Patellar luxation (PL) is graded on a 1–4 scale based on manual reducibility and spontaneous reluxation. Grade I: the patella can be manually luxated but spontaneously reduces when released. Grade II: the patella luxates on stifle flexion or manual manipulation and remains luxated until the stifle is extended or manually reduced. Grade III: the patella is continuously luxated but can be manually reduced. Grade IV: the patella is permanently luxated and cannot be manually reduced. Journal of the…

Surgical intervention is warranted for grade III and IV luxations, and is indicated for symptomatic grade II disease. For grade II medial patellar luxation (MPL) managed non-surgically in initially asymptomatic adult dogs, 50% subsequently develop chronic lameness or require surgery at an average of 15 months after initial presentation. Journal of Smal… Early surgical treatment is recommended for higher-grade luxations, particularly in dogs with higher body weight, to prevent cartilage erosion and secondary osteoarthritis. American Journa…

Cartilage damage is already prevalent at the time of surgical correction and increases with grade. In dogs surgically treated for MPL, patellar cartilage erosion is present in 47.6% of stifles and femoral trochlear erosion in 54.4%, with both increasing in prevalence and extent at higher grades. American Journa… Symptom duration is independently associated with the extent of cartilage erosion, reinforcing the case for early intervention rather than prolonged conservative management. American Journa…

Surgical outcomes are grade-dependent. For grade II MPL in Pomeranians, surgical success is 100% with an overall recurrence rate of 10% across all grades combined. Veterinary and… For grade III MPL, recurrence occurs in approximately 11% of cases, rising to 36% for grade IV in the same population. Veterinary and… In small-breed dogs with grade IV MPL treated with trochlear block recession, tibial tuberosity transposition, and soft tissue techniques, no major or catastrophic complications were observed, though minor and major complications occurred in 36.4% of stifles. Open Veterinary… For grade IV MPL across mixed breeds and sizes, full function is achieved in 42.6% of cases and acceptable function in an additional 40.4%, with unacceptable function in 17%; the overall complication rate is 25.5% and revision surgery is required in 12.8%. Journal of the…

Lateral patellar luxation (LPL) follows the same grading system and surgical principles as MPL. Non-traumatic LPL predominantly affects medium and large breed dogs, with a median age at presentation of 10 months, and genu valgum is the most common associated conformational abnormality. Veterinary and… Surgical outcomes for LPL are comparable to MPL, with good or excellent surgeon-assessed outcomes in 47 of 51 dogs available for review; complications occurred in 22 of 58 operated stifles, with 16 managed conservatively, 4 requiring implant removal, and 6 requiring revision surgery. Veterinary and…

Concurrent cranial cruciate ligament (CCL) disease must be assessed at the time of diagnosis, as 13–25% of dogs presenting with PL have concurrent CCL rupture. Veterinary Surg… Increased radiographic stifle soft tissue opacity in a PL patient is an accepted indicator of potential concurrent CCL disease. Veterinary Surg…

Would you like to review the specific surgical techniques — trochlear block recession, trochlear wedge recession, tibial tuberosity transposition, and when to add corrective osteotomy — and how to choose among them by grade and breed size?