Effects of Early Active Motion versus Early Passive Motion on Functional Recovery after Surgical Repair of Zone-II Flexor Digitorum Tendon: An Assessor-Blinded Randomized Control Trial

Abstract

To investigate the effects of early active motion versus early passive motion on functional recovery of repaired flexor digitorum tendon in Zone-II, and the feasibility of shear wave elastography in monitoring the tension of flexor tendons. Thirty-six patients were randomly divided into early active motion (n=18) and early passive motion (n=18) groups for accordingly treatments. Before treatment, Young’s modulus of flexor tendon was measured with shear wave elastography. The total active motion was evaluated at 4, 8, 12, and 16 w post-operation. At 16 w; grip strength, pinch strength, adjusted Strickland’s classification and the disabilities of the arm, shoulder and hand score were assessed. At a 16-w follow-up, the total active motion (215.48±22.75°) and grip strength (21.07±5.84 kg) of the early active motion group was significantly higher than those (191.00±33.15° and 15.75±7.91 kg) early passive motion group (p<0.05). The repeated measurement method of the general linear model of total active motion showed that treatment protocol, time, and the interaction between two elements had significant effects on the functional results. According to the adjusted Strickland’s system, the good and excellent recovery rate was 100 % in the early active motion group and 76.1 % in the early passive motion group. Early active mobilization had better tendon gliding and excursion even with the two-strand repair as active motion will decrease adhesion formation, with significant difference compared with the passive group. No significant differences between these two groups were found in the pinch force and disabilities of the arm, shoulder and hand score. Young’s Modulus in active finger flexion was significantly higher than that of immobilization position, and it was lowest in passive flexion status (p<0.05). Early active motion contributes to better joint mobility and grip strength after Zone-II flexor tendon repaired. Application of shear wave elastography in monitoring flexor tendon tension appears feasible.