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Objective The aim of the present study was to evaluate the 10‐year outcomes of cementless total hip arthroplasty (THA) in adult patients with the late sequelae of septic arthritis of the hip. Methods We followed 166 consecutive patients (168 hips) who underwent cementless THA between March 2001 and December 2011. There were 79 men and 87 women, with a mean age of 50.4 years (range 21–76 years) at the time of index THA, all of whom had hip osteoarthritis secondary to hip pyogenic infection. The average duration of follow up was 10.6 years (range 6.9–17.2 years). Preoperative and postoperative clinical ratings were evaluated, including the hip dysfunction and osteoarthritis outcome score (HOOS), the Harris hip score (HHS), range of motion, a 100‐point visual analog scale for hip pain, and the severity of limp and limb length discrepancy (LLD). The anteroposterior and lateral radiographs of the hip and full‐length view of the lower extremities were obtained to assess the position of the components, radiolucent lines, osteolysis, loosening of components, and heterotopic ossification. The intraoperative and postoperative complications were also recorded. Results The mean HSS and hip pain score were 44.2 points (range 29–66 points) and 42.5 points (range 32–64 points), respectively, before the index surgery and significantly improved to 88.1 points (range 78–96 points) and 15.1 points (range 10–26 points), respectively, at final follow‐up examination. The HOOS and range of motion also improved significantly. The mean limb length discrepancy was reduced from 2.6 to 0.8 cm. The limp at last follow‐up examination was moderate in 3 cases because of hip osteoarthritis in the other limb, slight in 26, and absent in 137. A radiolucent line was observed in 12 hips (7.1%) around the acetabular or femoral components. A progressive radiolucent line around the undersized femoral stem in all zones was seen in 1 hip, resulting in aseptic loosening and breakage of the femoral component. There were 8 cases of intraoperative fracture, 7 cases of dislocation, and 7 cases of transient nerve palsy. Recurrence of infection occurred in 2 hips. Revision surgery was conducted in 2 hips because of isolated loosening of the acetabular cup and the femoral stem, respectively. Kaplan–Meier survival was 97% at 10 years, with revision for any reason with any component as an end‐point. Conclusion Improved surgical techniques and development of components with various sizes provided favorable results for cementless THA conducted for late sequelae of sepsis in these young and active patients. Although the incidence of complications was relatively high, the complications were treated successfully., Favorable results can be obtained from cementless THA for late sequelae of pyogenic arthritis. Although the incidence of complications is relatively high, the complications can be treated successfully.

Objective To investigate the effect of acetabular component orientation on the basic stress path above the acetabular dome in the recommended safe zone. Methods A subject-specific normal hip finite element model was generated and a convergence study carried out to determine the number of material properties for trabecular bone using a normal hip model. Four abduction angles (35°, 40°, 45° and 50°) and four anteversion angles (10°, 15°, 20° and 25°) from the recommended safe zone of acetabular cup orientation were chosen to simulate acetabular reconstruction. The distribution and level of periacetabular stress was assessed using a normal hip model as a control and 16 reconstructed acetabula in simulated single-legged stances. Results The error of the average stress between plans four and five (50 and 100 materials for trabecular bone respectively) was 4.8%, which is less than the previously defined 5% error. The effect of acetabular component orientation on stress distribution in trabecular bone was not pronounced. When the acetabular component was at 15° anteversion and the abduction angle was 40° or 45°, the stress level on posterolateral cortical bone above the acetabular dome was as stable as that in the normal hip model. Conclusions Acetabular component orientation affects the basic stress path above the acetabular dome. Thus, orientation should be considered when attempting to restore normal biomechanics in the main load-bearing area.

