Changes Of Bone Metabolism After Knee Arthroplasty

Background:Knee osteoarthritis(OA)is a chronic joint disease caused by multiple factors.It is characterized by degenerative degeneration of articular cartilage and secondary hyperplasia of periarticular bone.The symptoms of knee osteoarthritis are mainly knee pain,and the general history is long,especially after activities,can be relieved at rest,symptoms gradually aggravated,not accompanied by obvious systemic symptoms.At present,many studies after knee replacement mainly focus on recovery,rehabilitation and functional exercise after knee replacement,but there are few studies on changes of bone metabolism before and after knee replacement surgery.From the onset of knee osteoarthritis,with the gradual aggravation of patients’ symptoms,patients’ basic living habits,walking gait,posture and other corresponding changes,further compensation leads to other joint activity disorders of patients,bone density reduction,bone metabolism abnormalities,and even serious osteoporosis leading to fractures in patients.After the recovery of joint function,the patient’s activity increased,and the patient’s bone density improved compared to before.Purpose:The purpose of this study is to explore the changes of bone metabolism after knee osteoarthritis joint replacement,to explore the matters that should be paid attention to after knee replacement,and to take measures and treatment for such changes.Method:55 patients in our department who were planning to undergo knee replacement were collected.All patients were admitted to hospital for knee osteoarthritis,and all patients were treated by the same surgeon for all knee replacement operations.The same prosthesis was used intraoperatively,and the changes of lumbar and hip bone mineral density and blood bone metabolism indexes were monitored regularly before and after surgery.The patients underwent knee rehabilitation exercise under the guidance of the physician after surgery,followed up regularly,and the functional status of the patients after knee replacement was quantitatively scored.In this study,various indicators of patients before surgery,3 months,6 months,and 12 months after surgery were evaluated.These included the patient’s Bone Mineral density Density(BMD)(measured at hip and lumbar vertebrae),blood bone metabolism indexes(parathyroid hormone(PTH),25-hydroxyvitamin D(VD(25-0H)),β-collagen degradation products(β-CTX),Total type I collagen amino terminal extension peptide(total-p1NP),calcitonin(CT)and osteocalcin N terminal N-MID),Body Mass Index(BMI),Hospital for Special Surgery(HSS),Visual Analogue Scale for pain,VAS).All data were summarized and classified,and SPSS 25.0 software was used for statistical analysis.Results:All patients were followed up for 12 months,among which 5 patients failed to complete the follow-up for various reasons,and 50 patients were finally included.The mean age of patients in this study was(66.74±7.70)years.The average body mass index(BMI)was(26.99±2.53)kg/m2,and all of them were below 30 kg/m2.The follow-up results were analyzed statistically,the average preoperative HSS score of the patients was 52.40 points,and the average postoperative HSS score was 74.20 points,86.26 points and91.84 points in 3 months,6 months and 12 months,respectively.The average VAS score was 5.94 points,2.46 points,1.70 points and 0.96 points in 3 months,6 months and 12 months,respectively.;Bone mineral density of patients 3 months and 6 months after surgery was lower than that before surgery,with statistical significance(P < 0.05);Bone mineral density of patients 12 months after surgery was unchanged or increased compared with that before surgery,with no statistical difference(P > 0.05).Bone mineral density of osteoporosis patients increased 3 months and 6 months after surgery,but there was no statistical difference(P > 0.05).Bone mineral density increased 12 months after surgery,and there was statistical significance(P < 0.05);The changes of blood bone metabolism indexes in 3 months and 6 months after surgery were statistically significant compared with those before surgery(P < 0.05),but there was no statistical significance in 12 months after surgery(P > 0.05).Conclusion:The range of motion and pain of knee arthritis in middle-aged and elderly patients were improved after joint replacement.Bone mineral density decreased at the early stage,and then gradually increased,among the patients with osteoporosis,bone mineral density increased.Bone metabolism index showed that promoting bone component increased early after surgery,promoting bone resorption component decreased early after surgery,and remained unchanged in the later period.After knee replacement,the long-term knee function of the patient improved,but the bone density decreased in the early stage.Appropriate anti-osteoporosis therapy is recommended to reduce the occurrence of postoperative complications.