Acute Arthrotomy Dehiscence after Primary Total Knee Arthroplasty: Depth of Injury Impacts Outcome.

Introduction: Arthrotomy dehiscence is a challenging complication following total knee arthroplasty (TKA). As early mobilization and fast-track rehabilitation protocols become increasingly popular, arthrotomy dehiscence incidence will likely increase. This study aimed to evaluate the clinical outcomes of acute, traumatic arthrotomy dehiscence, with and without superficial skin involvement, following primary TKA.

Methods: A retrospective review identified 39 acute (< 90 days), surgically managed arthrotomy dehiscences following primary TKA. The arthrotomy + skin dehisced in 25 (64%) cases, while the other 14 (36%) involved the arthrotomy only. The mean time from TKA to dehiscence was longer in the arthrotomy-only cohort (31 versus 17 days, P = 0.005), as was the time from dehiscence to repair (13.1 versus 1.9 days, P < 0.0001). Failure was defined as all-cause reoperation or reoperation for periprosthetic joint infection (PJI).

Results: The one-year survivorship free from all-cause reoperation was 75%. When stratified by arthrotomy type, one-year survivorship free from all-cause reoperation was 73% for the arthrotomy-only cohort versus 76% for the arthrotomy + skin cohort (P = 0.94). At six months, survivorship free from reoperation for PJI was 100% in the arthrotomy-only cohort versus 83% in the arthrotomy + skin cohort (P = 0.13). There were eight (21%) total failures, including four PJIs, all occurring in the arthrotomy + skin cohort, and four extensor mechanism complications, three of which occurred in the arthrotomy-only cohort and one in the arthrotomy + skin cohort (P = 0.28).

Conclusion: Overall, arthrotomy dehiscence, regardless of superficial skin involvement, shows concerningly low one-year all-cause reoperation survivorship. Arthrotomy dehiscence with early, aggressive treatment had poor early survivorship free from reoperation for PJI. Our results suggest that surgeons should take all possible precautions to prevent infection and counsel patients regarding the risk of infection and potential extensor mechanism complications following traumatic arthrotomy dehiscence events.