Local and Systemic Complications of Knee and Hip Arthroscopy: A Matched-Cohort Study

BACKGROUND: Surgeons are familiar with the complication rates and risks of knee arthroscopy, but comparative data between hip arthroscopy and knee arthroscopy are lacking. PURPOSE: To compare complications in knee arthroscopy, the most common arthroscopic procedure, with those in hip arthroscopy. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective matched-cohort study analyzing patients who received a primary hip or knee arthroscopy was performed using the PearlDiver database. A total of 19,735 patients were identified for each cohort. Systemic complications and readmissions were assessed at 3 months postoperatively. Local complications and reoperations were assessed at 6 months, 12 months, and 24 months postoperatively. All categorical variables were compared using chi-square analysis. RESULTS: Hip arthroscopy had significantly higher rates of nerve injury, stiffness, heterotopic ossification, and avascular necrosis (all P < .001) than knee arthroscopy at all observed time periods postoperatively. Hip arthroscopy also had a greater rate of all local joint complications than knee arthroscopy (16.79% vs 11.80%; P < .001). Knee arthroscopy was found to have higher incidences of deep vein thrombosis (0.98% vs 0.66%; P < .001) and myocardial infarction (0.06% vs 0.00%; P < .001) as well as a higher overall systemic complication rate (3.93% vs 3.44%; P = .013). Hip arthroscopy was found to have higher rates of subsequent arthroscopy, arthroplasty, and overall reoperation when compared with knee arthroscopy (11.99% vs 14.99%; P < .001) at all time periods up to 24 months postoperatively. CONCLUSION: Although the systemic complication rate was higher in knee arthroscopy, local joint complications, reoperation, and total complication rates were higher for hip arthroscopy. Surgeons should be aware of these potential differences to best discuss and mitigate risks with this expanding patient population.