A patellar luxation occurs when a dog’s kneecap slips out of its proper position. In this situation, the knee becomes unable to fully glide down the groove of the femur. A medial patellar luxation (MPL), the most common type, occurs when the kneecap slides to the inside of the knee. This is normally caused by a congenital abnormality like a misshapen femur or tibia, shallow femoral groove or hip dysplasia. It can also occur as a result of knee trauma. Small breeds are more prone to MPL, but it can occur in larger dogs as well.
If left untreated, medial patellar luxations can lead to osteoarthritis, cartilage damage and ligament tears.
Medial patellar luxations are graded according to the severity of the injury and the frequency of displacement:
Grade I: Occasional patella displacement, but remains in the groove the majority of time. Symptoms may include skipping or kicking the leg out.
Grade II: Frequent patella displacement characterized by a persistent skipping gait and a mild degree of lameness. Patella can be manipulated back into the groove.
Grade III: Patella is always displaced and there is frequent lameness. Patella can be manipulated into the groove but will pop back out immediately.
Grade IV: Patella is always displaced and cannot be manipulated back into the groove. Constant lameness, signs of physical deformity and a bow-legged appearance are present. The knee cannot extend.
Diagnosing and Treating Medial Patellar Luxation
Patellar luxations are often discovered during annual physicals and other general veterinary examinations. If your Dana Niguel veterinarian suspects your pet is suffering from an MPL, they will examine your pet’s knee for signs of displacement and will use a radiograph (X-ray) to confirm the diagnosis.
Surgery is recommended to treat MPL grades II, III and IV. During the procedure, the surgeon realigns the patella using a number of techniques. Some options include deepening the femoral groove, altering the alignment of the patellar ligament, readjusting the leg bones and fixing the joint attachments.
Recovering from MPL Repair
An MPL repair is a major surgery that requires a 12-week recovery period. We prescribe painkillers, anti-inflammatory medications and antibiotics following surgery to minimize discomfort and prevent infection. Pets that are prone to licking wounds must wear a collar to prevent bacteria from entering the bloodstream.
Your dog’s mobility should be restricted during recovery to allow for proper healing. Exercise should be limited to short walks for the first six weeks, then gradually increased weekly until your pet returns back to full strength. We often recommend physical therapy as well to enhance the recovery process and maximize joint strength and mobility.
Think your pet may be suffering from a medial patellar luxation? Schedule a consultation at Dana Niguel Veterinary Hospital by calling 949-661-6375.