Tarsus

Tarsal Osteochondritis Dissecans (OCD)

OCD is a developmental condition that affects the joints of young, rapidly growing dogs. It arises from a disturbance in when bones are forming from cartilage during skeletal growth. The condition typically affects large and giant breeds, with rapid growth rates and genetic predispositions playing crucial roles. Developmental factors, such as excessive nutrition, trauma, and hormonal imbalances, may contribute to the development of OCD lesions in the tarsal joint.

Clinical signs of tarsal OCD often present in young dogs, usually between 4 to 12 months of age. Common symptoms include lameness, intermittent or persistent joint swelling, and pain upon palpation. Dogs affected by tarsal OCD may exhibit a reluctance to bear weight on the affected limb, and in severe cases, joint instability may be observed.

Evidence of tarsal OCD lesions can often be seen on radiographs. These signs include subchondral bone defects, joint effusion, and the presence of loose cartilage fragments within the joint space. CT scans are often used to confirm the diagnosis and provide more detailed information about the extent and location of the lesions, aiding surgical planning if required.

The management of tarsal OCD lesions in dogs involves both conservative and surgical approaches. Conservative management may include rest, controlled exercise, weight management, and anti-inflammatory medications to alleviate pain and reduce inflammation. However, surgical intervention is may necessary for cases where conservative measures prove inadequate. Surgical options for Tarsal OCD may include debridement of the lesion (sometimes using arthroscopy). In cases of severe joint damage and/or subsequent osteoarthritis arthrodesis or joint replacement surgery may be considered. Post-operative rehabilitation and physiotherapy/hydrotherapy can help with recovery.

Plantar Ligament Degeneration

The plantar ligament is a structure that provides support to the underside of a dog foot allowing them to walk in an upright position. Failure of this support cause the foot to ‘collapse’ down towards the ground (this is described as a plantigrade stance). Plantar ligament degeneration commonly affects Shetland Sheepdogs and Collie breeds. Similar issues can be caused be trauma. A diagnosis can often be made following radiographs (sometimes including stressed views) though a CT scan may sometimes be performed. In most cases a partial tarsal arthrodesis (fusion) is performed to stabilise the joint.

Collateral Ligament Injuries

The collateral ligaments support either side of the tarsal joint. They can be damaged following trauma, sometimes in conjunction with soft tissue injuries (often following road traffic accidents). The soft tissue injuries can be extensive and require significant treatment before the orthopaedic injuries can be treated. In some cases, it is possible to repair/’replace’ the ligaments with sutures that stabilise the joint. If there is significant instability arthrodesis (fusion) may be required. 

Tarsal Fractures

Tarsal fractures occur following trauma, but in some breeds (racing Greyhounds/Dalmatians) stress fractures are reported. These fractures can be diagnosed on radiographs, but are often complex, so a CT scan is often performed to help decide on treatment. Some fracture can be repaired but arthrodesis (more commonly partial) is sometimes necessary.

*For a number of these conditions if surgical management is not an option custom made orthotics (splints) can be used to improve function. Custom fitting reduces the incidence of rubbing.