Histomorphology Of PCL Mechanoreceptors In Patients With Osteoarthritis Of The Knee

Background:The knee cruciate ligament not only has the function of stabilizing the biomechanics of the knee joint,but also participates in providing the function of maintaining the proprioception of the knee joint.The proprioception is mainly accomplished through the mechanical receptors in the ligament.Among them,PCL is one of the important structures to maintain the stability of the knee joint.It is a connective tissue between the bone and the bone.There are many blood vessels and nerve tissues.In addition to maintaining the stability of the joint,limiting the excessive displacement of the tibia backward,etc.The biomechanical function also has the proprioceptive function of sensing the spatial motion sense and position sense of the knee joint,which has important clinical significance for controlling the stability of the knee joint,correcting the posture of the body,and maintaining the balance of the body.Studies have confirmed that the PCL proprioceptive function mainly comes from a variety of mechanoreceptors that exist in itself,and its function is related to the number of mechanoreceptors.The function of each mechanoreceptor is also different,and its morphological characteristics,quantity,and distribution are still controversial.The study found that acute knee injury caused PCL rupture and late atrophy and loss of ligaments caused by mechanical wear and inflammation and erosion of PCL in KOA patients,which would cause changes in the shape and number of PCL mechanoreceptors.Most patients with advanced KOA need to choose TKA to solve joint deformity and restore joint function.The choice of PS or CR prosthesis in the TKA operation on the proprioception of the knee joint is still controversial.Therefore,it has important clinical guiding significance for the related research of the PCL ligament mechanoreceptor.ObjectiveTo observe the type,shape,quantity and distribution of the mechanoreceptors in the PCL,and to explore whether they are related to the age,course of disease and X-ray severity of patients with KOA,so as to provide a theoretical basis for TKA to retain PCL.MethodsFrom March to October 2019,36 TKA patients were selected from Guangzhou first people’s Hospital for KOA,including 9 males and 27 females,aged 56-83 years;25 left and 17 right knees;all of them were PS prosthesis.The patients were divided into three groups according to age,course of disease and X-ray classification.According to age,the patients were divided into three groups: group A: age 55≤age<65 years,group B: age 65≤age<75 years,group C: age≥75 years;according to the course of disease,the patients were divided into three groups: group I: course of disease<10 years,group II: course of disease<20 years,group III: course of disease≥20 years;according to the severity of X-ray manifestations can be divided into moderate and severe groups.PCL was divided into three parts: Tibial appendage,middle part and femoral appendage.Six slices were taken from each part.Three sections were randomly selected for HE staining,the remaining 3 sections were stained by immunohistochemistry.Then,the type,shape,quantity and distribution characteristics of the mechanoreceptors in different parts of PCL were observed with optical microscope,and then photos,counts and statistical analysis were taken.ResultsWe found four kinds of mechanoreceptors,which are mainly distributed in the tibia and femoral appendage,but less in the middle part.The number of PC was the largest,followed by RE,and the number of FNE was the least on the PCL.The GTOE only found 8,so it is not included in the statistics.In the KOA patients with age,long course and serious lesions,the number of mechanoreceptors in PCL decreased significantly.A total of 1238 mechanoreceptors were observed in PCL,there were 608 mechanoreceptors in tibial,107 in the middle and 523 in the femoral appendages,which PC a total of 590,RE a total of 399,and a total of 249 FNE.The total number of PC,RE and FNE were statistically significant(P<0.05).The number of mechanoreceptors in tibia,middle and femur of PCL was statistically significant(P<0.05).The number of mechanoreceptors in groups A,B and C of different age groups were significantly different(P<0.05).There was no significant difference in the number of mechanoreceptors between group II,group I and group III(P>0.05),but there was significant difference between group I and group III(P<0.05).There was significant difference in the number of mechanoreceptors between moderate and severe groups(P<0.05).Conclusion:1.Four kinds of mechanoreceptors were observed in PCL of patients with KOA,mainly in tibia and femoral appendage,but less in the middle.The number of PC was the largest,followed by RE,and the number of FNE was the least on the PCL.2.The number of mechanoreceptors in PCL of KOA patients with old age,long course and serious X-ray manifestations decreased,and obvious atrophy and deformation appeared.It is of little significance to retain PCL in TKA operation of this kind of KOA patients.