Patellar luxation is displacement of the kneecap out of the femoral trochlear groove, most often medially. It is one of the commonest orthopaedic problems of dogs, mainly a developmental disease of small breeds, and a frequent cause of the intermittent "skipping" hindlimb lameness owners describe. Its importance lies in grading it correctly, spotting a concurrent cruciate ligament tear, and choosing between monitoring and surgery.
Key facts
Luxating patella (patellar luxation) at a glance- Species and system: dogs (also cats); musculoskeletal, stifle extensor mechanism.
- Cause: usually congenital or developmental malalignment of the quadriceps mechanism; occasionally trauma.
- Who: toy and small breeds above all (Pomeranian, Chihuahua, Yorkshire Terrier, French Bulldog); medial luxation predominates even in large breeds; lateral luxation is less common and relatively more frequent in large dogs.
- Classic presentation: a young small-breed dog that carries a hindlimb for a few strides, then puts it down and carries on normally.
- How common: diagnosed in 1.3% of dogs in English primary-care practice.
- Zoonotic/reportable: no; heritable, so affected dogs should not be bred.
What's inside
12 sections in the full guide- Key facts
- How the NAVLE tests this
- Cause and pathophysiology
- Clinical signs
- Diagnosis
- Differential diagnoses
- Treatment and management
- Prevention, control and public health
- Prognosis
- Quick review
- Test yourself
- References
The full guide also has 4 tables, 3 figures, 3 self-test questions and 10 references, available to NAVLE members.
Read the full study guide
The full guide is part of every NAVLE plan, with diagnosis and treatment tables, figures, a quick review and self-test questions. Start a free trial to try the question bank, or log in if you are already a member.