Impact of Time to Re-vascularization on Patients with Avascular Lower Extremity Open Fractures.

Objectives: To evaluate the impact of time to revascularization on nonunion, deep surgical site infection (SSI), and amputation in Gustilo-Anderson (GA) Type 3C open lower extremity fractures.

Methods: Design: Retrospective cohort review.

Setting: Single, academic, level-1 trauma center.

Patient selection criteria: Patients aged 18-79 years with GA type 3C open lower extremity fractures and documented avascularity at presentation, treated at a level-1 trauma center between 2016 and 2022 with either immediate amputation or revascularization (direct primary repair, graft reconstruction, or temporizing shunt) and osseous fixation were included. Exclusion criteria were initial admission to another facility, death prior to initial surgery, and unavailable injury time (based on 911 call time in EMS reports).Outcome Measures and Comparisons: The primary outcome was amputation. The secondary outcome was limb salvage with complication, defined as nonunion or deep surgical site infection (SSI). The primary exposure was time from injury to restoration of distal arterial flow. For patients with temporary shunts, this was used as the time to restoration of flow. Multinomial logistic regression was used to evaluate associations between revascularization times and outcomes, adjusting for American Society of Anesthesiologists (ASA) score, sex, and smoking status. Mean times to revascularization were compared among outcome groups (delayed amputation, limb salvage without complication, and limb salvage with complication).

Results: Forty-five patients (46 limbs) were included: 10 (21.7%) underwent limb salvage without complication (median age 25 years, 100% male), 9 (19.6%) underwent limb salvage with complication (median age 36 years, 89% male), 12 (26.1%) underwent delayed amputation (median age 52 years, 67% male), and 15 (32.6%) underwent acute amputation without revascularization (median age 49 years, 60% male), most commonly due to irreparable popliteal or trifurcation-level vascular injuries with severe soft tissue loss. Of the 31 revascularized limbs, 12 (39%) required delayed amputation a mean 18 days post-injury. Nineteen limbs (19/46, 41%) were ultimately salvaged; nine (47% of salvaged; 20% overall) developed nonunion or deep SSI (limb salvage with complication). Mean time to revascularization was 277 minutes for limb salvage without complication, 430 minutes for delayed amputation (mean difference 153 minutes; 95% CI, 48 - 259, p<0.01) and 390 minutes for limb salvage with complication (mean difference 113 minutes; 95% CI, 15 - 211, p=0.03). Each additional hour of ischemia increased the odds of delayed amputation by 3.4-fold (95% CI, 1.1-10.6; p=0.04). When time to revascularization exceeded 6 hours, the probability of limb salvage without complication decreased to 12% (95% CI, 0-25%). ASA classification, DM, HTN, depression/anxiety, smoking, and obesity did not significantly predict likelihood of delayed amputation, nonunion, or deep SSI (p=0.36, 0.81, 0.49, 0.22, 0.23, and 0.66, respectively).

Conclusions: In this cohort of patients with avascular GA Type 3C open lower extremity fractures, prolonged time to revascularization was associated with delayed amputation and limb salvage complications (nonunion, and deep SSI). Revascularization beyond 6 hours of ischemia time was fraught with complications.

Level of evidence: Prognostic Level III.