Outcomes after revision of metal on metal hip resurfacing to total arthroplasty using the direct anterior approach
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Function after revision total hip arthroplasty (THA) in failed metal-on-metal (MoM) hip resurfacing arthroplasty (HRA) is variable, but post-operative complication rates are reportedly high. We hypothesized HRA conversion to THA using the direct anterior approach (DAA) would be associated with optimal outcome.
Seventeen MoM-HRAs in 15 patients (seven males, eight females) were revised through the DAA. The mean age was 45 years (28–59 yrs). The most common indications for revision were aseptic loosening of the acetabular component or of the femoral component and femoral neck fracture. In 16 hips, a conversion to a ceramic-on-ceramic (CoC) (13 hips) or to a metal-on polyethylene (MOP) (2), or to a large-head MoM (1) THA was done. An isolated femoral revision was done in one hip.
After 6.7 ± 3 years, no hip had required a re-revision. The Postel-Merle d’Aubigne (PMA) functional score improved from 9 (4–14) to 16 (12–18) (p < 0.001). An intra-operative fracture of the greater trochanter (one hip) and dysesthesia of the lateral femoral cutaneous nerve (four hips) were reported. Mean serum chromium concentration decreased from 33.2 μg/L (11.8–62 μg/L) pre-operatively to 5.8 μg/L (0.4–35.5 μg/L) post-operatively (p < 0.001), and mean serum cobalt concentration decreased from 35.8 μg/L (6.3–85.5 μg/L) to 4.7 μg/L (0.26–25.7 μg/L) (p = 0.003).
Revision of failed MoM-HRA using the DAA resulted in an acceptable clinical outcome, no specific complication and no further surgery. A consistent decline in serum ion levels may be expected following HRA conversion to THA.
KeywordsHip resurfacing Metal-on-metal Revision Total hip arthroplasty Serum ion level
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Informed consent was obtained from all individual participants included in the study.
- 5.National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (2016) National Joint Registry 13th Annual Report. Retrieved from http://www.njrreports.org.uk/Portals/4/PDFdownloads/NJR%2013th%20Annual%20Report%202016.pdf
- 12.DeLee JG, Charnley J (1976) Radiological demarcation of cemented sockets in total hip replacement. Clin Orthop Relat Res (121):20-32Google Scholar
- 13.Gruen TA, McNeice GM, Amstutz HC (1979) “Modes of failure” of cemented stem-type femoral components: a radiographic analysis of loosening. Clin Orthop Relat Res 141:17–27Google Scholar
- 18.Furnes O, Paxton E, Cafri G et al (2014) Distributed analysis of hip implants using six national and regional registries: comparing metal-on-metal with metal-on-highly cross-linked polyethylene bearings in cementless total hip arthroplasty in young patients. J Bone Joint Surg Am 96:25–33CrossRefGoogle Scholar
- 23.US Food and Drug Administration. Medical Devices. Metal on Metal Hip implants. Information for Orthopaedic Surgeons. http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/MetalonMetalHipImplants/