Adequacy of Semitendinosus Tendon Alone for Anterior Cruciate Ligament Reconstruction Graft and Prediction of Hamstring Graft Size by Evaluating Simple Anthropometric Parameters

Introduction. Preoperative identification of patients with inadequate hamstring grafts for anterior cruciate ligament reconstruction is still a subject of interest. Purpose. The purpose of this study was to determine whether the semitendinosus tendon length is adequate for four-strand graft harvested by common technique (without bone plug) and whether there is correlation of gracilis and semitendinosus tendon grafts length and diameter of quadrupled graft with anthropometric parameters. Materials and Methods. In this retrospective study, 61 patients (45 males, 16 females) undergoing ACL reconstruction using four-strand hamstring autograft tendons were included. Results. The length of semitendinosus tendon, harvested by the common technique, was in 21% of our cases inadequate in order to be used alone as a four-strand graft especially in females (43%). There was moderate correlation between semitendinosus and gracilis graft diameter and patient’s height and weight and fair correlation to BMI. We found no statistically important predictor for graft diameter in female patients. Conclusions. The length of semitendinosus tendon, harvested by common technique, is usually inadequate to be used alone as a four-strand graft especially in females. The most reliable predictor seems to be patient’s height in males. In female patients, there is no statistically important predictor. 1. Introduction The anterior cruciate ligament (ACL) is the most commonly reconstructed ligament of the knee [1]. An injury to the ACL can result in significant functional impairment [2]. Strength and stiffness of the graft are important components in order to decide the kind of graft and the technique of tendon replacement. It is widely accepted that four-strand hamstring autograft represents a successful option for ACL reconstruction [3–7]. A possible complication when using both the semitendinosus (ST) and gracilis (G) tendon graft is that of hamstring strength deficit in deep flexion and internal rotation [8–10]. Gobbi and Francisco suggest to use only ST tendon in a four-strand graft with bone plug in order to reduce donor’s site morbidity and to increase graft’s diameter [11], while later on in another study Gobbi again suggests a double bundle using only semitendinosus tendon for better functional rehabilitation of the knee [12]. In this type of operations, it would be essential for the surgeon to be able to predict preoperatively graft length in order to choose the ideal graft type and to avoid scar formation, pain, operating time and infection risk. Prediction of graft length