Treatment of nontraumatic osteonecrosis of the femoral head using bone impaction grafting through a femoral neck window.

Nontraumatic osteonecrosis of the femoral head (non-ONFH) is a disorder that can lead to femoral head collapse and the need for total hip replacement. Various head-preserving procedures have been used for this disease to avert the need for total hip replacement. These include various vascularised and nonvascularised bone grafting procedures. We examined the effect of bone-grafting through a window at the femoral head-neck junction known as the "light bulb" approach for the treatment of osteonecrosis of the femoral head with a combination of demineralised bone matrix (DBM) and auto-iliac bone. The study included 110 patients (138 hips; 41 females, 69 males; mean age 32.36 years, range 17-54 years) with stage IIA-IIIA nontraumatic avascular necrosis of the femoral head according to the system of the ARCO (Association Research Circulation Osseous). The bone grafting procedure is called "light bulb" procedure in which the diseased bone was replaced by a bone graft substitute (combination of DBM and auto-iliac bone).The outcome was determined by the changes in the Harris hip score, by progression in radiographic stages, and by the need for hip replacement. The mean follow-up was 25.37 months (range 7-42 months). All data were processed by a statistics analysis including Cox risk model analysis and Kaplan-Meier survival analysis. Pre- and postoperative evaluations showed that the mean Harris hip score increased from 62 to 79. Clinically, 94 of 138 hips (68%) were successful at the latest follow-up, and radiological improvement was noted in 100% of patients in stage IIA, 76.67% of patients in stage IIB and 50.96% of patients in stage IIC and IIIA cases. Excellent and good results according to the Harris score were obtained in 100% of cases in stage IIA, 93.33% in stage IIB and 59.62% in stages IIIA and IIC stage, with a survivorship of 85% in stages IIA and IIB and 60% in stage IIIA and IIC cases. Cox risk model analysis showed that the clinical success rate correlated with both pre-operation stage and the necrotic area of the femoral head. The complications included ectopic ossification, lateral femoral cutaneous nerve lesion and joint infection. This procedure may be effective at avoiding or forestalling the need for total hip replacement in young patients with early to intermediate stages of osteonecrosis of the femoral head. Therefore, it may be the treatment of choice particularly in nontraumatic osteonecrosis of the femoral head of pre-collapse stage with small and middle area (<30%, or the depth of collapse <2 mm).

Treatment of nontraumatic osteonecrosis of the femoral head with the implantation of core decompression and concentrated autologous bone marrow containing mononuclear cells.

BACKGROUND: Since self-limited repair ability of the necrotic lesion may be a cause for failure of the technique, the possibility has been raised that bone marrow mononuclear cells (BMMCs) containing BMSCs implanted into a necrotic lesion of the femoral head with core decompression (CD) may be of benefit in the treatment of this condition. For this reason, we studied the implantation of the concentrated autologous bone marrow containing mononuclear cells in necrotic lesion of the femoral head to determine the effect of the method. METHODS: The study included 45 patients (59 hips, 9 females, 36 males; mean age 37.5 years, range 16-56 years) with stages I-IIIA nontraumatic avascular necrosis of the femoral head according to the system of the Association Research Circulation Osseous. Concentrated bone marrow (30-50 ml) containing mononuclear cells has been gained from autologous bone marrow (100-180 ml) obtained from the iliac crest of patient with the cell processor system. Concentrated bone marrow was injected through a CD channel into the femoral head. The outcome was determined by the changes in the Harris hip score, by progression in radiographic stages, and by the need for hip replacement. The mean follow-up was 27.6 months (range 12-40 months). RESULTS: Pre- and post-operative evaluations showed that the mean Harris hip score increased from 71 to 83. Clinically, the overall success is 79.7%, and hip replacement was done in 7 of the 59 hips (11.9%). Radiologically, 14 of the 59 hips exhibited femoral head collapse or narrowing of the coxofemoral joint space, and the overall failure rate is 23.7%. The number of BMMCs increased from 12.2 +/- 3.2 x 10(6)/ml to 35.2 +/- 12 x 10(6)/ml between pre-concentration and post-concentration. CONCLUSION: The concentrated autologous bone marrow containing mononuclear cells implantation relieves hip pain, prevents the progression of osteonecrosis. Therefore, it may be the treatment of choice particularly in stages I-II nontraumatic osteonecrosis of the femoral head.

