Abstract
Background
Acute soft tissue defects (wound dehiscence or necrosis) after a total knee arthroplasty (TKA) may be the cause of the devasting complication of deep infection. When a medium (4–6cm) defect is present, in patellar or infra-patellar localization, a medial hemi-gastrocnemius flap is widely used to cover it, because of its low morbidity and high functional results. Normally, this coverage is not associated to a debridement, antibiotics and implant retention surgery (DAIR).
When facing this situation, we should consider associating to the coverage treatment, like muscle flap, a DAIR procedure, in order to treat the possible acute infection, even when the diagnosis of infection is not clear. We could not find any studies comparing the benefice of this association in the same surgical act to isolated treatment of soft tissue defects.
Our hypothesis was that when a TKA surgical wound defect is present, the risk of an acute infection is elevated and the patient would benefit from a muscle flap with DAIR procedure and polyethylene exchange.
Methods
We performed a retrospective study to compare TKA infection clearance in patients with DAIR and flap in the same surgical act against those who received an isolated flap procedure for soft tissue coverage after an acute surgical wound defect. Patients were identified from a prospectively collated TKA database.
Between 2005 and 2021, 19 patients met our inclusion criteria. A medial hemi-gastrocnemius flap was performed in 15 patients (78%).
Healing or TKA infection clearance was defined as the presence of the original prosthesis after soft tissue coverage intervention, no need of DAIR after soft tissue coverage or no suppressive antibiotic treatment.
Results
We obtained two groups. The first one, included those patients who had received the association of DAIR with polyethylene exchange and Flap (n=12). The other group included those who had received an isolated flap (n=7). We did not find differences in comorbidities and risk factors between both groups.
In the combination treatment group 66,6% patients healed after treatment. In the other group, these favourable results decrease to 42,9%. Even though results were better in the combination treatment group, no significant differences were found.
Conclusion
Although no significant statistical differences were found, probably due to small sample, the association of DAIR with polyethylene exchange and muscle flap is recommended in the coverage over an acute dehiscence or necrosis after TKA. More studies, with bigger sample are needed to extrapolate results in general population.
