The effect of tourniquet type and thigh conicity on the length of hamstring autograft

We studied the effect of using wide contoured pneumatic tourniquet (PT) versus ultra-narrow sterile exsanguination tourniquet (SET) on the length of hamstring autograft for anterior cruciate ligament (ACL) reconstruction in patients with tubular and conical thighs.

Fifty-eight patients undergoing ACL reconstruction between 2012 and 2013 were assigned to either SET or PT groups. We measured the tendon graft length and width as well as the patients' height, weight, and thigh circumference of 10 cm proximal to the patella and the distance from the anterior-superior iliac spine to the medial malleolus (ASIS-MM). We defined the ratio between the ASIS-MM and the thigh circumference as the conicity index (CI). All grafts were measured after folding into half, and the found value was recorded as functional graft length (FGL). Tendon graft dimensions were correlated with the individual anthropometric data and with CI in each of the groups.

PT was used in 34 patients and SET on 24 patients. FGL was 12.7 ± 0.84 mean + standard deviation for the SET group versus 11.5 ± 1.61 for the PT group ( p = 0.0011) with a strong positive correlation between FGL and CI for the PT group ( R² = 0.625; p = 2.6 × 10^-8) but nonsignificant correlation for the SET ( R² = 0.222). Graft thickness was correlated with the patient age ( R² = 0.450) but not with CI or type of tourniquet used. We found the CI to be a better measure of thigh conicity than thigh circumference, length, height, weight, or body mass index individually.

We conclude that using the SET which occupies less space on the thigh yielded significantly longer hamstring autologous ACL graft compared to the PT and the FGL became essentially independent from the CI when the SET was used.