The role of preoperative magnetic resonance imaging in the prediction of triple hamstring tendon graft size in patients undergoing anterior cruciate ligament reconstruction: a prospective study

Background
Hamstring tendon grafts are efficacious and safe options for the reconstruction of anterior cruciate ligament (ACL) tears. However, a minimum graft size of seven millimeters is required to enhance its outcomes. Therefore, it is crucial to seek an effective and noninvasive way to predict the graft size to properly choose the reconstruction method.
Patients and methods
We prospectively included the data of 93 cases undergoing ACL reconstruction using triple hamstring graft. The measured graft size was correlated with cross-sectional area (CSA) of gracilis (G) and semitendinosus (ST), measured by magnetic resonance imaging (MRI) before the operation.
Results
The measured CSA of G and ST had mean values of 7.07 (range, 4–10.3) and 11.35 millimeters (range, 7.8–17.6), respectively. The combined CSA ranged between 12 and 27.6 mm (mean = 18.41). The cutoff point that was correlated with a graft diameter greater than or equal to 8 was a combined CSA of 16.9 mm. A significant positive correlation was detected between graft diameter and patients’ weight, height, G CSA, ST CSA, and combined CSA. The area under the curve was 0.8, 0.801, and 0.833 for G CSA, ST CSA, and combined CSA, respectively. Linear regression analysis showed the reliable ability of MRI parameters to predict graft diameter.
Conclusion
MRI has a reliable predictive ability for the hamstring graft size used in ACL reconstruction. Its application should be encouraged in the orthopedic setting for such patients.