OBJECTIVE: It has been reported that acute‐phase reactions (APR) after infusion of 5 mg zoledronic acid for the first time is common. This study surveyed the incidence and characteristics of APR in Chinese postmenopausal women receiving 5 mg zoledronic acid intravenously for osteoporosis and to evaluate the efficacy of non‐steroidal anti‐inflammatory drugs (NSAID) in preventing or alleviating APR following the first 5 mg zoledronic acid infusion. METHODS: A total of 2601 patients with an average age of 68.14 ± 9.89 years and a mean body mass index of 22.90 ± 3.24 kg/m(2) from 62 centers in China were treated with 5 mg zoledronic acid intravenously for the first time. The incidence of fever and pain were observed in these patients, and the time of fever or pain onset and duration, and the intensity of fever and grade of pain were also recorded. The dosage, duration, and efficacy of NSAID and safety outcomes were also documented. RESULTS: At the end of the study, 18 patients are eliminated due to incomplete records of temperature. The incidence of fever was 28.65% (740/2583) within 7 days following zoledronic acid infusion; 98.34% (727/740) occurred at 1.03 ± 0.66 days after infusion and lasted 1.72 ± 0.93 days. A total of 456 (17.53%) patients had newly onset pain (312 of 1187, 26.28%) or experienced pain aggravation (144 of 1414, 10.18%), which mostly occurred within 3 days after zoledronic acid infusion. A total of 1246 (47.6%) patients had received NSAID for a median time of 2.63 ± 2.45 days. Using NSAID for at least 2 days could decrease body temperature by 0.54 ± 0.86°C, increase the percentage of pain‐free patients by 6.17%, and reduce the percentage of patients with moderate to severe pain by 8.7%. CONCLUSIONS: Compared with Western populations, Chinese patients had a higher rate of fever and pain after their first zoledronic acid infusion. These symptoms were often mild to moderate in intensity and transient in duration. NSAID could effectively reduce the incidence and severity of such APR.

This study is to compare the therapeutic effect of posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation on treatment in adult degenerative spondylolisthesis. A retrospective analysis of 187 patients to compare the complications and associated predictive factors of the two techniques of one level lumbar fusion. Ninety-one had PLIF with two cages and pedicle fixation (group 1), and ninety-six had TLIF with one cage and pedicle fixation (group 2). The two groups had similar age and sex distribution, and level of pain. Inclusion criteria and outcome measurements were identical in both groups. The two groups were operated on with autograft and cage with pedicle fixation. Before surgery and at the 2-year follow-up, pain (VAS) and functional disability (JOA) were quantified. The results showed there were no intraoperative deaths in our study. In the end 176 cases had 2-year follow-up while 11 cases were lost to follow-up. The follow-up rate was 93.4% (85/91) in the PLIF group and 94.8% (91/96) in the TLIF group. All patients had bone fusion, and there were no cases of cage extrusion. The pain index improved from 7.08 +/- 1.13 to 2.84 +/- 0.89 in PLIF patients and improved from 7.18 +/- 1.09 to 2.84 +/- 0.91 in TLIF patients (P0.001). There were 42 cases of excellent, 29 cases of good, 11 cases of general, and 3 cases of poor results in PLIF group. There were 46 cases of excellent, 31 case of good, 12 case of general, and 2 cases of poor results in TLIF group. The JOA score in all patients was 84.1% of good or excellent (83.5% in PLIF and 84.6% in TLIF, P0.05). The average preoperative slip was 30.1 +/- 7.2% in PLIF group while in the TLIF it was 31.4 +/- 8.3%. Immediately post operatively it was reduced to 7.3 +/- 2.1% and 7.4 +/- 2.7% and at last F/U it was 8.1 +/- 2.8% and 8.2 +/- 2.6%, respectively. The average of reduction rate was 75.2 +/- 6.4% in PLIF and 75.4 +/- 6.2 in TLIF on the initial post operatively X-ray, and 72.6 +/- 5.2% and 72.4 +/- 5.4% on the follow-up. The percentage rate, reduction rate and lost of reduction rate between the two groups was similar (P0.05). The average pre operative disk and foramen height in the PLIF group improved from 6.8 +/- 2.3 and 14.2 +/- 1.7 preoperatively to 11.6 +/- 1.5 and 18.7 +/- 1.8 post operatively, respectively. At last follow up there was minimal lost of correction down to 11.24 +/- 1.2 and 18.1 +/- 1.8, respectively. Similarly in the TLIF group, pre operative disk and foramen height were improved from 6.7 +/- 1.7 and 14.1 +/- 1.8 to 11.4 +/- 1.6 and 18.5 +/- 1.6 immediately post operative. At last follow up minimal lost of correction was noted with average disc height of 11.3 +/- 1.4 and 18.2 +/- 1.7. Both techniques achieve statistical significance in restoration of disc and foraminal (P0.01); however, there was no statistical difference between the two techniques. In conclusion, interbody fusion with either a PLIF technique or a TLIF technique provides good outcomes in the treatment of adult degenerative spondylolisthesis. The TLIF procedure is simpler and is as safe and effective as the PLIF technique.

