Medial Luxating Patella in Dogs: A 2025 Vet Guide by Dr Duncan Houston 🐾

Medial Luxating Patella in Dogs: A 2025 Vet Guide by Dr Duncan Houston 🐾

By Dr Duncan Houston, BVSc – July 2025

Introduction 🎯

Welcome! I’m Dr Duncan Houston. Today we explore **medial luxating patella** (“trick knee”), a common orthopedic issue in small and toy‑breed dogs. In this 2025 vet guide, I’ll walk you through the signs, diagnosis, treatment, and recovery—complete with clear explanations, emoji highlights 😊, and professional recommendations. Let’s dive in!

🐕 What Is a Medial Luxating Patella?

A **luxating patella** occurs when a dog’s kneecap (patella) slips out of its groove in the femur. Most commonly, it luxates medially—toward the body’s center—but may occasionally move laterally in larger breeds :contentReference[oaicite:2]{index=2}.

Owners often spot a characteristic “skip” in their dog’s step. The dog may hold a hind leg up briefly then resume walking normally—miraculously appearing unaffected :contentReference[oaicite:3]{index=3}.

About 50% of affected dogs have both knees involved :contentReference[oaicite:4]{index=4}.

🧮 Grading the Severity

Luxating patella is graded I–IV based on severity of displacement and physical characteristics:

• Grade I: Patella can be manually moved but returns to normal—usually asymptomatic, treatment rarely needed :contentReference[oaicite:5]{index=5}.
• Grade II: Patella luxates occasionally; dog has intermittent lameness but often self-corrects; surgery considered if symptoms persistent or to prevent progression :contentReference[oaicite:6]{index=6}.
• Grade III: Patella is luxated most of the time, but manually reducible; dogs often display persistent lameness or bow-legged posture—surgery strongly recommended :contentReference[oaicite:7]{index=7}.
• Grade IV: Patella permanently luxated and irreducible; severe conformational changes and gait issues; surgery necessary though outcomes may vary :contentReference[oaicite:8]{index=8}.

📋 Who’s Typically Affected?

This condition most often shows up between **4–9 months of age**, particularly in toy and small breeds like Poodles, Chihuahuas, Yorkies, Maltese, Cavalier King Charles Spaniels, Pomeranians and Bichons :contentReference[oaicite:9]{index=9}.

It may be congenital or hereditary due to limb malalignment, shallow trochlear groove, tibial and femoral bone deformities, or soft‑tissue laxity :contentReference[oaicite:10]{index=10}.

🔍 Clinical Signs & Diagnosis

Common signs:

• “Skipping” rear limb with occasional lameness, often self-correcting :contentReference[oaicite:11]{index=11}.
• Hopping, reluctance to run or jump, a bowed leg or knock-kneed stance :contentReference[oaicite:12]{index=12}.
• Advanced cases: crouching posture, leg weakness, persistent lameness :contentReference[oaicite:13]{index=13}.
• Later-onset arthritis or cranial cruciate ligament tears, especially in grades III–IV :contentReference[oaicite:14]{index=14}.

Diagnosis Steps:

• Physical palpation and grading of patella movement.
• Orthopedic exam including gait assessment and limb alignment.
• Radiographs to evaluate bone deformities and joint changes :contentReference[oaicite:15]{index=15}.
• Advanced imaging like CT/MRI if planning complex surgeries :contentReference[oaicite:16]{index=16}.

⚖️ Medical vs Surgical Treatment

🐾 Conservative (Non‑Surgical) Care

Appropriate for Grade I and some **Grade II** dogs with mild/intermittent lameness:

• Maintain ideal weight to reduce joint stress :contentReference[oaicite:17]{index=17}.
• NSAIDs or anti-inflammatory medications during flare-ups.
• Joint supplements, physical rehab, exercise restriction :contentReference[oaicite:18]{index=18}.
• Physiotherapy (e.g., joint exercises, hydrotherapy) may improve outcome :contentReference[oaicite:19]{index=19}.

