Knee dislocations and popliteal artery injury: A single centre experience from Karachi.

OBJECTIVE To determine the association of popliteal artery injury with simple knee dislocations or knee fracture dislocations, and to evaluate the role of clinical assessment and colour Doppler ultrasound examination in diagnosing these injuries. METHODS The prospective case series study was done at the Liaquat National Hospital, Karachi, and comprised patients with simple knee dislocations or knee fracture dislocations presenting between February 2013 and April 2014. All patients underwent clinical assessment including distal pulse examination and signs of vascular trauma. Following reduction of dislocation, repeat clinical examination and assessment of limb with colour Doppler ultrasound was carried out. RESULTS Out of 9 patients in the study, 6(66.7%)had simple dislocations, while 3(33.3%) sustained fracture dislocations of the knee. Two (22%) patients sustained injury to the popliteal artery which was effectively managed via surgical treatment. Clinical examination of the affected extremities effortlessly revealed the 2(22%) vascular trauma cases. Doppler ultrasound was carried out in 8(89%) cases and it successfully excluded 7(78%) cases for vascular trauma and identified 1(11%) injury with reduced flow. This case underwent computed angiography scan and later surgery revealed popliteal artery trauma. Doppler ultrasound was not carried out in 1(11%) case which was a spontaneously relocated knee with hard signs of vascular injury. CONCLUSIONS Popliteal artery injury can be a limb-threatening complication following trauma to the knee. Carefully performed clinical examination and colour Doppler ultrasound are effective tools for identification of such cases.