Adverse local tissue reactions associated with abnormal wear considerably slowed down the general use of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), now limited to a few specialized centres. In this study, we provide the clinical results of 400 consecutive MoM HRAs implanted more than 20 years ago in one such centre. A total of 355 patients (400 hips) were treated with Conserve Plus HRA between November 1996 and November 2000. There were 96 female (27%) and 259 male patients (73%). Their mean age was 48.2 years (SD 10.9). The University of California, Los Angeles (UCLA) hip scores and 12-item Short Form Survey (SF-12) quality of life scores were reported. Survivorship was assessed using Kaplan-Meier analyses.Aims
Methods
In previous studies, we identified multiple factors influencing the survivorship of hip resurfacing arthroplasties (HRAs), such as initial anatomical conditions and surgical technique. In addition, the University of California, Los Angeles (UCLA) activity score presents a ceiling effect, so a better quantification of activity is important to determine which activities may be advisable or detrimental to the recovered patient. We aimed to determine the effect of specific groups of sporting activities on the survivorship free of aseptic failure of a large series of HRA. A total of 661 patients (806 hips) representing 77% of a consecutive series of patients treated with metal-on-metal hybrid HRA answered a survey to determine the types and amounts of sporting activities they regularly participated in. There were 462 male patients (70%) and 199 female patients (30%). Their mean age at the time of surgery was 51.9 years (14 to 78). Their mean body mass index (BMI) was 26.5 kg/m2 (16.7 to 46.5). Activities were regrouped into 17 categories based on general analogies between these activities. Scores for typical frequency and duration of the sessions were used to quantify the patients’ overall time spent engaging in sporting activities. Impact and cycle scores were computed. Multivariable models were used.Aims
Patients and Methods
This study presents the long-term survivorship, risk factors for prosthesis survival, and an assessment of the long-term effects of changes in surgical technique in a large series of patients treated by metal-on-metal (MoM) hip resurfacing arthroplasty (HRA). Between November 1996 and January 2012, 1074 patients (1321 hips) underwent HRA using the Conserve Plus Hip Resurfacing System. There were 787 men (73%) and 287 women (27%) with a mean age of 51 years (14 to 83). The underlying pathology was osteoarthritis (OA) in 1003 (75.9%), developmental dysplasia of the hip (DDH) in 136 (10.3%), avascular necrosis in 98 (7.4%), and other conditions, including inflammatory arthritis, in 84 (6.4%).Aims
Patients and Methods
A contact patch to rim (CPR) distance of <
10 mm has been
associated with edge-loading and excessive wear. However, not all
arthroplasties with a low CPR distance show problems with wear.
Therefore, CPR distance may not be the only variable affecting the
post-operative metal ion concentrations. We used multiple logistic regression to determine what variables
differed between the patients who had high and low cobalt (CoS)
and chromium (CrS) serum ion concentrations within a cohort of patients
with low (<
10 mm) CPR distances. A total of 56 patients treated
with unilateral hip resurfacing arthroplasty (HRA) had CoS and CrS
ion studies performed more than one year after surgery. The mean
age of the patients at the time of surgery was 51.7 years (29 to
70), with 38 women (68%) and 18 men (32%).Aims
Patients and Methods
Hip resurfacing arthroplasty (HRA) is an alternative to conventional
total hip arthroplasty for patients with osteonecrosis (ON) of the
femoral head. Our aim was to report the long-term outcome of HRA,
which is not currently known. Long-term survivorship, clinical scores and radiographic results
for 82 patients (99 hips) treated with HRA for ON over a period
of 18 years were reviewed retrospectively. The mean age of the 67
men and 15 women at the time of surgery was 40.8 years (14 to 64).
Patients were resurfaced regardless of the size of the osteonecrotic
lesion.Aims
Patients and Methods
Because the femoral head/neck junction is preserved in hip resurfacing, patients may be at greater risk of impingement, leading to abnormal wear patterns and pain. We assessed femoral head/neck offset in 63 hips undergoing metal-on-metal hip resurfacing and in 56 hips presenting with non-arthritic pain secondary to femoroacetabular impingement. Most hips undergoing resurfacing (57%; 36) had an offset ratio ≤ 0.15 pre-operatively and required greater correction of offset at operation than the rest of the group. In the non-arthritic hips the mean offset ratio was 0.137 (0.04 to 0.23), with the offset ratio correlating negatively to an increasing α angle. An offset ratio ≤ 0.15 had a 9.5-fold increased relative risk of having an α angle ≥ 50.5°. Most hips undergoing resurfacing have an abnormal femoral head/neck offset, which is best assessed in the sagittal plane.
