A dislocated kneecap (patellar dislocation) occurs when the patella slips out of the trochlear groove, usually moving toward the outside of the leg. This extremely painful injury often results from a sudden twisting motion or a direct blow to the knee, frequently occurring during sports. Attempting to manually reduce the kneecap at home is highly dangerous and must be avoided. A patellar dislocation is a medical emergency that requires professional assessment and treatment to prevent permanent joint damage. This guide outlines the immediate, safe actions to take and what to expect from professional medical care.
Identifying Patellar Dislocation and Why Self-Reduction is Harmful
The symptoms of a patellar dislocation are distinct and severe, starting with intense, sudden pain and a feeling of the knee “popping” out of place. The most obvious sign is a visible deformity, where the kneecap appears to be resting on the side of the joint. Significant swelling and bruising develop rapidly, and the person will be unable to bear weight on the affected leg.
The immediate danger of attempting self-reduction is the risk of causing severe injury to the knee’s internal structures. Forcing the bone back can shear off fragments of cartilage or bone (osteochondral fractures), which leads to long-term joint damage and arthritis. The primary stabilizing ligament, the Medial Patellofemoral Ligament (MPFL), is typically torn during a dislocation, and improper manipulation can worsen this tear or damage nearby blood vessels and nerves. Only a medical professional can assess the full extent of the damage before the patella is relocated.
Immediate Stabilization and Safe First Aid Measures
The most critical step following a suspected kneecap dislocation is to call for emergency medical services or arrange transport to a hospital emergency room. Until medical help arrives, stabilize the limb precisely in the position in which it was found; do not attempt to straighten, move, or manipulate the leg, as this could cause further injury. Support the leg with soft padding, such as rolled-up towels, while the patient is lying down comfortably. To manage initial swelling and pain, apply a cold compress or ice pack wrapped in a thin cloth, avoiding direct skin contact. Keep the injured limb immobilized and avoid putting any weight on it.
Professional Medical Reduction and Hospital Care
In a controlled medical environment, repositioning the kneecap is called reduction. This procedure is performed in an Emergency Room, often requiring strong pain medication or sedation to relax the surrounding muscles. The physician gently extends the leg while applying controlled pressure to guide the kneecap back into the groove. A successful reduction often results in a palpable “clunk” and an immediate decrease in pain.
Following reduction, X-rays confirm the patella is correctly positioned and check for associated fractures. An MRI scan is often necessary to evaluate soft tissue damage, such as an MPFL tear or loose osteochondral fragments that may require surgical removal. This detailed examination ensures all related injuries are identified, dictating the subsequent treatment plan.
Rehabilitation and Preventing Future Dislocations
After the kneecap is back in place, immediate treatment involves immobilizing the knee, often with a brace or splint for several weeks, allowing torn ligaments to begin healing. Long-term management focuses on a structured course of physical therapy centered on strengthening the muscles that stabilize the knee, particularly the quadriceps and hip abductors.
Strengthening the vastus medialis obliquus (VMO), the inner part of the quadriceps, helps keep the kneecap tracking correctly. Exercises also focus on improving balance and proprioception (the body’s sense of joint position) to reduce the risk of recurrence. Surgery, such as MPFL reconstruction, is reserved for cases involving chronic instability, severe initial tears, or when conservative rehabilitation fails.