Tibial Tubercle Osteotomy (TTO)

Why this approach — at MOS

TTO is a precise surgery where the pre-operative planning drives the intraoperative execution. We obtain CT measurements of TT-TG distance on every patient with patellar instability to quantify the bony component before planning surgery. When TT-TG is between 15–20 mm, the decision to combine TTO with MPFL reconstruction is individualized based on instability severity and associated anatomy. When TT-TG exceeds 20 mm, TTO is almost always included.

We prefer the anteromedial (Fulkerson) osteotomy for patients with both instability and patellofemoral pain because it simultaneously reduces the lateral vector of the patellar tendon and offloads the articular cartilage on the lateral and distal patellar facets. The amount of medialization and anteriorization is planned specifically for each patient rather than using a fixed distance.

Patients from Bethesda, Germantown, Rockville, and across Montgomery County who present with recurrent patellar instability receive a complete anatomic assessment — TT-TG, trochlear morphology, patella height, and limb rotation alignment — before any surgical planning. This ensures that the surgical procedure addresses the specific anatomic driver of the patient's instability, not a generic approach.

Who is a candidate?

Indications

• Patellar instability with significantly elevated TT-TG distance (>20 mm) — MPFL reconstruction alone is insufficient when the bony lateralizing force is excessive
• Patellofemoral pain syndrome with lateral facet overload that has failed non-surgical management, confirmed by imaging
• Patella alta (high-riding patella) causing instability or pain — distal transfer corrects the height
• Recurrent patellar dislocation combined with trochlear dysplasia and elevated TT-TG
• Patellofemoral arthritis limited to the lateral or distal facet — anteromedial transfer unloads the arthritic segment

Contraindications

• Diffuse patellofemoral or tricompartmental arthritis — osteotomy does not address generalized arthritis
• Active bone infection
• Skeletally immature patient with open tibial growth plate (proximal tibial physis) — growth plate must be closed
• TT-TG within normal range — TTO not indicated when bony alignment is appropriate

Conservative Treatment First

TTO is a bony procedure reserved for patients who have failed appropriate non-surgical management for their patellofemoral complaint. For patellar instability, structured physical therapy (VMO and hip strengthening, taping, bracing) is tried after dislocation events before surgery is considered. For patellofemoral pain, a supervised program of quadriceps strengthening, hip abductor and external rotator exercises, activity modification, and patellar taping or bracing is appropriate for 3–6 months before surgical options are discussed. Surgery is indicated when these measures fail to control symptoms and the anatomy (elevated TT-TG, patella alta) confirms a surgically correctable bony cause.

The procedure

What Is Tibial Tubercle Osteotomy (TTO)?

Tibial tubercle osteotomy (TTO) is a surgery that detaches the bony prominence (tibial tubercle) where the patellar tendon attaches to the shinbone and repositions it to correct abnormal kneecap alignment. By moving the attachment point inward, downward, or anteriorly — depending on what the problem is — TTO corrects the bony geometry that causes patellar instability or patellofemoral pain.

The tibial tubercle is the bump at the top of the shinbone where the patellar tendon inserts after crossing the kneecap. The position of the tibial tubercle relative to the trochlear groove (the channel in the femur where the patella rides) determines the direction and magnitude of forces acting on the patella during quadriceps contraction. When the tubercle is positioned too far laterally — measured as an elevated TT-TG distance (tibial tubercle-to-trochlear groove) — the patella is pulled too far outward, predisposing it to dislocation, subluxation, or abnormal contact pressure.

TTO corrects this bony malalignment directly. The specific direction of transfer depends on the problem: medialization reduces lateral pull in patellar instability; anteriorization (Maquet procedure) offloads the patellofemoral joint in patellofemoral pain; anteromedial transfer (Fulkerson osteotomy) achieves both simultaneously and is the most commonly performed variant. TTO is often combined with MPFL reconstruction when both bony and soft tissue factors contribute to instability.

What Happens During Tibial Tubercle Osteotomy?

TTO is performed at a hospital under general anesthesia. The patient is positioned supine. A tourniquet is applied to the upper thigh. An incision is made over the anterior tibia, exposing the tibial tubercle and the surrounding bone.

The osteotomy plane is marked based on pre-operative planning — CT measurements of TT-TG and patella height dictate the exact amount of medialization and/or anteriorization needed. A thin, angled osteotomy cut is made using an oscillating saw, leaving the distal periosteal hinge intact to preserve the blood supply to the tubercle fragment and prevent complete detachment.

The tubercle fragment is mobilized to the planned position and temporarily held with K-wires while alignment is confirmed with fluoroscopy. The patella is assessed for tracking — it should run centrally in the trochlear groove through full range of motion. Once position is confirmed, two or three cortical screws are placed to definitively fix the tubercle in its new location. The periosteal hinge remains intact, supporting healing.

The wound is closed in layers. Most patients require an overnight or 1-2 night hospital stay because of the extent of the bony work and the multimodal pain management needed in the first 24 hours.

Recovery timeline

Frequently Asked Questions