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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.

To study the distribution and drug resistance of pathogens causing periprosthetic infections after hip and knee arthroplasty, and to formulate prevention and treatment strategies for drug-resistant bacteria.The data of 146 cases of periprosthetic infection after primary hip and knee arthroplasty from 2010 to 2015 were collected, including 111 cases of periprosthetic infection after hip arthroplasty and 35 cases of periprosthetic infection after knee arthroplasty. The culture positive rate, pathogenic bacteria composition and drug resistance rate were counted over the years, and the change trend of pathogen distribution and drug resistance was analyzed.One hundredand eight strains of pathogenic bacteria were detected in 146 cases, and the positive rate of culture was 73.97%. Gram positive bacteria accounted for 55.48%, Staphylococcus epidermidis and Staphylococcus aureus accounted for 25.34% and 15.07% respectively. Gram negative bacteria accounted for 13.01%, including Enterobacter cloacae, Pseudomonas aeruginosa and Escherichia coli. There were 4 cases of Mycobacterium tuberculosis infection and mixed infection. The results of culture over the years showed that the constituent ratio of Gram positive bacteria had an increasing trend, fluctuating from 39.13% to 76.47%. The results of drug sensitivity showed that the pathogens were highly resistant to β-lactams, quinolones, clindamycin and gentamicin, and the drug resistance rate was increasing, but it was still sensitive to rifampicin, nitrofurantoin, tigecycline, linezolid and vancomycin.Gram positive bacteria are the main pathogens of periprosthetic infection, and the proportion is increasing gradually.The pathogens have high resistance to many kinds of antibiotics, and the resistance rate is still increasing. To strengthen the monitoring of the distribution and drug resistance of pathogenic bacteria is helpful to grasp its change trend and formulate targeted prevention and control strategies.

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.

It is still controversial on the optimal timing of tourniquet used in total knee arthroplasty (TKA). Most previous studies focused on the comparison of different tourniquet application in controversial TKA, while the aim of our work was to compare three strategies of tourniquet application in minimally invasive TKA. 90 patients were enrolled in this study. Based on the different tourniquet application strategies, they were divided into three groups. Group A: using tourniquet during the whole surgery; Group B: tourniquet inflated before incision and deflated after the hardening of the cement; Group C: using tourniquet during the cementation. Blood loss and serum levels of C-reactive protein, IL-6, creatine kinase and myoglobin were checked preoperatively. The HSS knee score, VAS pain score, range of motion (ROM), limb swelling and hospital stays were also recorded. The mean levels of Hb and Hct were lower in Group C (104.2 ± 10.4 g/L, 31.8 ± 3.2 %) than those in Groups A (111.4 ± 14.4 g/L, p = 0.035; 34.1 ± 4.1 %, p = 0.032) and B (112.8 ± 14.3 g/L, p = 0.013; 34.5 ± 3.7 %, p = 0.011) immediately after the surgery. Compared with Groups A and B, both serum inflammation and muscle damage markers were lower in Group C. There were no significant differences between the groups in terms of HSS knee score, ROM, estimated blood loss, swelling ratio, VAS pain score and hospital stays. Using a tourniquet full time in minimally invasive TKA causes less intraoperative blood loss and more excessive inflammation and muscle damage. However, the advantage of part-time using tourniquet did not show in early functional outcomes.

To analyze the incidence and anatomic distribution of venous thrombosis after total hip and knee arthroplasty by using the data of the patients with primary total hip and knee replacement.From December 2013 to December 2014, total hip and knee arthroplasty were performed in 1 686 patients, of which 928 were THA and 758 were TKA. Before and after discharge, all patients were routinely performed double lower limb vein color Doppler ultrasound, the conventional use of anti fibrinolytic drugs, postoperative anticoagulation for 14 d. The types and distribution of thrombosis after operation were statistical analysis.Among 928 cases of primary total hip arthroplasty, there were 30 cases of thrombosis, 27 cases of isolated muscle vein thrombosis, followed by the involvement of the anterior or posterior tibial vein thrombosis, no central thrombosis. Among 758 cases of primary total knee arthroplasty, there were 87 cases of thrombosis, 81 cases peripheral thrombosis, 4 cases of thrombus of center type, the remaining 2 cases for mixed thrombus;74 patients with thrombosis involving a single vein, 65 cases involved muscle vein, 4 cases of femoral vein, 3 cases of posterior tibial vein, 2 cases of superficial vein; 13 cases of thrombosis involving multiple veins, involving muscle vein, posterior tibial veins, the peroneal veins and popliteal vein in 2 or 3 branches. The comparison results showed that the incidence of thrombosis after total knee arthroplasty was higher, the difference was statistically significant (The incidence of thrombosis in patients with primary hip and knee replacement is low, and the incidence and anatomic distribution of the patients with primary hip and knee replacement are different.

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.

