Injury to the popliteal artery and its anatomic location in total knee arthroplasty

Injury to the popliteal artery during total knee arthroplasty (TKA) is a de vastating complication. Although infrequent, these injuries can result in t he need for further surgery, including revascularization or possibly even a mputation. Several mechanisms are capable of producing direct trauma to the popliteal artery, including the use of posterior retractors. We investigat ed the proximity of the popliteal artery to the tibial joint surface during TKA to identify crucial steps in the procedure at which the artery was at highest risk for injury. TKA was performed on cadaveric specimens, and seri al intraoperative arteriograms were taken throughout the procedure, demonst rating the potential for arterial injury by the instrumentation. Additional ly, 50 transverse magnetic resonance imaging scans of unrelated knees were analyzed for the position of the popliteal artery relative to the midline o f the tibial plateau as well as at a level 5 to 10 mm below this, at the si te of a typical resection during TKA. All of the arteriograms showed the ar tery to be a lateral structure at the joint line. Additionally a posterior retractor placed the artery at risk when it was placed in a position latera l to the posterior cruciate ligament or when it was injudiciously inserted more than 1 cm into the soft tissues. Hyperextension of the knee, which mig ht occur during preparation of the patella, produced dramatic tenting of th e artery over the posterior joint line. These results demonstrate that the popliteal artery is at significant risk during TKA, particularly if posteri or retractors are placed in a position lateral to the midline of the joint. Both hyperflexion and especially hyperextension produced severe deformitie s and kinking of the artery and would particularly jeopardize an artery wit h atherosclerosis. Our findings suggest that the popliteal artery may be at least risk during TKA if posterior retractors are placed medial to the mid line of the tibial plateau and if care is taken to avoid extremes of both f lexion and extension.