Triggering mechanisms of neuroarthropathy following conservative surgery for osteomyelitis.

Background: The purpose of this study was to raise awareness and stimulate discussion of the possible triggering factors of Charcot neuroarthropathy by presenting the case of one patient who had both undergone surgery and was suffering from osteomyelitis.

Case Report: We have extracted one case from our data set for a patient who underwent conservative surgery for osteomyelitis and subsequently developed acute Charcot in the midfoot. We present the clinical findings, photographs and X-ray studies. Preoperative X-ray showed irregular severe bone destruction in the fourth metatarsal head and a fracture of the fourth metatarsal bone. No signs of midfoot Charcot neuroarthropathy were found in this preoperative X-ray. The third and fourth metatarsal bones were both removed and the surgical wound was left open to heal by second intention. Histopathological study confirmed osteomyelitis in the bone sample. Twenty-five days after surgery, the surgical wound showed no signs of infection and healing progressed in a satisfactory way. However, the foot was swollen, erythematous and warm. Skin temperature was two degrees higher than the contralateral foot. X-ray was taken and acute neuroarthropathy of the tarso-metatarsal joints was diagnosed.

Conclusions: Charcot neuroarthropathy appears to have been triggered by bone infection and/or surgery. We believe that the pivotal factor in the development of acute Charcot neuroarthropathy in this case was the weight bearing in the deformed foot so soon after the operation. Immobilization of the foot is critical as it serves to decrease the inflammation which has a key role in the development of Charcot neuroarthropathy.