To validate the function score for adult Tibetans with Kashin-Beck disease (FSAT- KBD) measuring daily life and work functional status of KBD patients.From September to October 2010, 352 adult KBD patients in Rangtang County of Aba Tibetan autonomous region were invited to complete FSAT-KBD. The internal consistency of FSAT-KBD was assessed using Cronbach's alpha coefficients. Principal component analysis with varimax rotation was performed to explore factor structure of the instrument, with item-domain correlations being examined using Spearman's rank correlation tests. Discriminant validity of the FSAT-KBD was assessed by comparing scores of the respondents with different ages and different functional status. Convergent validity of the FSAT-KBD was assessed through a comparison with the medical outcomes study short form health survey (SF-12) and visual analogue scale (VAS).338 KBD patients (a response rate of 96.0%) completed the questionnaire in an average of (3.2 +/- 1.6) min. The instrument achieved a Cronbach's alpha of 0.945, with item-to-domain correlations exceeding 0.0. Two latent factors were extracted, which explained 72.8% of the total variance. The factor structure fitted well with our conceptual hypothesis. Respondents with different age, duration of suffering and number of affected joints had different FSAT-KBD scores. The FSAT-KBD results were correlated with those of SF-12 and VAS.FSAT-KBD is a reliable and valid instrument for measuring daily functional status of adult KBD patients in Aba Tibetan autonomous area in China.

To simulate acetabular morphology and perform acetabular quantitative analysis in high dislocated developmental dysplasia of the hip (DDH) patients using three-dimensional (3D) surface reconstruction technique, in order to understand the acetabular anatomic features and develop operative strategies for acetabular reconstruction.3D pelvic images were reconstructed by Mimics software from CT data of 13 patients (13 hips) with high developmental DDH and 13 normal persons (26 hips). True acetabular superior-inferior diameter, anterior-posterior diameter, acetabular depth, medial wall thickness, abduction angle and anteversion angle were measured and compared between the two groups of participants.Irregular acetabular shape was found in high dislocated group, showing a triangle with wide upper and narrow lower. The acetabular quantitative analysis revealed (38.29 +/- 2.71) mm superior-inferior diameter, (21.74 +/- 5.33) mm anterior-posterior diameter, (15.50 +/- 2.93) mm acetabular depth, (6.80 +/- 2.97) mm medial wall thickness, (49.29 +/- 7.40) degrees abduction angle and (23.82 +/- 11.21) degrees anteversion angle in high dislocated patients. The superior-inferior diameter, anterior-posterior diameter and acetabular depth of high dislocated patients were significantly smaller than those of the normal contirols (P0.05). However, the medial wall thickness, abduction angle and anteversion angle of high dislocated patients were significantly bigger than those of the normal controls (P0.05).3D reconstruction technique can restore true acetabular morphology and perform quantitative analysis. Compared with normal controls, high dislocated DDH patients have acetabular features: irregular shape, lower opening, higher medial wall and bigger abduction and anteversion angles. Joint arthroplasty surgery in high dislocated DDH patients needs to look at these acetabular features.

Nitric oxide has important effects on bone cell function. To verify that nitric oxide can protect against bone loss associated with estrogen deficiency, which is dependent on different concentrations of nitric oxide, we applied different doses of nitric oxide to ovariectomized rats. Fifty 12-week-old Sprague-Dawley female rats had ovariectomies, and 10 rats had sham operations. The ovariectomized rats were randomized into five groups: ovariectomized only; 17-beta-estradiol; low-dose nitroglycerin; middle-dose nitroglycerin; and high-dose nitroglycerin. After 12 weeks, the bone mineral density, dry weight, ash weight, calcium content, and nitric oxide concentration were determined. Compared with these same measurements in the sham-operated group, the bone mineral density, dry weight, ash weight, calcium content, and nitric oxide concentration decreased in the control group. Treatment with low-dose nitroglycerin, middle-dose nitroglycerin, and 17-beta-estradiol maintained bone mineral density and reversed the effects of ovariectomy on dry weight, ash weight and calcium content when compared with those in the control group. There were no differences in the bone mineral density, dry weight, ash weight, or calcium concentration between the ovariectomized-only rats and the rats treated with high-dose nitroglycerin. Results of this study suggest that nitric oxide treatment can counteract bone loss in ovariectomized rats. Furthermore, supplementation with a similar or slightly greater than physiologic concentration of nitric oxide has a potentially positive impact on osteoporosis.

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.

