Aims. The aim of this study was to assess the functional gain achieved following hip resurfacing arthroplasty (HRA). Patients and Methods. A total of 28 patients (23 male, five female; mean age, 56 years (25 to 73)) awaiting Birmingham HRA volunteered for this prospective gait study, with an age-matched control group of 26 healthy adults (16 male, ten female; mean age, 56 years (33 to 84)). The Oxford Hip Score (OHS) and gait analysis using an instrumented treadmill were used preoperatively and more than two years postoperatively to measure the functional change attributable to the intervention. Results. The mean OHS improved significantly from 27 to 46 points (p < 0.001) at a mean of 29 months (12 to 60) after HRA. The mean metal ion levels at a mean 32 months (13 to 60) postoperatively were 1.71 (0.77 to 4.83) µg/l (ppb) and 1.77 (0.68 to 4.16) µg/l (ppb) for cobalt and chromium, respectively. When compared with healthy controls, preoperative patients overloaded the contralateral good hip, limping significantly. After HRA, patients walked at high speeds, with symmetrical gait, statistically indistinguishable from healthy controls over almost all characteristics. The control group could only be distinguished by an increased push-off force at higher speeds, which may reflect the operative approach. Conclusion. Patients undergoing HRA improved their preoperative gait pattern of a significant limp to a symmetrical gait at high speeds and on inclines, almost indistinguishable from normal controls. HRA with an approved device offers substantial functional gains, almost indistinguishable from healthy controls. Cite this article: Bone Joint J 2019;101-B:1423–1430

Aims

The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients.

This study compared the demographic, clinical and patient-reported outcomes after total hip replacement (THR) and Birmingham Hip Resurfacing (BHR) carried out by a single surgeon. Patients completed a questionnaire that included the WOMAC, SF-36 scores and comorbid medical conditions. Data were collected before operation and one year after. The outcome scores were adjusted for age, gender, comorbid conditions and, at one year, for the pre-operative scores. There were 214 patients with a THR and 132 with a BHR. Patients with a BHR were significantly younger (49 vs 67 years, p < 0.0001), more likely to be male (68% vs 42% of THR, p < 0.0001) and had fewer comorbid conditions (1.3 vs 2.0, p < 0.0001). Before operation there was no difference in WOMAC and SF-36 scores, except for function, in which patients awaiting THR were worse than those awaiting a BHR.

At one year patients with a BHR reported significantly better WOMAC pain scores (p = 0.04) and in all SF-36 domains (p < 0.05). Patients undergoing BHR report a significantly greater improvement in general health compared with those with a THR.