Exposure of a total knee prosthesis represents a limb-threatening condition and a challenging reconstructive problem, 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, a number of authors have reported salvage of exposed prostheses using local muscle flap coverage. However, the complex three-dimensional geometry of the soft tissue surrounding the knee, as well as the requirement for high sustained local tissue levels of antibiotics to re-sterilize the hardware, suggest that microvascular tissue transfer may be the most advantageous means of permanent wound coverage and may increase both limb salvage and prosthesis salvage rates. The experience using free tissue transfer to reconstruct these difficult three-dimensional wounds was reported.
Eleven complex wounds with exposed total knee arthroplasty prostheses were treated with free tissue transfer. Three of the 11 patients had failed prior local muscle rotation flap coverage. Latissimus dorsi muscle flaps and 5 rectus abdominis muscle free flaps were used in the reported series. Wounds were closed after aggressive surgical debridement, antibiosis, irrigation, and intravenous antibiosis.
Eleven of 11 free flaps were successful (100%); limb salvage was achieved in 11/11 limbs (100%) and prosthesis salvage in 10/11 knees (91%).
The advantages of microvascular tissue transfer are well-suited to the treatment of difficult wounds that result from exposure of total knee prostheses. The reliable rectus abdominis and latissimus dorsi muscle 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.
