Patellar Luxation
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.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Patellar luxation occurs when the kneecap moves out of the groove at the front of the knee instead of tracking smoothly during flexion and extension. In cats, the patella most often shifts towards the inside of the leg, although outward luxation can also occur. The problem may be developmental or follow trauma.
Mild luxation can be intermittent. A cat may briefly skip, hold up a hind leg or shake the limb and then continue normally once the patella returns to position. More severe grades remain displaced for longer periods and can alter the alignment of the leg. Repeated luxation damages cartilage and can contribute to osteoarthritis.
Some cats show few signs despite an unstable patella, while others become reluctant to jump or develop persistent lameness. Bilateral disease can make the gait appear generally awkward rather than producing a clear one-sided limp. The condition can also occur alongside hip or other hindlimb abnormalities.
The veterinarian palpates the kneecap through a range of motion and grades how easily it moves out of the groove and whether it returns spontaneously.
Patellar luxation is not always a surgical disease. A low-grade stable patella in a comfortable cat may simply be monitored. Recurrent pain, higher-grade displacement or progressive limb deformity makes corrective surgery more appropriate. The goal is to restore stable tracking before chronic instability causes avoidable joint damage.
Repeated displacement can also change how force travels through the knee, contributing to wear beyond the patella itself. This is why a cat that only “skips” occasionally as a youngster may later develop persistent osteoarthritis if the instability is substantial and left uncorrected.
Because mild disease may not cause obvious lameness, palpation is more informative than appearance alone.
Screening & Early Detection
Kittens and young cats can have patellar stability checked during routine examinations, especially in breeds or family lines where luxation has occurred.
At home, intermittent skipping, sudden lifting of a hind leg, reluctance to jump or a change in the way the cat lands can be early clues. Videos are useful because the kneecap may be back in position by the time the cat reaches the clinic.
The veterinarian grades the luxation and assesses the alignment of the femur, tibia and hip. Radiographs help identify bone deformity, arthritis and other causes of hindlimb pain. CT is rarely required but can assist planning in complex deformities.
There is no universal DNA screening test for patellar luxation. Breeding assessment is based on physical examination and, when needed, imaging. Early detection allows weight and activity management to begin before repeated instability contributes to arthritis, and it identifies cats that should be excluded from breeding because of clinically important conformational disease.
Diagnosis is mainly physical. Radiographs assess bone alignment and arthritic change and are important before surgery.
Treatment & Management
A cat with mild luxation and no pain may be managed conservatively. Keeping body weight lean reduces joint load, while regular comfortable activity maintains muscle that supports the knee. Pain relief is used when secondary osteoarthritis develops.
Surgery is recommended when the patella remains displaced, recurrent luxation causes lameness or abnormal bone alignment is progressing. Procedures can deepen the femoral groove, reposition the attachment of the patellar tendon and tighten or release surrounding soft tissues. The exact combination is selected from the individual anatomy.
Postoperative care includes restricted activity followed by gradual rehabilitation. Pain medication is provided and follow-up imaging may be used to confirm healing. Cats generally recover well because of their light body weight and ability to adapt.
Conservative cases still need reassessment if skipping becomes more frequent or jumping ability declines. Surgery treats the mechanical instability but cannot remove arthritis that has already developed, so early correction of significant disease can improve long-term comfort. Breeding decisions should avoid perpetuating severe inherited or conformational luxation.
Long-term weight control remains important after surgery because an anatomically corrected knee can still develop osteoarthritis over time.
Breeds or species affected
Abyssinian
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Bengal
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Bombay
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Burmese
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Cornish Rex
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Devon Rex
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Minuet
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Minskin
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Munchkin
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Scottish Fold
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Siamese
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Somali
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Thai
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Tonkinese
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Bambino
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Cheetoh
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Dwelf
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Genetta
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Kinkalow
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Lambkin
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Skookum
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