June 2013 Case Study. Author: T. Walker Robinson, MD, MPH, Nationwide Children s Hospital

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1 June 2013 Case Study Author: T. Walker Robinson, MD, MPH, Nationwide Children s Hospital Chief Complaint: Right ankle pain HPI: A 10 year old female dancer presents to the clinic with a five day history of right lateral ankle pain after striking her foot on a brick while playing tag outside her home. After the injury, she was unable to continue playing, and limped home. There was mild swelling reported laterally over the subsequent hours. She iced the ankle several times, but reported worsening pain over the subsequent 4 days, to the point that she needed crutches. On a side note, as you are walking out of the room, the mother mentions that the patient has been complaining of chronic right medial ankle pain over the past six months. The chronic pain is described as insidious, with no clear precipitating injury. It has been intermittent in frequency, with periods of no pain. The patient reports occasional locking of her ankle and the mother notes that she occasionally limps during these painful episodes. She has been able to keep up competitive dancing through this pain. There is no history of previous injuries to the right ankle. Physical Exam: GENERAL APPEARANCE: well-appearing, age-appropriate, in no acute distress GAIT: antalgic SKIN: normal without rashes or lesions EXAMINATION OF THE RIGHT ANKLE: Inspection - mild, diffuse right ankle swelling overlying anterior and lateral ankle; ecchymosis over lateral ankle distal to fibula. Range of Motion/Strength Limited in plantar flexion, dorsiflexion, inversion and eversion secondary to pain Palpation Tender to palpation over ATFL, distal lateral and medial malleoli, distal fibular physis and talar dome. Special Tests - negative anterior drawer and talar tilt; syndesmotic squeeze test positive; unable to walk on toes, heels, or to hop secondary to pain NEUROVASCULAR: 2+ distal perfusion in her bilateral lower extremities, with capillary refill < 2 seconds; lower extremity sensation grossly intact Differential Diagnosis: Possible causes of ankle pain in this 10 year-old skeletally immature dancer include: ACUTE INJURY (1) ATFL sprain (2) Salter-Harris 1 fracture of the distal fibula/tibia (3) Base of the 5 th metatarsal fracture or avulsion (4) Other bony fracture (cuboid, 4 th or 5 th metatarsal) (5) Contusion (bony or soft tissue) (6) Peroneal tendon rupture (7) Syndesmotic sprain CHRONIC PAIN (8) Recurrent ligamentous sprain (ATFL, deltoid) (9) Tarsal coalition

2 Imaging: (10) Tendinitis (posterior tibial or peroneal) (11) Talar osteochondritis dissecans (OCD) (12) Inappropriately healed ankle fracture (13) Accessory navicular (14) Metatarsal or tarsal stress fracture

3 X-ray: Mortise and lateral view right ankle showed a shallow defect in the medial aspect of the talus measuring 9 mm by 8 mm, involving the medial articular surface and associated with sclerosis in the adjacent tibial articular surface.

4 Right Ankle MRI T2-weighted sagittal sequence demonstrated a 9 x 8 mm osteochondritis dissecans (OCD) lesion involving the cortex and subarticular bone of the talus at its medial and posterior articular surface, with no evidence of impending loose body. There was some loss of talar contour noted, but no disruption of overlying cartilage. Final/Working Diagnosis: Acute soft tissue contusion in the setting of chronic osteochondritis dissecans (OCD) of the talus Treatment: Immobilization with placement of a short-leg posterior splint (and later a short leg cast) for a total of 5 weeks, nonweight-bearing on crutches Outcome: Five weeks after her initial evaluation, the patient reported significant improvement in her pain. She was put in a walking boot, and began advancing her weight-bearing over the subsequent month with a goal of pain-free ambulation. At roughly 10 weeks from initial diagnosis, the patient was pain-free with ambulation out of the boot, and was started in physical therapy for strength, ROM, and proprioception. At six months post-diagnosis, she had been advanced back to all recreational activities by her physical therapist. Repeat X-rays at that six month follow-up visit showed essentially complete resolution of the previous posteromedial OCD lesion with normal talar contour. She was given permission to begin progressing back to competitive dance at that time.

