[A pedicle gastrocnemius muscle flap transposition for salvage of an exposed prosthesis and deep infection of knee joint after total knee arthroplasty].

Objective

To explore the effect of a delayed pedicle gastrocnemius muscle flap transposition for the treatment of a knee joint deep infection secondary to wound necrosis after total knee arthroplasty (TKA).

Methods

The clinical data of 7 patients treated in Shanxi Provincial People's Hospital with a delayed pedicle gastrocnemius muscle flap transposition from December 2015 to September 2019 for wound necrosis, exposed prosthesis and deep infection of knee joint after TKA were analyzed retrospectively. Before the muscle flap transplantation, 5 of the patients had received at least one debridement but failed for relapse, and resulted in an exposed prostheses and infected knee joint. Four patients were positive in their wounds or joint exudates bacterial culture, while the other 3 patients were negative but only with an obvious purulent secretion. The radiographs in all of the patients had no signs of lucent peripheral to or sink of the prosthesis.

Results

The patients were followed-up for a mean time of 16.5 months (7-39 months). The flap and skin graft survived uneventfully with no pain, sinus, fistula, edema, and hematoma occurred. The appearances of the legs were normal. Only 1 patient had a mild limp, and the others gained almost a normal gait. One of the patients recurred 5 months after the gastrocnemius muscle flap transposition, and a two-stage revision procedure was applied, that involving a prosthesis remove and vancomycin impregnated cement (4 grams of vancomycin powder mixed with forty grams of polymethylmethacrylate) spacer implanted, and a new prosthesis was re-implanted 6 months later. The assessment of Knee Society Score (KSS) graded as: 4 patients classified as excellence, 2 as fine, 1 as general.

Conclusions

Delayed pedicle gastrocnemius muscle flap transposition is an effective method for the complication of wound necrosis, deep infection, prosthesis exposure after TKA. This protocol was appropriate for those who have experienced a comparative long time of infection while had no signs of prosthesis loosening, and with which the implant may be salvaged, the defect be closed, and the infection be eradicated.