Application of intraoperative limb-length measurement by a new osteotomy device in hemiarthroplasty for treating femoral neck fracture

Limb length discrepancy is one of the most common complications after hip arthroplasty. We developed a device - intraoperative limb-length measurement and osteotomy device (ILMOD), and applied it to patients who were treated with hemiarthroplasty for femoral neck fracture to improve limb length discrepancy by providing an accurate osteotomy during hemi-arthroplasty. Between April 2012 and October 2013, 65 patients were treated with hip hemiarthroplasty for femoral neck fracture at our trauma center. 31 patients met the inclusion criteria and were randomly enrolled into two groups ILMOD group and control group. Hemiarthroplasty in this study was performed with cement fixation. Treatment-related measurements such as the operation time, attempts of osteotomy, and the volume of intra-operative blood loss were collected. In both groups, postoperative (1 month) radiologic analysis on anteroposterior weight-bearing pelvic view was performed to evaluate limb length discrepancy. The results showed significant improvement in limb length discrepancy in ILMOD group, and analysis of postoperative radiographs found the mean length difference is 2.1 ± 1.9 mm in ILMOD group compared to 8.8 ± 5.1 mm in control group (P