Arthrodesis is defined as the irreversible fusion of two or more bones of a joint. This creates an osseous bridge, preventing joint motion, and allows the arthrodesed joint to transmit weight-bearing forces. There are several small tarsal joints that together make up the hock or ankle joint. Almost all of the range of motion in the tarsal joint takes place at the articulation between the tibia (shin bone) and one of the tarsal bones call the tibio-tarsal bone. A partial tarsal arthrodesis involves the fusion of the other small, less mobile joints in the tarsus and so maintains a relatively normal range of motion in the joint following surgery. Fusion of these smaller tarsal joints is often indicated when there is irrevocable traumatic damage, often involving ligament damage.
It is important to understand that an arthrodesis is a salvage procedure. This means that the procedure is irreversible once performed. As a result, an arthrodesis is generally performed when conservative management has failed or unlikely to be successful.
Arthrodesis Indications
- Joint instability, often caused by ligament damage, is the most common indication for performing a partial tarsal arthrodesis The high tensile forces following normal weight bearing make conservative treatment futile.
- Intractable arthritis or joint pain.
- Persistent luxation or instability of the joint
- Non-reconstructable articular fractures of the tarsal bones
- Neurological injury
Partial Tarsal Arthrodesis Surgery
The small tarsal joints and metatarsal joints are opened, and the articular cartilage is removed. Cancellous bone grafts taken from another part of the body (usually the humerus or tibia) are inserted into the joint spaces. Specialised surgical plates are affixed with surgical screws to the intertarsal and tarso-metatarsal bones as required as required to rigidly fix or hold the joint in a static position.
A splint bandage may be used to support the leg and joint post-operatively.
All patients will receive pain medications to reduce their post-operative discomfort. Your pet should be kept calm and quiet for the first two weeks after surgery to allow for tissue healing. A collar is necessary to prevent the patient interfering with the surgical site. Following post-operative instructions carefully is essential in order to ensure that the procedure is as successful as possible.