Patellar luxation surgery
Surgical correction of a kneecap that slips out of the groove of the femur. The procedure is chosen according to the grade of luxation and the structure of the limb, and assessed on X-ray before and after surgery.
What it involves
In patellar luxation the kneecap — a small bone in the tendon of the quadriceps muscle — slips out of the groove at the end of the femur, most often towards the inside. With a low grade of luxation it returns by itself; with a high grade it stays out of the groove permanently and the limb starts to become deformed. The scale has four grades, and the method of treatment depends on them.
The aim of the operation is to restore the correct path of the kneecap. Depending on the result of the examination and X-ray, we combine several elements: deepening the groove of the femur, moving the tibial tuberosity (where the patellar ligament attaches) and correcting the soft tissues on both sides of the joint. In dogs with marked deformity of the femur, a corrective osteotomy may be needed.
The result is a stable knee in which the kneecap works in the right place, which stops the progressive damage to the cartilage and allows the animal to walk normally.
When it is used
We recommend surgery for grade 2 luxation with symptoms and for grades 3 and 4 — regardless of age, although in young, growing animals earlier correction avoids the deformity becoming fixed. We usually just monitor grade 1 luxation without symptoms.
Patellar luxation often occurs together with a ruptured cruciate ligament; in that case we plan both elements in a single procedure.
Indications: symptoms that should prompt a visit
- Every so often a dog hops on three legs for a few steps and then walks normally again.
- A small dog (Yorkshire Terrier, Chihuahua, Pomeranian) kicks a hind leg straight out backwards to snap the kneecap back into place.
- The animal is lame more and more often, and the hind legs look bent or turned inwards.
- A cat is reluctant to jump and walks crouched on its hind legs.
- During the examination the veterinarian easily moves the kneecap out of the groove.
- Lameness gets worse despite anti-inflammatory medication.
Conditions for which we use it in particular
Diagnostics beforehand
The basis is an orthopaedic examination that determines the grade of luxation, plus digital X-rays of both knees and the whole of the hind limbs under sedation — we look for deformities of the axis of the femur and tibia that must be taken into account in the plan.
Before the procedure we carry out pre-anaesthetic assessment (STD-01): a clinical examination and blood tests.
How it proceeds
The patient arrives fasted. After premedication, a regional block and induction of general anaesthesia, the team monitors vital signs in line with standard STD-02. The operation takes roughly 60–90 minutes: we open the joint, deepen the groove of the femur, move the tibial tuberosity and fix it with a wire or screw, and finally tighten the joint capsule on the side opposite to the luxation. We check the path of the kneecap through the full range of movement.
After the procedure we take a check X-ray. The animal wakes up in the in-patient hospital with pain control; in most cases it goes home the same evening or the following morning.
Aftercare
For 4–6 weeks activity is limited to short walks on a lead, with no jumping or stairs; a collar until the stitches are removed after 10–14 days. Pain relief according to the schedule. Check-up after 2 weeks, check X-ray after 6 weeks.
Call us if, after initial improvement, the dog starts “skipping” again or the knee swells.
Frequently asked questions
Should we operate if my dog only limps occasionally?
It depends on the grade of luxation and the dog's age. With grade 2 and symptoms in a young dog, correction prevents degeneration — we discuss the decision after the examination and X-ray.
Do both legs need to be operated on?
The luxation is often on both sides. We usually operate on the worse side first, and on the other after recovery, if it causes symptoms.
Can the kneecap slip out again after the operation?
Recurrence is possible, but with a correctly chosen technique it rarely happens. The most important thing is to keep to the activity restrictions in the first weeks.
We manage every case individually. The scope, indications and course described above are indicative; we agree the exact diagnostic and treatment plan during the consultation. This content is for information only and does not replace a veterinary consultation.
Have questions about patellar luxation surgery?
Call us or book a consultation. We will set out the diagnostic and treatment plan in writing, before you decide.