Patellar Dislocation !
A patellar dislocation is when the kneecap slips out of its groove, almost always to the outer side, after a twist or a direct blow.
Updated 2026-10-23
Structures involved
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What it is
The kneecap moves out of its groove, usually laterally, after a twisting injury or direct blow.
Risk factors
- Patella alta
- Trochlear dysplasia
- Previous dislocation
Symptoms and signs
- Sudden pain and deformity of the kneecap
- Swelling
- Inability to straighten the knee fully
Diagnosis
- Clinical
- History and exam
- Imaging
- X-ray to rule out fracture; MRI for cartilage or soft-tissue injury
Treatment
- Rehabilitation
- Reduction if needed, bracing, and physical therapy for first-time dislocations.
- Surgical
- MPFL repair or reconstruction for recurrent dislocations.
Complications
- Recurrent instability
- Osteochondral fracture
- Patellofemoral osteoarthritis
Related conditions
Educational information, not medical advice. For any symptom, see a health professional.
Sources: Patella Dislocation (StatPearls (NCBI Bookshelf), 2024).
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Representative model, for educational purposes only.
