My Kneecap Dislocated. What Should I Do?

Medically reviewed by Dr. Sabrina Strickland, MD · Orthopedic Surgeon, Hospital for Special Surgery · Last reviewed: April 30, 2026

Quick Summary

A dislocated kneecap (patella) happens when the patella slips out of its groove at the front of the knee, usually after a twisting or direct-blow injury. If the kneecap has not slid back into place on its own, seek immediate medical care for reduction, then arrange an MRI with an orthopedic specialist to check for cartilage or ligament damage. Most first-time dislocations heal with bracing and physical therapy, but recurrent dislocations or significant cartilage injury often need MPFL reconstruction or related stabilization surgery.

August 15, 2025

If your kneecap has dislocated, seek immediate medical attention so the patella can be reduced (placed back in the groove), then have an orthopedic specialist evaluate the knee with an MRI to check for cartilage or ligament injury. A dislocated patella, or kneecap, occurs when the patella slips out of its normal groove at the front of the knee, usually causing sudden pain, swelling, and difficulty moving the knee. Here’s what you should know and the steps you should take if you have a kneecap dislocation.

Immediate Steps After a Kneecap Dislocation

If your kneecap hasn’t returned to its normal position on its own, go to an emergency room or call 911 — a clinician will gently guide the patella back into place in a process called reduction. A healthcare provider (an orthopaedic surgeon, emergency room doctor, or, in some cases, a trained EMT or paramedic) is the right person to perform this maneuver. Do not try to forcibly reduce the kneecap yourself, since the surrounding cartilage and ligaments are vulnerable while the patella is out of place.

In most cases, this can happen spontaneously as you straighten your knee, where the kneecap “pops” back into place on its own. After the kneecap is back in position, your knee will likely be swollen and painful. Rest, ice, and elevation can help reduce swelling in the first few days. Your doctor may also recommend a knee brace or splint and crutches to keep weight off the joint while it heals from the kneecap dislocation.

Diagnosis and Imaging

After a kneecap dislocation, an MRI is the best way to assess damage to the cartilage, ligaments (especially the MPFL), and bone — even if the patella has returned to its groove. X-rays alone can miss the soft-tissue injury that often accompanies a dislocation, so I always recommend an MRI in our practice. Even after a single kneecap dislocation, cartilage damage can occur, and the risk of future dislocations increases, especially in younger patients or those with certain anatomical risk factors. Learn more about patellar instability, including risk factors and treatment options.

Treatment Options

Non-Surgical Care

For many first-time kneecap dislocations without significant cartilage or bone injury, non-surgical treatment — bracing followed by physical therapy — is the appropriate first step. This typically involves a very short period of immobilization in a brace or splint, followed by physical therapy to restore range of motion and strengthen the muscles around the knee. Early physical therapy is important for you to regain normal movement and be able to support the kneecap, helping to prevent future instability (and kneecap dislocations).

Surgical Care

Surgery is generally considered when you have a high risk of recurrence, multiple kneecap dislocations, or imaging evidence of loose cartilage or bone fragments that could cause locking or further damage. Procedures may include reconstructing the medial patellofemoral ligament (MPFL), repairing or replacing the cartilage, or realigning the bones to better support the kneecap. The goal of these surgeries is to stabilize the knee joint, protect the cartilage, and reduce the risk of arthritis.

Recovery and Prevention

Recovery from a kneecap dislocation typically takes 6–12 weeks for non-surgical cases and 4–6 months when MPFL reconstruction or related stabilization surgery is needed. Exact timelines vary depending on the severity of the injury, the presence of cartilage damage, and whether surgery is required. Read more about MPFL recovery timelines. Physical therapy is an important element of both surgical and non-surgical recovery, helping you regain strength, flexibility, and confidence in the stability of your knee. It’s important to follow your care team’s instructions closely and to avoid returning to high-risk activities until your knee is fully healed.

When to Seek Further Help

If you experience repeated dislocations, persistent pain, or a sense of instability in your knee, consult an orthopedic specialist promptly. Ongoing instability can lead to progressive cartilage damage and increase the risk of arthritis in the future.

Key articles for further reading:

If you’ve experienced a kneecap dislocation, timely evaluation and appropriate care are important ways to help you make a full recovery and protect your knee in the future.

Photo by Keagan Henman on Unsplash.

arthritis, cartilage damage, dislocated patella, kneecap dislocation, Medial patellofemoral ligament, MPFL, MRI, non-surgical treatment, orthopedic specialist, patella, patellar instability, patellar reduction, Physical Therapy, recovery, surgical care

Frequently Asked Questions

How long does it take to recover from a kneecap dislocation?

For first-time dislocations without major cartilage injury, most patients recover in 6 to 12 weeks with bracing and physical therapy. If MPFL reconstruction or another stabilization procedure is required, expect a 4 to 6 month recovery before returning to high-impact sports. The exact timeline depends on the severity of the injury, whether there is cartilage damage, and how consistently you complete physical therapy.

Will my kneecap dislocate again after the first time?

The risk of a second dislocation after a first-time kneecap dislocation is significant — published data suggests roughly 30 to 50%, with higher rates in teenagers and patients with anatomical risk factors like a shallow groove on the thigh bone or a high-riding kneecap. That is one of the reasons I always recommend an MRI and an in-person evaluation after a first dislocation, so we can identify whether early stabilization is warranted.

Do I need surgery after a dislocated kneecap?

Most first-time dislocations are managed without surgery. Surgery — most commonly MPFL reconstruction, sometimes combined with cartilage repair or a tibial tubercle osteotomy — is typically reserved for patients with multiple dislocations, loose cartilage or bone fragments on MRI, or significant anatomical risk factors. The goal of surgery is to stabilize the joint and protect the cartilage, not to chase a single event.

Can I walk on a dislocated kneecap?

Even after the kneecap has been put back in place, you should avoid putting full weight on the knee until you have been evaluated by a clinician. Most patients use crutches and a brace or knee immobilizer for the first few days while the swelling settles. Walking on an unstable knee with cartilage or ligament injury risks making the damage worse.

What is the difference between a dislocation and a subluxation?

A dislocation means the kneecap fully comes out of its groove; a subluxation means it partially shifts out and slips back in. Both are part of the kneecap instability spectrum and both deserve evaluation — subluxations can damage cartilage and can predict future full dislocations. Read more about telling whether your kneecap is slightly dislocated.