Osteonecrosis in patients after severe acute respiratory syndrome (SARS): possible role of anticardiolipin antibodies.

OBJECTIVES: This study examined the anticardiolipin antibodies in post-SARS (severe acute respiratory syndrome) osteonecrosis patients to investigate the etiology of post-SARS osteonecrosis, and to eventually provide valuable information for the early diagnosis of nontraumatic osteonecrosis and for the susceptible population screening. METHODS: This study recruited 62 post-SARS osteonecrosis patients and 52 age- and gender-matched healthy controls. Fasting blood samples were collected from all the subjects through cubital veins. Immunoglobulins A, G and M (IgA, G and M) types of anticardiolipin antibodies were examined by enzyme-linked immunosorbent assay. The routine examinations of prothrombin time, thrombin time, prothrombin activity, and international normalized ratio were also performed. RESULTS: There were 21 of 62 post-SARS osteonecrosis patients (33.9%) who showed at least one type of anticardiolipin antibodies. The titers of specific IgA, IgG, and IgM were 11.33 +/- 11.209 APL, 5.127 +/- 5.927 GPL, and 17.821 +/- 10.606 MPL, respectively. There were only 4 of 52 subjects in the control group (7.7%) who showed positive anticardiolipin antibody with titers of IgA at 10.702 +/- 3.126 APL, IgG at 5.184 +/- 4.780 GPL, and IgM at 14.684 +/- 5.516 MPL. There were significant differences between the 2 groups confirmed by t-Test and chi(2) test (P < 0.05), while no significant differences were observed in prothrombin time, thrombin time, prothrombin activity, and international normalized ratio results between the 2 groups. CONCLUSIONS: The incidences of anticardiolipin antibodies were increased in the post-SARS osteonecrosis patients and anticardiolipin antibodies may play a role in the pathogenesis of post-SARS osteonecrosis.

Decreased proliferation of mesenchymal stem cells in corticosteroid-induced osteonecrosis of femoral head.

The ability of self-repair in patients with corticosteroid-induced osteonecrosis of the femoral head is limited, and it has been suggested the cause is likely relevant to the poor proliferation activity of mesenchymal stem cells in the femoral head region. This study measured the number and proliferation activity of human mesenchymal stem cells in patients both with and without corticosteroid-induced osteonecrosis of the femoral head. Bone marrow was collected from the proximal femur in patients with steroid-induced osteonecrosis of the femoral head (osteonecrosis group, n=18) and patients with new femoral neck fractures without osteonecrosis (control group, n=11). Mesenchymal stem cells were isolated by density gradient centrifugation, and then selected by the adhesive method. The MTT reduction assay method was used to evaluate the level of proliferation. Cells from osteonecrosis patients showed reduced proliferation ability compared with the control patients. The percentage of cells in the S+G2/M phase was decreased significantly (P<.01) in the osteonecrosis group. The decreased proliferation ability of mesenchymal stem cells may play a role in the low repair capacity of steroid-induced osteonecrosis of femoral head. The altered function of mesenchymal stem cells may be responsible for the pathogenesis and progression of osteonecrosis.

[Measuring blood flow change of osteonecrosis of femoral head with laser doppler flowmetry].

OBJECTIVE: To detect the blood perfusion of the necrotic area and the femoral head and neck junction in the patients diagnosed as osteonecrosis of femoral head (ONFH) with laser doppler flowmetry (LDF). METHODS: From 2007 to 2008, 50 patients with ONFH 82 hips were performed core decompression and autologous stem cells transplantation. Group A was for ARCO stage II 46 hips (IIA 6 hips, IIB 22 hips, IIC 18 hips), and Group B was for stage III 36 hips (IIIA 20 hips, IIIB 10 hips, IIIC 6 hips). Blood perfusion of necrotic area and femoral head and neck junction with LDP were detected during the operation. Statistical analysis was made. RESULTS: In Group A, the perfusion volume of necrotic area was (30.2 +/- 3.0) PU, and the perfusion volume of femoral head and neck junction was (103.4 +/- 4.4) PU. In Group B, the perfusion volume of necrotic area was (30.6 +/- 2.8) PU, and the perfusion volume of femoral head and neck junction was (103.4 +/- 3.9) PU. In Group A and Group B, the perfusion volume of necrotic area was lower than that of femoral head and neck junction, and the difference was significant (P < 0.01). CONCLUSIONS: LDF can effectively detect that the perfusion volume of ONFH decreased, which provides a theoretical basis in order to further study the pathogenesis of ONFH. Meanwhile, there is application value of LDF on the study of ONFH.

