Luxating Patella
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
Breeding advice appliesUse the condition’s screening guidance and veterinary or genetics advice before breeding an affected or at-risk animal.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
A luxating patella is a kneecap that slips out of the groove at the front of the knee where it normally tracks during movement. Medial luxation, in which the patella moves toward the inside of the leg, is especially common in small and toy breeds and has a strong inherited component. Lateral luxation is less common and can occur in both small and large dogs. Although the underlying limb alignment is developmental, clinical signs can become more obvious as the dog grows.
The patella is part of the quadriceps mechanism. When the hip, femur, tibia and soft tissues are not aligned normally, the pull of the quadriceps can draw the kneecap out of its groove. A mildly affected dog may occasionally skip for a few steps and then resume normal movement when the patella returns to position. More severe luxation causes persistent lameness, abnormal limb posture and progressive deformity.
Veterinarians grade patellar luxation from one to four according to how easily the patella leaves the groove and whether it remains displaced. Repeated luxation wears cartilage and can contribute to osteoarthritis. It can also alter forces through the knee and increase the risk of other problems, including cranial cruciate ligament disease.
Not every grade-one luxation needs surgery, but the condition should not be dismissed simply because the dog is small or only “skips” occasionally. The key issues are pain, frequency of displacement, progression and whether abnormal tracking is changing the developing limb.
The kneecap may slip only occasionally in a mildly affected dog or remain displaced most of the time in a severe case, so clinical impact ranges from an intermittent skipping gait to persistent lameness and limb deformity.
They also reveal arthritis and help plan surgery. Report intermittent skipping, carrying a hind leg for several strides, bunny hopping or difficulty jumping. These signs can occur before constant lameness develops.
Screening & Early Detection
Patellar luxation is usually detectable by an experienced veterinarian through physical examination, making clinical screening practical in predisposed breeds. Puppies can be checked during routine veterinary visits, and breeding animals should undergo formal patellar examination at the age required by the relevant health scheme.
The veterinarian palpates each kneecap while the leg is flexed and extended and determines whether it can be displaced from the trochlear groove. The result is graded according to severity. Both knees are examined because bilateral disease is common even when the owner has noticed skipping on only one side.
Radiographs are not required to detect every mild luxation but are useful when lameness is present, the grade is higher or limb deformity is suspected. A growing puppy with persistent bowing or twisting of the leg may need earlier imaging.
A dog that has had surgical correction should still be recorded as affected for breeding purposes, because surgery changes the individual knee but not the inherited conformation that contributed to the disease.
Diagnosis is usually made by palpating the knee during an orthopaedic examination. Radiographs help assess bone alignment, arthritis and the degree of deformity, while advanced imaging may be useful before complex surgery.
Treatment & Management
Treatment depends on the luxation grade, frequency of clinical signs, age and degree of limb deformity. Dogs with a mild grade-one luxation that is rarely symptomatic may be managed with weight control, sensible exercise and monitoring. Maintaining strong thigh muscles and a lean body condition helps support the knee but does not correct abnormal patellar tracking.
Surgery is commonly recommended when luxation is frequent, painful, persistent or associated with skeletal deformity. Procedures are tailored to the anatomy and may include deepening the trochlear groove, repositioning the tibial crest so the quadriceps mechanism pulls in a straighter line, tightening or releasing soft tissues around the kneecap, and correcting major bone angulation when necessary.
Early surgery in a growing dog can prevent some progressive deformity and reduce repeated cartilage damage. Post-operative rehabilitation is important for restoring range of motion and muscle strength while protecting the repair during healing.
Dogs with established arthritis may continue to need anti-inflammatory medication or other osteoarthritis management even after the patella is stabilised. In older dogs with mild intermittent signs, conservative treatment may be appropriate when surgical benefit is expected to be limited.
The long-term outlook is generally very good after appropriate correction of uncomplicated disease. Monitor the opposite knee and seek reassessment if skipping becomes more frequent, lameness persists or the dog suddenly becomes markedly painful, as cruciate ligament injury can occur alongside patellar luxation.
Breeds or species affected
Affenpinscher
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American pit bull terrier
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Basset hound
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Boston terrier
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Chihuahua
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English toy terrier (black and tan)
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Eurasier
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Havanese
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Lhasa apso
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Miniature Pinscher
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Miniature Poodle
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Pekingese
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Pharaoh hound
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Pomeranian
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Toy Poodle
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Shih tzu
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Silky terrier
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Staffordshire bull terrier
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Yorkshire terrier
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