 days, 120 days), discharge destination, length of hospital stay, complications and mortality (within 120 days), quality of life and place of residence (120 days). Results: Participants' mean age was 84.6 years (SD 7.2); 168 (69%) were women. Primary outcome: little evidence of a difference in OHS at 120 days; adjusted mean difference (SPAIRE-lateral) -1.23 (95% CI -3.96 to 1.49, p=0.37). Secondary outcomes: indication of lower participant-reported pain at 3 days in SPAIRE arm; no differences between arms for remaining outcomes. Conclusions: Participants' mobility and function are similar in the short term (3 days) and longer term (120 days), whether receiving the SPAIRE or lateral approach. Neither approach confers benefit over the other in terms of length of hospital stay, return to prefracture residence, survival within 120 days, or quality of life at 120 days. Participants receiving SPAIRE approach may experience less pain in the early postoperative period. Modifying the posterior approach in hip hemiarthroplasty to the SPAIRE approach gives equivalent patient outcomes to the lateral approach within 120 days. Trial registration number: NCT04095611.

Factors associated with implant survival following total hip replacement surgery: A registry study of data from the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man.

BACKGROUND: Nearly 100,000 people underwent total hip replacement (THR) in the United Kingdom in 2018, and most can expect it to last at least 25 years. However, some THRs fail and require revision surgery, which results in worse outcomes for the patient and is costly to the health service. Variation in the survival of THR implants has been observed between units and reducing this unwarranted variation is one focus of the "Getting it Right First Time" (GIRFT) program in the UK. We aimed to investigate whether the statistically improved implant survival of THRs in a high-performing unit is associated with the implants used or other factors at that unit, such as surgical skill. METHODS AND FINDINGS: We analyzed a national, mandatory, prospective, cohort study (National Joint Registry for England, Wales, Northern Ireland and the Isle of Man [NJR]) of all THRs performed in England and Wales. We included the 664,761 patients with records in the NJR who have received a stemmed primary THR between 1 April 2003 and 31 December 2017 in one of 461 hospitals, with osteoarthritis as the only indication. The exposure was the unit (hospital) in which the THR was implanted. We compared survival of THRs implanted in the "exemplar" unit with THRs implanted anywhere else in the registry. The outcome was revision surgery of any part of the THR construct for any reason. Net failure was calculated using Kaplan-Meier estimates, and adjusted analyses employed flexible parametric survival analysis. The mean age of patients contributing to our analyses was 69.9 years (SD 10.1), and 61.1% were female. Crude analyses including all THRs demonstrated better implant survival at the exemplar unit with an all-cause construct failure of 1.7% (95% CI 1.3-2.3) compared with 2.9% (95% CI 2.8-3.0) in the rest of the country after 13.9 years (log-rank test P < 0.001). The same was seen in analyses adjusted for age, sex, and American Society of Anesthesiology (ASA) score (difference in restricted mean survival time 0.12 years [95% CI 0.07-0.16; P < 0.001]). Adjusted analyses restricted to the same implants as the exemplar unit show no demonstrable difference in restricted mean survival time between groups after 13.9 years (P = 0.34). A limitation is that this study is observational and conclusions regarding causality cannot be inferred. Our outcome is revision surgery, and although important, we recognize it is not the only marker of success of a THR. CONCLUSIONS: Our results suggest that the "better than expected" implant survival results of this exemplar center are associated with implant choice. The survival results may be replicated by adopting key treatment decisions, such as implant selection. These decisions are easier to replicate than technical skills or system factors.

The SPAIRE technique allows sparing of the piriformis and obturator internus in a modified posterior approach to the hip.

INTRODUCTION: The Sparing Piriformis and Internus, Repair Externus (SPAIRE) technique allows a muscle sparing mini-posterior approach to the hip. METHOD: We present in this article a description of an adaptation of the familiar posterior approach (PA) in which the only tendon released is obturator externus. Termed SPAIRE, this muscle sparing technique enables preservation of the piriformis tendon and conjoint insertion of obturator internus and the gemelli. The technical description allows for safe and reliable replication by any surgeon familiar with the posterior approach (PA) to the hip without reliance on additional equipment, and without compromising the ability to convert into a more extensile approach. CONCLUSIONS: This technical description and brief discussion of rationale outlines the ongoing work of the authors in developing the SPAIRE technique as part of the spectrum of the posterior approach to the hip. The senior author now uses this technique routinely for total hip replacements and hemiarthroplasty. Patients are mobilised with no postoperative restrictions whatsoever. Other potential advantages include improved gait, more anatomical restoration of hip function, and enhanced stability. Projects have been initiated in our unit to objectively assess the possible clinical advantages relating to use of the SPAIRE technique using gait analysis, objective measurement of muscle power and studies of hip stability.

Dislocation after total hip replacement - there is no such thing as a safe zone for socket placement with the posterior approach.

INTRODUCTION: Malorientation of the socket contributes to instability after hip arthroplasty but the optimal orientation of the cup in relation to the pelvis has not been unequivocally described. Large radiological studies are few and problems occur with film standardisation, measurement methodology used and alternative definitions of describing acetabular orientation. METHODS: A cohort of 1,578 patients from a single institution is studied where all patient data was collected prospectively. Risk factors for patients undergoing surgery are analysed. Radiological data was compared between a series of non-dislocating hips and dislocating cases matched 2:1 by operation type, age and diagnosis. RESULTS: The overall dislocation rate for all 1,578 cases was 3.23% but the rate varied according to the type of surgery performed. The rate in uncomplicated primary cases was 2.4% which increased to 9.3% for second stage implantation for a two stage procedure for infection. There was no significant difference in the variability of the dislocating and non-dislocating groups for either inclination (p = 0.393) or anteversion (p = 0.661). CONCLUSIONS: A "safe zone" for socket orientation to avoid dislocation could not be defined. The cause of dislocation is multifactorial, re-establishing the anatomic centre of rotation, balancing soft tissues and avoidance of impingement around the hip are important considerations.