Five-Year Results of Metal-on-Metal Resurfacing Arthroplasty in Asian Patients

Background Modern metal-on-metal hip resurfacing arthroplasty designs have been used for over a decade. Risk factors for short-term failure include small component size, large femoral head defects, low body mass index, older age, high level of sporting activity, and component design, and it is established there is a surgeon learning curve. Owing to failures with early surgical techniques, we developed a second-generation technique to address those failures. However, it is unclear whether the techniques affected the long-term risk factors. Questions/purposes We (1) determined survivorship for hips implanted with the second-generation cementing technique; (2) identified the risk factors for failure in these patients; and (3) determined the effect of the dominant risk factors on the observed modes of failure. Methods We retrospectively reviewed the first 200 hips (178 patients) implanted using our second-generation surgical technique, which consisted of improvements in cleaning and drying the femoral head before and during cement application. There were 129 men and 49 women. Component orientation and contact patch to rim distance were measured. We recorded the following modes of failure: femoral neck fracture, femoral component loosening, acetabular component loosening, wear, dislocation, and sepsis. The minimum followup was 25 months (mean, 106.5 months; range, 25-138 months). Results Twelve hips were revised. Kaplan-Meier survivorship was 98.0% at 5 years and 94.3% at 10 years. The only variable associated with revision was acetabular component position. Contact patch to rim distance was lower in hips that dislocated, were revised for wear, or were revised for acetabular loosening. The dominant modes of failure were related to component wear or acetabular component loosening. Conclusions Acetabular component orientation, a factor within the surgeon's control, determines the long-term success of our current hip resurfacing techniques. Current techniques have changed the modes of failure from aseptic femoral failure to wear or loosening of the acetabular component.

Section: Introductionmentioning

confidence: 99%

Socket Position Determines Hip Resurfacing 10-Year Survivorship

Amstutz

Duff

Johnson

2012

“…In the 1970s, hip resurfacing with metal femoral components and cemented polyethylene acetabular components was popular, but early failures (30% to 56%) [50,85] within 5 years resulting from osteolysis and component loosening caused them to fall out of favor [7,50,85]. Although the short-and midterm results (93%-97% survivorship at mean 5 years) of contemporary metal-on-metal resurfacing implants surpass previous resurfacing designs [13,29,37,49,61,72,75,84,86], there are no long-term results (longer than 10 years) available for these current-generation hip resurfacing implants.…”

Section: Introductionmentioning

confidence: 99%

Is Patient Selection Important for Hip Resurfacing?

Nunley¹,

Valle²,

Barrack³

2009

The optimal implant option for hip arthroplasty in the young, active patient remains controversial. There has been renewed interest for metal-on-metal hip resurfacing due to improved design and manufacturing of implants, better materials, enhanced implant fixation, theoretical advantages over conventional total hip arthroplasty, and recent Food and Drug Administration approval of two devices. Recent studies indicate satisfactory short-and midterm clinical results (1-to 10-year followup) with low complication rates, but there is a learning curve associated with this procedure, a more extensive surgical approach is necessary, and long-term results have yet to be determined. Proper patient selection may help avoid complications and improve patient outcomes. Patient selection criteria in the literature appear based predominantly on theoretical considerations without any consensus on stratifying patient risk. The most commonly reported complications encountered with hip resurfacing include femoral neck fracture, acetabular component loosening, metal hypersensitivity, dislocation, and nerve injury. At the time of clinical evaluation, patient age; gender; diagnosis; bone density, quality, and morphology; activity level; leg lengths; renal function; and metal hypersensitivity are important factors when considering a patient for hip resurfacing. Based on our review, we believe the best candidates for hip resurfacing are men under age 65 with osteoarthritis and relatively normal bony morphology. Level of Evidence: Level V, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

“…Clinical success has been reported in 94% to 100% of patients who underwent resurfacing at short-to midterm followup [1,6,11,12,[14][15][16]. Survival rates have improved as surgeons have moved beyond their learning curves and refined their techniques [8,10], so resurfacing may provide comparable results to conventional THA.…”

Section: Introductionmentioning

confidence: 99%

Resurfacing is Comparable to Total Hip Arthroplasty at Short-term Followup

Mont

Marker

Smith

et al. 2009

Metal-on-metal total hip resurfacing arthroplasty has had excellent reported results at early to midterm followup, and some studies suggest that outcomes are comparable to conventional THA. We compared the clinical and radiographic outcomes of two closely matched groups of 54 patients who underwent resurfacing and conventional THA, respectively. Each group consisted of 36 men and 18 women who had a mean age of 52 years and a mean body mass index of 29 kg/m 2 . At a minimum followup of 24 months (mean, 40 months; range, 24-60 months), the mean Harris hip scores increased similarly in both groups (from 52 to 90 points and from 50 to 91 points for the resurfacing and conventional groups, respectively). Radiographic outcomes, revision rates, complications, pain scores, and satisfaction ratings of the two groups were similar. The patients who underwent resurfacing had higher postoperative weighted activity scores than the patients who underwent conventional THA, although they had higher preoperative weighted activity scores as well. The early outcomes of resurfacing are comparable to those of conventional THA.