Publications

Myoton Clarification Note: A Guide to Interpreting the Inverse Relationship Between Logarithmic Decrement and Tissue Elasticity

This study aims to compare knee and ankle muscle/function outcomes following anterior cruciate ligament reconstruction using autologous hamstring tendon (HT) versus peroneus longus tendon (PLT).

In this retrospective study, patients who underwent anterior cruciate ligament reconstruction with either PLT or HT grafts between 2015 and 2024 were analyzed. Postoperative follow-up data included muscle properties (tone-F, stiffness-S, elasticity-D) around the knee, International Knee Documentation Committee and Lysholm scores, and thigh circumference difference. For the PLT group, muscle properties (F, S, D) of ankle muscles (gastrocnemius, peroneus longus, tibialis anterior) and American Orthopedic Foot and Ankle Society scores were also assessed. Fifteen patients (average age 28 ± 9.83 years) were included.

No significant differences were found between groups in knee muscle properties (F, S, D), International Knee Documentation Committee, or Lysholm scores (P > .05). However, thigh circumference reduction was significantly smaller in the PLT group (4.90 (4.00, 5.40)) compared to the HT group (3.45 (2.65, 4.33)) (P < .05). In the PLT group, ankle assessment revealed significant differences in elasticity (D) for the gastrocnemius and peroneus longus (P < .05) (gastrocnemius muscle: donor side [1.48 ± 0.04], healthy side [1.55 ± 0.02]; peroneus longus muscle: donor side [0.65 ± 0.27], healthy side [1.17 ± 0.03]), and in stiffness (S; donor side [391.60 ± 19.73], healthy side [433.60 ± 7.57]) and elasticity (D; donor side [1.07 ± 0.13], healthy side [1.41 ± 0.04]) for the tibialis anterior, with the healthy side showing superior values (P < .05). The American Orthopedic Foot and Ankle Society score was also significantly lower for the donor ankle side (92.20 ± 4.21) versus the healthy side (100.00 ± 0.00; P < .05).

This study suggests that while both autologous PLT and HT grafts provide comparable postoperative knee function, the HT graft is associated with greater thigh muscle atrophy. The use of the PLT graft, however, leads to weakened muscle state and function around the donor ankle joint. Both grafts have distinct advantages and disadvantages, indicating that the choice should be tailored to the individual patient’s circumstances.

Keywords: anterior cruciate ligament reconstruction, hamstring tendon, MyotonPRO, peroneus longus tendon, retrospective analysis

According to our retrospective study, There is no significant difference in postoperative knee function between autologous PLT and autologous HT in ACLR, but the thigh circumference of HT group is significantly reduced, while the state and function of the donor muscles around the ankle joint in PLT group are weakened. The 2 autogenous tendon grafts have their own advantages, and can be used in combination with the patient’s situation in clinical practice.