LAUSR

INTRODUCTION The purpose of this study was to demonstrate the effectiveness of controlled telescoping system for lateral hip pain caused by sliding of the blade following intramedullary nailing of trochanteric fractures. MATERIALS AND METHODS A retrospective cohort study was performed to compare the controlled telescoping system (Compression Hip Nail; CHN) with the conventional sliding system (Proximal Femoral Nail Antirotation; PFNA) for trochanteric fractures. 74 cases in the PFNA group and 77 cases in the CHN group were included from two university hospitals in this study. All patients had a minimum of 12-month follow up period. Lateral hip pain was evaluated and operation time and blood loss during the surgery were measured. The fracture classification was evaluated. The quality of postoperative reduction and other complications after surgery were also evaluated and tip-apex distance (TAD), telescoping and lateral protrusion of the blade and lag screw were measured. RESULTS The mean age was 78.5 years in the PFNA group and 74.7 years in the CHN group (p=0.25). The mean telescoping was 19.2mm in the PFNA group and 10.7mm in the CHN group (p<0.001). The mean length of lateral protrusion was 10.5mm in the PFNA group and 2.5mm in the CHN group (p<0.001). Twenty-eight patients in the PFNA group complained of lateral hip pain, whereas 12 patients in the CHN group did (p=0.002). These four variables showed statistically significant differences between the PFNA and CHN groups (p<0.05). The length of lateral protrusion was the only variable significantly related to lateral hip pain through multivariate logistic regression analysis (p=0.045). CONCLUSIONS The degree of lateral protrusion was mainly related to lateral hip pain. Therefore, controlled telescoping would help to decrease lateral hip pain by decreasing the lateral protrusion beyond the lateral femoral cortex.