Management of exposed total knee prostheses with microvascular tissue transfer

Abstract

Exposure of a knee endoprosthesis represents a limb-threatening condition, requiring long-term antibiosis, irrigation, and serial debridement to avoid knee arthrodesis or amputation. Although traditional orthopedic surgical doctrine mandates removal of exposed hardware under a dehisced wound, salvage of exposed prostheses using local muscle flap coverage has been reported. However, the complex three-dimensional geometry of the soft tissue surrounding the knee as well as the requirement for sustained local tissue levels of antibiotics to re-sterilize the hardware suggest that microvascular tissue transfer may constitute an advantageous means of wound coverage, increasing both limb and prosthesis salvage rates. We report our experience with free tissue transfer reconstruction of these complex wounds. We treated 11 complex wounds with exposed total knee arthroplasty prostheses with free tissue transfer. Three of 11 patients had failed previous local muscular rotation flap coverage. Five latissimus dorsi muscle flaps and 6 rectus abdominis muscle flaps were used in our series. Wounds were closed after aggressive surgical debridement, antibiotic irrigation, and intravenous antibiosis. Eleven of 11 free flaps were successful (100%), and we achieved limb salvage in 11/11 limbs (100%) and prosthesis salvage in 10/11 knees (91%), with one prosthesis removed at an outside facility followed by knee arthrodesis. The advantages of microvascular tissue transfer are well suited to the treatment of exposed knee endoprostheses. The reliable rectus and latissimus flaps provide robust local perfusion to the wound, fill complex three-dimensional contour defects around knee implants, and lead to a high rate of salvage of both limbs and prostheses.