Abstract
Background
There are limited data on the complication rates and risk of periprosthetic joint infection (PJI) in patients who have an acute wound dehiscence after total knee arthroplasty (TKA).
Methods
From 2002 to 2018, 16,134 primary TKAs were performed at a single institution. Twenty-six patients (0.1%) had a traumatic wound dehiscence within the first 30 days. Mean age was 68, 38% were female, and mean BMI was 33 kg/m2. Median time to dehiscence was 13 days. The dehiscence resulted from a fall in 22 cases, including 4 in-hospital falls (3 with femoral nerve blocks), and sudden flexion after staple removal in 4 cases. The arthrotomy was disrupted in 58%, including a complete extensor mechanism disruption in 4 knees. A surgical debridement was performed within 48 hours in 19 of 26 knees. Two-thirds were discharged on antibiotic therapy.
Results
Only two knees were complicated by PJI (cumulative incidence of 11% vs. 1% in all other primary TKAs, HR 6.5, p <0.01). One patient who developed a PJI was initially treated with a bedside closure in the ER rather than surgical debridement. The second patient had a complete extensor mechanism disruption at the time of dehiscence and was treated with surgical debridement, but did not receive a subsequent course of antibiotics. There were no PJIs in any of the cases that were treated with surgical debridement and a course of antibiotics. Three knees required reoperation (cumulative incidence of reoperation was 16% at 2 years, compared to 6% in all other primary TKAs, p=0.32) including 1 two-stage exchange for PJI, 1 irrigation and debridement with component retention for PJI, and 1 revision for tibial component aseptic loosening.
Conclusion
Despite having a traumatic wound dehiscence, with nearly 60% resulting in arthrotomies that exposed implants, the risk of PJI was low but significantly higher than not having a traumatic arthrotomy. We recommend urgent surgical irrigation and debridement, inspection of arthrotomy integrity, and antibiotic treatment to decrease the risk of PJI.
Summary
An acute, traumatic wound dehiscence with in the first 30 days after primary TKA results in a 11% risk of infection at 2 years.
