Evolution of pre- and post-operative balance characteristics in patients undergoing anterior cruciate ligament...

Anterior cruciate ligament (ACL) injuries frequently necessitate anterior cruciate ligament reconstruction (ACLR), yet balance deficits persist during preoperative and postoperative periods. However, comprehensive longitudinal comparative studies remain scarce. This study utilized a high-resolution plantar pressure system to thoroughly assess these balance characteristics, aiming to optimize clinical rehabilitation.

Fifty participants [25 in the ACLR group, 25 in the normal control (NC) group] were assessed using the SMARTX-MFS plantar pressure system. The ACLR group was assessed preoperatively, 2 months postoperatively, and 6 months postoperatively. The static parameters included the pressure proportion of the affected side (P_A), the center of pressure (COP) 95% confidence ellipse area (S_COP) and the COP trajectory length (L_COP). The dynamic parameters included COP medial-lateral offset length (L_COP-ML), COP anterior-posterior offset length (L_COP-AP), gait line length (L_G), single-leg support line length (L_S), maximum moving speed of COP (V_MAX), proportion of swing period (P_SW), support period (P_S), weight-bearing response period (P_WB), single-leg support period (P_SL), pre-swing period (P_SP), and the maximum pressure in the forefoot (P_MAX-F), arch (P_MAX-A) and heel (P_MAX-H). Inter-group and intra-group comparisons were conducted.

Preoperatively: The ACLR group exhibited impairments in both static and dynamic balance, alongside profound bilateral asymmetry. Two Months Postoperatively: Only L_COP-AP showed significant improvement (P > 0.05). Six Months Postoperatively: Static balance and most dynamic parameters showed no statistically significant differences compared to the NC group, except for increased L_COP-ML (P < 0.05) and decreased L_G and L_S of the affected side (P < 0.05). Within the ACLR group, the affected side still exhibited extremely significant decreased L_G, L_S, and P_MAX-F (P < 0.001), while P_MAX-A and P_MAX-H decreased significantly (P < 0.05).

The ACLR group showed significant balance deficits at pre-operation. Only the L_COP-AP showed significant improvement at 2 months post-operation. The deficits basically recovered at 6 months post-operation. However, the asymmetry of COP trajectory and plantar pressure still existed. The study provided a basis for clinical rehabilitation assessment.