Shorter Relative Patellar Defect Length After Bone-Patellar Tendon-Bone Autograft Anterior Cruciate Ligament Reconstruction Is associated With Better Postoperative Patient-Reported Outcomes at 1-Year Follow-Up.

PURPOSE: To evaluate bone-patellar tendon-bone autograft anterior cruciate ligament reconstruction patellar defect dimensions over time and associate these with patient-reported outcomes.

METHODS: Patients undergoing bone-patellar tendon-bone autograft autograft anterior cruciate ligament reconstruction by 1 of 7 surgeons between June 2020 and June 2023 were recruited to obtain knee magnetic resonance imaging at 6 weeks and 1 year postoperatively and complete a knee injury and osteoarthritis outcome score (KOOS) survey at 1 year postoperatively. Patellar bony defect dimensions relative to the entire patellar dimensions were measured on magnetic resonance imaging and associated with KOOSs at 1 year.

RESULTS: For the 23 patients (15 men) with a mean ±  standard deviation age 25.5 ± 5.2 analyzed, shorter relative patellar defect length at 6 weeks postoperatively was associated with better 1-year KOOS activities of daily living (R2 = 0.481, P = .002) and function in sports and recreation (R2 = 0.436, P = .002), and showed trends for associating with better pain (R2 = 0.196, P = .078) and knee-related quality of life (R2 = 0.222, P = .054). Participants with longer relative defects were more likely to report difficulty with kneeling (R2 = 0.278, P = .020). These associations were not altered by considering patient age or sex. The average relative patellar defect width and depth decreased from 6 weeks to 1 year (P < .001), whereas relative defect length was unchanged. Intraobserver reliability was good to excellent for all measurements at 6 weeks and 1 year. Relative defect width and depth, at both 6 weeks and 1 year, had no significant associations with KOOSs at 1 year.

CONCLUSIONS: Shorter relative patellar defect length after bone-patellar tendon-bone autograft autograft anterior cruciate ligament reconstruction is associated with better patient-reported outcome measures at 1 year, and thus, individual patient patellar size should be a consideration during graft harvest.

LEVEL OF EVIDENCE: Level IV, retrospective case series.