Medial Patellar Luxation (MPL)
Medial Patellar Luxation (MPL) is a common orthopedic condition in pets, especially small-breed dogs, where the kneecap (patella) slips out of its normal position toward the inside (medial side) of the leg. This abnormal movement can cause pain, limping, and long-term joint damage if left untreated.
Contributing factors may include:
- A shallow groove in the femur where the patella sits
- Abnormal alignment of the femur or tibia
- Tight or imbalanced soft tissues around the knee
- Intermittent skipping or hopping on a hind leg
- Sudden lameness that resolves quickly
- Stiffness or difficulty rising
- Decreased activity or reluctance to jump
- Chronic limping in more advanced cases
MPL is graded from Grade I to Grade IV, based on how easily the patella moves out of place and whether it stays luxated.
Treatment Options
Medical Management
Mild cases may be managed with:
- Weight management
- Activity modification
- Anti-inflammatory or pain medications
- Joint supplements
Surgical Treatment
Surgery is recommended for pets with:
- Persistent or worsening lameness
- Moderate to severe MPL (Grade II–IV)
- Pain or progression of arthritis
- Deepening the groove the patella sits in (trochlear block or wedge recession) (Trochleoplasty)
- Realigning the attachment of the patellar tendon (Tibial Tuberosity Transposition)
- Tightening or releasing surrounding soft tissues (Lateral Imbrication)
- Pain medications
- Anti-inflammatory medications
- Antibiotic Medications
- Detailed activity restriction and rehabilitation instructions
- Keep the incision clean and dry
- Prevent licking or chewing
- An E-collar (cone) must be worn at all times when not directly supervised
- Strict rest is required initially, with leash-only bathroom breaks
- Gradual return to activity over several weeks
- Physical rehabilitation and at-home exercises are strongly recommended to rebuild strength and improve outcome
The prognosis for medial patellar luxation surgery is generally excellent, especially when addressed early and followed by proper rehabilitation and weight management.
Contact a veterinarian if you notice:
- Increased swelling, redness, or discharge at the incision
- Persistent or worsening lameness
- Signs of pain, lethargy, or fever
- The incision opening or sutures coming loose
Our goal in treating medial patellar luxation is to reduce pain, improve mobility, and prevent long-term joint damage. If you have questions about MPL or whether surgery is right for your pet, please contact us, we’re happy to help guide you through the decision and recovery process.
