Limb Salvage and Outcomes among Patients with Traumatic Popliteal Vascular Injury: An Analysis of the National Trauma Data Base

Philip Mullenix, General Surgery, Madigan Army Medical Center, Tacoma, WA; Scott Steele, MD, Minneapolis, MN; Charles Andersen, MD, Tacoma, WA; Benjamin Starnes, MD, Tacoma, WA; Ali Salim, Los Angeles, CA; Matthew Martin, MD, Los Angeles, CA;

Purpose: Popliteal vascular trauma carries the greatest risk of limb loss of any peripheral vascular injury. Few large recent series describe this uncommon and potentially devastating problem. The purpose of this study is to analyze a large cohort of patients suffering traumatic popliteal arterial injury from a national, multi-center trauma registry.
Methods: Retrospective analysis of prospectively collected trauma data from the National Trauma Data Bank (NTDB) of the American College of Surgeons. We studied all patients with popliteal arterial injury in terms of demographics, injury patterns, interventions, limb salvage, resource utilization, and outcomes.
Results: There were 1395 popliteal injuries identified among the >1M patients in the NTDB for an incidence <0.2%. They were 82% male, mean age 33 yrs, and presented with a mean initial SBP 124 mmHg, base deficit -4.6, injury severity score (ISS) 11.8, and extremity abbreviated injury score (AIS) 2.6. The mechanism was blunt in 61%, penetrating in 39%, and significant differences existed between the two groups (table). Associated ipsilateral lower extremity trauma included combined popliteal arterial and venous (AV) injuries (24%); femur (25%), knee (20%), or tib-fib (46%) fractures or dislocations; and sciatic, femoral, tibial or peroneal nerve injuries (14%). Fasciotomies were performed in 49%, complex soft tissue repairs in 24%, and amputations in 16% (AKA 8.5%; BKA 7.1%). The overall mean hospital and ICU lengths of stay were 16.9 and 5.9 days respectively. Discharge functional independence measures (FIM) for locomotion ranged from 1 (full assistance required) to 4 (independent ambulation), with a mean 2.8. In-hospital mortality was 4.5% and did not significantly differ by mechanism (4.9% blunt vs. 3.9% penetrating). Amputation rates were 15% with combined AV injuries; 21% for associated nerve injuries; 12% for major soft tissue disruptions; and 21% for femur, 12% for knee, and 20% for tib-fib fractures or dislocations respectively. Among the 312 patients with combined AV injuries, those with blunt mechanism had a significantly higher amputation rate than those with penetrating injury (27% vs. 9%, p<0.001). Adjusting for age, gender, mechanism, and overall physiologic impact of injuries sustained, independent predictors of amputation in logistic regression analysis of the entire cohort included fracture (odds ratio [OR] 2.4; 95% confidence interval [CI] 1.4 to 4.1), complex soft tissue injury (OR 1.9; 95% CI 1.2 to 3.0), nerve injury (OR 1.7; 95% CI 1.1 to 2.8), and extremity AIS (OR 1.6; 95% CI 1.2 to 2.2).
Conclusions: Popliteal vascular injury remains an uncommon but challenging clinical entity associated with significant rates of limb loss, functional disability, and mortality. Blunt vs. penetrating mechanism in particular is associated with longer hospital stays, worse functional oucomes, and twice the amputation rate.

Comparison of Study Variables by Mechanism (all p<0.05)