OBJECTIVE: To investigate the effect of acetabular component orientation on the basic stress path above the acetabular dome in the recommended safe zone. METHODS: A subject‐specific normal hip finite element model was generated and a convergence study carried out to determine the number of material properties for trabecular bone using a normal hip model. Four abduction angles (35°, 40°, 45° and 50°) and four anteversion angles (10°, 15°, 20° and 25°) from the recommended safe zone of acetabular cup orientation were chosen to simulate acetabular reconstruction. The distribution and level of periacetabular stress was assessed using a normal hip model as a control and 16 reconstructed acetabula in simulated single‐legged stances. RESULTS: The error of the average stress between plans four and five (50 and 100 materials for trabecular bone respectively) was 4.8%, which is less than the previously defined 5% error. The effect of acetabular component orientation on stress distribution in trabecular bone was not pronounced. When the acetabular component was at 15° anteversion and the abduction angle was 40° or 45°, the stress level on posterolateral cortical bone above the acetabular dome was as stable as that in the normal hip model. CONCLUSIONS: Acetabular component orientation affects the basic stress path above the acetabular dome. Thus, orientation should be considered when attempting to restore normal biomechanics in the main load‐bearing area.

OBJECTIVE: To determine the rate of curing the infection and mid‐ to long‐term outcomes of using extensively coated non‐modular stems in two‐stage revision for infected total hip arthroplasty (THA). METHODS: The clinical data of 33 patients (33 hips) in whom extensively coated non‐modular stems had been used in two‐stage revision THA for deep infection were retrospectively analyzed. All operations received two‐stage reimplantation, which included resection arthroplasty, thorough debridement, insertion of a hand‐molded antibiotic‐impregnated cement spacer with stainless steel reinforcement, a course of intravenous antibiotics, and delayed reimplantation. Microorganism‐specific antibiotics had been chosen according to the results of microbiological studies performed postoperatively. All patients received i.v. antimicrobial therapy for 4 weeks and oral antibiotics to which their organisms were sensitive for a further 6 weeks. Harris hip score (HHS) and plain X‐ray films were used to perform clinical and radiological evaluations. RESULTS: During follow‐up for a minimum of 5 years, no reinfection or loosening were found. Cultures of samples taken during the second stage were all negative for infection. The mean HHS improved from 42 preoperative to 89 at the final follow‐up. All granular bones had fused well with the host bones by 12 months after the surgery. CONCLUSION: Using extensively coated non‐modular stems combined with intramedullary allografts in two‐stage revision for treating infected THAs can achieve satisfactory outcomes.

OBJECTIVE: To assess the difference between drainage and non‐drainage after total hip arthroplasty (THA) in Chinese subjects by evaluating post‐operative complications and joint function. METHODS: One hundred and sixty‐eight patients undergoing THA were randomly allocated into drainage (83 patients) and non‐drainage groups (85 patients). All surgeries were performed by one surgical team using the same pre‐, intra‐, and postoperative techniques. Measured items included: hemoglobin (Hb), superficial and deep wound infection, volume of blood transfusion, wound hematoma thickness, range of motion (ROM) of the hip, wound healing time, ecchymosis and tension vesicles around the wound. RESULTS: Early after THA, the Hb decreased significantly in the drainage group. There was no significant difference between non‐drainage and drainage groups in need for or volume of blood transfusions (9.6% vs 8.2%, P = 0.100; 3.8 units vs 2.9 units, P = 0.089, respectively). In the non‐drainage group, the incidence of superficial infection, ecchymosis and tension vesicles was significantly higher than in the drainage group (10.6% vs 2.4%, P = 0.031; 12.9% vs 3.6%, P = 0.026; 16.5% vs 4.8%, P = 0.013, respectively). In addition, the non‐drainage group had a greater volume of hematomas (P = 0.000). Patients in the non‐drainage group had smaller ROMs early after surgery but the final ROMs did not differ significantly between groups. No deep infection occurred in either group. CONCLUSION: Non‐drainage may reduce postoperative blood loss but has no benefits regarding blood transfusion or deep infection. It may cause more post‐operative complications because of restriction of early postoperative exercise by pain and swelling. Therefore we suggest routine use of drainage after THA.

