19 research outputs found
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Range of motion after stemmed total hip arthroplasty and hip resurfacing - a clinical study.
Range of motion after total hip arthroplasty is becoming an important topic as today's patients present at a younger age and are more active. An effective study design to carry out comparisons of clinical performance between two implants should eliminate patient-related extraneous variables (e.g., age, gender, activity level, among others). The aim of the present study was to compare the range of motion results achieved postoperatively between metalon-metal hip resurfacing (HR) and conventional total hip arthroplasty (THA) in a cohort of bilateral patients implanted with both designs. Thirty-five patients who had undergone bilateral surgery with one hip receiving an HR device and the contralateral hip receiving a THA were retrospectively selected. Sixty-nine percent of the patients were male, and at the time of implantation of the resurfacing device the mean age of the patients was 53 years. The mean follow-up time was 88 months for the hips treated with HR and 96 months for the hips that received a THA. We found no difference in any of the range of motion measurements between HR and THA even after separating the cohort into two groups based on the femoral head size of the THA (femoral heads under 40 mm and femoral heads greater or equal to 40 mm). Our investigation showed that, for most patients, prosthetic design is unlikely to be a limiting factor of range of motion after surgery provided that the positioning of the acetabular component is adequate
Clinical and radiographic results of metal-on-metal hip resurfacing with a minimum ten-year follow-up.
BackgroundThere was a need for information about the long-term performance of the modern generation of hip resurfacing implants. A retrospective review of the first 100 hips that had implantation of one resurfacing design and had been followed for a minimum of ten years was performed.MethodsBetween 1996 and 1998, 100 CONSERVE PLUS hip resurfacing devices were implanted by a single surgeon in eighty-nine patients. The mean age of the patients was 49.1 years, and fifty-nine patients were male. Primary osteoarthritis was the etiology for sixty-four hips. All patients were assessed clinically and radiographically.ResultsThe mean duration of follow-up was 11.7 years (range, 10.8 to 12.9 years). Two patients were lost to follow-up, and five patients died of causes unrelated to the surgery. Eleven hips had conversion to total hip arthroplasty because of loosening of the femoral component (eight), a femoral neck fracture (one), recurrent subluxation (one), and late infection (one). The Kaplan-Meier survivorship was 88.5% at ten years. None of the resurfacing arthroplasties failed in the twenty-eight hips that had a femoral component of >46 mm and no femoral head cystic or necrotic defects of >1 cm. Five hips had narrowing of the femoral neck, three had radiolucent zones interpreted as osteolysis, and twenty had signs of neck-socket impingement. Five hips had radiolucencies around the metaphyseal stem (two partial and three complete) that had been stable for 7.8 to 10.2 years. The mean scores on the University of California at Los Angeles (UCLA) system at the time of the latest follow-up were 9.5 points for pain, 9.3 points for walking, 8.9 points for function, and 6.8 points for activity; the mean scores on the physical and mental components of the Short Form-12 (SF-12) were 47.3 and 50.5 points, respectively; and the mean Harris hip score was 90 points.ConclusionsThe results of the present series constitute a reference point to which subsequent series should be compared. These ten-year results in a group of young patients are satisfactory, and the low rate of osteolysis is encouraging, but longer follow-up is required for comparison with conventional total hip arthroplasty
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Benefits of thin-shelled acetabular components for metal-on-metal hip resurfacing arthroplasty.
The theoretical advantage of using thinner acetabular components in hip resurfacing has not yet been clinically verified. Our purpose was to test the hypothesis of bone conservation and assess the effects of using a thinner acetabular component on hip biomechanics and clinical outcome. We compared the bone conservation, biomechanical results, and functional outcomes between hips in 35 patients who received bilateral metal-on-metal resurfacing arthroplasties with acetabular components of 5 mm thickness on one side and 3.5 mm thickness on the other. Acetabular abduction angle and acetabular anteversion were measured using Ein-Bild-Röentgen-Analysis software. Medial acetabular wall thickness and position of the hip center of rotation were measured using Image J software. The change in position of the hip center of rotation was minimal and did not reach significance. Thin-shelled components showed greater bone conservation on the acetabular side measured by an increase in the medial acetabular wall thickness. Bone conservation on the femoral side was achieved as well with thin shells. Range of motion, pain scores, and complication rates were comparable. No appreciable difference was found in bone-cup radiographic appearance between the two types of components. These data suggest that patients can experience good clinical outcomes for resurfacing with either thin or thick-shelled acetabular components. However, thin-shelled components preserve acetabular bone stock and allow the use of a larger femoral component. The use of thinner acetabular components is an improvement in bone conservation for a hip resurfacing design