That Skipping Step Your Small Dog Takes Is Not Harmless
If you have noticed your small dog occasionally holding up a back leg for a few steps before suddenly running on normally, you have likely witnessed a luxating patella. It is one of the most common orthopaedic conditions seen in small and toy breeds, affecting dogs such as Chihuahuas, Yorkshire Terriers, Pomeranians, Cavalier King Charles Spaniels, and Miniature Poodles. Many owners assume it is a quirk or temporary stiffness. In reality, it is a structural problem that, if left unaddressed, can cause progressive joint damage and significantly diminish a dog's quality of life.
What Is a Luxating Patella?
The patella, or kneecap, normally sits within a groove at the base of the femur called the trochlear groove. Tendons and ligaments keep it tracking in a straight line as the knee flexes and extends. In dogs with patellar luxation, this alignment is compromised — the patella slips out of its groove, typically to the inside of the leg in small breeds. This is termed medial patellar luxation and accounts for the vast majority of cases in small dogs. Lateral luxation occurs more commonly in large breeds.
The condition is largely developmental and often hereditary. Underlying skeletal abnormalities including a shallow trochlear groove, a displaced tibial crest, or rotational deformities of the femur contribute to abnormal forces that pull the patella out of alignment.
The Four Grades and What They Mean
Patellar luxation is classified into four grades, and this grading system directly informs management decisions.
Grade one luxation means the patella can be manually pushed out of the groove during examination but returns spontaneously. The dog rarely shows clinical signs. Grade two means the patella luxates spontaneously with flexion of the stifle or with manual pressure, but reduces — returns to position — either on its own or when the leg is extended. This correlates with the intermittent skipping gait owners commonly describe. Grade three means the patella remains luxated most of the time but can be manually replaced, only to luxate again immediately when pressure is released. Grade four means the patella is permanently luxated, cannot be replaced manually, and is associated with significant limb deformity. Dogs at this grade typically bear weight poorly or adopt a crouching posture.
When Is Surgery the Right Decision?
Grade one luxations in dogs without clinical signs are often monitored conservatively, with owners watching for progression. However, the decision to operate is not simply determined by grade alone. A grade two dog that skips frequently, shows pain, or is developing muscle atrophy may be a stronger surgical candidate than a grade three dog that has adapted well. The dog's age, activity level, concurrent orthopaedic problems, and the owner's long-term expectations all factor into a nuanced conversation with a veterinary orthopaedic surgeon.
Most veterinary orthopaedic specialists recommend surgical correction for grade two dogs showing consistent clinical signs, and for all grade three and four cases regardless of clinical presentation. The rationale is that persistent patellar luxation causes ongoing cartilage wear within the stifle joint and significantly increases the risk of cranial cruciate ligament rupture — a far more serious and expensive condition to manage.
Surgical Techniques Used
Trochlear block recession
Deepening the trochlear groove is central to most surgical corrections. The most widely used technique is trochlear block recession, in which a block of cartilage and bone is removed, the groove is deepened, and the block is replaced. This preserves the cartilage surface that the patella glides on. In very young dogs, trochlear chondroplasty — a technique that deepens the groove without removing bone, utilising the pliability of immature cartilage — may be used instead.
Tibial crest transposition
Where the attachment point of the patellar tendon on the tibia is displaced medially, surgically moving and pinning the tibial crest laterally corrects the pull direction on the patella, helping it track centrally within the deepened groove.
Soft tissue reconstruction
Tightening the joint capsule on the lateral side and releasing contracted tissue on the medial side addresses the soft tissue imbalances that contribute to luxation. This is performed alongside bony corrections rather than as a standalone procedure in most cases.
In dogs with significant femoral or tibial deformity, corrective osteotomies to address rotational or angular bone abnormalities may be necessary, though this is less common in small breeds than in large breed lateral luxation cases.
Post-Operative Recovery and Rehabilitation
Recovery following patellar luxation surgery requires strict rest and controlled rehabilitation, typically over eight to twelve weeks. The immediate post-operative period involves cage or pen rest, restricted lead walks for toileting only, and management of surgical site comfort under veterinary guidance. Owners often find this the most challenging aspect, particularly with young and energetic small dogs.
Physiotherapy introduced progressively from two to three weeks post-operatively supports muscle rebuilding and joint range of motion. Passive range-of-motion exercises, gentle massage, and hydrotherapy are commonly incorporated. Return to normal activity is gradual and should be guided by follow-up assessment rather than owner perception of recovery.
Complication rates following patellar luxation surgery are generally low in experienced hands, but re-luxation can occur, particularly if the underlying deformity was severe or if activity restrictions are not maintained during healing. Implant failure in tibial crest transposition, infection, and seroma formation are recognised but infrequent complications.
What Owners Should Know and Do
- Do not dismiss intermittent skipping in a small dog — have the stifle joints evaluated by a vet
- Ask for grading of both knees, as bilateral luxation is common
- Seek referral to a veterinary orthopaedic specialist for grade two with clinical signs, and all grade three and four cases
- Understand that surgery prevents progression to cruciate ligament rupture — earlier intervention generally means simpler correction and faster recovery
- Commit fully to the rest and rehabilitation protocol post-operatively; this is where many recoveries are compromised
- Maintain lean body weight long-term to reduce joint loading
- Discuss physiotherapy with your vet — it is not optional, it is part of the treatment