Surgical Correction of Patellar Luxation in Dogs

Surgical correction of Patellar Luxation in dogs aims to realign the structure of the stifle joint (knee) so that the patella (kneecap) sits properly within the trochlear groove of the femur. Treatment selection depends on the severity of the condition, ranging from Grade I to IV.

Generally, surgery involves a combination of several procedures to correct joint and bone alignment abnormalities

1. Trochlear Groove Modification

In dogs where the trochlear groove is too shallow, causing the kneecap to slip out easily, veterinarians perform surgery to deepen the groove so the patella remains in the correct position:

• Trochlear Wedge Recession: A wedge-shaped piece of bone and cartilage is removed from the groove. The underlying area is deepened, and the wedge is replaced.

• Trochlear Block Recession: This is similar to the wedge method, but the bone is removed in a rectangular block shape instead.

2. Tibial Tuberosity Transposition (TTT/TCT)

This is considered the most important procedure in many cases, especially for Medial Luxation (inward displacement), which is the most common type.

• The veterinarian cuts the portion of the shin bone (tibia) where the patellar ligament attaches, known as the tibial tuberosity.

• This piece of bone, with the ligament still attached, is moved (transposed) to a new, appropriate position—usually outward.

• This realigns the pull of the quadriceps muscle with the trochlear groove.

• The bone fragment is secured in its new position using wires or pins.

3. Soft Tissue Reconstruction

• Release Incision/Desmotomy: Tissues that are too tight on the side where the patella has shifted (e.g., the inner side in Medial Luxation) are cut to reduce tension.

• Capsular Imbrication: The loose or stretched tissues on the opposite side are tightened with sutures to help keep the patella aligned.

4. Corrective Osteotomy

In severe cases (typically Grade III or IV) or when there is significant deformity of the femur or tibia, it may be necessary to cut and realign the bones to correct bowing or curvature. The bones are then stabilized using plates and screws.

Post-operative Care

Post-surgical care is vital for success:

• Restricted Movement: Strict activity restriction is required according to the veterinarian’s instructions.

• Physical Therapy: Rehabilitation is necessary to help restore muscle and joint function.

• Prognosis: Surgery typically yields excellent results, with more than 90% of dogs diagnosed with Grade I, II, or III returning to normal leg function after the procedure.