MRI evaluation to predict tendon size for knee ligament reconstruction

Background: The aim of this study is to evaluate a possible correlation between specific anthropometric parameters and sizes of knee tendons commonly used for ACL reconstruction. We hypothesized that specific clinical and radiological knee measurements could be better tendon sizes predictors than age, gender, height and weight. Materials and methods: 100 consecutive patients were enrolled and 77 patients met the inclusion criteria of the study. All patients underwent a MRI of the knee with a 1.5 T super conducting MR System. For each patient, anthropometric data such as gender, height, weight, body mass index (BMI) and knee circumference were recorded. Specific MRI knee measurements were performed on each study: patellar tendon (PT) thickness and length, quadriceps tendon (QT) thickness, semitendinosus tendon (ST) diameter, gracilis tendon (GR) diameter, the largest patella and intercondylar width. Results: The mean ST diameter, QT thickness and PT thickness were higher in males than in females. No significant differences were noted between males and females concerning GT diameter and the knee circumference. In addition, male knees had greater patellar and intercondylar width than female knees. Significant, but only weak correlations were found between patient anthropometric data and hamstrings diameter, PT length, and QT and PT thickness. Intercondylar and patellar width present a moderate correlation between PT thickness, PT length and ST diameter. Conclusion: The intercondylar and patellar width presented a moderate correlation with PT thickness, PT length and ST diameter. Further, weak correlations were found between patient anthropometric data (gender, weight, height, BMI) and GR and ST diameter, PT length, and QT and PT thickness. This results may help surgeons during preoperative planning, specifically regarding graft choice and size.