‘Rigor like’ acute equinovarus contracture followed by delayed relaxation in a patient with knee dislocation with popliteal artery injury- A case report

A knee dislocation associated with a popliteal artery injury often result in an amputation if there is a delay in diagnosis and treatment. The recommended protocol is early diagnosis with angiography followed by immediate revascularization. We report a patient who presented with a fracture dislocation of the knee with an ischemic limb 4 h after a road traffic accident. At presentation, he had a fixed equinovarus deformity of the foot. He underwent immediate revascularization and fasciotomy. The equinovarus deformity persisted after revascularization despite stretching, traction and partial excision of ischemic soleus and tibialis posterior muscles. The foot deformity gradually improved over the next 36 h, however he required multiple debridement due to extensive ischemia of deeper muscles and eventually underwent an above knee amputation. This presentation of limb ischaemia with a fixed equinovarus deformity followed by relaxation is similar to what is seen in ‘Rigor Mortis’, that is rigidity followed by relaxation. We were unable to find any similar reports in literature. We feel that this presentation suggests severe ischemia with irreversible muscle injury, and it is preferable to proceed with primary amputation instead of attempting revascularization.