Patellar Luxation: The ‘Slipping Kneecap’ in Maine Coons#

We worry so much about Hip Dysplasia in this breed that we often forget the knees. Patellar Luxation is a condition where the kneecap (patella) pops out of its groove.

While it is more common in small dogs, it is a known issue in Maine Coons due to their rapid growth rate and heavy bone structure. If you see your cat running and suddenly “skip” or hop on three legs for a second, then go back to normal—that was likely their knee popping out and snapping back in.

The “Grades” of Luxation#

Vets grade this from 1 to 4.

• Grade 1: The knee pops out if the vet pushes it, but snaps back in instantly. The cat rarely limps.
• Grade 2: It pops out occasionally on its own (the “skip”). The cat might shake their leg to pop it back in.
• Grade 3: The knee is out most of the time but can be pushed back in. This causes arthritis and pain.
• Grade 4: The knee is permanently out and stuck. The leg looks bowed. This requires surgery.

Is it Hips or Knees?#

• Hip Dysplasia: Causes a swaying, “bunny hop” gait and reluctance to jump.
• Patellar Luxation: Causes an intermittent skip or locking of the leg.
• Diagnosis: Your vet can tell simply by feeling the joint (palpation).

Managing the Condition#

• Keep Them Lean: I sound like a broken record, but weight management is the cure for everything orthopedic. A heavy cat puts torque on the knee.
• No Slick Floors: If they slide on hardwood, they can tear their CCL (the cat version of an ACL). Put down rugs.
• Surgery: If it is Grade 3 or 4, surgery is recommended. It is expensive ($2,000–$4,000 per knee), but it fixes the problem permanently.

Conclusion#

Most Grade 1 or 2 cats live happy lives without surgery. Keep them on Joint Supplements (Glucosamine) and watch their weight. If they start limping consistently, it’s time for X-rays.

Resources & Further Reading#

• ACVS: Patellar Luxations in Cats (Surgical Guidelines).
• Orthopedic Foundation for Animals: Patella Database.