A patella dislocation, where your kneecap is forced out of its normal groove and shifts laterally, is a serious injury that requires prompt evaluation and management. Yet, some people try to wait it out or do not seek orthopedic care, especially if the kneecap slips back into place on its own and the swelling improves over a few days. It’s completely understandable to hope it will get better on its own, but that’s often when important injuries are missed.
What truly happens if a patella dislocation is left untreated? Let’s explore the consequences, long-term risks, and best practices based on my decades of experience with knee injuries.
Understanding Patella Dislocation
When the patella dislocates, it often tears or stretches the medial patellofemoral ligament (MPFL), a crucial structure that keeps your kneecap tracking properly in its groove. In addition to ligament damage, it’s common for patients to have cartilage injuries and sometimes bone fragments that break loose during the initial trauma.
Some people have underlying anatomic risk factors that make a dislocation more likely and make recurrence more common, such as a shallow groove on the femur (trochlear dysplasia), a high-riding kneecap (patella alta), or an increased distance between the tibial tubercle and the trochlear groove (TT–TG distance).
When a patient comes in after a first dislocation, one of the first things I look for is whether any of these underlying factors are present, because they help predict how likely your kneecap is to slip out again and what kind of treatment will give you the most confidence going forward.
Immediate Consequences of Untreated Patella Dislocation
1. Ongoing Knee Instability and Repeat Patella Dislocation
One of the most common outcomes of neglecting a dislocated patella is that the knee remains unstable. Once the MPFL is torn, it does not heal back to its original strength or tension by itself. That’s why you might feel like you can never fully trust your knee again, even if the pain settles down between episodes.
This leaves the patella much more likely to dislocate again, sometimes during normal activities, not just when you’re playing sports. In fact, depending on your age and anatomy, the risk of recurrence after a first dislocation can range from about 15% in low‑risk patients to 80% or higher in younger, high‑risk individuals, especially when you have underlying structural issues in your knee.
2. Worsening Cartilage and Bone Damage
When the kneecap shifts out and back in, it can chip or gouge the smooth cartilage on the undersurface of the patella or the front or lateral side of the femur. Without medical attention, these injuries may go unrecognized and unaddressed, leading to loose fragments in the joint or progressive cartilage wear.
This is particularly worrisome because cartilage does not regenerate, and injuries here set the stage for early joint degeneration and arthritis.
Long-term Risks
1. Development of Patellofemoral Arthritis
Recurrent instability and untreated cartilage damage dramatically increase the chances of developing patellofemoral (kneecap) arthritis, even years or decades later. Patients with a history of multiple untreated dislocations may begin experiencing persistent pain, swelling, stiffness, and grinding in the knee. Ultimately, this can limit walking, exercising, or stair climbing, and may lead to the need for cartilage repair or even partial or total knee replacement down the road.
2. Chronic Pain and Activity Limitations
Many patients tell me that the worst part is not just the pain, but the constant worry that a simple misstep, a turn on the field, or even walking down stairs could make the kneecap pop out again. This loss of confidence can profoundly impact your involvement in athletic activities, work capacity, and quality of life. Some patients report a constant feeling of apprehension during basic activities like walking, going down stairs, or rising from a chair.
3. Muscle Atrophy, Weakness, and Poor Knee Function
When pain, swelling, or apprehension prevents normal use of the leg, the thigh muscles (especially the quadriceps) quickly weaken. This weakening can start within days to weeks of unloading the limb, which is why guided early motion and strengthening are important once you have the initial acute pain and swelling under control.
This weakness can further destabilize your knee and create a vicious cycle of increased instability. In severe cases, chronic atrophy may develop, making functional recovery much harder, even if you do eventually seek surgical intervention. The good news is that with the right plan, the quadriceps usually respond well to targeted strengthening especially with blood flow restriction therapy in physical therapy. It’s much easier to build and maintain that strength early than to rebuild it after months of guarding and avoidance.
Who Is Most at Risk?
Certain patients are much more likely to develop recurrent dislocations and long‑term damage if the initial event is not fully evaluated and treated, and part of my job during your visit is to sort out which group you fall into so you’re not guessing about your risk based only on a single scary event.
Younger patients (particularly those with open growth plates, a shallow trochlear groove, patella alta, or an increased TT–TG distance) are at a high risk for recurrence and progressive cartilage injury. When two or more of these risk factors are present, recurrence rates can approach 60–70% or more, which is why a tailored plan with imaging, rehab, and sometimes early surgery is so important.
Delayed or Missed Diagnosis of Associated Injuries
Sometimes a dislocation is associated with other serious injuries, such as osteochondral fractures (loose chunks of cartilage and bone), meniscus tears, or additional ligament injuries like damage to the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), or medial collateral ligament (MCL).
These are easy to miss without an MRI and a careful orthopedic exam. In most patients, especially those who are young or have a high‑energy injury, I strongly recommend an early MRI to look for osteochondral fragments and risk factors, with rare exceptions when a patient is asymptomatic and the clinical exam is completely normal. Delays in diagnosis can mean missing the window for effective cartilage surgery or leaving your knee vulnerable to further breakdown.
Patella Dislocation Standard of Care
Expert consensus and published guidelines recommend prompt evaluation and consultation with an orthopedic or sports medicine specialist after any kneecap dislocation. Most patients benefit from imaging: X‑rays to rule out obvious fractures and, in most cases, MRI to evaluate cartilage, bone, and the key risk factors outlined above.
I recommend treatment plans based on your anatomy and goals, ranging from bracing and supervised physical therapy to advanced surgical stabilization. In practice, that means we sit down together, review your imaging, talk about your sport or work demands, and decide whether a carefully structured rehab program, surgery, or a combination is the best way to get you back to the activities you care about.
For a first‑time dislocation without a major osteochondral fracture or high‑risk anatomy, nonoperative care with early supervised physical therapy remains the standard initial approach in many guidelines. Often, surgery is reserved for patients who develop recurrent instability or have significant loose fragments. When there are multiple risk factors or repeated dislocations, I consider early surgical stabilization more carefully to protect the cartilage and restore your confidence in that knee.
Bottom Line
If you simply ignore a dislocated patella, there’s a high likelihood of recurring instability, progressive cartilage injury, arthritis, chronic pain, and diminished function over time. When you come in early and we create a plan, whether that’s focused physical therapy, bracing, surgery, or a combination, you greatly reduce the risk of recurrent dislocation, cartilage damage, and early arthritis, and you give yourself the best chance to stay active over the long term.
My goal with every patient is to help you understand your specific risks, choose the least invasive option that will actually protect your knee, and get you back to moving with confidence instead of fear.
For more best practices and patient resources, check out the AAOS patellar instability guide.
For detailed diagnosis, risk evaluation, treatment, and recovery information, explore more of the resources on my website, including:
It’s important that you don’t leave a patella dislocation untreated. Please seek appropriate medical care if you dislocate your patella; it’s an investment in your lifelong knee health and mobility.
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