Prediction of quadriceps tendon-patellar bone autograft diameter in adolescents with 2-dimensional magnetic resonance imaging and anthropometric measures.

Abstract

This study evaluates the correlation between the bone end and soft tissue end of the quadriceps tendon-patellar bone autograft (QPA) size and pre-operative MRI measurements of the quadriceps tendon along sections to be included in the graft harvest in adolescents. We also assessed association between graft diameter and anthropometric measures (height, weight, and BMI), age, and sex. Patients (10-18years) who underwent QPA ACL reconstruction and had a pre-operative MRI were considered for inclusion. Age, height, and weight, tibial and femoral side graft diameter, and patellar bone block dimensions were collected. Using a pre-operative 2D sagittal plane MRI, we measured the quadriceps at 10-mm increments above the patella, up to 40mm. We assessed correlation between the bone-end graft diameter and the AP measure at 10mm above the patella, and correlation between the soft-tissue end graft diameter and the most proximal AP measure. A total of 103 patients were included. A significant correlation between the soft-tissue side graft diameter and most proximal AP measurement was observed (rs = 0.51; p < 0.001). However, measurements significantly underestimated the soft-tissue end graft diameter (9.6 ± 0.8 vs. 7.4 ± 1.1; p < 0.001). There was no correlation between the bone-end graft diameter and AP measurement 10mm above the patella. Anthropometric measures were not associated with graft size. Skeletal maturity was associated with smaller graft size (p = 0.08). Soft-tissue end graft diameter is associated with the AP measure of the quadriceps at 20-40mm above the superior pole of the patella.