The kneecap (patella) normally rests in a small groove at the end of the thighbone (femur). As the knee bends and straightens, the patella glides smoothly within this groove. A patellar dislocation occurs when the kneecap slips partially or completely out of this track.
This may happen due to a fall, a direct blow, or underlying structural issues in the knee. Even if the kneecap shifts back into place on its own, a medical evaluation is important to assess pain, swelling, or potential damage to surrounding structures.
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What Causes Patellar Dislocation?
Patellar dislocations can result from a combination of structural, biomechanical, and traumatic factors, including:
- A shallow or uneven trochlear groove in the femur
- Loose or flexible ligaments that allow excessive joint movement
- Muscle imbalance or weakness around the knee
- Direct blows or falls, especially during sports or high-impact activities
- Twisting movements, such as planting the foot and pivoting
- Knee arthritis, because the cartilage under the kneecap wears away (this is also called subluxation)
Even individuals with normal knee anatomy can experience a dislocation during sudden directional changes or awkward landings.
Symptoms of Patellar Dislocation
A patellar dislocation may cause:
- Pain around the kneecap
- Swelling in the knee
- A sensation that the kneecap is shifting or sliding out of place
- Knee buckling or giving way
- A popping sound at the moment of dislocation
- Visible deformity or change in knee appearance
- Apprehension or fear when bending, running, or changing direction
Diagnosing Patellar Dislocation or Knee Instability
A specialist will typically review how the injury occurred and evaluate your symptoms. The knee will be examined for swelling, tenderness, range of motion, and alignment. Imaging such as X‑rays or MRI scans may be used to assess bone structure, cartilage, and ligament integrity.
Treating Dislocation of the Kneecap
Treatment depends on whether the kneecap has returned to place, the extent of soft tissue injury, and the individual’s risk of recurrence.
Immediate Care
- If the kneecap remains dislocated, go to the emergency room immediately
- Reduction: The doctor may administer pain medication and gently guide the kneecap back into place
Nonsurgical Treatment
Most first-time dislocations can be managed without surgery, using a combination of the following:
- Immobilization: A brace may be used for several weeks to stabilize the knee.
- Reduced Weightbearing: Crutches may help reduce pain and protect the knee during early healing.
- Physical therapy: Strengthening the quadriceps and surrounding muscles helps restore stability and motion.
- Recovery timeline: Many people return to normal activity within 3–6 weeks, depending on injury severity.
Ongoing strengthening and low-impact exercises, such as cycling, can help prevent future dislocations.
Patellar Dislocation Surgery
Surgery may be needed if the kneecap repeatedly dislocates, remains unstable despite bracing and therapy or if there are structural abnormalities.
Surgical options include:
- Ligament reconstruction: Repairing or stabilizing the ligaments that hold the kneecap in place
- Knee scope: Minimally invasive surgery using small incisions. T
- Patellofemoral Replacement: surgical replacement of the kneecap
- Complex reconstruction: For significant bone or alignment issues
Return to Activity
Individuals can resume activities once knee strength and motion have fully returned. High-demand sports may require a longer recovery period, and confidence in knee stability is an important factor in returning safely.
Treat Patellar Dislocation at OrthoNebraska
If you’re experiencing patellar instability or have recently dislocated your kneecap, OrthoNebraska is here to help. Our team focuses on understanding your symptoms, ensuring your comfort, and guiding you toward an effective treatment plan. With proper care, we can help reduce pain and improve your quality of life.
