Identifying A Dancer's Chronic Ankle Pain
A patient comes into the office with pain in the posterior aspect of her ankle. She doesn’t recall injuring the leg, but notes she has had the pain for over six months and that it is present at all times. An active dancer with the local ballet company, the patient adds that she experiences chronic pain when doing any form of dancing. She says the pain is far worse with high heels and ballet shoes en-pointe, but finds it more tolerable when wearing stable flat shoes. The pain is deeper than the superficial Achilles tendon region and does not radiate to any region. An examination of the patient reveals a normal vascular examination with biphasic pulses of both the dorsalis pedis and tibial arteries. The dermatologic exam shows minimal edema or erythema. There is a small effusion of edematous region medial to the Achilles tendon on the medial ankle region. This region is slightly erythematous, yet the erythema decreases with elevation of the leg. The medial ankle is also slightly painful to touch. Although there is no loss of sensation or positive Tinnel’s sign of the tibial nerve, the patient does have some localized burning in the region of the tibial nerve medial to the Achilles tendon. The musculoskeletal examination shows minimal pain in the Achilles insertion or central portion. There is some edema and pain medial to the Achilles just proximal to the insertion of the tendon on the calcaneus. There is pain with pressure on the posterior and medial aspect of the ankle joint. Range of motion of the hallux does not cause pain, yet the patient says she feels a “clicking of something” on the posterior ankle. Ranges of motion of the ankle and foot are within normal limits. The patient has a slight gastrocnemius equinus, but this is not severe or irritating to the patient. The ankle is more painful when it is placed in plantarflexion and range of motion of the hallux is being performed. Radiographs of the ankle and foot show no deformity or bony injury. There is no fracture and there are no signs of arthritic changes to the foot or ankle. What Is The Probable Diagnosis? 1. Achilles tendonitis/ tendinosis 2. Tarsal tunnel syndrome 3. Osteochondral lesion of the medial ankle 4. Shepard’s fracture of the posterior talus process 5. Flexor hallucis tenosynovitis/ stenosis Diagnostic Answers Achilles tendonitis and tendinosis are possible but in this case, it’s very rare. The patient’s pain is deep to the Achilles and she has no pain with pressure of the Achilles region. With Achilles pain, you’ll often see bulbous swelling of the tendon, usually in the central watershed area. Although Achilles tendonitis may present without a great deal of swelling, the pain the patient has with range of motion of the hallux is rare in Achilles tendonitis cases. This patient also notes some burning of the medial ankle, yet does not have any Tinnel’s signs. There is also no pain with compression of the tarsal tunnel region. If this were of great concern, you could obtain an MRI to rule out a foreign material in the tunnel and also perform a nerve conduction study to see if there are any signs of compression at the tunnel region. When it comes to tarsal tunnel cases, it’s important to rule out compression and disc injury to the lower back. An osteochondral lesion of the ankle is possible. There is edema and pain in the medial ankle region, but there is also pain with hallux range of motion, which is not in line with this ailment. Osteochondral lesions are also related to a twisting injury to the ankle, which this patient did not have. Obtaining an MRI or CT scan can be helpful in ruling out this ailment. The most common injury and cause of pain in this case would be either a Shepard’s fracture or a flexor dysfunction. Patients with flexor hallucis dysfunction commonly have chronic pain with an increase in pain after activity. They essentially have the pain all of the time but they don’t have any feeling of weakness. There is pain to dorsiflexion of the hallux and palpation of the posterior ankle. Often, these patients will also complain of a “sticking” or popping feeling in the posterior ankle. A Shepard’s fracture of the posterior process of the talus is also associated with an acute injury. In this case, it may be due to en-pointe dancing that causes compression of the posterior process of the talus at the ankle level. Often, these patients will notice the pain following an acute injury, which is often a forced plantarflexion of the ankle causing the posterior talus to get crushed between the calcaneus and posterior ankle. They may experience pain with range of motion of the flexor hallucis tendon during dorsiflexion of the hallux. They will also feel pain with direct pressure on the posteromedial ankle. The region of pain is usually chronic and grows worse with sports or activity, yet weakness is not a common finding. Our patient has the proper presentation for both of these symptoms. Diagnosis And Treatment In order to rule out either problem, an MRI is an ideal test. It will show possible stenosis of the flexor hallucis tendon and also show edema and fracture of the posterior talus. After the MRI, if you still have concerns about a possible Shepard’s fracture and cannot see it on radiographs, it may be helpful to get a CT scan. Furthermore, performing a diagnostic intralesion injection of dye within the flexor hallucis sheath can show blockage level of the flexor tendon at the site of stenosis. In this case, the MRI was positive for a flexor hallucis dysfunction/stenosis. This is a commonly missed problem in patients who present with posteromedial ankle pain. Often, an MRI will show edema and fluid collection in the posterior ankle. There may also be fluid in the flexor hallucis tendon sheath distal to the site of stenosis. The site of stenosis is posterior to the ankle in the region of the posterior talar process. Although stenosis is possible with a Shepard’s fracture, in most cases, you’ll find the stenosis is due to thickening and scarring of the posterior sheath of the flexor tendon at an impingement site of the posterior talar process. In certain cases, you’ll find the MRI to be non-diagnostic and a tenogram is preferable. Be aware that a tenogram is very difficult to perform and very radiologist-dependent. The tendon sheath is injected with dye and stenosis of dye is noted on the posterior talar process in cases of flexor dysfunction. When it comes to flexor hallucis dysfunction, you would commonly use surgical treatment. A three- to four-week course of physical therapy including massage, range of motion and antiinflammatory modalities may be helpful and relieve symptoms. Often, this is short lived due to the chronic stenosis and a decompression of the flexor sheath is needed. To perform the decompression, make an incision just medial to the Achilles tendon. Take care to protect the neurovascular bundle, which is slightly anterior and superficial to the flexor hallucis longus tendon. Identify the tendon and release the superficial sheath. Once you’ve released the sheath, place the tendon through range of motion by moving the hallux into dorsiflexion. In severe cases, the tendon may be scarred to the posterior ankle or talus and you may need to free it. Once you’ve freed the tendon, close the subcutaneous tissue and skin. Cast the patient for two weeks and then have the patient emphasize physical therapy once wound healing has occurred. The patient should be able to return to weightbearing at four weeks and may return to sports activity at about eight weeks. Physical therapy is essential for good outcomes and must entail range of motion, strengthening and balancing activity. Dr. Baravarian is an Assistant Clinical Professor in the Department of Surgery/Division of of Podiatric Surgery of the UCLA School of Medicine.