Patellar Dislocation Treatment
A kneecap dislocation is dramatic and usually brief. The kneecap slides out of its groove toward the outer side of the knee, and it frequently relocates on its own the moment the leg is straightened, which is why some patients arrive describing a knee that “gave out” without realizing what actually happened.
A kneecap that has dislocated once is considerably more likely to do it again, particularly in younger patients, and that risk drives the treatment decision. Steven Struhl, MD is board certified in orthopedic surgery and separately in sports medicine and arthroscopic surgery, completed his sports medicine fellowship at Penn State University, and has practiced in New York since 1991.
What Happens During a Kneecap Dislocation
- Lateral Displacement: the kneecap moves outward out of the groove, the pattern in nearly all cases.
- MPFL Tear: the ligament restraining outward movement tears in most dislocations.
- Cartilage Damage: the kneecap can shear cartilage off its own surface or the groove edge on the way.
- Loose Fragments: those sheared pieces can become loose bodies within the joint.
The cartilage damage is the part patients do not expect. A dislocation that reduces on its own and settles within days can still have taken a fragment off the joint surface, which is why imaging matters even when the knee feels better.
Who Dislocates a Kneecap
- Adolescents And Young Adults: the peak age range by a considerable margin.
- Shallow Groove: a flatter than normal trochlea gives the kneecap less containment.
- High Riding Kneecap: a patella sitting high engages the groove later during bending.
- Alignment: a wider pelvis or inward thigh rotation increases the outward pull.
After a First Dislocation
- Imaging: X rays and MRI to identify cartilage injury, loose fragments, and MPFL tearing.
- Brace Or Immobilization: a short period of protection while acute symptoms settle.
- Physical Therapy: quadriceps and hip strengthening to restore control of the kneecap.
- Fragment Removal: arthroscopic surgery when a loose cartilage fragment is identified.
Most first time dislocations in patients with normal anatomy are treated without ligament surgery, since a meaningful proportion never dislocate again. What does warrant surgery early is a displaced cartilage fragment, which does not resolve on its own.
When It Happens Again
Recurrence changes the conversation. A second dislocation makes a third considerably more likely, and each episode carries another chance of cartilage damage.
At that point MPFL reconstruction becomes the standard option, sometimes combined with a procedure addressing the underlying anatomy where the groove is shallow or the kneecap sits high.
Schedule a Knee Evaluation in New York City
A kneecap that dislocated and then felt better within a week has not necessarily healed without consequence, since the cartilage damage that happens during the event is not something a settling knee reports. Dr. Struhl evaluates patellar instability at his Manhattan and White Plains offices. Contact the practice to schedule an appointment.
