The effect of exercise rehabilitation on bone mineral density, muscle strength, and physical function outcomes in ACL ruptures: A randomized controlled clinical trial

The purpose is to explore the effects of Exercise rehabilitation (ER) on bone mineral density (BMD) of the knee, muscle strength (MS), and physical function (PF) after ACL rupture. Finally, A total of 58 patients were randomized into 2 groups (Control Group [CON]: conventional treatment, male ​= ​16, female ​= ​13, age ​= ​[31.63 ​± ​8.01] years; Exercise rehabilitation group [ER]: 6-week ER on CON basis, male ​= ​17, female ​= ​12, age ​= ​[31.26 ​± ​7.07] years). At baseline and 6 weeks, the knee BMD was measured using DEXA, MS and PF measures were recorded by isokinetic strength test, IKDC, Lysholm, and VAS score. T-tests, analysis of variance (ANOVA), and Mann-Whitney tests were used for comparisons. The BMD outcomes: after a 6-week period, the BMD of the CON ([1.47 ​± ​0.24] g·cm^-2) was significantly lower than that of the ER ([1.65 ​± ​0.37] g·cm^-2) at lateral condyle of femur (LCF) (<i>p</i> ​= ​0.041). MS outcomes: at 6 weeks, the relative peak torque (RPT) of the quadriceps and hamstrings during concentric contractions in ER group were significantly higher than that in CON group (<i>p</i> ​< ​0.001, <i>p</i> ​= ​0.017). Similarly, during eccentric contractions in ER group, the RPT of the quadriceps and the H/Q ratio revealed significant variations from the CON group (<i>p</i> ​= ​0.033, <i>p</i> ​= ​0.043). PF outcomes: the IKDC, Lysholm, and VAS scores of the ER group were significantly improved compared to the CON group (<i>p</i> ​< ​0.001, <i>p</i> ​< ​0.001, <i>p</i> ​= ​0.002). The conclusion is that 6 weeks of ER intervention for patients with ACL rupture can effectively delay the decline of BMD in the LCF of the knee joint, and enhance the restoration of MS and PF. This provides guidance for clinical rehabilitation.