Magnetic Resonance Imaging Versus Anthropometric Parameters in Predicting Hamstring Graft Length for Anterior Cruciate Ligament Surgery.

Abstract

Context: With the increasing number of anterior cruciate ligament reconstruction (ACLR) surgeries following sports injuries, situations may arise where hamstring graft is found to be inadequate. The authors hypothesized that the harvested hamstring graft length may be predicted preoperatively from both magnetic resonance imaging (MRI) and anthropometric parameters in ACLR surgery.

Aims: The study aimed at assessing the relationship between anthropometric and MRI parameters and hamstring graft length.

Settings and design: The study is a prospective, observational, and comparative study.

Subject and methods: A total of 52 patients recruited for ACLR were prospectively evaluated. Anthropometric parameters and Tegner activity score before the injury were recorded. Eight linear MRI measurements were obtained by two observers at an interval of 0 and 30 days. Semitendinosus (ST) and gracilis (G) tendons were harvested and a semitendinosus gracilis (STG) was prepared by a standard technique, and the lengths calculated.

Statistical analysis used: The intra- and inter-rater reliability of the MRI measurements was measured. Pearson's (r) and Spearman's (rho) correlation coefficients were calculated, and linear regression analysis was performed to establish a relationship between the preoperative parameters and hamstring graft length.

Results: The mean graft length for ST was 29.44 ± 1.89 cm and G was 24.44 ± 3.34 cm. The final STG graft length was 8.98 ± 0.19 cm. Transepicondylar distance (TD) had the highest intra- and inter-observer reliability among the MRI measurements. Univariate linear regression analysis revealed that height, weight, thigh length (TL), leg length, and TD were predictive of ST (R2 range: 0.240-0.380) and G graft (R2 range: 0.104-0.299) lengths. TL, body mass index, TD, and lateral femoral condyle anteroposterior dimension (LFAP) were predictive of STG graft length (R2 range: 0.076-0.215). On multiple regression analysis, height and TD were significant predictors of ST (R2: 0.449) and G lengths (R2: 0.288).

Conclusions: Our study concludes that anthropometric parameters may be supplemented with MRI measurements for accurate hamstring graft size predictions.