Outcome Predictors in Traumatic Popliteal Artery Injury

BACKGROUND: In the last century, significantly reduced amputation rates in patients with traumatic popliteal artery injury have been achieved with improved revascularization techniques; however, failed revascularization remains a vexing problem for clinicians and has a devastating outcome for patients. We reviewed our experience with popliteal artery injuries at a civilian Level I Trauma Center. The objective of the current study is to document the mechanism of popliteal artery injury, methods of repair, and to determine risk factors for amputation.
METHODS: From January 2002 to June 2009, 68 patients with popliteal artery injuries were identified in the Trauma Registry. We conducted a retrospective chart review documenting age, mechanism of injury, associated orthopedic injury, venous injury, use of fasciotomy, mangled extremity severity score (MESS), and injury severity score (ISS). Univariate and multivariate analysis was performed to determine risk factors for amputation.
RESULTS:
70 popliteal artery injuries were identified in 68 patients. Median age was 33 years (range=5,88). 57 (81%) patients were male. 51 (73%) injuries resulted from blunt trauma. Associated venous injuries were present in 16 (23%) cases. Associated orthopedic injuries included 19 (27%) dislocations and 49 (70%) fractures. Median MESS was 5 (range= 2,9) and median ISS was 9 (range=4,41). 15 (21%) patients required amputation: 8 (11%) primary and 7 (10%) secondary. Revascularization was performed in 62 cases (89%). 23% of patients had documented compartment syndrome and 56% of patients underwent fasciotomy.
Univariate analysis was calculated for each predictor variable. Four variables were significantly associated with amputation: MESS (OR=2.44, p<0.0001);ISS>10 compared to ISS<9 (OR=7.41, p<0.0429); blunt injury (OR=10.69,p=0.0088), and fractures (OR=0.13, p<0.0437). Using multiple exact logistic regression, MESS (p<0.05) was the only significant predictor of amputation. The increased odds of amputation was similar for both primary (OR=2.60, p=0.001) and secondary (OR=2.39, p=0.002) amputations.
CONCLUSION: Patients with traumatic popliteal artery injury are at high risk for amputation. Blunt injury, associated fractures, MESS and ISS >9 were significantly associated with amputation. MESS was a significant predictor of amputation and should be considered if planning revascularization in these critically injured patients.