Safe Zone for the Descending Genicular Artery in the Midvastus Approach to the Knee

Abstract

Minimally invasive total knee arthroplasty is performed using a modified version of the standard total knee arthroplasty without complete knee exposure. Traditional medial parapatellar arthrotomy has been criticized because it may disturb patellar blood flow and the extensor mechanism. Devascularization of the patella leading to osteonecrosis places the patella at risk for fracture. Alternative vastus-orientated approaches have the potential to preserve the descending genicular artery. Although this arterial supply to the patella potentially can be compromised throughout surgery, it is particularly vulnerable during deep dissection and arthrotomy. Knowledge of the anatomic course of the descending genicular artery would likely be helpful in its preservation. We investigated the course of the descending genicular artery and its entry angle to peripatellar network to determine the distance between the artery and superomedial patella during medial parapatellar arthrotomy and proximal capsular release. We dissected the descending genicular artery in 15 cadaveric knees. The average entry angle was 32.6 degrees , and the average distance between the descending genicular artery and superomedial pole of the patella during parapatellar arthrotomy was 13.5 mm. The safest distance for splitting the vastus medialis during median parapatellar arthrotomy was 15 mm from the superior pole of the patella because of the course of the descending genicular artery.

Radiological assessment of the safe zone for medial minimally invasive plate osteosynthesis in the distal femur with computed tomography angiography

“…Basarir et al [16] found a 208-408 entry angle of the DGA to the superomedial pole of the patella in defining a safety zone for the midvastus approach for total knee arthroplasty. Visser et al [17] reported similar angles of the DGA, which was easily recognisable during the limited subvastus approach for the distal femur closing wedge osteotomy in their cadaveric study.…”

Patellar blood flow during knee arthroplasty surgical exposure: Intraoperative monitoring by laser doppler flowmetry

“…3,10,11 Midvastus approaches to the knee joint gained popularity because the descending genicular artery is preserved. 23 Limited soft tissue dissection in less invasive knee arthroplasty also avoids splitting of the rectus and limits disruption of patellar blood supply. But, also after standard medial parapatellar arthrotomy, we have found no significant decrease of patellar blood supply.…”

Osteonecrosis of bipartite patella following total knee arthroplasty without lateral release

“…Medial parapatellar arthrotomy is the most popular approach technique for TKA and is known to be safe. However, an interruption to the blood supply from the medial circumflex arterial network may occur with the medial parapatellar arthrotomy approach 4 . Nicholls et al 5 reported a patellar blood flow reduction of 53% after a medial parapatellar arthrotomy.…”