OBJECTIVE: To assess whether computed tomography (CT)‐based 3‐dimensional (3D) computerized pre‐operative planning is accurate and reliable in patients with high‐riding dislocation developmental dysplasia of the hip (DDH) undergoing total hip arthroplasty (THA). METHODS: Between September 2009 and February 2011, a prospective study with an inbuilt means of comparing predictive techniques in 20 patients (20 hips) with high‐riding dislocation DDH was undertaken. All patients had pre‐ and post‐operative CT scans, data from which were transferred digitally to Mimics software. 3D pre‐operative planning to predict the acetabular component size, hip rotation center position and acetabular component coverage was performed using Mimics software. The results and post‐operative course were compared with those of the traditional acetate templating technique. RESULTS: Using 3D computerized planning, 14/20 components (70%) were predicted exactly and 6/20 (30%) within one size, whereas with the conventional acetate templating technique, 5/20 components (25%) were predicted exactly, 9/20 (45%) within one size and 6/20 (30%) within two or more sizes. There was a strong correlation between the 3D computerized planned acetabular component size, hip rotation center distance, acetabular component host coverage and that found postoperatively. Five patients were considered to need structural bone graft on the basis of 3D computerized planning; this was highly coincident with the intraoperative findings in all five cases. CONCLUSION: CT‐based 3D computerized pre‐operative planning using Mimics software is an accurate and reliable technique for patients with high‐riding dislocation DDH undergoing THA.

To review the recent developments in the mechanisms of glucocorticoids induced osteonecrosis of femoral head (ONFH) and introduce a new theory of ONFH.Both Chinese- and English-language literatures were searched using MEDLINE (1997 - 2011), Pubmed (1997 - 2011) and the Index of Chinese-language Literature (1997 - 2011).Data from published articles about mechanisms of glucocorticoids induced ONFH in recent domestic and foreign literature were selected. Data extraction Data were mainly extracted from 61 articles which are listed in the reference section of this review.Glucocorticoids are steroid hormones secreted by the adrenal cortex that play a pivotal role in the regulation of a variety of developmental, metabolic and immune functions. However, high dose of exogenous glucocorticoids usage is the most common non-traumatic cause of ONFH. Glucocorticoids can affect the metabolisms of osteoblasts, osteoclasts, bone marrow stromal cells and adipocytes which decrease osteoblasts formation but increase adipocytes formation and cause ONFH finally.Glucocorticoids affect the differentiation of mesenchymal stem cells, through activating or inhibiting the related transcript regulators of osteogenesis and adipogenesis. At last, the size and volume of mesenchymal stem cells derived adipocytes will increase amazingly, but the osteoblasts will be decreased obviously. In the meantime, the activity of the osteoclasts will be activated. So, these mechanisms work together and lead to ONFH.

