NAVIGATED FEMORAL COMPONENT INSERTION OF THE BIOMET RECAP HIP TOTAL RESURFACING SYSTEM: REVIEW OF TECHNIQUE AND RADIOLOGICAL ASSESSMENT OF TEN CASES

Abstract

Introduction: Optimal positioning of the femoral component in hip resurfacing is determined by accurate guidwire placement in the centre of the femoral neck. This can be a challenging procedure. The more extensile approach needed, patient size, the shape of the femoral head and the presences of osteophytes can all result in sub-optimal guidewire positioning and ultimately in varus insertion or femoral notching both of which have been shown to increase the risk of post-operative fracture, the commonest cause of implant failure. Various alignment guides are available but these are cumbersome and time consuming and their accuracy is highly operator dependent. Anecdotally, accuate guidewire insertion is regarded as the most challenging part of this procedure with heightened anxiety levels particularly when low down on the‘learning curve’.

Methods: We describe the technique, difficulties and learning curve experienced with the first ten navigated hip resurfacing procedures at our institution. Post-operative radiographs were obtained and randomly incorporated into a series of 40 post-operative resurfacing radiographs. Radiographic assessment was undertaken by a senior colleague with experience of over 600 resurfacing procedures (blinded to which cases utilised navigation) and classified as poor, satisfactory or good.

Results: The use of navigation in femoral resurfacing has a definite but short learning curve. It provides a means of achieving excellent alignment of the femoral component without any subjective increase in operation time. Anxiety levels associated with accurate guidewire positioning are greatly reduced. Navigation should offer benefits to all surgeons particularly those low down on the ‘learning curve’ for this procedure reducing the risk of femoral component malpositioning and early failure.