The calcaneofibular ligament runs from the anterior border of the lateral malleolus to the lateral surface of the calcaneus (Fig. 168.1). Also known as the fibulocalcaneal ligament, the calcaneofibular ligament is susceptible to strain at the joint line or avulsion at its origin or insertion. The calcaneofibular ligament is frequently injured from inversion injuries to the ankle that occur when tripping when high heels, stepping off a high curb, landing hard or running on hard uneven surfaces, and during dancing, soccer, and basketball. The pain of calcaneofibular ligament damage is localized anterior and inferior to the lateral malleolus and is made worse with inversion of the ankle joint. Point tenderness just below and behind the lateral malleolus is often present on physical examination. Significant swelling and ecchymosis is often evident after acute injury. Activity, especially involving weight bearing, plantar flexion, and inversion of the ankle, will exacerbate the pain. Local heat and decreased activity as well as elevation of the affected ankle may provide a modicum of relief. Sleep disturbance is common in patients suffering from trauma to the calcaneofibular ligament of the ankle. Coexistent fracture, bursitis, tendonitis, arthritis, or internal derangement of the ankle may confuse the clinical picture after trauma to the knee joint making clinical diagnosis difficult.

Plain radiographs and/or arthrography is indicated in all patients who present with calcaneofibular ligament pain, especially after ankle trauma (Fig. 168.2). Based on the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging and/or ultrasound imaging of the ankle is indicated if internal derangement or occult mass or tumor is suspected as well as to confirm the diagnosis of suspected calcaneofibular ligament injury (Figs. 168.3 and 168.4). Bone scan may be useful to identify occult stress fractures involving the joint, especially if trauma has occurred.

The ankle is a hinge-type articulation between the distal tibia, the two malleoli, and the talus. The articular surface is covered with hyaline cartilage, which is susceptible to arthritis. The joint is surrounded by a dense capsule that helps strengthen the ankle. The joint capsule is lined with a synovial membrane that attaches to the articular cartilage. The ankle joint is innervated by the deep peroneal and tibial nerves.

The major ligaments of the ankle joint include the talofibular, anterior talofibular, calcaneofibular, and posterior talofibular ligaments, which provide the majority of strength to the ankle joint. The calcaneofibular ligament is not as strong as the deltoid ligament and is susceptible to strain. The calcaneofibular ligament runs from the anterior border of the lateral malleolus to the lateral surface of the calcaneus (see Fig. 168.1).

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 lateral curledup position (Fig. 168.5). The skin over the lateral malleolus

and heel overlying the calcaneofibular ligament is then prepped with antiseptic solution. A sterile syringe containing 2.0 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 then placed in the longitudinal position with the superior aspect of the transducer placed just over the bottom of the lateral malleolus with the superior aspect of the transducer rotated toward the anterior ankle with the inferior aspect of the transducer pointed at the calcaneus (Fig. 168.6). A survey scan is taken, which demonstrates the hyperechoic calcaneofibular ligament running from the lateral calcaneus to the lateral malleolus of the fibula (Fig. 168.7). After the calcaneofibular ligament is identified, the needle is placed through the skin ˜1 cm above the middle of the anterior aspect 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 to place the needle tip within proximity to the calcaneofibular ligament but not within the substance of the ligament (Fig. 168.8). When the tip of needle is thought to be in satisfactory position, a small amount of local anesthetic and steroid is injected under real-time ultrasound guidance to confirm that the needle tip is not within the substance of the calcaneofibular 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.