CONDITION

Patellar Luxation

Why this matters now

Patellar luxation is extremely common in small and toy breed dogs, often developing within the first year of life as skeletal development completes. Breeds such as Chihuahuas, Yorkshire Terriers, Pomeranians, and Miniature Poodles are frequently affected. The condition also occurs in larger breeds, where it tends to involve outward (lateral) displacement rather than the inward (medial) luxation typical in small dogs.

Many dogs live with mild patellar luxation throughout their lives without significant problems. However, the abnormal tracking can lead to progressive cartilage wear and osteoarthritis over time. Dogs with more severe grades may experience increasing lameness and joint deterioration. Some dogs that initially had occasional luxation may develop more frequent or permanent displacement as supporting structures stretch.

Signals & patterns

Early signals

Intermittent skipping or hopping gait

Dogs may hold up a back leg for a few steps then resume normal walking as the kneecap pops back into place.

Occasional yelping during activity

A sudden vocalisation may occur when the kneecap dislocates, particularly during jumping or turning.

Preference for holding one leg up briefly

Owners may notice the dog periodically lifting a hind leg, then continuing normally.

Kicking the leg out behind

Dogs sometimes extend the affected leg backward, which may help the kneecap return to its groove.

Later signals

More frequent or constant lameness

As the condition progresses, episodes may become more frequent or the kneecap may remain out of position.

Bunny hopping gait

Dogs may move both back legs together rather than alternating normally, particularly when running.

Decreased activity or reluctance to jump

Joint discomfort and instability may lead to reduced exercise tolerance and avoidance of certain movements.

Visible changes in leg conformation

Over time, dogs with severe luxation may develop bowed legs or rotational changes in limb alignment.

Click to read about the biological mechanisms

How this is usually investigated

Diagnosis of patellar luxation typically combines physical examination with imaging to assess severity and plan any intervention.

Orthopaedic examination

Purpose: To assess kneecap stability, grade the luxation, and evaluate for other joint problems
Considerations: The examiner manually moves the kneecap to determine how easily it displaces and whether it returns to position spontaneously.

Gait analysis

Purpose: To observe movement patterns and identify lameness
Considerations: Watching the dog walk and trot helps assess functional impact. Some dogs with luxating patellas show minimal gait abnormality.

Radiographs

Purpose: To evaluate bone alignment, groove depth, and arthritic changes
Considerations: X-rays reveal skeletal structure and any degenerative joint changes. Helpful for surgical planning if intervention is considered.

Assessment of other joints

Purpose: To check for concurrent problems such as cruciate ligament disease or hip dysplasia
Considerations: Patellar luxation increases strain on other knee structures, and multiple orthopaedic conditions may coexist.

Options & trade-offs

Management depends on the grade of luxation, clinical signs, and individual circumstances. Not all cases require surgical intervention.

Monitoring and conservative management

Observation, weight management, and controlled exercise for dogs with mild disease and minimal symptoms.

Trade-offs: Appropriate for lower-grade luxation with infrequent or no lameness. Regular monitoring helps identify progression requiring reassessment.

Joint supplements and physical therapy

Nutritional support for joint health and exercises to strengthen supporting muscles.

Trade-offs: May help maintain joint function and comfort. Does not address the underlying anatomical problem but can support joint health.

Surgical correction

Various procedures to deepen the groove, realign structures, and stabilise the kneecap.

Trade-offs: Typically recommended for grades III-IV or lower grades causing significant lameness. Multiple techniques exist; the approach depends on specific abnormalities present.

Pain management

Anti-inflammatory medications or other analgesics when needed for comfort.

Trade-offs: Provides symptomatic relief. Long-term use requires monitoring. Does not address progression of underlying joint changes.

Common misconceptions

Misconception:

"Patellar luxation always requires surgery"

Reality:

Many dogs with lower-grade luxation live comfortably without surgical intervention. Treatment decisions depend on functional impact and progression, not grade alone.

Misconception:

"The skipping gait is just a quirky behaviour"

Reality:

The characteristic intermittent hopping typically indicates the kneecap temporarily moving out of position. This is a structural issue rather than a behavioural choice.

Misconception:

"Small dogs naturally have leg problems"

Reality:

Whilst patellar luxation is common in certain breeds, it represents a genuine orthopaedic condition rather than a normal variant. Breeding programmes can reduce prevalence.

Tracking how often limping episodes occur and what activities trigger them provides useful context. Noting whether symptoms are becoming more frequent or severe over time helps guide discussions about management. Maintaining a healthy body weight reduces stress on joints, and understanding what movements cause problems can help adapt daily activities.

Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS