Ankle osteochondral lesions are defined as the separation of a fragment of articular cartilage (i.e., cartilage lining the bone), with or without subchondral bone (i.e., bone underneath the cartilage) of the talus. Ankle osteochrondral lesion of the talus is an important cause of residual pain, particularly with weight-bearing, after a severe ankle sprain. Symptoms include impaired function, limited range of motion, joint and muscle stiffness, joint catching, locking and swelling may be present. Walking, working and performing sporting activities can be severely compromised in these individuals.
History of Ankle Osteochondral Lesions
Osteochondral fractures of the talar dome usually occur in presentations of ankle sprain when there is a compressive component to the inversion injury, for example when landing from a jump and rolling on the outer surface of the ankle. The talar dome is compressed by the end part of the tibia (i.e., tibial plafond), leading to damage of the osteochondral surface. The lesions mostly affect the superomedial (i.e., top and inner part) corner of the talar dome.
Causes of Ankle Osteochondral Lesions
- Stage I. In normal biomechanics, the foot is inverted (i.e., turned inwards) on the leg, the lateral or outer border of the talar dome is compressed against the face of the fibula (i.e., the outer shin bone), while the collateral ligament remains intact.
- Stage II. Further inversion ruptures the lateral ligament and may cause avulsion (i.e., shear force from ligament fractures bone) at its attachment.
- Stage III. The lateral ligament can then completely detached, but remain in place.
- Stage IV. If inversion forces are strong enough, there is compete detachment with displaced. With this excessive invertion force, the talus is rotated laterally within the joint, impacting and compressing the talus against the fibula.
Signs and Symptoms of Ankle Osteochondral Lersions
Large fractures are often identified at the time of injury. The fracture will be tender to touch, sometimes swollen soft tissue, and evident on plain x-rays. However, talar osteochondral lesions are often not picked up initially and the patient presented later with unremitting ankle aching and locking and catching, despite management of ankle sprain. Patients usually give a history of initially progressing well following a sprain, but then develop symptoms of increasing pain and swelling, reduced range of motion, stiffness and perhaps catching or locking as activity is increased.
The reason why a talar osteochrondral lesion causes these symptoms is poorly understood. However, it is thought that a small spot of bone loss causes a loss in structural support in the talar bone and ankle joint, causing cyclical changes in bone pressure with walking, which triggers pain receptors in the subchondral bone.
Treatment of Ankle Osteochondral Lesions
The treatment of ankle osteochondral lesions of the talus is multimodal and complex, and many non-surgical and surgical options including marrow stimulation techniques and tissue transplantation have been reported on in the scientific literature. All treatment options have some limitations, mainly because of the poor regenerative capacity of the articular cartilage and limited access to the ankle joint.
Chronic (i.e., longstanding) grade 1 or 2 lesions should be treated conservatively. Lesions which involve painful clicking, locking or the sense of the joint giving way that persist after 2-3 months of conservative management will require medical intervention. Medical intervention may include arthroscopy to remove or fix loose bodies within the joint.
1. Short-term conservative measures include:
- soft tissue massage
- electrotherapy (e.g., ultrasound)
- anti-inflammatory medication
- ice or heat treatment
- joint mobilisation
- ankle taping and bracing
- activity modification advice
- the use of a protective boot
2. Long-term conservative measures with the best evidence-base include:
- triple-phase rehabilitation (i.e., acute, subacute, advance/functional phases)
- graded and gradual weight-bearing protocol
- biomechanical correction of the foot and ankle to improve flexibility
- a gradual return to activity program
- closed-chain balance and proprioception activities with peroneal muscle strengthening to
- improve neuromuscular control (e.g., balance) of the ankle, preventing recurrence
As the treatment for ankle osteochondral lesions is multimodal, it is common for patients to trial several conservative measures in unison. If there is no sign of improvements, further investigation is required. X-ray, CT scan, MRI or a review by a specialist who can advise on any procedures that may be appropriate to improve the condition. A review with a podiatrist may also be indicated for the prescription of orthotics and appropriate footwear advice.
Please visit our website and blog page for more information on ankle and foot conditions:
- Injury Prevention, Ankle Biomechanics & Footwear in Runners
- Ottawa Ankle Rules
- Ankle & Foot Overview
- Lateral Ankle Sprain
- Medial Ankle Sprain
- Bruised Heel
- Broken Heel Bone (Calcaneal Fracture)
- Athletes Foot
- Ingrown Toenail
- Heel Spurs
- Extensor Tendonitis
- Acute Metatarsal Fracture
- Stress Fractures
- Achilles Tendon Rupture
- Achilles Tendonitis
- Anterior Ankle Impingement
- Calf Muscle Tear