The Clinical Study Of The Collapse Correspondent Mechanic Factors Of Steroid Osteonecrosis Of The Femoral Head And Related Strategy Of Treatment

Objectives:The first purpose of this research is to review the cases of steroid osteonecrosis of the femoral head(SONFH)during JAN 2002 to DEC 2005 treated in our department.The second purpose is to analyze the correspondent mechanic factors and to find key factors related to the femoral head survivorship.The third purpose is to analyze the mechanic factors' effect on prognosis,and to conclude the mechanic principles and then to find specific therapy for different cases.The last one is to analyze the indication of the medicine 'sheng mai cheng gu' and to find their effects on clinical symptoms and survivorship of femoral head.Methods:1.Research casesThere were 115(207 hips)SONFH cases all together,including 61 male cases (53.04%)and 54 female ones(46.96%);23 of 115 patients(20%)were single hip evolved,and 92 of 115 patients(80%)were both sides;In all patients, 6 hips(2.9%)were assigned to stageⅠ(according to ARCO classification), 58 hips(28%)were assigned to stageⅡ,127 hips(61.4%)were assigned to stageⅢand 16 hips(7.7%)were assigned to stageⅣ;four hips' lesion were injured in region A(1.9%),26 were injured in region B(12.6%),102 were injured in region C1(49.3%),75 were injured in region C2(36.2%);32 hips' lesion extended to class 1(15.5%),37 did to class 2(17.9%),69 did to class 3(33.3%),69 did to 33.3%;In AP view,81 hips(39.1%)did not collapse,72 hips(34.8%)collapsed within 2mm,36(17.4%)collapsed from 2 to 4mm,18(8.7%) collapsed more than 4mm;In frog lateral view,87 hips(42%)did not collapse, 74 hips(35.7%)collapsed within 2mm,32(15.5%)collapsed from 2 to 4mm,14 (6.8%)collapsed more than 4mm;For 149 hips with MRI,25 hips'(16.8%)bone marrow edema(BME)belonged to stage 0,18 hips(12.1%)belonged to stage 1, 59 hips(39.6%)belonged to stage 2,47 hips(31.5%)belonged to stage 3.2.Treatment:Different treatments were adopted,such as bone graft and vessel bundles implantation,core decompression(CD)and bone graft with screw support,CD and bone impaction with screw support,and traditional Chinese medicine(TCM).3.Collection and analysis of clinical and radiographic dataThe data of follow-up cases were collected such as age,gender,pain index, pain occurrence time,diagnosis time,date of operation,range of motion(ROM) of hip before operation,Harris hip score(HHS)before operation,operation duration,pain index at the end point of observation,ROM at the end point, HHS at the end point,ARCO classification,collapse degree in AP view,collapse degree in frog lateral view,lesion' s location,lesion' s extent,BME in proximal femur,re-collapse after operation.The end point of observation was determined when the re-collapse after operation was more than two mm.All of the data was analyzed by the statistical packages SPSS 15 for windows.The t test and one-way ANOVA or Kruska1-Wallis rank sum test were used for measurement data;χ~2 for categorical data;Logistic regression for analysis of related factors;Kaplan-Meier curve for survivorship of the femoral head.There were 23 patients(23 hips)treated with simplex TCM therapy in this study,who were controlled with the group of untreated cases.Follow-up study was persisted at least two years in these two groups More than two mm collapse was used as the end point.Two groups' NPRS data were compared and the survivorship was analyzed by Kaplan-Meier curve.Results:1.the correlation between pre-operative mechanic factors and collapseSpearman rank correlation coefficient test suggested the less pre-operative collapsed in AP view,the less pre-operative collapsed in frog lateral view.The collapse risks increased under the condition that lesion in region C2,lesion' s extent in class 3-4,BME in stage 2 and further.There was linear correlation between collapse in AP or frog lateral view and pain index,ROM,HHS.2.the correlation between pre-operative mechanic factors and survivorship of femoral head.2.1 Logistic regression analysis suggested that 1)the OR of re-collapse in the case with pre-operative collapse in frog lateral view is 2.79 times higher than those without pre-operative collapse;2)there was significant difference between the result of non-pre-collapse group,less than 2mm group and more than 2 mm group.2.2 The correlation between the preoperative mechanic factors and survivorship suggested that the risk of re-collapse in cases with region C2 lesion was 4.22 times higher than those with C1.There was significant difference between the survivorship of C2 group and that of C1 with B group.There was significant difference between the group of extent more than class 4 and others.The survivorship of cases with BME less than stage 1 was higher than those with BME stage 2-3.2.3 Multi-factor Logistic regression suggested that there was correlation between the pre-operative ROMand re-collapse.Liner regression suggested that pre-operative collapse in AP view increased the risk of collapse in frog lateral view,collapse in either AP view or frog lateral view increased the pain index and decreased the ROM and HHS.3.Mechanic factors and operative method' s effect on survivorship of femoral head.For the operation of CD and graft with screw support,the survivorship of femoral head.was higher in cases that stage in ARCOⅡ,lesion in C1,collapsed less than two mm.The extent of lesion and BME had no significant effect on survivorship of femoral head..For the operation of CD and impaction graft with screw support,the survivorship of femoral head.was higher in cases that stage in ARCOⅡ,lesion in C1,extent within 300°,BME within stage 1 and collapsed less than two mm.For the operation of graft and vessel bundles implantation,the survivorship was higher in cases that stage in ARCOⅢ,collapsed less than two mm.The location of lesion,the extent of lesion and BME had no significant effect on survivorship of femoral head..4.The different operative method' s effect on clinical factorsHHS increased in every operation group.There was linear correlation between collapse in AP or frog lateral view and pain index,ROM,HHS.The result suggested that collapse deteriorated the symptoms.5.TCM' s clinical effectThere was no significant difference between the survivorship of TCM group and that of natural history group.Since the survivorship of TCM in region C1 or more medial was higher,there was a tendency for TCM to increase the survivorship.The NPRS in TCM group is better than that in natural history group and there was significant difference.The result suggested that the TCM of "sheng mai cheng gu" improved the symptoms.Conclusions:1.The effect of pre-operative mechanic factors suggested that there was correlation between preoperative collapse in AP view and frog lateral view. The collapse risks increased under the condition that lesion in region C2, lesion' s extent in class 3-4,BME in stage 2 and further.There was positive correlation between collapse and pain index.There was negtive correlation between collapse and ROM or HHS.2.The correlation between mechanic factors and re-collapse suggested that there was positive correlation between re-collapse and pain index.There was negtive correlation between re-collapse and ROMor HHS."Early treatment to prevent deterioration" should focus on prevent collapse.Prevention of progress should focus on prevent re-collapse.The key factors included collapse more than two mm,lesion in region C2,extent more than 300°and BME in more than stage 2.3.The indication for different operation:1)For the operation of CD and graft with screw support,the cases were indicated that stage in ARCOⅡ,lesion in B or C1,cbllapsed less than two mm;2)For the operation of CD and impaction graft with screw support,the cases were indicated that stage in ARCOⅡ,stage in ARCOⅢbut the collapse was less than four mm and lesion in C1,lesion in region C2 and the collapse was less than two mm;3)For the operation of graft and vessel bundles implantation,the cases were indicated that lesion in region C2,collapse between two and four mm,the extent of lesion more than class 3,slop like collapse,younger age,hoping to delay the hip replacement and without significant change in acetabular.The hip replacement was indicated for the cases that collapse is more than four mm,lesion is in region C2,the extent is above class 3. 4.The indication for TCM was that lesion in region C1 or medial lesion.And TCM improved symptoms of the most cases of ONFH.