The direct superior approach (DSA) is a modification of the posterior approach (PA) that preserves the iliotibial band and short external rotators except for the piriformis or conjoined tendon during total hip arthroplasty (THA). The objective of this study was to compare postoperative pain, early functional rehabilitation, functional outcomes, implant positioning, implant migration, and complications in patients undergoing the DSA versus PA for THA. This study included 80 patients with symptomatic hip arthritis undergoing primary THA. Patients were prospectively randomised to receive either the DSA or PA for THA, surgery was undertaken using identical implant designs in both groups, and all patients received a standardized postoperative rehabilitation programme. Predefined study outcomes were recorded by blinded observers at regular intervals for two-years after THA. Radiosteriometric analysis (RSA) was used to assess implant migration. There were no statistical differences between the DSA and PA in postoperative pain scores (p=0.312), opiate analgesia consumption (p=0.067), and time to hospital discharge (p=0.416). At two years follow-up, both groups had comparable Oxford hip scores (p=0.476); Harris hip scores (p=0.293); Hip disability and osteoarthritis outcome scores (p=0.543); University of California at Los Angeles scores (p=0.609); Western Ontario and McMaster Universities Arthritis Index (p=0.833); and European Quality of Life questionnaire with 5 dimensions scores (p=0.418). Radiographic analysis revealed no difference between the two treatment groups for overall accuracy of acetabular cup positioning (p=0.687) and femoral stem alignment (p=0.564). RSA revealed no difference in femoral component migration (p=0.145) between the groups at two years follow-up. There were no differences between patients undergoing the DSA versus PA for THA with respect to postoperative pain scores, functional rehabilitation, patient-reported outcome measurements, accuracy of implant positioning, and implant migration at two years follow-up. Both treatment groups had excellent outcomes that remained comparable at all follow-up intervals

Aims

Excellent outcomes have been reported following CT-based robotic arm-assisted total hip arthroplasty (rTHA) compared with manual THA; however, its superiority over CT-based navigation THA (nTHA) remains unclear. This study aimed to determine whether a CT-based robotic arm-assisted system helps surgeons perform accurate cup placement, minimizes leg length, and offsets discrepancies more than a CT-based navigation system.

Aims

Pelvic incidence (PI) is a position-independent spinopelvic parameter traditionally used by spinal surgeons to determine spinal alignment. Its relevance to the arthroplasty surgeon in assessing patient risk for total hip arthroplasty (THA) instability preoperatively is unclear. This study was undertaken to investigate the significance of PI relative to other spinopelvic parameter risk factors for instability to help guide its clinical application.

Aims

Accurate placement of the acetabular component during total hip arthroplasty (THA) is an important factor in the success of the procedure. However, the reported accuracy varies greatly and is dependent upon whether free hand or navigated techniques are used. The aim of this study was to assess the accuracy of an instrument system that incorporates 3D printed, patient-specific guides designed to optimise the placement of the acetabular component.

Objectives

High failure rates of metal-on-metal hip arthroplasty implants have highlighted the need for more careful introduction and monitoring of new implants and for the evaluation of the safety of medical devices. The National Joint Registry and other regulatory services are unable to detect failing implants at an early enough stage. We aimed to identify validated surrogate markers of long-term outcome in patients undergoing primary total hip arthroplasty (THA).

The early failure and revision of bimodular primary total hip arthroplasty prostheses requires the identification of the risk factors for material loss and wear at the taper junctions through taper wear analysis. Deviations in taper geometries between revised and pristine modular neck tapers were determined using high resolution tactile measurements. A new algorithm was developed and validated to allow the quantitative analysis of material loss, complementing the standard visual inspection currently used.

The algorithm was applied to a sample of 27 retrievals (in situ from 2.9 to 38.1 months) of the withdrawn Rejuvenate modular prosthesis. The mean wear volumes on the flat distal neck piece taper was 3.35 mm³ (0.55 to 7.57), mainly occurring in a characteristic pattern in areas with high mechanical loading. Wear volume tended to increase with time to revision (r² = 0.423, p = 0.001). Implant and patient specific data (offset, stem size, patient’s mass, age and body mass index) did not correlate with the amount of material loss observed (p >  0.078). Bilaterally revised implants showed higher amounts of combined total material loss and similar wear patterns on both sides. The consistent wear pattern found in this study has not been reported previously, suggesting that the device design and materials are associated with the failure of this prosthesis.

Cite this article: Bone Joint J 2015;97-B:1350–7.