The Clinical Analysis Of Developmental Dysplasia Of The Hip With Acetabulum Defect Fixed By Biodegradable Pure Magnesium Screw

Purpose: The aim of this study was to determine if biodegradable pure magnesium screws are equivalent to standard titanium screws for fixation of bone graft during THA in patients with acetabular defect.Methods: From December 2014 to February 2015,20 patients were randomly assigned in two groups to undergo total hip arthroplasty and acetabular reconstruction with structural bone graft fixed by either degradable magnesium screw or titanium screw,all the patients with the same postoperative treatment. The 12 months follow-up period included clinical,radiographic,laboratory and the postoperative complications assessments.Results:The hip activity of the 20 patients obviously improved,the hip joint pain significantly reduced,the prostheses position was good, the bone block was fixed reliable,the serum levels of calcium magnesium phosphate ions were within the normal range and the ESR and CRP of postoperative had no obvious change compared with that of preoperative.The postoperative HHS of two groups of patients significantly improved compared with that of preoperative(P <0.05),the postoperative VAS of two groups of patients significantly reduced compared with that of preoperative(P <0.05),and there was no statistical difference between the two groups significantly(P >0.05).The diameter of magnesium screws in X-ray film decreased gradually,and the bone growth around magnesium screws was better than that of titanium group(at 12 months,the CT value of magnesium group 693.8±21.5 Hu, titanium group 508.3±15.7 Hu, P <0.05).Prosthetic loosening,shift or absorption of the bone graft,infection around the prosthesis,deep venous thrombosis(DVT) or pulmonary embolism were not observed during thefollowing-up period.Conclusion:Degradable magnesium screws are clinically equivalent to titanium screws for the fixtion of bone graft in acetabular reconstruction.In addition, magnesium screws don’t need to be taken out with second surgery and degradation products of magnesium screw can also promote bone growth.The magnesium screws can be widely used in reconstruction of acetabulum with structural bone graft.