First published in Hip International / Vol. 15 no. 3, 2005 / pp. 155-158 © Wichtig Editore, 2005 EARLY FAILURE MODALITIES IN HIP RESURFACING
S. CUTTS, A. DATTA, K. AYOUB, H. RAHMAN, T. LAWRENCE
Solihull Hospital, Birmingham - UK
ABSTRACT:
Between 1996 and 2002, we treated 60 patients (65 hips) by hip resurfacing. The notes and radiographs of these cases were studied retrospectively and the modalities of failure identified. At a mean follow-up of 51 months, 14 of these cases (22%) required revision surgery. One patient had died from unrelated causes and one was lost to follow-up. At the time of primary surgery, the mean age of the patients in our series was 55 years. The commonest mechanism of failure in our series was fractured neck of femur (six cases). Four of these occurred in females over the age of 60. None of the fractured necks of femur were associated with trauma. There were four cases of loose acetabular components and one case of progressive AVN (avascular necrosis). Two patients required revision surgery for ongoing hip pain and one required a two-stage revision for early deep infection. (Hip International 2005; 15: 155-8) KEY
WORDS: Hip resurfacing, Revision surgery, Failure modalities
INTRODUCTION
Over the course of the last fifty years, various attempts have been made to produce a viable resurfacing implant, with the Smith Peterson cup representing one of the earliest. Sir John Charnley himself experimented with a resurfacing design using polyethylene components but was forced to abandon the concept after a series of early failures. In recent years there has been a resurgence of interest in the concept of hip resurfacing. Proponents of hip resurfacing cite reduced blood loss, non-violation of the proximal femoral shaft and reduction of proximal femoral stress shielding as benefits of the technique (1,2).
The modern era of resurfacing began in the early 1990s with the introduction of metal-on-metal components with hybrid fixation. Hybrid fixation combines an osteo integrating acetabular component with a cemented femoral component. A new generation of prosthesis designers attempted to overcome earlier disappointments with careful attention to materials and design. Between January 1996 and July 2002, 60 patients (65 hips) were treated in our unit by five consultant surgeons, using the Corin cobalt chrome metal-on-metal hip resurfacing. These patients were the subjects of our study. The Corin acetabular component is an uncemented, hydroxyapatite-coated, osteo-integrating device. The femoral component is secured with polymethylmethacrylate cement.
PATIENTS AND METHODS
This study was based on 65 consecutive hip resurfacing cases (60 patients) identified from the theatre logbook. The case notes and radiographs of these patients were studied retrospectively. Fifty-nine patients were also contacted at home by telephone to determine their current status. One patient was lost to follow-up. The Cormet Hip resurfacing (Corin, UK) was used in all 65 cases. Forty-one procedures (63%) were performed on male patients and 24 (37%) on female. Patient demographics are summarised in Table 1. The average age of our patients at the time of primary surgery was 55 years. The mean follow-up was 51 months (range 36 to 108 months). All five of the consultants involved had attended an appropriate course before commencing hip resurfacing. They also had experience of working with colleagues in the region
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