Review Question - QID 1076

Contrary to popular belief, the major blood supply to the ACL does not originate from its bony attachments. The ACL is supplied mainly by the vessels that originate from the middle genicular artery which leave the popliteal artery and directly pierce the posterior capsule (Illustration A). Branches enter the synovial membrane at the junction of the joint capsule distal to the infrapatellar fat pad. The ligament is ensheathed by the synovial plexus along its entire length. Smaller connecting branches penetrate the ligament and anastomose with a network of endoligamentous vessels that are oriented in a longitudinal direction and lie parallel to the collagen bundles within the ligament.

The vascular supply to the medial and lateral menisci of the knee originates predominantly from the lateral and medial genicular arteries (both inferior and superior). The middle genicular artery, along with a few terminal branches of the medial and lateral genicular arteries, also supplies vessels to the menisci through the vascular synovial covering of the anterior and posterior horn attachments.

The referenced study by Toy et al is a cadaveric study that reported ACL vascularization arises primarily from the middle genicular artery; the artery gives rise to periligamentous vessels which form a web-like network within the synovial membrane. They also found that the extremities of the ACL seem to be better vascularized than the middle part, and the proximal portion seems to have a greater vascular density than the distal portion.