Patellar Dislocation: Rehab, Recovery Time and Return to Sport

What happens in a patellar dislocation

The kneecap (patella) glides in a groove at the end of the thigh bone (the trochlea). On the inner side, a band called the medial patellofemoral ligament (MPFL) acts as a check rein that stops the kneecap sliding outward. In a dislocation, usually from a twist on a planted foot with the knee slightly bent, the kneecap jumps over the outer rim of the groove. The MPFL tears in almost every first dislocation, and the kneecap often strikes the thigh bone as it pops back, which can bruise bone or chip off cartilage.

Many kneecaps go back into place on their own when the knee is straightened. For first aid and what to do right away, see dislocated kneecap. If the kneecap keeps slipping, see patellar instability.

Before rehab starts: what doctors check

• X-rays to confirm the kneecap is back in place and look for bone fragments.
• MRI in most first dislocations, to look for osteochondral fractures (a piece of cartilage with bone), MPFL tear location, and anatomy such as a shallow groove or high-riding kneecap.
• Exam of joint laxity, alignment and the opposite knee.

A loose fragment that blocks movement or a large cartilage piece that can be reattached usually means early surgery. Without one, rehab is the standard first step.

Patellar dislocation rehab: phase by phase

Timelines are typical ranges. Progress is based on milestones, not dates.

Key exercises

• Quadriceps strengthening, especially the inner part (VMO), starting with isometric quad sets and progressing to leg press and squats in a range that does not provoke pain or apprehension.
• Hip abductor and external rotator strength: clams, side-lying leg raises, banded side steps. Weak hips let the knee collapse inward, which pushes the kneecap outward.
• Core and balance training: single-leg stance, then on unstable surfaces.
• Landing mechanics: landing softly with the knee over the toes rather than collapsing inward.

Bracing and taping

A hinged brace or immobilizer is often used briefly for comfort in phase 1. Prolonged rigid immobilization causes stiffness and muscle loss and is not recommended. A patellar stabilizing sleeve or taping may help confidence when returning to sport, though evidence that it prevents redislocation is limited.

Swelling and pain

A large swelling may be drained by a doctor to relieve pain and speed quadriceps recovery. Ice, compression, elevation and acetaminophen (paracetamol) or ibuprofen at the label dose help in the first weeks.

Return to sport after patellar dislocation

Most athletes return in 3 to 6 months. Common criteria before returning to cutting and jumping sports:

• no swelling and full, pain-free range of motion
• no apprehension when the kneecap is pushed outward
• quadriceps and hamstring strength at least about 90% of the other leg
• hop tests (single, triple, crossover, timed) at least about 90% of the other side
• good control on single-leg squat and landing tests
• confidence in the knee

Returning before these milestones raises the risk of another dislocation.

Recurrence risk and when surgery is better

About a third of people dislocate again after a first episode, mostly within 2 years. Risk is higher with:

• age under about 16, with open growth plates
• trochlear dysplasia (a shallow or flat groove)
• patella alta (a high-riding kneecap)
• a large distance between the shin bone attachment and the groove (raised TT-TG distance)
• generalized joint hypermobility
• a previous dislocation of the other knee

Surgery is usually advised for a loose or displaced fragment, or after a second dislocation. The main operation is MPFL reconstruction, using a tendon graft to rebuild the ligament. A tibial tubercle osteotomy realigns the kneecap's tendon attachment when alignment is the problem, and trochleoplasty deepens a very shallow groove in selected cases. After MPFL reconstruction, return to sport typically takes 6 to 9 months.

Long-term outlook

Most people return to their previous activities. Repeated dislocations damage the cartilage behind the kneecap and raise the risk of kneecap pain and patellofemoral arthritis later, which is a main reason to prevent recurrence. Continuing a short strength program 2 to 3 times a week after rehab ends helps keep the knee stable.

Frequently asked questions

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

Most people walk normally within 2 to 6 weeks, return to light jogging at around 3 months, and return to full sport in 3 to 6 months. Recovery depends on swelling, cartilage injury and how quickly strength returns. After surgery, return to sport usually takes 6 to 9 months.

What exercises are best after a dislocated kneecap?

Early on, quad sets, straight leg raises and heel slides restore muscle activation and motion. Later, leg press, step-ups, split squats and hip strengthening such as clams and banded side steps build stability. Balance and landing drills prepare you for sport. A physical therapist adjusts these to your knee.

Should I wear a brace after a patellar dislocation?

A brace is often used for comfort for the first 1 to 2 weeks. Long periods in a rigid brace cause stiffness and weak muscles. A stabilizing sleeve may help confidence when returning to sport, but strength training matters far more for preventing another dislocation.

Why do teenagers dislocate their kneecap more often?

Teenagers play pivoting sports, often have more flexible ligaments, and may have anatomical features such as a shallow groove or high kneecap that become more noticeable during growth spurts. Young age with open growth plates is one of the strongest predictors of a repeat dislocation.

Will my kneecap dislocate again?

About a third of people have another dislocation, usually within 2 years. The risk is lower with completed rehab and good strength, and higher with a shallow groove, high kneecap, loose joints or young age. Surgery is often recommended after a second dislocation.