The coronary ligaments, which are also known as the meniscotibial ligaments, are thin fibrous bands that serve to anchor the medial meniscus to the tibial plateau. The coronary ligaments are direct extensions of the joint capsule (Fig. 139.1). These ligaments are most commonly damaged when the knees are subjected to trauma from forced rotation with the medial coronary ligaments damaged much more frequently than their lateral counterparts. Patients with medial coronary ligament damage present with pain over the medial joint and increased pain on passive external rotation of the knee. Flexion and external rotation of the knee when carrying out the activities of daily living will cause an exacerbation of the patient’s pain. Rest and heat may provide some relief. The pain associated with damage to the medial coronary ligaments is characterized as constant and aching and may interfere with sleep. Coexistent bursitis, tendonitis, arthritis, or internal derangement of the knee, in particular the medial meniscus, may confuse the clinical picture after trauma to the knee joint.

Plain radiographs are indicated in all patients who present with coronary ligament syndrome pain. Based on the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, sedimentation rate, and antinuclear antibody testing. MRI of the knee is indicated if internal derangement or occult mass or tumor is suspected as well as to confirm the diagnosis of coronary ligament damage or meniscal tears (Fig. 139.2). Bone scan may be useful to identify occult stress fractures involving the medial joint, especially if trauma has occurred.

The rounded condyles of the femur articulate with the condyles of the tibia below and the patella anteriorly. The articular surface is covered with hyaline cartilage, which is susceptible to arthritis. The joint is surrounded laterally and posteriorly by a capsule, which provides support for the joint. As extensions of the joint capsule, the coronary ligaments are thin bands of fibrous tissue that anchor the medial meniscus to the tibial plateau (see Fig. 139.1). The capsule is absent anteriorly and in its place is the suprapatellar and infrapatellar bursa. Laterally and medially, the joint is strengthened by the tendons of the vastus lateralis and medius muscles. Posteriorly, the joint is strengthened by the oblique popliteal ligament. Also adding to the strength of the joint are a variety of extracapsular ligaments, including the medial and lateral collateral ligaments and the ligamentum patellae anteriorly and the oblique popliteal ligament posteriorly. Within the joint capsule, there are also a variety of ligaments that add to the strength of the joint, including the anterior and posterior cruciate ligaments (Fig. 139.3). The joint capsule is lined with a synovial membrane that attaches to the articular cartilage and gives rise to a number of bursae, including the suprapatellar and infrapatellar bursae. The knee joint is innervated by the femoral, obturator, common peroneal, and tibial nerves. In addition to arthritis, the knee joint is susceptible to the development of tendonitis, bursitis, and disruption of the ligaments, cartilage, and tendons.

The benefits, risks, and alternative treatments are explained to the patient and informed consent is obtained. The patient is then placed in the supine position with the lower extremity externally rotated (Fig. 139.4). The skin overlying the medioposterior knee is then prepped with antiseptic solution. A sterile syringe containing 4.0 mL of 0.25% preservative-free bupivacaine and 40 mg of methylprednisolone is attached to a 1½-inch, 22-gauge needle using strict aseptic technique. A high-frequency linear ultrasound transducer is placed over the medial coronary ligament joint in the oblique longitudinal plane with the superior portion of the ultrasound transducer turned about 20 degrees toward the patella (Fig. 139.5). A survey scan is taken, which demonstrates the characteristic appearance of the medial joint space with the hyperechoic medial margins of the femur and the tibia with the thick hyperechoic filaments of the medial collateral ligament overlying the triangular-shaped medial meniscus (Fig. 139.6). The medial meniscus is visualized as a triangular-shaped hyperechoic structure resting between the bony medial margins of the femur



and tibia (Fig. 139.7). At the superior margin of the hyperechoic medial margin of the tibia lies the medial portion of the coronary ligaments (Fig. 139.8). After the medial margin of the tibia is identified, the needle is placed through the skin ˜1 cm above the middle of the longitudinally placed transducer and is then advanced using an out-of-plane approach with the needle trajectory adjusted under real-time ultrasound guidance until the needle tip lies in proximity to the junction of the medial meniscus as it abuts against the superior tibial margin (Fig. 139.9). When the tip of needle is thought to be within satisfactory position, a small amount of local anesthetic and steroid is injected under real-time ultrasound guidance to confirm that the needle tip is next to the medial coronary ligament. There should be minimal resistance to injection. After intra-articular needle tip placement is confirmed, the remainder of the contents of the syringe is slowly injected. If synechiae, loculations, or calcifications are present, the needle may have to be repositioned to ensure that the entire intra-articular space is treated. The needle is then removed, and a sterile pressure dressing and ice pack are placed at the injection site.