Objective: To compare the results of long proximal femoral nail antirotation (PFNA‐long) and plate combinations in the treatment of ipsilateral intertrochanteric and femoral shaft fractures. Methods: Between March 2004 and April 2009, 23 patients with ipsilateral intertrochanteric and femoral shaft fractures were treated with PFNA‐long or plate combinations. The patients were divided into two groups. Group I contained 13 patients who were treated with dynamic hip screws (DHS) combined with compression plate fixation. The 10 patients in Group II were treated with PFNA‐long. Results: The average follow‐up was 17.8 and 16.8 months for Groups I and II, respectively. The average union time for intertrochanteric fractures was 17.4 and 16.6 weeks in Groups I and II, respectively, and for femoral shaft fracture 22.2 and 21.5 weeks, respectively. There were nine good, two fair, and two poor functional results in Group I, and eight good, one fair, and one poor in Group II. There was nonunion of two femoral shaft fractures in Group I and one in Group II. There were no significant differences between the two groups in functional outcomes or major complications. Conclusion: Both treatment methods achieve satisfactory functional outcomes in patients with ipsilateral intertrochanteric and femoral shaft fractures. PFNA‐long is the better choice for the treatment of complex fractures, having the advantages of minimal exposure, reduced perioperative blood loss, and achievement of biological fixation of both fractures with a single implant.

Traumatic asymmetrical bilateral dislocation of the hip joint is a rare occurrence. Herein we report a case of traumatic asymmetrical bilateral dislocation of the hip caused by a falling object. A 31-year-old healthy male was injured by a falling wall of weighing approximately 100 kg from behind in the lumbosacral area. The patient sustained a pelvic fracture, posterior dislocation of the right hip joint associated with a comminuted fracture of the right acetabulum, and anterior dislocation of the left hip joint. Manual reduction of both hip dislocations was performed in the Emergency Department. The posterior wall fracture of the right acetabulum was treated with open reduction and internal fixation by plate and screw. Reduction of both hips was successful and no femur necrosis or arthrosis was found during the four-year follow-up. Heterotopic ossification was found but it did not affect joint function. Prompt reduction of hip dislocations in the Emergency Department can reduce the incidence of avascular necrosis of the femoral head.

To retrospectively analyse the clinical outcome of emergency treatment of senile intertrochanteric fractures with proximal femoral nail antirotation (PFNA).From September 2008 to March 2009, 35 senile patients with intertrochanteric fracture, aged from 65 to 92 years with an average age of 76.5 years, were treated with PFNA within 24 hours after injury. There were 10 type I fractures, 19 type II and 6 type III according to upgraded Evans-Jensen classification system. All patients were complicated with osteoporosis, and 19 patients had preexisting internal medical diseases. According to the rating scale of disease severity by the American Society of Anesthesiologists (ASA), there were 9 grade I, 14 grade II, 8 grade III, and 4 grade IV.The duration for operation ranged from 45 to 73 minutes with an average of 57.6 minutes. The volume of blood loss during operation ranged from 50 to 120 ml with an average of 77.5 ml. Patients could ambulate 2-4 days after operation (mean 3.5 days). Hospital stay was 4-7 days (mean 5.3 days). Full weight bearing time was 10-14 weeks (mean 12.8 weeks). During hospitalization period, there was no regional or deep infection, hypostatic pneumonia, urinary tract infection and bedsore except for 2 cases of urine retention. All cases were followed up with an average period of 12.3 months, and bone healing achieved within 15-18 weeks (mean 16.6 weeks). No complications such as delayed union, coxa vara or coxa valga, screw breakage or backout occurred and only 2 cases had trochanter bursitis because of thin body and overlong end of the antirotated nail. According to the Harris grading scale, the results were defined as excellent in 21 cases, good in 9 cases and fair in 5 cases, with the excellent and good rates of 85.7%.The emergency treatment of senile intertrochanteric fracture with proximal femoral nail antirotation has the advantages of minimal invasion, easy manipulation, less blood loss, shorter length of stay, less complications, and the preliminary clinical effect is satisfactory.

