Prediction of hamstring tendon autograft diameter and length for anterior cruciate ligament reconstruction.

The purpose of this study was to determine whether common physical measurements in patients undergoing anterior cruciate ligament (ACL) reconstruction with autologous hamstring tendon could be used to predict autograft length and diameter. One hundred nineteen consecutive patients undergoing hamstring autograft ACL reconstruction had these preoperative measurements taken: age, height, weight, bilateral leg length, and bilateral thigh girth 5 and 10 cm proximal to the superior pole of the patella. Correlations between these measurements and graft length and diameter were evaluated. There was a strong correlation between leg length and hamstring autograft length (r = .73, P<.001). Weight (r = .51, P<.001) and leg length (r = .42, P<.001) had only moderate correlations with graft diameter. All other correlations were weak. Regression analysis demonstrated that leg length can be used to predict hamstring autograft tendon length to within 20 mm and that weight can be used to predict graft diameter to within 1.2 mm using regression equations. In conclusion, several simple measurements correlate with doubled semitendinosus and gracilis tendon autograft length and diameter. This new information may prove useful to surgeons who want hamstring autografts of a certain diameter or of a long length.