The Study On The Possibility About Retention Of PCL In Chinese TKA

Background Our country has entered the aging society,knee osteoarthritis patients showed an increasing trend year by year which has reached 50 million people.Along with the continuous development of biomedicine,material engineering and surgical technique,total knee arthroplasty(TKA)has become an important treatment for knee osteoarthritis.The posterior cruciate ligament is a significant structure of the knee,which plays an important role of stabilization in knee flexion,extension and rotation.With the development of modern knee joint replacement,posterior cruciate-retaining knee prosthesis(CR prosthesis)and posterior stabilized knee prosthesis(PS prosthesis)have become the two main types of prosthesis.In clinical treatment and academic discussion of lon g-term process,such as how to choose the prosthesis is always the debate focus of scholars.The complete preservation of the posterior cruciate ligament during the operation was an important prerequisite for CR function after operation.The Department of orthopedics doctors mostly choosed PS type TKA in the treatment of knee osteoarthritis.In recent years,along with CR type TKA gradually increased,whether it was suitable for Chinese knee joint anatomy and physiology had become the focus of this study investigating the feasibility of PCL retention characteristics and Chinese people during TKA.Objectives1.To study whether the residual PCL and its residue were remained in the Chinese PS TKA after tibial plateau 0 degree tilt and 9mm osteotomy,the influen cing factors of PCL residue in Chinese PS TKA were investigated.2.With the purpose of exploring the feasibility and technical essentials of CR type TKA in Chinese people,we compared the short-term effects of CR type TKA and PS type TKA.Method1.A total of 36 cases affiliated by total knee replacement were selected from May 2015 to August 2016 in Department of orthopedics Xinqiao Hospital at the Third Military Medical University.All patients were single knees in which there were 18 men and 18 women.Their ages ranged from 52 to 75 years old and the height ranged from 145 cm to 173 cm.The above patients signed informed consent for this study and operation consent.All the infamation including age,sex,height and the ratio of retained PCL.PCL retention ratio measurement was used to fix the tibial plateau osteotomy.Posterior cruciate ligament specimens,decalcification,taking the tendon bone interface section and staining were made by software analysis AutoCAD2014 on PCL retention ratio.2.Of the patients who underwent unilateral PS total knee arthroplasty,16 patients had 16 knees,including 9 females and 7 males,aged 55-75 years,with an average age of 65.1 years from May 2015 to May 2016 in Department of orthopedics.Of the patients who underwent unilateral PS total knee arthroplasty,16 patients had 16 knees,including 11 females and 5 males,aged 58-73 years,with an average age of 65.0 years from May 2015 to May 2016 in Department of orthopedics.All patients were single knees in which there were 18 men and 18 women.Their ages ranged from 52 to 75 years old and the height ranged from 145 cm to 173 cm.The above patients signed informed consent for this study and operation consent.PS-TKA underwent routine surgical procedures.The study of CR type TKA operation essentials: through the study of residue PCL of PS type TKA tibial osteotomy,we found that most of the patients in CR during TKA were unable to retain the integrity of PCL under 0 degrees tibial retroversion,9mm osteotomy.Therefore,in the CR TKA this study take steps such as the PCL bone island(by Kirschner wire and bone surrounding the island protection)and spliting osteotomy(secondary osteotomy on bone inside and outside the island side and front).In this process,PCL remained in a relaxe d state avoiding the occurrence of bone fracture of the island.Tibial osteotomy after routine femoral condylar osteotomy used self-made tools to detect knee flexion gap balance after prosthesis installation which could effectively reduce the repeated use of test mode measurement flexion extension gap.It could lead to bone island fracture incidence.VAS score,AKS score,WOMAC score,knee joint mobility(ROM)and femoral condyle roll distance were used to compare the clinical efficacy of PS type TKA and CR type TKA.Results1.Height had influence on the internal and external diameter of the tibial plateau,the size of the anterior posterior diameter,the proportion of the posterior cruciate ligament and the length of the tibia.The gender had no significant effect on the internal and external diameter of the tibial plateau,the anteroposterior diameter,the proportion of posterior cruciate ligament,and the length of tibia.There was a linear relationship among the height,the anteroposterior diameter of the tibial plateau,the internal and external diameter,the length of the tibia and the degree of PCL retention.There was a positive correlation.The present study showed that when the height was 171 cm,the retention ratio of PCL was 50% which was generally low.2.In this study of CR-TKA,although taking the PCL bone island(Kirschner wire for bone surrounding the island protection)and gradeing osteotomy(secondary osteotomy on bone inside and outside the island side and front)method of tibial plateau 0 degrees retroversion,9mm osteotomy,2 cases of patients with bone island avulsion fracture.We changed to PS prosthesis and the remaining 14 patients retained the integrity of PCL.The ROM,femoral condyle roll distance and VAS score of patients with type TKA CR wer e significantly better than those of patients with type TKA PS after 3 days after operation.The satisfaction rate of patients was improved and the rehabilitation cycle and average length of stay were significantly shortened.There was no significant difference in AKS score,WOMAC score,VAS score and ROM between CR type TKA and type TKA PS patients 3 months after operation.ConclusionHeight had influence on the internal and external diameter of the tibial plateau,the size of the anterior posterior diameter,the proportion of the posterior cruciate ligament and the length of the tibia.The gender had no significant effect on the internal and external diameter of the tibial plateau,the anteroposterior diameter,the proportion of posterior cruciate ligament,and the length of tibia.There was a linear relationship among the height,the anteroposterior diameter of the tibial plateau,the internal and external diameter,the length of the tibia and the degree of PCL retention.There was a positive correlation.The present study showed that when the height was less than 171 cm,the retention ratio of PCL was 50% below which was generally low.Residual PCL did not exert its normal physiological function after operation.For most Chinese people undergoing TKA,height was below 170 cm.If using the posterior cruciate ligament retaining prosthesis TKA,we could confront the difficulty of the operation,technology and time requirements increasing and increased risk of avulsion fracture bone island during surgery.Temporaril y the operation plan was changed,using PS prosthesis.reserved PCL bone island in the present study(by Kirschner wire and bone surrounding the island protection),split osteotomy(secondary osteotomy on bone inside and outside the island side and front),during the operation,PCL remained in a relaxed state,the use of homemade tools to detect knee flexion gap balance can effectively reduce the repeated use of test mode measurement flexion extension gap leads to bone island fracture incidence.Reserving PC L bone island in the present study(by Kirschner wire and bone surrounding the island protection)and spliting osteotomy(secondary osteotomy on bone inside and outside the island side and front)during the operation were used.PCL remained in a relaxed state and the use of homemade tools to detect knee flexion gap balance could effectively reduce bone fracture incidence.The ROM,femoral condyle roll distance and VAS score of patients with type TKA CR were significantly better than those of patients with type TKA PS after 3 days after operation.The satisfaction rate of patients was improved and the rehabilitation cycle and average length of stay were significantly shortened.But there was no significant difference in AKS score,WOMAC score,VAS score and ROM between CR type TKA and type TKA PS patients 3 months after operation.Therefore,in view of the majority of the population of TKA,the height of the patient in China was below 170 cm.When the tibial plateau was bent 0 degrees and the 9mm osteotomy was performed,the PCL was retained successfully.The difficulty of operation and technical requirements were high so the operation time was increased.The failure of the posterior cruciate ligament retention was obvious.There was no significant difference in long-term efficacy between two types of prosthesis after TKA(P>0.05).So most OA patients in China should not be suitable for CR type TKA who needed to be more strict with the operation indications.