To review the challenges and countermeasures in the hospital care for Wenchuan earthquake casualties and draw lessons for the protective response in the future. Medical records and laboratory findings of the victims admitted in West China Hospital (WCH) were retrospectively analyzed. Related data were compared between beforemath and aftermath of the earthquake and between WCH and frontier county hospitals. One thousand and thirty-one earthquake survivors were hospitalized, 1 358 victims underwent surgery and 142 victims were transferred to intensive care unit. The incidence of infection, crush syndrome and multiple organ dysfunction syndrome (MODS) was 39.6%, 20.7% and 2.3% respectively. Wound classification showed that the incidence of extremity damage was 72%, while the incidence of chest trauma, abdominal trauma and brain trauma was less than 10% respectively. Isolating rates of environmental pathogens were increased in the aftermath of earthquake, and the spectrum of the pathogens and related antibiotic sensitivities were quite different from those in the beforemath of earthquake. The social economic and population conditions in the earthquake-stricken areas affected the composition of the victims and the geographic features restricted the efficiency of rescue. Trauma-induced MODS, crush syndrome and severe infections all constituted the dilemma for the hospital care, to resolve whether the multidiscipline team work was proved to be an optimizing choice. For a more effective disaster protective response in the future, the study on rescue plan and the ladder therapies for massive casualties should be potentiated.

To retrospectively analyze the medical treatment of 332 patients with lower leg fracture in Wenchuan earthquake admitted in West China Hospital.From May 12, 2008 to June 15, 2008, 332 patients with lower leg fracture injured in Wenchuan earthquake were treated in our hospital. The data on trauma condition and clinical treatment were collected and analyzed.Among the 332 cases of lower leg fracture, there were 179 cases of open fracture, accounting for 53.9%, in which 91% belonged to Gustilo II or III injury with serious pollution. Many patients had posttraumatic complications, vascular and nerve injury, wound infection or osteofascial compartment syndrome. After medical treatment, blood vessels were reconnected, wound surface was repaired and wound infection was under control.For the patients with lower leg fracture in earthquake, we followed the principle of "complete debridement - restoring the continuity of bone bracket-timely recovering blood supply of limbs and repairing nerve damage - repair the wound surface at stage I or II " so as to reduce the incidence of amputation and infection.

To investigate the potential of small interfering RNA (siRNA) against human peroxisome proliferator activated receptor gamma (PPARgamma) to suppress the adipogenic effect of alcohol on human bone marrow-derived mesenchymal cells (hBMSCs) and increase osteogenesis.hBMSCs collected from joint replacement surgery were cultured, passaged, and transfected with PPARgamma-siRNA by using liposomal-based strategy. Then the cells were maintained in culture and treated with alcohol 50 mmol/L and dexamethasone, an osteogenic inducer, for 24 days. Oil red O staining was used to observe the fat drops in the cells so as to count the number of adipocytes. Histochemistry was performed to detect the protein expression of alkaline phosphatase, osteocalcium, and type 1 collagen on days 24 and 28 after treatment. Real-time PCR and Western blotting were used to detect the mRNA and protein expression of osteoblast-specific transcription factor-2 (Osf2)/core-binding factor alpha subunit 1 (Cbfa1) on day 10.The adipocyte number of the PPARgamma-siRNA group was significantly lower than those of the alcohol-induced group and the controls (adipogenic group, liposomal group, and negative siRNA group) (all P0.05). The Calcium nodule formation rate of the PPARgamma-siRNA group was significantly higher than alcohol-induced group and the controls (adipogenic group, liposomal group, and negative siRNA group) (all P0.05). PCR and Western blotting showed significantly higher mRNA and protein expression of the human adipocyte-specific markers:Cbfa1, ALP, type 1 collagen, and osteocalcin, than the other groups.The adipogenic effect of alcohol on hBMSCs can be inhibited with a concomitant increase in osteogenesis by using siRNA technique to specific targeted human PPARgamma gene in vitro cell culture systems. PPARgamma-siRNA strategy may be a useful tool for studying the mechanisms of alcohol-induced osteoporosis and provides theoretical basis for its genetic therapy.

