What is a Luxating Patella in Dogs
Luxating patella is the displacement of the kneecap from its normal position in the groove of the thigh bone called the femur, either toward the outer side (lateral) or inner side (medial) of the groove.
This condition can vary in severity: low-grade often only requires monitoring if no significant lameness is caused, whereas high grade surgery is generally advised.
Patellar luxation is a developmental condition, with genetics playing a key role, but certain injuries or metabolic conditions can predispose to its development. The vast majority are developmental with no other clear predisposing cause identified.
It is usually classified into four grades depending on the tendency for the kneecap to dislocate. This ranges from grade 1 where the kneecap can be dislocated but immediately reduces back to the groove, to grade 4 where the kneecap is dislocated permanently and cannot be pushed back into place.
Written by Dr. Mariella Roberts, Veterinary Surgeon, Animal Trust Vets CIC | Published January 2025 | Review date January 2027 | This advice is for UK pets only and is not a replacement for seeing a vet
Symptoms of Patella Luxation
Low grade luxations are often asymptomatic but high grade and low grade luxations may show signs including:
skipping and hopping on the affected leg intermittently or continuously
sudden limping
stiffness after resting
difficulty jumping or running
whimpering and in pain when the knee is touched
When to contact your vet
When you notice your dog is skipping or limping. If your dog is crying in pain or any swelling in the area.
Diagnosis of Luxating Patella in Dogs
By a physical examination of the affected leg to feel if the kneecap is moving out and taking x-rays to observe the position of the kneecap, the shape of the groove and if any signs of arthritis are present. Also, assessing the legs for any other possible causes of limping.
Treatment of Patella Luxation
It can be medical or surgical depending on the severity of the condition:
Medical treatment (usually for grades 1 & 2) with weight control, physiotherapy and exercise regime to build up muscle tone around the kneecap and the use of anti-inflammatory medications to reduce the pain and the inflammation.
Surgical treatment when there is repeated luxation of the kneecap or repeated pain or limping (usually grades 3 & 4 and some grades 1 & 2) is recommended. Surgery aims to improve the stability and alignment of the kneecap by realigning the bones involved and deepening the groove the kneecap sits in.
Post-op Advice / Aftercare
Aftercare includes restricted exercise for the first few weeks, painkillers and physiotherapy to strengthen muscles around the joint.
Prevention of Luxating Patella in Dogs
Any breed of dog can develop patellar luxation, but certain breeds (often small and toy breeds) have a greater predisposition. These include Chihuahuas, Pomeranians, Yorkshire Terriers, French Bulldogs, Toy Poodles and Boston Terriers.
Prevention can start with responsible breeders avoiding breeding from animals diagnosed with luxating patellas. Also, weight control and an active, healthy life help to maintain the dog’s joint mobile and mitigate the impact of osteoarthritis on affected joints.
Outlook
Generally, with prompt treatment and good aftercare, many dogs show significant improvement, with most achieving resolution of limping altogether.
Arthritis is inevitable with this condition but usually does not cause a significant issue and is best mitigated by maintaining a lean body weight and ensuring they have regular exercise.