To evaluate the outcomes of open high tibial osteotomy through small incision with annular external fixator for treating genu varum deformity.We reviewed 8 cases of open high proximal tibia osteotomy through small incision with annular external fixator for patients (10 knees) with genu varum due to high tibia varum. The patients were followed up 1, 2, 3, 6, 12, 24 and 36 months after the operations. Data about infection, healing, varus angle, knee distance and Insall-Salvati index were retrieved and analysed.The patients had a mean varus angle of 15. 3 degrees +/- 2. 3 degrees (range, 10 degrees - 28 degrees) before the operations. The operations were all recorded as successful following a (29. 3 +/- 3. 1) month (range, 24-36 months) post-operation follow-up, with external fixator remaining stable and no instrument failures. The bones were healed at an average of (11. 2 +/- 1. 5) weeks (range, 8-12 weeks) and there was no nonunion or delayed union. The operations reduced varus angle of the knees to - 1. 1 degrees +/- 0. 6 degrees (range, - 7 degrees - 3 degrees ), indicating a significant improvement compared to that of the preoperations. There were 2 cases of superficial pin infections.Open high tibial osteotomy through small incision with annular external fixator has good fixation stability and satisfactory clinical outcomes with little complications for treating patients with genu varum deformity.

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.

To systematically analyze and compare the clinical characteristics of orthopedic inpatients in Lushan and Wenchuan earthquake, so as to provide useful references for future earthquakes injury rescue.Based on the orthopedic inpatients in Lushan and Wenchuan earthquakes, the data of the age, gender, injury causes, body injured parts and speed of transport were classified and compared.The duration of patients admitted to hospital lasted long and the peak appeared late in Wenchuan earthquake, which is totally opposed to Lushan earthquake. There was no significant difference in the patient's age and gender between the two earthquakes. However, the occurrence rate of crush syndrome, amputation, gas gangrene, vascular injury and multiple organ dysfunction syndrome (MODS) in Wenchuan earthquake was much higher than that in Lushan earthquake. Blunt traumas or crush-related injuries (79.6%) are the major injury cause in Wenchuan earthquake, however, high falling injuries and falls (56.8%) are much higher than blunt trauma or crush-related injuries (39.2%) in Lushan earthquake. The incidence rate of foot fractures, spine fractures and multiple fractures in Lushan earthquake was higher than that in Wenchuan earthquake, but that of open fractures and lower limb fractures was lower than that in Wenchuan earthquake.The rapid rescue scene is the cornerstone of successful treatment, early rescue and transport obviously reduce the incidence of the wound infection, crush syndrome, MODS and amputation. Popularization of correct knowledge of emergency shelters will help to reduce the damage caused by blindly jumping or escaping while earthquake happens.

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 compare the clinical efficacy and serum concentrations of cobalt, chromium metal ion in three different hard-on-hard bearings after total hip arthroplasty at 2-years postoperatively.Ninety (90) THA patients were divided into ceramic-on-ceramic (COC), ceramic-on-metal (COM), metal-on-metal (MOM) group (n = 30 in each group). At preoperative and 3, 6, 12, 24 months postoperative 5 time points, serum concentrations of cobalt and chromium metal ion were measured, Harris hip score was evaluated, X-rays and color doppler ultrasound examination of the ipsilateral hip also were observed.The excellent rates of Harris hip score were 100% in three groups. Continuous X-rays showed no radiolucent line around the acetabular component, no osteolysis, and no inflammatory pseudotumor. After the THA operation, the metal ion levels in COM and MOM groups increased rapidly, and stabilized at 12 months, then showed a downward trend, but the chromium ion level of MOM continued to rise at 24 months, with a significant difference when compared with that at 12 months (an increase of 0.48 microg/L, P = 0.021). The serum concentrations of metal ion in COC group were relatively constant at all time points, and the cobalt, chromium ion levels of MOM group were significantly higher than those of COC and COM group.The postoperative functional recovery of the three hard-on-hard bearings all were good, and no inflammatory pseudotumor and osteolysis were found. The serum levels of cobalt, chromium ion of COM were lower than those of MOM, but higher than those of COC.

To evaluate the clinical effectiveness and safety of using granular type nano-hydroxyapatite and polyamide 66 (n-HA/PA66) composite in repairing bone defects caused by giant cell tumors.48 patients with giant cell tumors, who underwent lesion curettage, inactivation and cavities fill-in with granular type n-HA/PA66 from December 2007 to May 2011, were followed up. Routine blood tests, liver and kidney functions, serum calcium and phosphorus, and immunologic parameters were examined before and after the surgeries. Radiological examinations were carried out 1 week and 1, 3, 6 and 12 months post operations to monitor the bone repairing process. The n-HA/ PA66 in bone issues was detected with hematoxylin-eosin staining.45 patients completed the follow-up. No significant abnormalities in routine blood tests, serum calcium and phosphorus, and immunologic parameters were found pre- and post-operations. Nor abnormal liver and kidney functional lesions were identified. The radiological examination showed gradual increase in the density of the focal zone after bone implanting operations. The bone density of the implanted areas got close to normal 1 year after operations. The histological examination found that osteoblasts grew into the hole of n-HA/PA66; calcium was deposited on the materials; and large amount of osteocytes inlaid into the composite. The composite was integrated into new bone and surrounding tissues.n-HA/PA66 has good biocompatibility and biological safety. It also has good osteoconduction and osteogenesis activity. The n-HA/PA66 composite is one perfect bone repair material.