Influencing Factors Of Heterotopic Ossification After Primary Total Hip Arthroplasty

Objective:To analyze the incidence of heterotrophic ossification and related i nfluencing factors after primary total hip arthroplasty,and to evaluate the effe ct of heterotopic ossification on hip joint function.Methods: Retrospective analysis of cases was done with the patient who presented with heterotopic ossification incidence among the cases who performed total hip arthroplasty.Number of 114 cases(118 hip)included.Pelvis X Ray and Brooker assessment score were diagnostic criteria.65 cases were study group and 52 cases were control group.65 cases were represented with heterotopic ossification and 52 cases with no heterotopic ossifican complication.In our study,the factors of the two groups were divided into general factors,operative factors and experimental factors.General factors involved age,sex,smoking history,complications,body mass index and combined diseases.Operative factorss were the amount of blood transfusion,the methods of anaesthesia used during operation,the operation interval,the blood loss during operation,the bone cement used or not.Experimental factors involved pre-operatives and post operatives serum calcium,pre operatives and post operatives white blood cell count,pre operatives and post operatives serum alkaline phosphates,pre operatives and post operatives neutrophils count.T test and chi-square test analysis was performed.The statistically significant factors obtained.These statistically significant factors were analyzed by multi-factor Logistics regression analysis.Brooker score assessment was introduced and the related factors were calculated.These factors were conducted Spearman correlation analysis and heterotopic ossification degree and relation were assessed.Results: Of the 118 hips,HO had 66(55.93%)and No HO52(44.07%).Among them,Brooker Ⅰ level of 47 hips(39.83%),Ⅱ level of 14 hips(11.86%),Ⅲ level of 5 hips(4.24%)did not find Ⅳ level.Unifactorial analysis showed that the percentage of postoperative neutrophils,postoperative alkaline phosphatase,epidural anesthesia,smoking and history of hip surgery were all the influencing factors of heterotopic ossification after total hip replacement(p<0.05);Multiariable Logistic regression analysis results showed that the patient’s postoperative neutrophil percentage,postoperative alkaline phosphatase and smoking were all independent risk factors for heterotopic ossification after hip replacement group(p<0.05);Spearman correlation analysis showed heterotopic ossification grading and postoperative neutrophil percentage of patients,postoperative alkaline phosphatase was correlated and smoking(p < 0.05).The brooker classification was introduced to Spearman correlation analysis of the postoperative neutrophil percentage,postoperative alkaline phosphatase and smoking history and the rank of hetrotopic ossification.The results showed that the occurrence of heterotopic ossification was positively correlated with the postoperative neutrophil percentage,postoperative alkaline phosphatase and smoking history.Conclusion: 1.The incidence of heterotopic ossification was higher after primary total hip arthroplasty.The percentage of Neutrophil,Alkaline phosphatase and smoking history were high risk factors for heterotopic ossification and positively correlated with Ho grade.2.Heterotopic ossification had little effect on postoperative function in most patients,but Brooker III heterotopic ossification had significant effect on hip motion.