Objective To explore the indication, to describe the key of operative technique in detail and to summarize the early results in mini-incision and minimally invasive surgery (MIS) total hip arthroplasty (THA) for hip disorders. Methods From Mar. 2003 to Mar. 2005, 43 patients (49 hips) were performed with MIS THA. The mean age of patients was 53.2 years ranging from 22 to 79 years. There were 22 males and 21 females. The average body mass index (BMI) was 23.4 ranging from 17.1 to 30.2. Using the modified postero-lateral approach, MIS THA was performed with cementless prostheses. For comparison, 35 patients (43 hips) were performed with standard THA at the same period. The age and BMI of patients in both groups were similar, but the pattern of disorders was different. The comparative items included preoperative bleeding, operative time, incisional length, postoperative functional recovery, and prosthetic position. Results 31 patients (MIS THA) and 25 patients (standard THA) were followed from 6 to 24 months (mean 13.1 months). No complications occurred in MIS THA. Dislocation appeared in one patient with standard THA at the two days after operation. The length of incision was 9.3 cm (range, 8.7 to 10.5 cm) in MIS group and 16.8 cm (range, 14 to 20 cm) in standard THA group. The difference was significant statistically (P

[Objective]To explore the correlation between anticardiolipin antibodies and post-SARS patients with osteonecrosis,investigate the etiology of post-SARS osteonecrosis,and select the sensitive molecular symbols for early diagnosis and distinguish the high risk population.[Method]The studied subjects were divided into two groups.Sixty-two post-SARS patients with osteonecrosis was one group,and 52 matched healthy people was as normal controlled group.Empty stomach blood samples from cubital veins were collected from both groups.IgA,IgG and IgM of anticardiolipin antibodies types were examined by ELISA.[Result]Twenty-one of 62 post-SARS osteonecrosis patients were tested at least one type of anticardiolipin antibodies positive,among them,with IgA(11.33?11.209)APL,IgG(5.127?5.927)GPL,IGM(17.821?10.606)MPL.Four of 52 control group persons were detected positive,with IGA(10.702?3.126)APL,IgG(5.184?4.780)GPL,IgM(14.684?5.516)MPL.There were significant differences between two groups,while,there were no difference in prothrombin time(PT),thrombin time(TT),prothrombin activity(PTA)and international normalized ratio(INR).[Conclusion]The study indicates an increased positive incidence of anticardiolipin antibodies in post-SARS patients with osteonecrosis.This has reflected that anticardiolipin antibodies may play a role in osteonecrosis.

Objective To explore the risk factors of collapse of osteonecro si s of the femoral head (ONFH) with a retrospective study, and put forward a treat ment protocol according to this study results. Methods From October 1993 to Apri l 2000, 40 cases (56 hips) were followed-up. The term of follow-up ranged from 1 2 to 68 months (average 29.2 months). The age of patients was from 16 to 60 year s old (average 36.8 years old). Preoperatively, the AP and frog view X-ray film, coronal and sagittal MRI were taken. The staging of ONFH proposed by ARCO was a dopted. Clinically the Harris score was used to assess the clinical outcome. The patients were divided into three groups: 1) Non-operative: 10 cases (14 hips), stage Ⅰin 7 hips(ⅠA 4,ⅠC 3),stageⅡin 7 hips (ⅡA 1,ⅡB 3,ⅡC 3); 2) Core dec ompression with vascularized iliac bone graft (VICBG): 18 cases (24 hips ), stag eⅠin 6 hips (ⅠB 4,ⅠC 2), stageⅡin 16 hips (ⅡA 4,ⅡB 8,ⅡC 4), stageⅢ in 2 hips (ⅢA); 3) Transtrochanteric rotational osteotomy(TRO): 12 cases (18 hips), stageⅡin 1 hip (ⅡC), stageⅢ in 17 hips (ⅢA 8, ⅢB 7,ⅢC 2). Harris score was 46 to 82 (mean 62.9). Results Collapse of the femoral head occurred in 9 hips a mong the 14 hips in the nonoperative group, in 10 hips among the 24 hips in the VICBG group. In TRO group, further deterioration was prevented in all but one hi p. Whether theres surgical intervention or not, no collapse occurred in both s tageⅠA and ⅡA, collapse occurred in both stage ⅠB and ⅡB was 7 hips among 15 hips (46.7%), 13 hips progressed into collapse of the femoral head with ⅠC and ⅡC (100%). The Harris score was 47 to 93(mean 77.4) postoperatively. Conclusio n With MR imaging, it is possible to predict the possibility of collapse of ONFH . The lower risk is below 30 percent of necrotic area, the higher risk is 30 to 60 percent of necrotic area, and the higherest risk is beyond 60 percent of necr otic area. The best results can be obtained if selection of treatment individual ly according to ARCO stage, patient age and necrotic extent.

