Risk Factors For Osteonecrosis Of The Femoral Head In Systemic Lupus Erythematosus

[Objective]To analyse the risk factors of osteonecrosis of the femoral head(ONF) in systemic lupus erythematosus(SLE).【Methods】Case-control study was made in our research.Case group was made up of 37 female SLE who have developed ONF. They were in-patients of Rheumatology and Immunology from January,2001 to March,2010.Information on clinical presentation,laboratory examination results and corticosteroid usage was obtained,and comparison was made between these patients and 74 control SLE patients who did not develope ONF. At the same time,we compared the usage of corticosteroid between these SLE patients who had ONF and 30 dermatomyositis/polymyositis patients who do not have ONF.Case group and control groups were match in gender and age and were in-patients from the same period.SPSS 16.0 statistical software were adopted.First,every suspected factors were analysed separately, Chi-Square test was adopted for classification variables and Mann-Whitney U test was adopted for numerical variables.13 factors were found to have statistical significance in the one-factor analysis above.Then multiple factor Logistic regression analysis was made.【Results】1. There was one SLE patient with ONF had never used glucocorticoid before she developed ONF in the 37 SLE patiens with ONF.36 patients had used glucocorticoid,and 24 patients(66.7%) developed ONF during the first 12 months after using glucocorticoid,32 patients(88.9%) developed ONF during 24 months after using glucocorticoid。2. One-factor statistical analysis:the following variables were found to exist statistical significance between case group and control group:the highest prednisolone dose more than 60mg/d,mean daily prednisolone dose more than 60mg/d in the first month,mean daily dose in the second and third months,4th to 6th months and 10th to 12th months,a sudden stop of using glucocorticoid,heamolytic anaemia, arthralgia,pain of kneens,SLE Disease Activity Index(SLEDAI), anti-AnuA, anti-SSB,Hs-CRP.The following variables were found to have no statistical significance:fever,age at onset of disease,oral ulcer,photosensitivity,CNS disease, serositis,Raynauds phenomenon,alop-ecia,cutaneous vasculitis, leucopenia, thrombocytopenia,arthralgia,anti-dsDNA,anti-sm,anti-rRNP,anti-AHA, and so on.3. Comparison was made between 37 SLE patients with osteonecrosis of the femoral head and dermatomyositis/polymyositis group.The following variables were found to have no statistical significance between the two groups:pulse methylprednisolone,the initial dose of glucocorticoid,, mean daily dose in the first month,in the second and third month,4th to 6th month,7th to 9th,10th to 12th,and 13th to 24th months.4. Multiple factor Logistic regression analysis:anti-AnuA, sudden stop of using glucocorticoid, pain of knees, the highest prednisolone dose more than 60mg/d,mean daily prednisolone dose more than 60mg/d in the first month have relationship with ONF in SLE patients.[Conclusions]To avoid developing ONF in SLE patients,the initial therapy with glucocorticoid is very important,especially in the first year.It is inadvisable to give a too high dose of glucocoticoid,especially the first month of therapy,mean daily dose is inadvisable to exceed 60mg/d.A sudden stop of using glucocorticoid is also an independent risk factor associated with ONF.These who had a pain of kneens should be on guard against ONF,magnetic resonance imaging examination should be given at regular intervals in order to detect ONF at an early stage.High level of anti-AnuA is also an independent risk factor for ONF.