To evaluate the effects of transplantation of human hepatocyte growth factor (hHGF) gene-modified osteoblasts combined with core decompression in treatment of avascular necrosis of femoral head (ANFH).The plasmid pcDNA3.1(+)-hHGF containing hHGF gene was constructed. Osteoblasts were isolated from fetal rabbits, cultured, and transfect3d with the plasmid pcDNA3.1(+)-hHGF or blank plasmid pcDNA3.1(+), or used as controls. Thirty-six adult New Zealand rabbits were made into ANFH models, underwent core decompression, and were randomly divided into 3 groups. Group A, transplanted with osteoblasts transfected with pcDNA3.1(+)-hHGF plasmid, Group B, transplanted with osteoblasts not transfected with pcDNA3.1(+)-hHGF plasmid, and Group C, injected with PBS medium. 2, 4, and 8 weeks later samples of femoral head were obtained to undergo CT, histological examination, and capillary ink infusion so as to observe the angiogenesis and osteogenesis.The pcDNA3.1(+)-hHGF transfected osteoblasts showed stable expression of hHGF. The numbers of newly formed vessels of the femoral heads of the group transfected with pcDNA3.1(+)-hHGF-transfected osteoblasts 2 and 4 weeks later were (29.47 +/- 1.64) and (34.02 +/- 1.72)/cm2 respectively, both significantly higher than those of the group transfected with blank plasmid-transfected osteoblasts [(20.61 +/- 1.91) and (25.57 + 2.20)/cm2 respectively, both P0. 01]. Eight weeks later the numbers of mature trabecular bone and bone marrow of Groups A and B were significantly higher than those of Group C.Core decompression combined with transplantation of HGF gene-modified osteoblasts promotes angiogenesis, enhances bone formation, and improves the restoration of avascular necrosis of femoral head.

To study the change and relationship among bone mineral density (BMD), collagen composition and biomechanical properties of the callus in the healing process of osteoporotic fracture.The osteoporotic rat model and fracture model were established through bilateral ovariectomy (OVX) and osteotomy of the middle shaft of the right hind tibiae, respectively. Ninety female SD rats were randomly divided into OVX group and sham group. With the samples of blood and callus, roentgenographic and histological observation were performed for the assessment of the healing progress of the fracture, and the serum concentration of TRAP-5b, proportion of type I collagen, BMD and biomechanical properties of the callus were measured.The OVX group experienced a significant delay of fracture healing. The mean serum concentration of TRAP-5b of rats in the OVX group was much higher than that in the sham group after the operation (P less than 0.05), but the difference at the same time point after fracture was smaller than that before fracture (P less than 0.05). The BMD of the callus in both groups reached the peak value at the 6 th week after fracture while the proportion of the type I collagen and the biomechanical strength reached the peak at the 8th week.The deficiency of estrogen after the ovariectomy could induce the up-regulation of the osteoclasts activities, whereas the potency of further activation after fracture was depressed. Although the synthesis of collagen together with its mineralization determines the biomechanical properties of new bone, the accumulation of collagen could be assessed as an index in the prediction of biomechanical strength of bones independent of the bone mineral deposition.

To discuss the method of reconstruction of acetabular bone defect with wire mesh, impaction bone-grafting and a cemented cup in acetabular component revision.21 hips in 21 patients, aged 50.1 (31 - 64), 2 hips being of the acetabular defect type I B, 1 hip of type II A, 4 hips of type II B, and 14 hips of type III according to the American Academy of Orthopaedic Surgeons (AAOS) grading system underwent reconstruction with wire mesh, impacted bone grafts and cemented polyethylene acetabular component, and then were followed up for 47 months (36 - 60 months).The mean Harris hip score improved from the preoperative 55.7 points to 92.9 points at the last time of follow-up. Radiographic incorporation between host the bone and allograft was achieved 11.4 months after the operation on average. The mean change of inclination of acetabular components was 2.2 degrees , in which one acetabular component developed a change of 15.5 degrees . The inclination of acetabular components increased by 1.7 degrees on average 3 months after the operation and 2.0 degrees 6 months after the surgery. The acetabular cup migrated medially and superiorly by 3.93 mm and 4.41 mm respectively, peaking in the sixth month after the operation. One hip developed heterotopic ossification (Brooker grade I). One hip received repeat revision because of the aseptic loosening of the acetabular component 25 months after the revision surgery.The changes of the position of acetabular cup mainly occur within six months after the reconstruction of severe acetabular bone defect with wire mesh, impacted bone graft and cemented polyethylene acetabular component. To prevent the displacement of the acetabular cup, it is necessary to keep initial stability of the acetabular cups within six months after the index surgery.

