What is a luxating patella and how is it treated in dogs?

A luxating patella, often referred to as a dislocated kneecap, is a condition in which the dog’s patella (kneecap) moves out of its normal position within the femoral groove. This orthopedic issue is commonly seen in small and toy breeds such as Pomeranians, Yorkshire Terriers, Chihuahuas, and Poodles, although it can also occur in larger dogs.

The condition may be congenital—meaning the dog is born with anatomical abnormalities that predispose the patella to dislocate—or it may be acquired, often due to trauma or progressive joint degeneration.

When the patella shifts out of place, it can cause intermittent lameness, a skipping gait, or a sudden yelp of pain. Some dogs may hold up their affected leg for a few steps before resuming normal movement, especially when the patella pops back into place on its own.

Over time, the repeated dislocation and relocation of the kneecap can lead to inflammation, cartilage wear, and arthritis in the joint. In more severe cases, the luxation becomes permanent, resulting in constant discomfort and an abnormal limb position.

Veterinarians typically diagnose the condition through physical examination and confirm its severity using radiographs. The condition is graded on a scale from I to IV, with Grade I being a patella that can be manually luxated but returns to position spontaneously, and Grade IV being a permanently displaced kneecap that cannot be manually repositioned. The treatment plan depends on the grade of luxation and the clinical signs observed.

Mild cases may be managed conservatively through weight management, physical therapy, joint supplements, and anti-inflammatory medications to relieve discomfort and improve muscle support. However, surgical intervention is often recommended for dogs with moderate to severe luxations, especially when the condition interferes with quality of life or causes progressive lameness.

The most common surgical procedures include deepening the trochlear groove (trochleoplasty), tightening or releasing the soft tissues that pull the patella medially or laterally, and repositioning the tibial crest (tibial tuberosity transposition) to realign the patellar tendon.

Postoperative recovery typically involves rest, restricted activity, and gradually reintroduced physical therapy. With proper care and rehabilitation, most dogs recover well and experience significant improvement in mobility and comfort. However, early diagnosis and timely intervention are key to preventing long-term joint damage and ensuring the best possible outcome for affected dogs.

References:

1. Arthurs, G.I., & Langley-Hobbs, S.J. (2006). Patellar luxation in dogs. Companion Animal, 11(9), 20–26.
   

2. Johnson, A.L., & Probst, C.W. (2003). Surgical treatment of medial patellar luxation in dogs. Veterinary Clinics of North America: Small Animal Practice, 33(1), 107–122.

About the autor

Felipe Garofallo is a veterinarian in Brazil, specialized in orthopedic and neurosurgical care for dogs and cats.

He is also the founder of Ortho for Pets – Veterinary Orthopedics and Specialties.