Isokinetic assessment post-ACL reconstruction: comparison of the semitendinous/gracilis and bone-tendon-bone techniques

The purpose of this study is to detect the differences in the isokinetic assessment after anterior cruciate ligament (ACL) reconstruction with the bone-patellar tendon-bone (BTB) and semitendinous/gracilis (STG) techniques.

Ninety-five patients with a minimum follow-up of six months were assessed with a Cybex 6000 dynamometer during concentric contraction at 60 degrees/s. The BTB technique was used in 27 patients and the STG technique in 68. The ANOVA and Pearson tables were used to analyze the flexion and extension strength deficit, peak torque (PT) strength in flexion and extension (Nm) and the muscle balance.

Mean loss of strength in flexion was 18.82% with BTB and 11.05% with STG (p = 0.04). Mean loss of strength in extension was 24.04% with BTB and 17.1% with STG (p = 0.75). The mean PT strength in flexion was 113.2 Nm (38-203) for BTB and 128.4 Nm (73-219) for STG (p = 0.603). The mean PT strength in extension was 187.2 Nm (68-363) for BTB and 194 Nm (107-339) for STG (p = 0.102). The mean muscle balance was 73.4% for STG and 68.6% for BTB (p = 0.961).

The flexion strength was more compromised after BTB reconstruction compared to the STG procedure. We documented a trend towards loss of PT strength in flexion and extension and muscle balance with flexor predominance post-BTB reconstruction.