To study cellular compatibility of improved scaffold material with deproteinized heterogeneous bone and provide experimental basis on choosing the scaffold material in bone tissue engineering.Bone marrow stromal cells (BMSC) were co-cultured with heterogeneous deproteinized bone in vitro. The contrast phase microscope, scanning electron microscope, MTT assay, flow cytometry were performed and the BGP content and ALP activities were detected in order to observe the cell growth, adhesion in the material, cell cycle and cell viability.The scaffold material of deproteinized heterogeneous bone had no inhibitory effect on cellular proliferation, differentiation and secretion function of BMSCs.The established heterogeneous deproteinized bone has good biocompatibility with BMSCs and is a potentially ideal scaffold material for bone tissue engineering.

To investigate the factors affecting the fixation, loosening and therapeutic effect of cementless acetabular prosthesis through following up the patients with total hip arthroplasty clinically and radiographically.From February 1998 to May 1999, 139 patients (148 hips) underwent total hip arthroplasty with cementless acetabular prosthesis in our department. In this study, the clinical therapeutic effect and the anteroposterior radiographs of the pelvis and anteroposterior and lateral radiographs of the hips of 109 patients (116 hips) made before operation, at 1 week, 3, 6, and 12 months after operation and annually thereafter were analyzed retrospectively. The clinical therapeutic effects were evaluated with Harris hip score. Radiographs were used to observe the position of prostheses and the bone changes around the implant, and to measure the wearing speed and direction of the acetabular cup. All evaluations were made by an independent examiner who did not participate in the operation. The patients were followed up for 5-6 years.The mean Harris score was 44 points (range, 10-70 points) before operation, but it increased to 92.4 points (range, 80-100 points) at the latest review after operation, which was significantly higher than that before operation (P0.05). No acetabular component was revised because of infection or aseptic loosening. And no acetabular component migrated. There was no revision of fixed acetabular component because of pelvic osteolysis secondary to polyethylene wear. The mean linear wear rate was 0.15 mm per year. All the acetabular prostheses were classified as stable on the radiographs.In terms of fixation, total hip arthroplasty with cementless acetabular components was successful. Although there is no aseptic loosening and a low incidence of osteolysis at the latest follow-up evaluation, polyethylene wear cannot be avoided and can lead to expansile osteolysis near the cups. This kind of osteolysis usually had no obvious clinical symptoms but it can be diagnosed early on radiographs. So radiographical follow-up for cementless acetabular components is very important.

To investigate Caspase-3 expression and its role in neuronal apoptosis.The T13-L2 spinal cord of rats was injured by traction after the amplitude of P1-N1 wave, monitored by a cortical somatosensory evoked potential (CSEP) monitor, decreased to seventy percent of that before operation. Then rats were killed in 6 h, 1 d, 4 d, 7 d, 14 d and 21 d respectively after operation. Flow cytometer terminal deoxynucleotldyl transferease-mediated biotinylated deoxynuridine triphosphate nick end labeling (TUNEL), Caspase-3 activity assay and immunohistochemical method were applied to investigate Caspase-3 expression in the spinal cord tissue and to study neuronal apoptosis in rats.After spinal cord injury, apoptotic cells detected by flow cytometry and TUNEL-positive cells were significantly more, and positive immunohistochemical staining of Caspase-3 and Caspase-3 activity were significantly higher in Group injury than in Groups control and laminectomy, respectively (P0.05, P0.01). Similar trend of changes was noticed in apoptotic cells, TUNEL-positive cells and positive immunohistochemical staining of Caspase-3, all of which reached their respective peak 7 days after operation. Caspase-3 activity reached its peak, however, 4 days postoperatively.Increased expression and activity of Caspase-3 protein in neurons after tractive spinal cord injury is the biochemical signal of early spinal cell apoptosis. It is of great significance for understanding the mechanism of spinal cord injury.