MRI Patellar Dislocation

A patellar dislocation occurs when the kneecap (patella) slips out of its normal position, usually to the side of the knee. This can result in pain, swelling, and difficulty moving the knee.

Causes

• Trauma: Direct impact to the knee, such as during a fall or collision.
• Sudden Twisting Movements: Rapid changes in direction or twisting motions, common in sports, can dislocate the patella.
• Weak or Imbalanced Muscles: Imbalance in the muscles around the knee, particularly the quadriceps, can increase the risk.
• Structural Abnormalities: Conditions such as a shallow trochlear groove (the groove in which the patella sits) or a high-riding patella (patella alta).
• Previous Dislocation: A history of patellar dislocation can weaken the structures around the knee, making recurrence more likely.

Symptoms

• Pain: Sudden, intense pain at the front of the knee.
• Swelling: Rapid swelling around the knee.
• Visible Deformity: The kneecap may be visibly out of place.
• Inability to Straighten the Knee: Difficulty in extending the knee fully.
• Feeling of Instability: The knee may feel unstable or give way.
• Tenderness: Tenderness along the edges of the patella and around the knee.

Diagnosis:

• Physical Examination: Checking for signs of dislocation, swelling, and tenderness.
• Imaging:
  • X-rays: To assess the position of the patella and check for associated fractures.
  • MRI: Provides detailed images of soft tissues, including ligaments and cartilage, to identify any additional injuries or predisposing factors.

Treatment:

• Reduction: The initial step is to manually guide the patella back into place, usually performed by a medical professional.
• Immobilization: Using a brace or cast to keep the knee stable and allow healing.
• Physical Therapy: Strengthening the muscles around the knee, improving flexibility, and restoring range of motion.
• Surgery: In cases of recurrent dislocation or when conservative treatments fail, surgical options may be considered. Procedures can include:
  • Lateral Release: Cutting tight structures on the outer knee to allow the patella to move more freely.
  • Medial Patellofemoral Ligament Reconstruction: Rebuilding the ligament that helps keep the patella in place.
  • Osteotomy: Realigning the bones to improve patella tracking