[Hematological changes and related gene mutation of post-severe acute respiratory syndrome patients with osteonecrosis].

OBJECTIVE: To investigate the hematological changes and related gene mutation of post-severe acute respiratory syndrome (SARS) patients with osteonecrosis so as to find the sensitive molecular symbols for early screening of the high risk populations. METHODS: Fast peripheral venous blood samples were collected from 61 post-SARS patients with osteonecrosis, 25 males and 36 females, aged 30.4 (20 - 60), and 52 sex and age-matched healthy persons as controls. ELISA was used to detect the coagulation and fibrinolysis indicators: activated partial thromboplastin time (APTT), protein C (PC), antithrombin III (AT-III), plasminogen activator inhibitor (PAI), activated protein C resistance (APC-R), plasminogen (PLG), von Willebrand factor (VWF), D-dimer (D-D), and fibrinogen (Fib). Real-time PCR was used to detect the mutation of factor V G1601A (FV Leiden) and prothrombin G20210A. RESULTS: The levels of PC, AT-III, and PLG of the osteonecrosis group were 85% +/- 34%, 84 +/- 29%, and 69 +/- 23%, significantly lower than that of the control group (109% +/- 20%, 104% +/- 14%, and 94% +/- 15% respectively, all P < 0.01). PAI of the osteonecrosis group was 16 U/ml +/- 14 U/ml, significantly higher than that of the control group (8.0 U/ml +/- 4.3 U/ml, P < 0.01). The percentage of patients with abnormal indicators was 99.5% (54/61) in the osteonecrosis group, significantly higher than that of the control group (36.5%, 19/52, P < 0.01). The percentage of patients with 3 or more abnormal indicators was 72.1% (44/61) in the osteonecrosis group, significantly higher than that of the control group (17.3%, 9/52, P < 0.01). No mutations of F V Leiden and prothrombin G20210A was found in both groups. CONCLUSION: Trends of hypercoagulation and hypofibrinolysis exist in the post-SARS patients with osteonecrosis. APTT, PC, AT-III, and PLG can be used as sensitive indicator for screening high risk populations of osteonecrosis.

[Clinical research of correlation between osteonecrosis and steroid].

OBJECTIVE: To explore the correlation between the dosage of corticosteroid, time of onset and incidence of osteonecrosis (ON) in patients with SARS. METHODS: From July 2003 to January 2004, general survey carried out for ON in 551 patients with SARS. Five hundred and fifty-one patients except 12 were administrated by corticosteroid from 80 mg to 30 000 mg. The age of patients was (33 +/- 9) years old ranging from 19 to 59 years old. One hundred and thirty-one were male, and four hundred and twenty were female. MRI and X-ray film were taken in all patients including both hips, knees, shoulders, ankles and wrists. CT scan was taken in partial patients. Common classification system were used for staging of hip (ARCO), knee (Lotka) and shoulder (Cruess). Independent test, rank-sum test and multiple factor logistic regression analysis were used for statistical analysis. RESULTS: No osteonecrosis was detected in 12 patients without corticosteroid. Osteonecrosis was detected in 176 patients (32.7 percent) among 539 patients. There were ON of femoral head in 130 cases (210 hips), ON of knee in 98 cases (130 knees), ON of humeral head in 21 cases (36 shoulders), ON of talus and calcaneus in 16 cases (26 ankles), ON of scaphoid and lunate in 11 cases (17 wrists), ON of patella in 3 cases (4 patella), ON of ilium in 1 case and bone infarction (femur, tibia) in 18 cases. One hundred and nineteen cases (195 hips) with ONFH were in stage I (IA 45 hips, IB 77 hips, IC 73 hips). Eleven cases (15 hips) were in stage II. All osteonecrosis of the knee and humoral head was stage I. Thirty-four patients with ON had one joint affected, 45 patients had 2 joints, 93 patients had more than 3 joints. The dosage of corticosteroid was (5842 +/- 4988) mg in ON group and (2719 +/- 2571) mg in non-ON group (P < 0.0001). The duration of steroid was (38 +/- 17) d in ON group and (27 +/- 15) d in non-ON group (P < 0.01). The dosage of pulse treatment was (340 +/- 207) mg/d in ON group and (211 +/- 160) mg/d in non-ON group (P < 0.01). The duration of pulse treatment was (28 +/- 13) d in ON group and (18 +/- 11) d in non-ON group (P < 0.01). All patients with ON were detected within 6 months from administration. CONCLUSION: About one-third patients with SARS who were treated with a high dose of corticosteroid occurred osteonecrosis. ON is frequently multiple focuses. The actual time of onset of ON is early of steroid used. MRI is golden standard for early diagnosis of ON. The patients who were treated with a high dose of corticosteroid should be inspected initially by MRI.