Objective To explore the relationship between the osteonecrotic volume (lesion size), angle and the index of necrotic extent on the femoral head. Methods Fifty-one hips in 39 patients with non-traumatic avascular osteonecrosis on the femoral head were divided into 12 equal segments from the head to the neck junction (a turning point of the spherical curve of the head) with whole hip displacement, each with 30 degrees on a coronal plane of weight-bearing surface. The osteonecrotic angle of the arc of each necrotic segment from the center of the femoral head was measured at the point of one- to 12-o'clock on imaging of two dimensional reconstruction of computerized tomography (CT) scans and anteroposterior and lateral radiographs. Necrotic volume on each segment of the femoral head was calculated with fluid displacement method. The index of osteonecrotic extent on the femoral head was calculated using direct anatomical measurements. Results Osteoneerotic volume on the femoral head at the point of 12- to one-o'clock on coronal plane was (74. 5 ± 7.4)% of the sphere equivalent of the whole femoral head, which was positively correlated to its necrotic angle [ (41.9±8. 3) degrees] at the point of one-o'clock on the plane, with a coefficient of correlation of 0. 843, and that at the point of one- to two-o'clock on the plane was (73.7 ±0. 4) %, which was positively correlated to its necrotic angle [ (41.9 ± 1.8) degrees] at the point of two-o'clock, with a coefficient of correlation of 0. 543. Osteonecrotic volume on the point of 11- to 12-o'cleck was (83.6±8.6)%, and the necrotic angle at the point of 12-o'clock was (44. 9±3.9) degrees, which were positively correlated each other, with a coefficient of correlation of 0. 701 (P <0. 01 ). Osteonecrotic volume on the femoral head was positively correlated to its necrotic angle , modified index of necrotic extent, index of necrotic extent and Kerboul conjugated necrotic angle, with coefficients of correlation of 0. 798, 0. 701, 0. 377 and 0. 398 ( P < 0. 01 ), respectively, at the point of one o' clock. Conclusions Measurements of osteonecrotic volume was positively correlated to the index of necrotic extent and necrotic angle on the femoral head, respectively. Necrotic angle on the plane at 30-degree of the trochanter on the femoral head can well reflect its necrotic volume.

Objective To evaluate the early and middle-term results of in-situ single-screw fixation and subtrochanteric osteotomy of femur with external fixator for slipped capital femoral epiphysis(SCFE).Methods From June 1998 to July 2008, eleven patients (12 hips) with SCFE were treated, including 7males (8 hips) and 4 females (4 hips) with an average age of 14.3 years (range, 9-18). The average BMI was 31.1 g/m2. According to the Southwick measurement, mild (＜30°) in 6 cases (7 hips), moderate (30°-50°) in 2 cases (2 hips), and severe (＞50°) in 3 cases (3 hips). All the mild and moderate cases were undergone insitu single screw fixation, and three severe cases were performed subtrochanteric osteotomy of femur with external fixator. All the cases were evaluated at 3 months, 6 months and every year postoperatively. Results All the cases were followed up for average 5.6 years (range, 2-12). The Harris hip score increased from mean 74.8 points preoperatively to 90.6 points postoperatively, with 10 hips excellent, 1 hip good, 1 hip fair and 0 hip poor. The excellent and good rate was 91.7% (11/12). The X-ray showed the epiphyseal closure in in-situ single screw fixation cases, and no further increase in epiphyseal-shaft angle. Partial reduction of slipped epiphysis with normal joint spaces was observed in subtrochanteric osteotomy of femur with external fixator cases. Conclusion In-situ single screw fixation provides a surgical treatment option to treat mild and moderate SCFE with satisfactory clinical outcome, and profit to the prevention further slip. Subtrochanteric osteotomy of femur with external fixator is suitable for severe SCFE with late deformity. The realignment procedure can correct deformity and postpone or avoid the occurrence of osteoarthritis.

