Coxofemoral Hip Luxation in Small Mammals

Coxofemoral luxation is the dislocation of the head of the femur, or the ball of the thigh bone, out of the socket of the pelvis (acetabulum). The luxation is usually the result of trauma and results in a non-weight-bearing lameness of the affected limb. The round ligament of the femoral head that normally holds the femoral head within the acetabulum, completely ruptures or pulls away from its attachment, causing the dislocation.

The potential long-term effects of hip luxation range from none, if the problem is addressed early, to severe arthritis in the joint if there is excessive delay in repair.

Diagnosis

Diagnostic tests that may be required to confirm the diagnosis and determine the presence of concurrent diseases or abnormalities include:

• A thorough physical examination, including an orthopedic exam
• X-rays of the pelvis to confirm a luxation
• Additional radiographs and lab tests, depending on any underlying trauma or possible disease process

Treatment

Treatment may consist of one or more of the following and will depend on the severity of the trauma, size of animal and cost concerns. Emergency care for concurrent problems caused by the trauma is paramount. Once the animal has been stabilized, your veterinarian will give specific treatment for the hip luxation, which may be performed either closed or open.

Closed Reduction

Closed reduction is a non-surgical replacement of the joint and is the most common treatment for hip luxation in small mammals. The outcome is best when the procedure is performed early after trauma. General anesthesia is needed to replace the femur into the acetabulum, and after the procedure, the limb is placed in a sling to prevent use of the leg and maintain reduction (replacement) of the joint.

Open Reduction

This technique is a surgical replacement of joint and is rarely used in small mammals, usually due to cost concerns as well as surgical difficulty in very small critters. Open reduction may be attempted when closed reduction fails or a fracture is present in the femur or pelvis. It, too, requires general anesthesia.

Open reduction allows direct visualization of the bones and joint capsule. The torn round ligament of the femoral head is removed and the head of the femur is replaced into the acetabulum. After surgery, the limb may be placed in a sling.

Home Care and Prevention

Take your pet to a veterinarian for immediate evaluation as soon as possible after any trauma. After closed reduction, the limb is generally be placed in a sling and your pet's activity is restricted for several weeks to allow the joint to heal.

If an open reduction technique is used, the leg may be placed in a sling and your pet's activity restricted. Additionally, the skin incision is monitored during the healing process.

Radiographs may be repeated in several weeks to make sure the hip is still in the joint.