[Acetabular centralization in total hip arthroplasty for acetabular dysplasia].

OBJECTIVE: To explore the correct localization of the acetabular component, surgical technique and the outcome in total hip arthroplasty (THA) for acetabular dysplasia with secondary osteoarthritis. METHODS: A retrospective review was undertaken of 39 hips (33 patients) that had been performed a total hip arthroplasty for acetabular dysplasia with secondary osteoanthritis from September 1989 to January 2003. These patients were divided into two groups, 16 patients (20 hips) who were performed by regular THA of Harris method were defined as group A and the other 17 patients (19 hips) by acetabular centralization technique as group B. The hip function was evaluated using Harris hip score before and after operation. The horizontal location of the center of the hip (the distance along the intertear drop line extending lateral or medial from the inferior point of the teardrop to the perpendicular line dropped from the center of the femoral head), abduction angle of the cup, and femoral offset was measured. RESULTS: At the most recent follow-up, the mean Harris hip score was 88.9 +/- 5.8, and 82.3 +/- 8.4 for the anatomical position reconstruction and the lateral displacement hips, respectively (P < 0.05). The horizontal distance between the teardrop and the hip center was significantly shorter in B group [(37.3 +/- 3.4) mm] than in A group [(46.1 +/- 5.3) mm] (P < 0.05). Two patients had bone resorption of autograft and malposition of the acetabular component during follow-up, while others had no revision, loosening, or migration of the acetabular component. CONCLUSION: Accurately confirmed acetabular position, stable acetabular component, and appropriate techniques are important to guarantee the clinical efficacy of THA.

[Restoration of femoral offset in total hip arthroplasty].

OBJECTIVE: To explore the factors effecting restoring femoral offset and the relation between femoral offset and hip abductor strength during total hip arthroplasty (THA). METHODS: Ninety-nine THA for 81 patients were performed from March 1998 to January 2002. And follow-up was finished. There were 53 women and 28 men and the average age was 57 years (29 to 80). The right hip had been replaced in 28 cases, the left in 35 cases and the bilateral in 18 cases. The mean duration of clinical and roentgenographic follow-up was 36.8 months (range, 19 approximately 66 months). A posterolateral approach was used in all THA. The femoral offset and the abductor lever arm were measured from each radiograph. The measurement of the hip abduction strength was made for some THA by the Cybex machine. Statistical data analysis was performed by SPSS10.0 software. RESULTS: Femoral offset correlated positively with the length of the abductor lever arm (r = 0.613; P < 0.001). Simple regression analysis showed that femoral offset was significantly and positively related to the length of femoral neck and neck-shaft angle (r = 0.451, P = 0.001; r = 0.567, P < 0.001). There was a highly significant and positive correlation between femoral offset (and consequently abductor lever arm) and hip abductor strength (r = 0.500, P = 0.009; r = 0.477, P = 0.014). CONCLUSIONS: It is very important to template both sides of hip preoperatively for restoring femoral offset in THA. Femoral component with more anatomical neck-shaft angle will be used with the increase in the femoral neck length.

[Acetabular component centralization in total hip arthroplasty for acetabular dysplasia].

