Improving MiniHip femoral prosthesis positioning using a cross-laser projection system in total hip arthroplasty by an anterolateral supine approach.

ABSTRACT

BACKGROUND: The authors developed a cross-laser projection system (CLP) to place a femoral neck-sparing short stem using the minimally invasive anterolateral supine approach in total hip arthroplasty. This study aimed to verify the utility of CLP. METHODS: Thirty joints were assessed with the MiniHip (Corin). The authors compared femoral component implantation with a patient-specific femoral osteotomy guide (PSG) for the femoral neck-cut (PSG group), with the CLP attached to the rasp handle to irradiate the cross-laser to the target of PSG (CLP group), and without PSG or CLP (control group). RESULTS: In the CLP group, the positional deviation of anteversion, anterior/posterior tilt and varus/valgus placement of the stem postoperatively were 1.8° ± 0.2°, 2.0° ± 2.0° and 2.0° ± 0.1°, respectively. The positional deviation of anteversion (p < 0.001) and anterior/posterior tilt (p = 0.036) were significantly smaller than those in the other groups. CONCLUSIONS: CLP improves the accuracy of MiniHip femoral prosthesis placement.