Poster 294: Patellar Tendon Insertion is Not Distalized following Tibial Tubercle Osteotomy with Distalization

Objectives: Patella alta is a common anatomic risk factor in patients with patellofemoral instability and/or cartilage lesions, occurring nearly 25% of these patients. Distalization tibial tubercle osteotomy (TTO) effective patella association and lesions. Prior studies have suggested that increased patellar tendon length itself for recurrent instability, proposed the addition tenodesis via placement suture anchor proximal to distalization TTO. However, concerns regarding stresses limited its adoption. The purpose this study was evaluate alignment parameters on preoperative postoperative MRI patient reported outcomes (PROs) following without alta. Methods: We conducted retrospective review 20 adult who underwent TTO at our institution (December 2014-August 2021). All magnetic resonance (MR) imaging affected knee. utilized wedge-shaped measuring ˜5cm fixed two 4.5mm bicortical fully threaded screws TT transfer. Caton-Deschamps (CDI), axial sagittal TT-TG indices 1 , distances from plateau insertion were assessed (Figure 1). PROs included IKDC Subjective Knee Evaluation, KOOS Quality Life Form, Kujala Anterior Pain From, Veterans RAND 12 Item Mental (VR12-MH) Physical Health (VR12-PH) Surveys. Clinical data, including demographics, complication perioperative obtained charts electronic medical record. Results: Average age time surgery 27.4 years (range: 14 – 42 years) all female. BMI 24.9 +/- 4.4 kg/m2. Eleven (55%) diagnosed isolated four (20%) associated lesions five (25%) both At distalization, eleven matrix-induced autologous chondrocyte implantation (MACI), nine (45%) MPFL reconstruction, lateral release/lengthening, three (15%) osteochondral allograft (OCA) implantation. Fourteen (70%) anteromedialization distalization. Radiographic demonstrated improved height (CDI decreased 1.36 1.11 (p < 0.001), rotational (axial 14.3mm 11.1mm = 0.018)) anteriorization (sagittal -4.3mm -1.4mm 0.037)) Distance PT 20.1mm preoperatively 17.9mm postoperatively (p< 0.020) 53.4mm 50.0mm 0.001). 6.4mm. scores 37.1 60.5 0.011), QOL 19.5 42.1 50.9 70.6 0.018), VR12-MH 52.7 59.2 0.024) VR12-PH 35.1 41.7 0.009). Of there no cases postoperatively. Ten (50%) elective removal hardware an average 10.7 months. There complications cohort, (10%) arthrofibrosis requiring manipulation under anesthesia, one case (5%) MRSA infection graft delayed union bone grafting revision fixation. Conclusions: surgical technique improving improvements radiographic cohort. does not appear be significantly distalized TTO, likely related scarring just site Given complexity factors provides additional tool patient-specific management, need tenodesis. References: 1. Lansdown DA, Christian D, Madden B, et al. Sagittal Tibial Tubercle-Trochlear Groove as Measurement Imbalance Patients Symptomatic Patellofemoral Chondral Lesions. Cartilage. 2021;13(1_suppl):449S-455S. doi:10.1177/1947603519900802 [Table: see text][Table: text]