OBJECTIVE: To explore the correct localization of the acetabular component, surgical technique and the outcome in total hip arthroplasty (THA) for acetabular dysplasia with secondary osteoarthritis. METHODS: A retrospective review was undertaken of 44 hips (38 patients) that had had a total hip arthroplasty for acetabular dysplasia with secondary osteoarthritis from September.1989 to April. 2003. 14 were male (one bilateral) and 24 patients were female (5 bilateral). The mean duration of clinical and roentgenographic follow-up was thirty-six months (range, eight to one hundred and sixty-eight months), and the mean age of the patients was fifty-one years (range, twenty-nine to eighty years). Twelve hips were classified as type I; twenty-four as type II; seven as type III; and one as type IV, according to the criteria of Crowe. The horizontal location of the center of the hip (the distance along the interior drop line extending lateral or medial from the inferior point of the teardrop to the perpendicular line dropped from the center of the femoral head) was measured. RESULTS: There were 24 acetabular components that were placed in the centralized position and the other 20 in no deepen placement post-operatively. At the most recent follow-up, the mean Harris hip score was 90.2, 86.3 for the centralized position and the undeepen placement hips respectively, there was a significant difference between these two groups. CONCLUSIONS: In order to obtain the stability of acetabular component, deepen acetabular reaming is necessary for the most acetabular dysplasia in THA. In this way the anatomical rotational center can be obtained medially and lowly. The excellent long-term function will be maintained.

[Transtrochateric rotational osteotomy for osteonecrosis of the femoral head].

OBJECTIVE: To explore the indications, operative technique and clinical results of the transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH). METHODS: Nineteen patients (23 hips) with ONFH underwent TRO from October 1992 to May 2001 were reviewed. There were 14 males and 5 females. The age was ranging from 22 to 43 years old with an average age of 33.4 years old. The etiology were as followed: alcoholism 10 cases (12 hips); steroid 6 cases (7 hips); trauma 2 cases (2 hips); caisson disease 1 case (2 hips). Ficat stage: II 8 cases 8 hips; III 11 cases 15 hips. Harris hip score 46 to 74 with mean score 56 preoperatively. In order to determine the location and extent of osteonecrosis, A-P view and accurate lateral view (the film should be placed parallel to the femoral neck with the hip in precisely 90 degrees and flexion 45 degrees of abduction and neutral rotation) were taken in both hips preoperatively. The surgical technique described by Sugioka were used in all patients. RESULTS: Seventeen patients (19 hips) were followed up ranging from 18 to 11 years with mean 54 months. The Harris hip score was from 55 to 94 with mean 80.5. Fourteen hips score more than 80 and good to excellent rate was 73.2%. Harris score were less than 79 in 5 cases and 4 hips of these 5 hips were revised by total hip arthroplasty. The rotation angle was from 55 degrees to 80 degrees with mean 60 degrees . COMPLICATIONS: The circumflex femoral medial artery injury was found in 1 hip; subtrochanteric fracture was found in 2 hips and 1 osteotomy site nonunion occurred. CONCLUSION: TRO can be used to treat ONFH. The indications include: (1) younger patients (less than 45 years old). (2) Ficat stage II and III with more than one third intact articular surface of the femoral head. The better results could be obtained using posterior rotation and lager rotational angle. The Sugioka osteotomy should be used carefully because of its complicated surgical technique.

Rotational acetabular osteotomy through an Ollier lateral U approach for early-stage osteoarthritis secondary to acetabular dysplasia.

OBJECTIVE: To explore the surgical technique and mid-term results of rotational acetabular osteotomy for early -stage osteoarthritis secondary to acetabular dysplasia. METHODS: Rotational acetabular osteotomies were performed on 14 hips of 12 patients from May 2000 to May 2006 and the patients followed up. All patients were female and their average age was 28.9 years (range, 13-46 years) at the time of surgery. The mean duration of clinical and roentgenographic follow-up was 6.0 years (range, 3.1-9.1 years). The lateral center-edge (CE) angle, acetabular roof angle and head lateralization index were measured on radiographs taken preoperatively, postoperatively and at the time of final follow-up. Clinical follow-up included use of the Harris hip score. The acetabular osteotomies were performed through an Ollier lateral U transtrochanteric approach and postoperative traction and cast immobilization were not used. RESULTS: All patients had satisfactory pain relief. The mean preoperative Harris score was 72 points; this had improved to a mean of 91 points at the time of last follow-up (P < 0.05). The mean CE angle improved from 0.9° preoperatively to 27° postoperatively (P < 0.05), the mean acetabular roof angle from 29° to 5° (P < 0.05) and the mean head lateralization index from 0.68 to 0.65. Solid bone-to-bone healing of the osteotomy sites and great trochanters occurred in all patients. CONCLUSIONS: Rotational acetabular osteotomy through an Ollier lateral U approach, which provides wide exposure and technical ease, for early-stage osteoarthritis secondary to acetabular dysplasia can relieve pain and delay the appearance or reduce the severity of osteoarthritis. Satisfactory mid-term results can be obtained.

