Importance of Early Diagnosis and Care in Knee Dislocations Associated with Vascular Injuries.

Background: Arterial injury secondary to acute knee dislocation (KD) is a rare but devastative complication. The aim of this study is to evaluate functional sequelae and factors of poor prognosis.

Methods: A retrospective monocentric series of consecutive KD with acute ischemia by popliteal artery injury was analyzed between 2005 and 2017. The main outcome was the amputation rate.

Results: Sixteen dislocations were included. Nine (56%) were due to public road accidents, 5 (31%) were due to falls from height, and 2 (13%) were due to sports injuries. Dislocation had occurred in the posterior location in 8 (50%) cases. Regarding arterial injury, there were 7 (44%) ruptures, 7 (44%) dissections, and 2 (13%) isolated thromboses. Eleven (69%) KDs with vascular trauma were associated with signs of acute ischemia. Revascularization was achieved by anatomical venous bypass in 14 (88%), resection and direct anastomosis in one (6%), and isolated thrombectomy in one (6%). Median time to surgery (time between trauma and vascular repair) was 7 hours (3.25-60.92 hours). Primary revascularization was performed in 12 (75%) cases. In three cases (19%), orthopedic reduction and stabilization were performed first. In one case, (6%) three-step management with vascular shunt at first, then with knee stabilization, and finally vascular bypass was carried out. Stabilization was achieved by using an external fixator in 13 (82%) cases, by open reduction and internal fixation in one case (6%), by ligamentoplasty in one (6%), and by using a long leg cast in one (6%). Fasciotomy was required in 12 (75%) cases. Two patients had early vascular complications, and 2 had early systemic complications. Three secondary transfemoral amputations were performed. Median follow-up duration was 23 months. No secondary amputation was recorded. At the end of follow-up, functional outcomes were evaluated using the Oxford Knee Score (OKS). The median OKS was 30 versus the pretrauma median OKS of 47 (P < 0.00028). No risk factor associated with limb amputation has been highlighted.

Conclusions: Analysis of these results provided indications for therapeutic management of this condition. This study shows poor functional outcomes because of severity of vascular lesion in patients with orthopedic trauma but with healthy arteries.