MPFL reconstruction

The medial patellofemoral ligament (MPFL) sits on the inner side of the kneecap and resists it sliding too far outward. When it is stretched or torn — most often during a dislocation — the kneecap can become unstable. MPFL reconstruction rebuilds that restraint, usually using a graft, to help keep the kneecap centered in its groove.

It is one possible treatment for selected patients, not an automatic one. Many people with patellar instability, especially after a first-time event, are managed without surgery.

Reconstruction may enter the conversation when instability keeps happening despite rehabilitation, or when a patient's injury pattern and activity make recurrence likely. The decision is individualized and is made together after your examination and imaging, weighing your symptoms, goals, and the underlying anatomy of your knee.

MPFL reconstruction addresses the soft-tissue restraint. It is distinct from every other procedure that may sometimes accompany instability surgery, and understanding the differences helps you have a clearer conversation with your surgeon:

• Isolated MPFL reconstruction — rebuilding the ligament alone, when the soft-tissue restraint is the main problem.
• Isolated tibial tubercle osteotomy (TTO) — repositioning the bony attachment of the patellar tendon to address alignment, tracking, patellar height, or cartilage loading, without reconstructing the MPFL.
• Combined MPFL reconstruction and TTO — when both the soft-tissue restraint and bony alignment are addressed together; the surgeon selects the combined plan.
• Distalization or other TTO variations — specific adjustments to the bony realignment for particular problems, such as a kneecap that sits too high.
• Additional cartilage or ligament procedures — sometimes needed when there is cartilage damage or another injury inside the knee.

Rehabilitation after MPFL reconstruction protects the healing graft early and then progresses in stages — restoring motion and quadriceps control, then strength and single-leg control, and later a graded return toward running and sport-specific activity when criteria are met. Your surgeon and physical therapist give you an individualized plan, and their instructions take precedence. When another procedure is performed at the same time, the more protective plan governs and recovery is adjusted accordingly.

Risks include stiffness, recurrent instability, persistent pain, arthritis, patella fracture, infection, blood clots in the leg, and problems related to the graft or its fixation. No operation guarantees that instability will never return. These trade-offs are discussed with your surgeon in the context of your own knee.