Socket Position Determines Hip Resurfacing 10-Year Survivorship

Abstract

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.

Risk of Impingement and Third-body Abrasion With 28-mm Metal-on-metal Bearings

“…Both positive [2,11] and negative reports [25,34,35,37,61] have emerged with regard to using MoM bearings. There are likely many risks that could trigger a need for MoM revision.…”

Does Femoral Neck to Cup Impingement Affect Metal Ion Levels in Hip Resurfacing?

“…1). This contact patch to rim distance estimation was computed as previously described in the literature [6,16,31], based on design coverage, component size, and acetabular cup abduction and anteversion angles measured from AP pelvis radiographs with Einzel-Bild-Roentgen-Analyse (EBRA) software (EBRA-CUP; University of Innsbruck, Innsbruck, Austria) [10,17]. The contact patch to rim distance represents the functional coverage of the femoral component by the socket.…”

“…Previous publications [3,6] described the Conserve 1 Plus hip resurfacing device, which features a onepiece acetabular component of variable femoral head coverage angle depending on component size. The coverage angle of the acetabular component sizes used in our study ranged from 160°to 163°.…”

Two-Stage Revision Hip Replacement Patiens With Severe Acetabulum Defect (Case Report)

“…по наблюдениям н.с. amstutz с соавторами, нестабильность вертлужного ком-понента появляется у 9,1% больных в течение 2 лет после операции [4]. Для восполнения кост-ного дефицита j. Meehan с соавторами предлага-ют использовать массивные аллотрансплантаты и ацетабулярные компоненты бесцементной фик-сации.…”

“…опорное антипротрузионное кольцо (апк) и чашку цементной фиксации (у больных старших возраст-ных групп) [4,5]. Во всех предлагаемых методиках замещение дефекта и имплантация ацетабуляр-ного компонента выполняются одномоментно.…”