Experimental study on phase-contrast imaging with synchrotron hard X-ray for repairing osteonecrosis of the femoral head.

Synchrotron radiation light is 1 of 4 artificial light sources, the others being electric light, X-ray, and laser. Phase-contrast imaging with hard X-ray has achieved wide application in many scientific fields, such as biomedicine and material science. This article compares the effectiveness of nanohydroxyapatite/collagen (nHAC) and autologous mesenchymal stem cell for the repair of defects in a rabbit model with osteonecrosis of the femoral head under the monitoring of phase-contrast imaging with synchrotron hard X-ray. We established models of bilateral osteonecrosis of the femoral head defect using New Zealand rabbits and divided them into 3 groups. Imaging techniques such as phase-contrast imaging and diffraction enhanced imaging with synchrotron hard X-ray were applied to assess the degradation and repair process of nHAC and mesenchymal stem cell at 4, 8, and 12 weeks postoperatively. We found phase-contrast imaging with synchrotron hard X-ray displayed the reparative process of the bone defect, degradation of nHAC, and osteocyte substitution. There were significant differences in the repair of the bone defect and osteogenesis in groups B and C compared with group A (control). Osteogenesis was more significant in group C. We provided experimental data for the development and application of synchrotron hard X-ray imaging techniques and concluded that phase-contrast microimaging with synchrotron hard X-ray displays the reparative process of bone tissue at a micro-level and plays an important role in the development of tissue engineering.

Early and middle term results after surgical treatment for slipped capital femoral epiphysis.

OBJECTIVE: To evaluate the early and middle-term results of in situ single screw fixation and subtrochanteric osteotomy of the femur with external fixator for slipped capital femoral epiphysis (SCFE). METHODS: From June 1998 to July 2008, 11 patients (seven male [eight hips] and four female [four hips]) of average age 14.3 years (range, 9-18 years) were treated in our hospital. According to the Southwick measurement, seven hips were mildly affected (<30°), two moderately (30-50°), and three severely (>50°). The average body mass index (BMI) was 31.1 g/m(2) (range, 27-35 g/m(2) ). All the mild and moderate cases underwent in situ single screw fixation, and the three severe cases subtrochanteric osteotomy of femur with external fixator. All cases were evaluated both clinically and radiographically at 3 months, 6 months and every year postoperatively. RESULTS: All cases were followed up for 2-12 years (average 5.6 years). The Harris hip score increased from a mean of 74.8 (70 ∼ 85) points preoperatively to 90.6 (70 ∼ 100) points postoperatively. X-ray films showed epiphyseal closure in the 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 after subtrochanteric osteotomy of the femur in the external fixator cases. CONCLUSION: In situ single screw fixation for treating mild and moderate SCFE has a satisfactory clinical outcome, and the advantage of prevention of further slippage. Subtrochanteric osteotomy of the femur with external fixator is suitable for severe SCFE with late deformity; the realignment procedure can correct deformity and postpone or prevent subsequent osteoarthritis.

Changes in coagulation and fibrinolysis of post-SARS osteonecrosis in a Chinese population.

The purpose of this study was to detect changes in coagulation and fibrinolysis of post-severe acute respiratory syndrome (SARS) Chinese patients with osteonecrosis, investigate the aetiology of post-SARS osteonecrosis (ON), and select the sensitive molecular markers for identifying the susceptible population. For this study, blood samples were collected from 88 patients with post-SARS ON and 52 healthy people. Activated partial thromboplastin time (APTT), protein C (PC), antithrombin III (AT-III), plasminogen activator inhibitor (PAI), activated protein C resistance (APC-R), plasminogen (PLG), von Willebrand's factor(vWF), D-dimer (D-D), fibrinogen (Fib), and homocysteine (HCY) were examined by enzyme-linked immunosorbent assay (ELISA). We noted that blood agents of patients with ON changed obviously. APTT, PC, AT-III, PAI, APC-R, and PLG were significantly different between the two groups. Hypercoagulation and hypofibrinolysis were found in patients with post-SARS ON. Therefore, these examinations can be used to screen a population susceptible to ON. Measurements of APTT, PC, AT-III, PAI, APC-R, and PLG are sensitive blood tests for screening purposes.