The use of hip resurfacing arthroplasty (HRA) has largely regressed due to the fear of metal-on-metal bearings. However committed HRA users continue to assert the functional advantages that a geometry retaining implant would have on a patient”s hip. Currently worldwide, HRA is only recommended to men who demand an active lifestyle. Despite this precarious indication, it is not clear to what extent HRA has on higher activity function. The aim of this study was to determine the functional extent to which could be achieved with HRA. The primary objective is to assess the loading pattern change for patients implanted with HRA at high walking speeds and inclinations. The second objective is to compare their loading features to a healthy group to determine if a normal gait pattern could be achieved. Between 2012 and 2016, a total of 28 prospective unilateral HRA patients were analysed on an instrumented treadmill from a single centre. All 28 patient patients had a uniform implant type and had no other lower limb operations or disease. Perioperative plain orthogonal radiographs were used to measure hip length and global hip offset change. A healthy control group (n=35) were analysed to compare. All HRA patients gait characteristics were assessed at incrementally higher speeds and inclinations to determine the extent of improvement HRA has on a challenging activity. A Student t-test along with a multivariate analysis was done with significance set at α=0.05. Weight and height variance was accounted with Hof normalisation. The HRA and control group were reasonably matched for age (57 vs 55yrs), BMI (27 vs 25) and height (175 vs 170cm) respectively.
Background. Since 2011, the knee service at the Nuffield Orthopaedic Centre has been offering a neutralising medial opening wedge high tibial osteotomy (HTO) to a group of patients presenting with early medial osteoarthritis of the knee, varus alignment and symptoms for more than 2 years. During development of this practice an association was observed between this phenotype of osteoarthritis and the presence of CAM deformity at the hip. Methods. A retrospective cohort study. All patients who underwent HTO since 2011 were identified (n=30). Comparator groups were used in order to establish whether meaningful observations were being made: Control group: The spouses of a high-risk osteoarthritis cohort recruited for a different study at our unit (n=20) Pre-arthroplasty group: Patients who have undergone uni-compartmental arthroplasty (UKA) for antero-medial osteoarthritis (n=20)All patients had standing bilateral full-length radiographs available for analysis using in house developed Matlab-based software for
Summary. Anatomical variations in hip joint anatomy are associated with both the presence and location of tibiofemoral osteoarthritis (OA). Introduction. Variations in hip joint anatomy can alter the moment-generating capacity of the hip abductor muscles, possibly leading to changes in the magnitude and direction of ground reaction force and altered loading at the knee. Through analysis of full-limb anteroposterior radiographs, this study explored the hypothesis that knees with lateral and medial knee OA demonstrate hip geometry that differs from that of control knees without OA. Patients and Methods. This cross-sectional study is an ancillary to the Multicenter Osteoarthritis Study (MOST), an observational cohort study of incident and progressive knee OA in community-dwelling men and women, ages 50–79 years. We report on 160 knees with lateral OA (LOA), 168 knees with medial OA (MOA), and 336 controls. All participants with LOA at the baseline MOST visit were included. An equal number of knees with MOA, and twice the number of control knees were then randomly selected. In participants with bilateral eligibility, a single knee was randomly selected so that all participants contributed only one case or one control knee to the analysis. Case knees were identified as having Kellgren/Lawrence (K/L) ≥ 2 with joint space narrowing (JSN) ≥ 1 in the specified compartment with no JSN in the adjoining compartment. Controls had no radiographic OA (K/L=0 or 1 and JSN=0) in either compartment. Hip joint anatomy parameters were assessed from full-limb standing radiographs using custom OsiriX software by an author (AB) blinded to knee OA status, and unreadable radiographs (N = 8) were discarded prior to unblinding. We measured parameters that influence the abductor moment arm of the hip, including: abductor lever arm, femoral offset, femoral neck length, femoral neck-shaft angle, height of hip centre, body weight lever arm, acetabular version, and abductor angle. All
