Posttraumatic pseudoaneurysm of popliteal artery following total knee arthroplasty
An 82-year-old female was subjected to right TKA for severe osteoarthritis. Right TKA was done using mobile-bearing knee prosthesis (DePuy, Warsaw, Indiana, USA) [Figure and ]. Anterior midline incision with a medial parapatellar arthrotomy approach was used. Total joint was replaced using the standard technique and patellar resurfacing was done. The operation proceeded without any apparent intraoperative complication. Postoperative rehabilitation was started on the 1st postoperative day and consisted of static exercises and continuous passive motion. For postoperative analgesia, IV Fentanyl patient controlled analgesia (PCA) dose 1.5 ml/h, along with intravenous paracetamol (1 g) thrice daily was used. On the 3rd postoperative day, she was disoriented, agitated, and had a fall while trying to get up from bed. The passive range of motion (ROM) was not affected following fall and there was no increase in swelling or hematoma formation. Disorientation continued, and on the 4th postoperative day, she had accidental fall again. She gave a significant history of direct blunt injury to the popliteal fossa with the railing of the bed. Clinically knee was not affected. Electrolyte levels were normal. Hemoglobin dropped from 8.4 gm% (1st postoperative day) to 6.7 gm%, and she was given packed blood cells.\nOn the 6th postoperative day, patient complained of swelling and severe pain in her calf, refusing to move her right lower limb. Swelling extended from popliteal fossa up to midcalf region and was nonpulsatile. Homan's sign was positive and squeezing of calf was very painful. Distal pulsations were well felt without any neurological deficit. Deep vein thrombosis (DVT) was suspected. Venous Doppler examination of the right lower limb was done, which showed no evidence of DVT. While doing the venous Doppler, the radiologist suspected an arterial injury. The arterial Doppler showed a pseudoaneurysm of the right popliteal artery, of size 3.9 × 2.6 cm, with hematoma collection extending into calf [Figure and ]. Computed tomography (CT) angiography was done for further evaluation and suggested extensive wall calcification of the abdominal aorta and iliac arteries. A 3 × 2.5 cm pseudoaneurysm in relation to the right popliteal artery just above the knee joint was seen []. Distal runoffs were present and distal vascularity was good [].\nVascular surgeon opined the need for repair of the rent in the artery causing the aneurysm. A repeat ultrasonographic examination done the next day did not show any increase in the size of the aneurysm. Exploration of the artery was done on 7th postoperative day. Considering the location of false aneurysm, the vascular surgeon decided to go posterior. On exploration, there were significant clots and the rent was found on the posterior surface of the artery of size 2 × 2 mm. The rent in the artery was repaired with 6-0 prolene. The rent was not on the anterior aspect, indicating that the injury to the artery was as a result of the impact on the popliteal region due to a fall in the immediate postoperative period and not an intraoperative incident as is seen in most of the reported cases of popliteal pseudoaneurysm following TKA. After 12 months, the patient remained asymptomatic without any vascular problems. On followup, she had well felt distal pulsations without any clinical evidence of pulsatile swelling in popliteal area. She refused to do followup Doppler or CT angiography.