Patient-specific factors influencing the traction forces in hip arthroscopy.

INTRODUCTION: The application of traction in hip arthroscopy is associated with peri-operative complications. Within a therapeutic case series, patient-related factors correlating with high-traction forces during hip arthroscopy and occurring complications should be identified.

MATERIALS AND METHODS: In 30 male and 38 female patients (mean age: 44.5 years), intra-operative traction forces were monitored continuously using a specialised measurement device. A multivariate analysis was employed to identify patient-related factors influencing the traction force. Peri-operative complications (follow-up: 12 weeks) were evaluated by performing a single-case analysis.

RESULTS: The mean initial force prior to penetration of the capsule ("initial force") was 477 N (men: 517 N; women: 444 N), decreasing after capsulotomy by an average of 17 %. The male gender (p < 0.001), Kellgren and Lawrence radiographic stage (p = 0.037), low minimum joint-space width (p = 0.029) and high body height/weight (p = 0.003/0.037) correlated significantly with higher distraction forces. The patient age and type of anaesthesia (general versus spinal) were not relevant. Complications were observed in ten patients on the first post-operative day. In two of these patients a partial sensory deficit of the lateral cutaneous femoral nerve persisted after 12 weeks. All patients with complications required initial traction forces of >400 N.

CONCLUSIONS: The study revealed several patient-specific risk factors correlating with high-traction forces during hip arthroscopy. With view to potential complications, these patient groups require special attention during surgical treatment as well as in future studies.