A 62-year-old woman with a valgus knee as seen in Figures A and B who underwent a primary total knee arthroplasty with a tourniquet presents 5 hours postoperatively with severe pain in the extremity and inability to dorsiflex or plantarflex the ankle. Narcotic pain medication does not improve her symptoms. The knee is flexed and the bandage is loosened and she is re-examined one hour later. On examination, the patient is unable to dorsiflex or plantarflex the foot and the pulses are asymmetric. What is the next most appropriate step in management?