Arterial injury in the lower limb from blunt trauma

The present study was performed to identify the factors associated with amputation in patients with blunt injuries to the lower limb associated with arterial injury. The ability of a scoring system to predict the outcome was tested.

There were 122 lower limb arterial injuries in 119 patients treated at the Royal Adelaide Hospital in the years 1962-1994. Prognostic factors considered were the site of the injury, the severity of the soft-tissue injury and shock, the presence of associated injuries and a description of the bone or joint injury. The mangled extremity severity score (MESS) was calculated retrospectively for each patient.

The outcome was primary amputation in 27 patients, delayed amputation in 36 patients and limb salvage in 59 patients. The seven deaths were all due to associated injuries. Factors associated with amputation were the severity of shock and soft-tissue injury (P < 0.01), and tibial artery injury compared with more proximal injury (P < 0.001). Factors that did not affect outcome included delay before repair, method of fracture fixation, or performance of fasciotomy. Amputation was performed in 48/71 (68%) patients with Gustilo type-IIIC fractures of the tibia. Applying the MESS to our patients resulted in a positive predictive value (PPV) of 71%, a negative predictive value (NPV) of 84% and an overall accuracy of prediction of 75%.

The major factor determining outcome was the severity of the soft-tissue injury. Progressive necrosis and infection was a major cause of late amputation. The MESS is not sufficiently precise to allow the decision regarding amputation to be made at the initial operation.