BACKGROUND:It is a clinical difficult in the treatment of osteonecrosis with joint preservation, and to solve this problem, a variety of bone graft substitutes are at the exploration stage. OBJECTIVE:To evaluate the clinical outcome of lightbulb operation with porous bioceramic β-tricalcium phosphate in a consecutive series of patients with osteonecrosis of the femoral head. METHODS:From January to December 2008, 58 patients (88 hips) who had undergone lightbulb operation with porous bioceramic β-tricalcium phosphate were involved in this study. Al patients were evaluated both clinicaly and radiographicaly at postoperative 3, 6, 12 months and annualy. Functional improvement was assessed with the Harris hip score. RESULTS AND CONCLUSION: Among these patients, 56 patients (85 hips) were folowed up for 2-5 years. According to the ARCO staging system, there were 27 hips of stage II, 40 hips of stage IIIa, 18 hips of IIIb. According to the hospital’s classification, type C was in 4 hips, L1 in 15 hips, L2 in 28 hips, and L3 in 38 hips. According to the Harris hip score system, excelent outcome was in 55 hips, good in 12 hips, fair in 5 hips and poor in 13 hips. Nine of 11 patients who failed to preserve their own joints were subjected to hip replacement. The  mean preoperative and postoperative Harris scores were 61.2 and 85.3, respectively, with a mean improvement of 24.1 points (P < 0.001). All hips were radiologically stable, with no progress of osteonecrosis, and bone density in the bone graft area increased obviously. The replacement time of porous bioceramic β-tricalcium phosphate was 1-1.5 years. These findings suggest that the porous bioceramic β-tricalcium phosphate provides an option to treat osteonecrosis of the femoral head with satisfactory clinical outcomes, and profits the repair and reconstruction of femoral head osteonecrosis. When in the lateral column of femoral head, the porous bioceramic β-tricalcium phosphate can play a supporting role in the lateral column of the necrotic area, and further prevent collapse, which is suitable for patients with osteonecrosis of the femoral head, especially for those with joint preservation.

ObjectiveTo evaluate the effectiveness of mesenchymal stem cell (MSC) in osteonecrosis of the femoral head defect(ONFH) repair. MethodsAniaml model of ONFH defect were established with rabbits, which were divided into 3 groups,group A did not infill anything as control, nano Hydroxyapatite/collagen(nHAC) as group B,nHAC+MSC as group C.Histology change were investigated 4,8,12 weeks after operation respectively.Results groups B and C were different with group A. The difference between groups A and C was more significant. ConclusionMesenchymal stem cell has a strong activity of osteoconduction,it has a value in repairing the bone defect of ONFH and the treatment of ONFH.

