MPFL Reconstruction Recovery
MPFL Reconstruction (Patellar Stabilization)
What the operation does
The medial patellofemoral ligament runs from the inner edge of the kneecap to the thigh bone and acts as a checkrein, stopping the kneecap sliding outward. It tears almost every time a kneecap dislocates. This operation replaces it with a graft — usually a hamstring tendon — anchored to the inner edge of the kneecap and into the thigh bone, restoring that restraint.
Why your kneecap dislocated
Almost always outward, and usually not from a direct blow — more often a twist on a planted foot, where the thigh rotates inward and the kneecap is left behind. Many people who dislocate have an underlying reason: a shallow groove for the kneecap to run in, a kneecap sitting high, a turned-out attachment on the shin, or generally loose ligaments. That is why the first dislocation so often leads to more.
Why the ligament is replaced rather than repaired
Stitching a torn MPFL back together sounds simpler and works poorly — the tissue is thin, often stretched rather than cleanly torn, and repairs stretch out again. Replacing it with a tendon graft gives a stronger restraint that holds, which is why reconstruction has become the standard where surgery is needed.
What else may need correcting
This is the question that decides how big your operation was. If the kneecap dislocated mainly because the ligament failed, reconstructing it is enough. If the bones are pulling it sideways — a shin attachment set too far out, or a kneecap riding too high — the ligament alone would be fighting that pull forever, so the bony attachment is moved and fixed with screws. That addition lengthens the recovery considerably and usually means a period of restricted weight-bearing that a ligament reconstruction alone would not need.
What you protect against early
Bending the knee under load, and anything pushing the kneecap outward. The graft is at its most vulnerable in deep bend, because that is where tension on it is highest. So bending is reintroduced in a controlled way over the first six weeks rather than all at once, and the brace limits how far you can go.
Getting the bend back matters here
More than after most knee ligament surgery. A kneecap that is not moving freely scars into place, and a stiff kneecap is the most common disappointment after this operation. That is why gentle kneecap gliding appears from the first week and controlled bending leads the second phase — the graft is protected by limiting the range, not by keeping the knee still.
A tunnel in the kneecap
The graft is anchored into the patella, usually through small tunnels or with anchors. The kneecap is a small bone, and a rare but recognised complication is a fracture through that area, usually from a fall or a heavy load early on. It is uncommon, and it is a reason the early restrictions are worth respecting even though the knee feels reasonable.
The graft can be fixed too tight
Worth knowing because it shapes what the surgeon was balancing. A graft tensioned too tightly presses the kneecap against the groove and causes pain at the front of the knee and difficulty bending. Too loose and the kneecap remains unstable. Getting that tension right is the technical heart of the operation, and it is why bending is measured carefully in the early weeks rather than pushed.
Apprehension — the feeling it will go again
Extremely common, and separate from the knee's actual stability. Having felt a kneecap come out, many people flinch from the positions where it happened long after the reconstruction is solid. It fades with strength and with graded exposure to those positions, which is part of what the later phases are doing. Mention it to your physiotherapist rather than working around it.
Why the hip work matters
The kneecap is pulled sideways when the thigh rotates inward, and what controls that is the muscle at the side of the hip rather than anything at the knee. Weak hip abductors let the knee fall inward on every step and land, which is exactly the position that dislocates a kneecap. That is why hip strengthening features so heavily here — it is treating the cause, not padding the programme.
Swelling and the front of the knee
Swelling settles over two to four months. Aching at the front of the knee with stairs and sitting for long periods is common in the early months and usually improves as the quadriceps rebuilds. Kneeling tends to be uncomfortable for six months or more.
Dislocating again
Reconstruction substantially reduces the risk compared with a knee treated without surgery, and most people never dislocate again. Where an underlying bony cause was present and not corrected, the risk is higher — which is why the assessment beforehand mattered as much as the operation.
Returning to running and sport
Running commonly returns around three to four months once strength and bend allow. Sport involving cutting, pivoting and jumping usually waits until six to nine months, and is judged on quadriceps and hip strength and on confidence in those positions rather than on a date. Where the bony attachment was moved as well, add time to both.
Driving and work
For a right knee, driving generally waits until you are out of the brace, comfortable bending, and could brake hard without hesitating — commonly around six weeks. A left knee in an automatic is much sooner. Desk-based work is often possible within one to two weeks; work on your feet commonly two to three months, and kneeling work later.
Staying in touch with your care team
Whether anything bony was corrected alongside the ligament changes this recovery substantially, and your surgeon knows what applied to your knee. If something about your recovery is worrying you or does not match what is described here — particularly a knee that is losing bend — contact your care team rather than waiting.
Exercises for MPFL Reconstruction
An illustrated, phase-by-phase exercise program for this procedure. View the MPFL Reconstruction exercise program.
Recovery education · Condition guides · Exercise programs
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This guide is general education and doesn't replace evaluation by a licensed provider. Recovery and treatment vary by person — follow the guidance of your own surgeon or care team.