Magnetic Resonance Imaging Can Predict Hamstring or Quadriceps Tendon Autograft Diameter in Pediatric or Adolescent Anterior Cruciate Ligament Reconstruction: A Systematic Review.

Objective: Insufficient graft diameter is an important factor that contributes to failure rates after anterior cruciate ligament reconstruction (ACLR). Although modalities, such as magnetic resonance imaging (MRI), have been well investigated in the adult population to predict graft diameter preoperatively, it is unclear whether similar strategies can be used in the pediatric population. This review aims to evaluate the utility of MRI in the preoperative estimation of autograft parameters in pediatric or adolescent patients undergoing ACLR.

Methods: Three databases were searched on January 31, 2024. The authors adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Revised Assessment of Multiple Systematic Reviews guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, graft characteristics, MRI imaging techniques, and statistical analyses correlating MRI parameters with graft length or diameter were recorded.

Results: Five studies consisting of 450 patients were included in this review (48.4% females). The mean (SD) age at ACLR was 14.7 (6.8) years. Three studies using hamstring tendon (HT) autografts found that combined semitendinosus and gracilis tendon cross-sectional area (ST+GT CSA) were able to predict graft diameter. One study reported an ST+GT CSA cutoff of 31.2 mm2 to have an 80% and 74% sensitivity and specificity, respectively, in predicting HT autograft diameter above 8 mm. Two studies using quadriceps tendon (QT) autografts found that tendon thickness on sagittal MRI view was able to predict graft diameter. One study reported a QT cutoff of 6.7 mm to have 97.5% and 46.6% sensitivity and specificity, respectively, in predicting the diameter of the QT graft to be above 8 mm. Associations between MRI parameters and graft length were not reported.

Conclusion: Although there is limited evidence, ST+GT CSA and QT thickness on sagittal view on MRI can be used to predict intraoperative HT and QT autograft diameter, respectively, in pediatric or adolescent ACLR. Future investigations should investigate correlations between imaging parameters and graft length, especially when using QT autografts in the pediatric population.

Level of evidence: Level III.