Objective To investigate the feasibility and accuracy of volumetric measurement of necrotic lesion using CT and MRI,and to assess the value of necrotic lesion volume in predicting collapse of the femoral head in patients with avascular necrosis of the femoral head(ANFH). Methods Comparison among CT,MRI and gross section was performed in 25 femoral heads of 18 patients who underwent total hip replacement for established ANFH.The volume of necrotic lesion was measured using fluid displacement.CT and MRI data were transferred to a computer to calculate the volume of necrotic lesion using software.One way ANOVA was used to compare the volumes of necrotic lesion measured by CT,MRI and gross section.A total of 62 patients (92 hips) who were diagnosed with ANFH but without collapse by CT were followed up 24 months.Student t-test was used to compare the ratio of the volumes of the necrotic lesion and entire femoral head in the hips with and without collapse and ROC curve analysis was carried out.Results CT and MRI coincided with gross section in the necrotic area,proliferative area and extralesional area.The volumes of the necrotic lesion measured by CT,MRI and gross section were ( 20.5 ± 5.2 ),( 21.4 ± 4.8 ),( 20.9 ± 5.2 ) cm3,respectively.There was no significant difference among the necrotic volumes measured by the three methods(F =0.185,P =0.831 ).In fifty-seven out of 92 hips,collapse of the femoral head occurred during the follow-up.The ratio of the volumes of the necrotic lesion and entire femoral head was higher in hips with collapse than in hips without collapse[ (34.5 ±9.3)％ vs.(23.4 ±8.4)％ ;t =5.749,P=0.000].The area under the ROC curve was 0.808. Conclusions The volume of the necrotic lesion plays an important role in the collapse of femoral head in patients with ANFH.Both CT and MRI can identify the shape and location of the necrotic lesion intuitively and stereospecifically and can determine the volume of the necrotic lesion accurately.

Objective To compare the effectiveness of nano-hydroxyapatite/collagen (nHAC)and autologous mesenchymal stem cells (AMSCs) for the repair of femoral defect in a rabbit model with femoral defect under the monitoring of the synchrotron radiation hard X-ray. Methods The rabbit models of traumatic bone defect were established and completely randomized into three groups. The femoral defects filled with nothing were used as control group (Group A) , the femoral defects filled with nHAC as Group B and the femoral defects filled with nHAC + AMSCs as Group C. Phase-contrast imaging with synchrotron radiation hard X-ray was applied to detect the degradation and repair process of each group at postoperative weeks 4, 8 and 12, respectively. Results Phase-contrast imaging with synchrotron radiation hard X-ray could display the reparative process. Four weeks after operation, there was collapse in some defect areas in Group A, and the degradation of nHAC and new bone formation were observed in Groups B and C. Eight weeks after operation, fibrous tissues were observed in the defect area in Group A, while osteogenesis and nHAC degradation were more obvious in Groups B and C. Twelve weeks after operation, the defect areas were still unhealed and were substituted by fibrous tissues in Group A, tissue densities of defect areas in Group C were identical with periphery areas, and trabecular bones were formed in Group C. There were statistical differences in the osteogenesis between Group A and Groups B and C,with Group C the best. Conclusion Phase-contrast imaging with synchrotron X-ray can detect the reparative process at a micro-level and plays an important role in the development of tissue engineering.

Objective To explore the regular progressive pattern of nontraumatic osteonecrosis of the femoral head (ONFH) in order to establish the reliable and convenient new classification of ONFH.Methods The coronal section of the femoral head was divided into three pillars (medial,central and lateral).The mid-coronal section of the femoral head on MRI was selected.The China-Japan Friendship Hospital (CJFH)classification of ONFH was established according to the site of necrotic focus in three pillars.A total of 153hips with ONFH were classified according to CJFH classification and Japanese Investigation Committee (JIC)classification,respectively.The collapse rate was observed and compared between both classifications of ONFH.Results The CJFH classification for ONFH consists of 3 types:type A,the medial pillar was involved; type B,the medial and central pillars were involved; type C,the lateral pillar was involved.According to site of necrosis focus in the lateral pillar,the type C was divided into 3 types:C1,there pillars were involved but there still was some normal tissue in lateral pillar;,C2,partial central pillar and all lateral pillar were involved; C3,the whole femoral head was involved.The natural history of the ONFH showed the collapse rate of type C2 and C3 in CJFH classification (95.3％) was higher than that (72.3％) of type C2 in JIC classification.Conclusion The CJFH classification of ONFH based on three pillars is more sensitive than JIC classification in predicting collapse of the femoral head.Moreover,the CJFH classification is convenient to use.