PAPER 022: PREVALENCE OF GROIN PAIN AFTER METAL-ON-METAL HIP RESURFACING

Abstract

Purpose: The prevalence of groin pain following total hip resurfacing is unknown. Based on recent literature, 4.3% of total hip replacement patients will complain of groin pain/iliopsoas tendonitis. This study aims to determine the prevalence of groin pain after metal on metal hip resurfacing.

Method: Out of 163 patients that underwent hip resurfacing at the Ottawa General Hospital by two orthopedic surgeons with a minimum follow up of 6 months, 93 patients were evaluated in this study. Patients were questioned about post-operative groin pain in detail. A physical exam was completed by an independent orthopaedic surgeon to measure range of motion, assess for a positive impingement sign, and assess pain with straight leg raise. Radiographic evaluation included anterior femoral head/neck offset ratio, presence of acetabular component uncoverage and component loosening.

Results: A total of 98 hips, in 93 patients were evaluated. Mean age was 50 years, with a mean follow up of 21.7 months (range 6–48 months), 21% had ongoing groin pain, 8% reported taking analgesics and 10% reported limitation of activities due to pain. 5 patients received a cortisone injection with a variable response. There were no statistically significant differences detected between groin pain and the radiological parameters inspected. There was no evidence of component loosening. Decreased range of motion was slightly correlated with groin pain. Patients with groin pain had lower RAND and WOMAC scores. Patients reporting a pain score of 5 or above on a visual pain score were found to have lower functional scores than those who scored less, though not statistically significant. Neither the surgeon nor the approach were associated significantly to pain, Pain distribution did not change over the course of the post operative period from 6 months to four years.

Conclusion: Groin pain after hip resurfacing appears more common than that after total hip replacement. The origin is most likely multi-factorial: surgical approach, implant positioning and reaction to wear debris. Further research is required in determining predisposing factors as well as its natural course.