5 Discussion: Osteochondritis dissecans (OCD) is a group of conditions affecting an articular surface that involves separation of a segment of cartilage and subchondral bone(1). It was first identified in the knee by Konig in 1883, and was later seen to occur in other bones such as the capitellum of the elbow and the talus of the ankle(2). The etiology of OCD is not clearly understood, though trauma, local ischemia, ossification defects, and genetic predisposition have been implicated. Arguments in the literature surrounding the presence of inflammation in OCD have led many to discount the term osteochondritis, instead substituting the terms osteochondral lesions to more appropriately classify this condition(3). OCD lesions are commonly classified as juvenile or adult forms of OCD, distinguished by the presence of open growth plates. Generally speaking, juvenile OCD has a better rate of bony healing with conservative (nonoperative) management than its counterpart in adult populations. Among pediatric patients, OCD lesions of the knee are most common, followed by the elbow and ankle. Juvenile OCD lesions are common in athletes, and as many as 60% of patients with OCD remember an inciting traumatic injury to the injured joint. Patients with osteochondral lesions typically describe dull, aching pain in the joint, with or without decreased range of motion, swelling, and intermittent locking episodes. As in our case above, patients often do not present until many months of nagging pain have passed. OCD lesions are typically graded radiographically as stages 1 through 4, with stage 1 characterized by articular surface damage only, stage 2 with cartilage injury and underlying bone fracture or edema, stage 3 with a detached (but not displaced) bony fragment under the articular surface, and stage 4 with a displaced subchondral bony fragment(4). Stage 4 lesions, as well as many stage 3 lesions, are typically treated

6 surgically, while initial conservative management is usually appropriate in stage 1 and 2 lesions, especially in pediatric patients. Talar OCDs make up 4% of the total OCD lesions in the pediatric population(3). There is a 2:1 male to female predominance amongst patients with talar OCD. These lesions are usually anterolateral or posteromedial in location, with the anterolateral ones more likely to result from acute trauma. Lateral lesions tend to be more shallow and more likely to heal conservatively than the often deeper, more medial lesions(5). Medial talar lesions are more common than lateral ones, with a prevalence of roughly 60% and 40% respectively (6, 7). Stable talar OCD lesions are typically treated conservatively, with some form of immobilization (partial weight-bearing vs. non-weight bearing in cast vs. walking boot) for 4-6 weeks followed by progressive weight-bearing over the subsequent 2-4 months. Case studies of stable talar OCD lesions in skeletally immature patients report success in as many as 90% of conservatively treated patients over 6-7 months(2, 8). Most patients with healed lesions after conservative management will not have any long-term sequelae of their condition, with no higher risk of long-term osteoarthritis of the ankle as compared to their peers(3, 8). Surgical management is outside the realm of this brief review, but many types of surgical procedures are utilized in failed conservative management (i.e. no healing of the lesion on follow-up radiographs within 6-12 months of diagnosis, persistent pain beyond 6-12 months of immobilization and subsequent therapy, and/or the development of an unstable OCD lesion) including excision with curettage, microfracture, bone grafting, osteochondral transplantation, and fixation(7). This case emphasizes the importance of being attentive to chronic issues in the setting of an acute injury. Had we been focused on the lateral soft tissue contusion and ignored the chronic symptoms, our patient may have been less successfully managed by conservative means. Chronic ankle pain in a young athlete is never normal, and must be investigated. In summary, juvenile talar OCD is a relatively rare condition which, with appropriate conservative management, can often heal completely without long-term sequelae. References: 1. Birrer RB, Griesemer BA, Cataletto MB. Pediatric Sports Medicine for Primary Care. Philadelphia, PA: Lippincott, Williams, & Wilkins; Madden CC, Putukian M, Young CC, McCarty EC. Netter's Sports Medicine. Philadelphia, PA: Saunders Elsevier; Santrock RD, Buchanan MM, Lee TH, Berlet GC. Osteochondral lesions of the talus. Foot Ankle Clin. 2003;8(1):73-90, viii. 4. Berndt AL, Harty M. Transchondral fractures (osteochondritis dissecans) of the talus. J Bone Joint Surg. 1951;41: Letts M, Davidson D, Ahmer A. Osteochondritis dissecans of the talus in children. J Pediatr Orthop. 2003;23(5): Naran KN, Zoga AC. Osteochondral lesions about the ankle. Radiol Clin North Am. 2008;46(6): , v. 7. Zengerink M, Struijs PA, Tol JL, van Dijk CN. Treatment of osteochondral lesions of the talus: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2010;18(2): Lam KY, Siow HM. Conservative treatment for juvenile osteochondritis dissecans of the talus. J Orthop Surg (Hong Kong). 2012;20(2):