The effects of treadmill training with different intensities on tendon-bone healing in rats after anterior cruciate ligament reconstruction
10.3760/cma.j.cn115530-20240518-00213
- VernacularTitle:不同运动强度跑台训练对前交叉韧带重建术后大鼠腱骨愈合的影响
- Author:
Ting LIANG
1
;
Liang ZHU
;
Xuliang ZHAO
;
Haibo ZHAO
;
Fan JIANG
;
Tengbo YU
Author Information
1. 青岛市市立医院（康复大学青岛医院）康复医学科，青岛 266071
- Keywords:
Anterior cruciate ligament;
Exercise therapy;
Knee;
Rats;
Tendon-bone healing
- From:
Chinese Journal of Orthopaedic Trauma
2024;26(10):890-898
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effects of treadmill training with different intensities on tendon-bone healing in rats after anterior cruciate ligament (ACL) reconstruction.Methods:Of the 99 adult male Sprague-Dawley (SD) rats used for this study, 90 were randomly selected to undergo ACL reconstruction with autologous caudal tendon. Two weeks after the surgical reconstruction, the 90 SD rats were randomized into a low-intensity group (group L, n=30) subjected to treadmill training at a speed of 12 m/min, a moderate-intensity group (group M, n=30) subjected to treadmill training at a speed of 18 m/min, and a free group (group C, n=30) subjected to free activities in the cage as a model control. The other 9 rats were set as a blank control (group N, n=9) subjected to no treatment at all. The treadmill training started at the end of 2 weeks after surgical reconstruction. Hematoxylin-eosin (HE), micro-CT analysis, mechanical testing, real-time quantitative polymerase chain reaction (qPCR) and western blot analysis were used to evaluate the quality of tendon-bone healing. Results:There were no significant differences in the areas of femoral and tibial lateral bone tunnels or the total bone volume ratio (BV/TV) between the 3 groups 2 weeks after surgery ( P > 0.05). At 4 weeks and 8 weeks after surgery, the areas of lateral tibial bone tunnel and lateral femoral tunnel in groups C, M and L showed a decreasing trend ( P < 0.05) while the BV/TV of lateral femoral tunnel and the BV/TV of lateral tibial tunnel in groups C, M and L showed an increasing trend ( P < 0.05). At 8 weeks after surgery, HE staining showed that the tendon-bone healing was the most mature in group L, followed by group M, and the least mature in group C, showing statistically significant differences ( P < 0.05). The stiffness and maximum failure load showed an increasing trend from group C to group M to group L to group N. The stiffness in group M and the stiffness and maximum failure load in groups N and L were significantly higher than those in group C ( P < 0.05). The relative mRNA expression levels of osteopontin (OPN) and collagen type Ⅱ alpha 1 chain gene (COL2 α 1), as well as the protein expression levels of osteocalcin, OPN, and COL2 α 1, showed an increasing trend from group C to group M to group L, showing significant differences between pairwise comparisons ( P < 0.05). Conclusions:Treadmill training starting at the end of 2 weeks after surgery is beneficial to tendon-bone healing and improves the biomechanical strength of the tendon-bone complex. Low-intensity mechanical stimulation is more conducive to new bone formation and collagen fiber remodeling in the tendon-bone complex.
