Abstract
Accurately measuring the length and diameter of the hamstring tendon autograft preoperatively
is important for planning anterior cruciate ligament (ACL) reconstructive surgery.
The purpose of this study was to assess the reliability of three-dimensional computed
tomography (3D CT) scanning technique to produce the actual measurement of the gracilis
and semitendinosus (GT and ST, respectively) tendon grafts' length and diameter for
surgery. Ninety patients were scheduled for ACL reconstruction with hamstring autograft.
Before the surgery, patients were examined under the multidetector row CT scanner
and the ST and GT tendons were qualitatively measured by a volume-rendering technique.
The length of ST and GT was measured with 3D CT compared with the length of the harvested
ST and GT. The cross-sectional area (CSA) of ST and GT measured with 3D CT compared
with the ST and GT graft diameter. Tendon size measured preoperatively and during
surgery were statistically compared and correlated. The GT tendons length and cross-sectional
area measured during surgery was both shorter and smaller compared with the ST tendon.
GT and ST tendon length were correlated to patients' body index such as the height
and weight (p < 0.05). However, the correlation levels were low to medium (r = 0.23–0.49). There was strong correlation between the lengths of GT (r = 0.76; p < 0.001) and ST (r = 0.87; p < 0.001) measured with the 3D CT and tendon length at surgery. There was a moderate
correlation between graft diameter measured at surgery and 3D CT cross-sectional area
(r = 0.31; p < 0.05). A multidetector row CT scanner can determine the ST and GT tendons' length
and diameter. These measurements can be used for preoperative planning to help determine
the surgical method and counsel patients on appropriate graft choices prior to surgery.
Keywords anterior cruciate ligament - prediction of tendon size - hamstring tendon size - 3D
CT volume rendering
