Overview
When the kneecap tracks too far laterally — or sits too high — the forces across the patellofemoral joint become abnormal and instability or wear follows. The attachment of the patellar tendon, the tibial tubercle, can be surgically moved to normalize those forces. The procedure is often combined with MPFL reconstruction when multiple anatomic factors contribute.
How the Procedure Works
We plan the direction and magnitude of the shift preoperatively using CT measurements — specifically the tibial-tubercle to trochlear-groove (TT-TG) distance for medialization, and the Caton-Deschamps ratio for distalization. The tubercle is cut as a long, tapered wedge of bone rather than a short block; the longer the osteotomy, the larger the contact surface for healing and the lower the stress per unit area at the fixation screws. We shift it the planned amount, confirm patellar tracking arthroscopically before fixing, and adjust if the patella still rides laterally or tilts. Two cortical screws hold the new position. When anteriorization is added — rotating the tubercle forward to offload a damaged patellar cartilage area — we plan that vector precisely so we don't inadvertently increase the Q-angle while trying to unload the joint surface.
When to Consider Tibial Tubercle Osteotomy
Tibial tubercle osteotomy is generally offered when symptoms, imaging, and a trial of non-operative care together point to surgery as the next step. The typical picture includes:
Instability with tubercle-trochlear offset
Imaging showing a lateralized tubercle that contributes to recurrent patellar dislocation.
Patella alta contributing to instability
A high-riding kneecap that engages the trochlea too late in flexion.
Patellofemoral arthritis realignment
Anteriorization or anteromedialization to unload a damaged area of patellar cartilage.
Conditions This Treats
Physicians Who Perform Tibial Tubercle Osteotomy
Providers Who Surgically Assist with Tibial Tubercle Osteotomy
Risks & Why We Still Recommend It
Every operation carries risk. The reason we offer this procedure is that the condition, left untreated, causes continued patellar maltracking, cartilage wear behind the kneecap, and recurrent instability events. That is the trade we are managing — not eliminating risk, but choosing the smaller of two unfavorable trajectories.
The risks we discuss with patients before tibial tubercle osteotomy include:
- bleeding and infection
- anesthesia risk
- tibial fracture through the osteotomy site
- hardware irritation that occasionally requires removal
- non-union of the transferred fragment
- stiffness
- blood clot (DVT/PE)
The indication to proceed is patellar maltracking or instability with measured bony malalignment (elevated TT–TG, patella alta) that a soft-tissue procedure alone won't fix. Patients who don't need this operation don't get it.
Further Reading
External patient-education references and related OSI pages for additional background: