Radiological validation of a fluoroscopic guided technique for femoral implant positioning during hip resurfacing.

Purpose: The positioning of the femoral cup in hip resurfacing is essential for the survival of the implant. We described a technique in 2005 to position the femoral cup guided by fluoroscopy independent of the approach performed. The main objectives were to study the positioning of the femoral components of the implant and the accuracy of the technique.

Methods: Between 2003 and 2011 we conducted a prospective study of 160 consecutive hip resurfacings all operated with this fluoroscopic-guided technique. Three independent observers performed a radiographic analysis at the pre-operative planning stage and on postoperative radiographs using OsiriX software. The statistical analysis was based on comparison of two groups by Student's t test.

Results: The entire implant was positioned in valgus, with an average of 7.816° valgus (p <0.001). All implants were positioned in neutral or anteverted with a mean of 1.98° (p <0.001). The risk of malpositioning on the antero-posterior plane was less than 1.41° with p <0.019. The risk of profile positioning error was lower than 0.80° with p <0.047.

Conclusion: This study validates a technique of femoral implant positioning for resurfacing. It is simple, precise and independent of the approach performed.