Preoperative Colonoscopy is a Risk Factor for Reoperation following Primary Total Hip Arthroplasty: A Population-Based Study.

Objective: We aimed to investigate the association between preoperative colonoscopy and re-operations following total hip arthroplasty (THA) for osteoarthritis.

Methods: We identified patients aged ≥ 18 years who underwent primary THA for osteoarthritis from 2003 to 2020 using administrative databases in Ontario, Canada. We identified patients who underwent colonoscopy up to one year before their THA and matched each colonoscopy patient to 10 controls using propensity score matching. We identified any instances of reoperation related to the primary THA up to five years postoperative. We used Cox Proportional Hazards models to determine the adjusted association between pre-operative colonoscopy and the time to reoperation, and the area under the receiver operating curve to identify the optimal cut-off time for preoperative colonoscopy. Between 2003 and 2020, 107,000 patients underwent THA for osteoarthritis in Ontario, Canada, while 1,733 (1.6%) of these received a pre-operative colonoscopy. We retained 1,515 colonoscopy patients and 15,150 controls following matching and observed no significant between-group differences in patient, hospital, or procedure characteristics in the matched cohort.

Results: In the colonoscopy group, 69 patients (4.0%) underwent a reoperation within five years postoperatively (versus 2,977 [2.8%] in the control group). The majority of reoperations in both groups were revision THA (colonoscopy: 65 of 69, 94%; control: 2,837 of 2,977, 95%). Undergoing a preoperative colonoscopy up to 12 months before THA was associated with a 1.39 (1.07 to 1.81) increased risk of re-operation within five years postoperative. This risk increased to 1.91 (1.18 to 3.12) if the colonoscopy was done within 83 days of THA.

Conclusion: Our results indicate that THA patients who undergo a diagnostic colonoscopy up to 12-months pre-operatively may have an increased risk of reoperation postoperatively. Furthermore, these data suggest a temporal relationship, where the risk may increase if the colonoscopy is performed closer to the THA.