Preoperative Magnetic Resonance Imaging Measurements of Hamstring Tendons' Cross-Sectional Area May Be Used to...

To determine if preoperative magnetic resonance imaging (MRI) measurements of semitendinosus and gracilis tendon cross-sectional area (CSA) could be used in predicting the intraoperative diameter of a 5-strand hamstring autograft.

A retrospective review was performed of patients who underwent anterior cruciate ligament (ACL) reconstruction with a 5-strand hamstring autograft. All patients undergoing a 5-strand hamstring autograft ACL reconstruction from a single surgeon between 2018 and 2021 were included in this analysis. CSA of both the semitendinosus (CSAst) and gracilis (CSAgr) tendons were measured on preoperative MRI. Demographic and operative data were recorded via chart review. Analyses of within-rater and between-rater reliability were performed. Multiple linear regression was used to analyze the predictors of graft diameter.

A total of 45 ACLs were included in this study. An initial multiple linear regression model included multiple patient-independent variables (R ² = 0.62, P < .001), but CSAst was the only significant predictor of graft diameter. Accordingly, a second multiple linear regression model was created using CSAst and CSAgr (R ² = 0.61, P < .001). Both CSAst and CSAgr were significant predictors of graft diameter. The resulting equation for determining the graft diameter based on CSAst and CSAgr is as follows: [Graft Diameter (mm)] = 5.324 + 0.124 ∗ [CSAst (mm²)] + 0.183 ∗ [CSAgr (mm²)].

CSA measurements of the semitendinosus and gracilis tendons on preoperative MRI axial imaging, measured at the level for which the femoral condyle was the widest, may be used to predict the intraoperative graft diameter for ACL reconstruction using the 5-strand autograft technique.

Predicting ACL autograft size on preoperative MRI can aid in preoperative planning, including choice of graft.