Prediction of the Graft Size of 4-Stranded Semitendinosus Tendon and 4-Stranded Gracilis Tendon for Anterior Cruciate Ligament Reconstruction

Background: Little information is available regarding parameters that would enable a surgeon to predict the size and length of 4-stranded semitendinosus (ST) and 4-stranded gracilis tendon (GT) grafts. Purpose: To evaluate whether certain preoperative anthropometric data enable prediction of the size of 4-stranded ST and GT autograft for anterior cruciate ligament (ACL) reconstruction. Study Design: Cohort study (prevalence); Level of evidence, 2. Methods: This study involved 235 Chinese Han patients who underwent double-bundle ACL reconstruction with 4-stranded autogenous ST and GT grafts. Preoperatively, the authors recorded height, weight, body mass index (BMI), gender, age, and sports activity. During surgery, the usable length of the ST and GT and the diameter of the 4-stranded grafts made of ST and GT were measured. Multiple regression analysis was used to determine relationships between anthropometric measurements and the length and diameter of intraoperatively measured ST and GT grafts. Results: Strongest correlations for ST and GT length and GT graft diameter were height and weight. The strongest correlations for ST graft diameter were gender and weight. Body mass index had only moderate correlations with ST and GT graft size. Self-reported activity level was not correlated. Women had significantly smaller GT and ST graft diameters and shorter tendon lengths than did men. Semitendinosus graft size was significantly larger and longer than was the GT graft (7.4 ± 0.7 mm vs 5.9 ± 0.6 mm and 279.9 ± 20.8 mm vs 251.5 ± 20.8 mm, respectively). Simple regression analysis demonstrated that height, weight, and BMI can be used to predict ST and GT autograft length and diameter. Conclusion: Several preoperative anthropometric measurements showed correlation with the length of the ST and GT and diameter of 4-stranded ST and GT grafts. The current data may provide surgeons with important preoperative information about size of ST and GT grafts and would be useful for patient counseling and alternative graft source planning.