Arthrofibrosis After Adolescent Anterior Cruciate Reconstruction with Quadriceps Tendon with Bone Block Autograft

Background: Anterior cruciate ligament reconstruction (ACLR) utilizing quadriceps tendon autografts with a patellar bone block (QTB) has gained popularity in children and adolescents, with favorable patient-reported outcomes being reported at 2 years postoperatively. The incidence of arthrofibrosis after ACLR in pediatric patients for all graft types is between 2% and 10%. However, there is a paucity of research focused on arthrofibrosis in pediatric patients undergoing ACLR with QTB. Purpose: To quantify children after ACLR with QTB and compare with previously published studies evaluating an all-soft tissue quadriceps autograft. Study Design: Case series; Level of evidence, 4. Methods: This was a retrospective review of children and adolescents aged ≤17 years who underwent primary ACLR with QTB between 2019 and 2023. Demographic characteristics (age, sex, body mass index [BMI]), insurance type, and pre-, intra-, and postoperative records were reviewed. The incidence of arthrofibrosis was assessed at 3 months postoperatively and at the last follow-up. Arthrofibrosis was defined as a 20° flexion deficit and/or a 10° extension deficit at 3 months. Results: A total of 80 patients with a mean age of 15.9 years (range, 12.8-17 years) were included. At 3 months, arthrofibrosis occurred in 22 of 80 patients (27.5%). At the last follow-up (mean duration of 13.3 months; range, 6-47 months), 7 of 80 patients (8.8%) required procedural intervention with manipulation under anesthesia (MUA). Those with arthrofibrosis at 3 months postoperatively had significantly reduced preoperative flexion compared with those without arthrofibrosis (120.5° vs 130.7°; P = .02) and at postoperative week 6 (91.7° vs 111.9° flexion; P < .001). The presence of medial meniscal repair (MMR) was significantly higher in the arthrofibrosis group ( P = .04). No significant difference in age, sex, or BMI existed ( P > .05). However, patients with government insurance were disproportionately more likely to develop arthrofibrosis at 3 months, as opposed to those with private insurance ( P = .02). Conclusion: More children and adolescents undergoing ACLR with QTB have a higher rate of arthrofibrosis at 3 months. However, return to the operating room for MUA is similar to other graft types. Reduced flexion preoperatively and at 6 weeks postoperatively, as well as concomitant MMR, were significant predictors of arthrofibrosis.