Patella Luxation Repair in Dogs
The patella, or kneecap, sits within the quadriceps tendon and normally glides smoothly up and down the femoral groove during movement. Patellar luxation occurs when this alignment is disrupted, causing the kneecap to slip sideways, either inward (medially) or outward (laterally). This condition typically results from a misaligned quadriceps mechanism or a shallow femoral groove. Most cases are genetic in origin, linked to bone deformities of the hip, femur, or tibia, or a naturally flattened groove that prevents normal patellar tracking.
At Elizavet, we welcome Patella Luxation referrals from first opinion practices and pet owners across London looking for better value. We offer expert orthopaedic assessment and patella luxation repair. Patella luxation and all our orthopaedic services are available to clients in Camden, Kilburn and the surrounding areas of North London and beyond.
Our comprehensive guide to Patella Luxation repair
Grades of Luxation
There are four grades of luxation. A patella luxation grade 2 may progress to a grade 3 following cartilage and bone erosion secondary to the patella popping in and out of the femoral groove.
- Grade 1: The patella can be luxated with manual pressure. There is no crepitus and no signs of bone deformity. This condition does not require surgical treatment.
- Grade 2: The patella spontaneously luxates during normal movement. Skipping lameness may be observed.
- Grade 3: The patella is luxated permanently but can be reduced with manual pressure. Pain may be detected when the patella is pushed within the groove.
- Grade 4: The patella is luxated permanently and cannot be pushed within the femoral groove. Limb rotation may be detected.
Clinical Signs and Diagnosis of Luxating Patella in Dogs
The typical clinical sign is ‘skipping lameness’. Patients lift the limb for a few steps when walking—especially when walking quickly—and then return to normal. The cause of this lameness is the patella moving in and out of the femoral groove. The popping out of the patella results in a locking of the stifle joint and skipping lameness. Initially, the problem is mechanical and painless, but abnormal movements of the patella cause cartilage erosion, osteoarthritis, pain, and lameness.
In severe conditions (grade 4), the patella may be permanently luxated. In these cases, the tibia may be rotated from 60 to 90 degrees. If not corrected early in life, severe bone and ligament deformity can develop.
Treatment and surgery for patella luxation repair
The aim of surgery for luxating patella in dogs is to align the quadriceps muscle mechanism and stabilise the patella within the femoral groove. A variety of techniques can be used to achieve normal alignment.
This surgical procedure deepens the femoral groove to better accommodate the patella. A V-shaped bone fragment is removed, the groove is deepened, and the fragment replaced, maintaining the same shape.
The use of a patellar groove replacement prosthesis reduces lameness linked to severe femoro-patellar arthritis, enhances patellar stability, and corrects the alignment of the extensor mechanism. Manufactured by Kyon, this prosthesis features a smooth Amorphous Diamond-Like Carbon (ADLC) coated groove surface for low friction.
This technique aligns the quadriceps mechanism by repositioning the patella within the femoral groove. A vertical cut is made on the front of the tibia, and the fragment is repositioned laterally or medially and stabilised with pins or wire. Healing occurs within 4–8 weeks.
These techniques stabilise the patella within the femoral groove. In moderate cases, fascia lata imbrication is performed on the opposite side of the luxation. In severe cases, contracted soft tissue on the luxation side is released, and fascia lata imbrication is performed on the opposite side.
Surgical complications are rare. Infections are treated with antibiotics, and skin irritation from pin migration may require removal. Strict rest is crucial, especially for active dogs. Sudden movement or jumping can compromise healing and may require revision surgery.
Should you walk a dog that has a luxating patella?
Exercise should be carefully controlled for dogs with a luxating patella. Gentle, low-impact walks on even surfaces may help maintain muscle tone without overstraining the joint. However, excessive activity or rough play should be avoided until after appropriate treatment or surgery has been completed.
References:
Hill’s Pet Products (2006). Hill’s Atlas of Veterinary Clinical Anatomy. Topeka, USA: Veterinary Medicine Publishing Company.
Veterinary Instrumentation (2019). Patella Luxation – A Step by Step Guide. Available from: https://veterinary-instrumentation.co.uk/vi-academy?procedure=10 [Accessed: 15/06/19].