Effects Of Combined Hip-knee Exercise On Anterior Knee Pain After ACL Reconstruction

Background:Anterior cruciate ligament(ACL)injury is a common sports injury,and ACL reconstruction surgery is the main way to treat ACL injury.Postoperative anterior knee pain is a common complication after ACL reconstruction.The traditional rehabilitation program focuses on the exercise of the muscles around the knee joint,and the patient still has anterior knee pain after treatment,so it is very important to improve the rehabilitation program.Studies have shown that muscle strengthening exercises around the hip significantly improve knee kinematics.For patients with anterior knee pain after ACL reconstruction,there is no similar report on whether the traditional rehabilitation program combined with strengthening training of the muscles around the hip joint can improve the anterior knee pain.Therefore,this current study investigated the effect of the hip-knee joint exercise rehabilitation program on anterior knee pain and patellofemoral joint kinematics after ACL reconstruction,explores the treatment mechanism of the hip-knee joint exercise rehabilitation program,and provides a new method for rehabilitation exercise after ACL reconstruction.Methods:The study was conducted between February 2021 and December 2021.Thirty-eight patients with confirmed ACL rupture and knee pain 12 weeks after ACL reconstruction were selected as the research subjects.The random numbers generated by SPSS23 were randomly assigned to 1:1,and the patients were randomly divided into the experimental group(n=19)and the control group(n=19).The subjects in the experimental group underwent joint exercise rehabilitation training for hip and knee.The subjects in the control group underwent traditional ACL reconstruction postoperative rehabilitation program training.Subjects’ knee injury and osteoarthritis outcome score,knee isokinetic muscle test and patellofemoral joint kinematics were evaluated at 3,6,and 9 months after surgery.P value level for statistical difference was set to 0.05.Results:Thirty-two patients completed full rehabilitation and associated assessments.There were no significant differences in gender,age,BMI,meniscus damage,cartilage damage,and time between injury and reconstruction between the two groups before the intervention.After different postoperative rehabilitation treatments,the pain and quality of life subjective scores of the hip-knee combined exercise group were significantly improved.In terms of isokinetic muscle strength test,the knee flexor muscle strength and knee extensor muscle strength of the two groups were improved compared with those before the rehabilitation exercise.Compared with the traditional rehabilitation program group,there was no significant increase in knee flexor muscle strength and knee extensor muscle strength in the hip-knee combined exercise group.For the comparison of patellofemoral joint kinematics,3 months after operation,the patella trajectory showed introversion,and there was no statistical difference between the two groups.At 6 months postoperatively,the patella trajectory showed inversion,but the inversion decreased in the traditional rehabilitation group.Nine months after the operation,the patella trajectory was mainly introversion,but the traditional rehabilitation group further reduced introversion,and there was a significant difference(P<0.05).With respect to patellar rotations,no significant difference was found between the two groups.Similar to the changes in the patella inversion and extroversion,the internal and external displacements also changed accordingly.At 3 months after operation,the internal and external trajectory of the patella showed that the patella moved inward and then outward,no difference was detected between the two groups.At 6 months after operation,the internal and external displacement trajectory of the patella showed that the patella moved inward and then outward,and the outward displacement in the traditional rehabilitation group decreased,nevertheless no difference was detected between the two groups.Nine months after operation,the internal and external trajectory of the patella showed internal movement first and then external movement,and the traditional rehabilitation group presented internal movement,and the end of knee flexion was significantly different from the experimental group(P<0.05).Conclusion:The results showed that the combined hip-knee exercise rehabilitation program improved symptoms and improved patellofemoral joint kinematics in patients with anterior knee pain after ACL reconstruction compared with traditional rehabilitation training.The hip-knee joint exercise rehabilitation program is an effective rehabilitation treatment for improving anterior knee pain after ACL reconstruction.