Many dogs thrive with conservative management—occasionally for life—but watch for progression and arthritis :contentReference[oaicite:20]{index=20}.

🔪 Surgical Correction

Recommended for **Grade II** (if symptomatic), and always for **Grade III/IV**:

• Soft-tissue techniques: lateral imbrication to tighten capsule, medial release, anti-rotational sutures :contentReference[oaicite:21]{index=21}.
• Trochlear modification: deepen groove via wedge/block recession or sulcoplasty (wedge recession sulcoplasty) :contentReference[oaicite:22]{index=22}.
• Tibial tuberosity transposition: realign tendon insertion to improve patellar tracking :contentReference[oaicite:23]{index=23}.
• DFO or femoral osteotomy: correct severe bone deformities like femoral varus :contentReference[oaicite:24]{index=24}.
• Ridgestop implant: builds up medial ridge to prevent luxation (new adjunct tool) :contentReference[oaicite:25]{index=25}.
• Rapid discharge with most outpatient procedures; success rates up to ~90% in grades I–III :contentReference[oaicite:26]{index=26}.

🩺 Surgery Timing: One Leg or Both?

Surgeons may choose staged or bilateral surgeries:

• Staged: One leg at a time, 6–8 weeks apart—ensures one functional leg during recovery.
• Bilateral (in young dogs): Avoids compensatory deformities in the non-operated leg.

Discuss your dog’s age, grade, and surgeon’s experience before deciding.

🛌 Post‑Op Recovery & Physical Therapy

Confinement: 3–4 weeks for soft-tissue only; 6–8 weeks if bony procedures used :contentReference[oaicite:27]{index=27}.

• Strict rest with controlled lead walks.
• Pain control (NSAIDs, opioids as needed) :contentReference[oaicite:28]{index=28}.
• Crate or small pen to limit activity post-surgery.
• Physical rehab if leg not used by 4 weeks :contentReference[oaicite:29]{index=29}.
• Radiographs at 6–8 weeks to confirm bone healing.

Hydrotherapy and guided exercises improve strength and prevent atrophy :contentReference[oaicite:30]{index=30}.

📈 Prognosis & Potential Complications

Overall prognosis is excellent for **grades I–III** with timely treatment; Grade IV outcomes are more variable :contentReference[oaicite:31]{index=31}.

Complications can include:

• Reluxation (especially in higher grades).
• Arthritis—common later in life despite successful surgery :contentReference[oaicite:32]{index=32}.
• Implant issues or superficial infection—minimized with proper post-op care :contentReference[oaicite:33]{index=33}.
• ACL injuries—reported in ~40% of dogs with high-grade luxation :contentReference[oaicite:34]{index=34}.

Early surgery helps preserve joint health and prevents secondary issues :contentReference[oaicite:35]{index=35}.

📊 Summary Table: At-a-Glance

✅ Dr Houston’s 2025 Vet Tips

• Early detection is vital—don’t ignore skips or hind-leg changes.
• Palpate and grade accurately during yearly exams.
• Conservative care can work, but be ready to escalate if signs worsen.
• Surgery before arthritis sets in yields best long-term outcomes.
• Post-op rehab and weight management are essential for lasting success.
• Communicate clearly with owners about risks, costs, and commitment.

🔧 Ask A Vet Support Services

The Ask A Vet team is here to support you—from teleconsults guiding diagnosis and surgical decisions, to physical rehab planning and post-op check-ins. Use our app to connect directly, schedule appointments, and monitor your dog’s progress. We’re with you and your dog every step. 🐶❤️

🐾 Final Thoughts

If your dog shows signs of a "trick knee", don't delay seeking veterinary assessment. Proper grading and timely intervention significantly improve outcomes. With early treatment—even serious cases can lead to a happy, active life.

— Dr Duncan Houston, BVSc

Visit AskAVet.com and download the Ask A Vet app for expert veterinary support anytime. 📱