Total hip arthroplasty following failure of tantalum rod implantation for osteonecrosis of the femoral head with 5- to 10-year follow-up.

BACKGROUND: Total hip arthroplasty (THA) with failure of tantalum rod implant for osteonecrosis of the femoral head (ONFH) will be the only choice for patients. However,it remains unknown whether tantalum rod implantation has an adverse effect on the survival time of implants following conversion to THA. The aim of this study was to retrospectively evaluate the clinical and radiographic outcomes of conversion to THA in patients who were previously treated with implantation of a tantalum rod. METHODS: This study included 31 patients (39 hips), who underwent conversion to THA due to failure of core decompression with an implanted tantalum rod. Among these 31 patients, 26 patients were male and five patients were female. The mean age of these patients was 49.3 years old (range: 36-64 years old). The control group included 33 patients (40 hips), who underwent total hip replacement without tantalum rod implantation. The hip Harris score, implant wear, osteolysis, radiolucencies and surgical complications were recorded during the follow-up. The distribution of tantalum debris in the proximal, middle and distal periprosthetic femoral regions, radiolucent lines and osteolysis were analyzed on post-operative radiographs. RESULTS: There were no significant differences in Harris score, liner wear and complications between the two groups (P > 0.05). Osteolysis and radiolucent lines more likely occurred in patients with tantalum debris distributed in three regions than in one or two regions (P < 0.05). CONCLUSIONS: The mid-term clinical outcome of patients who underwent THA with tantalum rod implantation was not different from those without a tantalum rod, suggesting that tantalum debris did not increase the liner wear rate. However, the distribution of periprosthetic tantalum debris in the proximal, middle and distal femoral regions may increase the risk of femoral osteolysis and radiolucent lines.

Quality of sexual life after total hip arthroplasty in male patients with osteonecrosis of femoral head.

BACKGROUND: Patients with osteonecrosis of the femoral head (ONFH) have a severe impact on their health status, functionality and quality of life. Sexual life is an important component of the quality of life and is still a frequently neglected domain in patients with ONFH. The aims of the study were to evaluate the influence of the disease and the total hip arthroplasty (THA) surgery on quality of sexual life (QSL) in these patients. METHODS: A prospective, self-controlled study was done. 247 patients of ONFH who underwent unilateral or bilateral THA were asked to complete a standardized QSL questionnaire, and the score of QSL was evaluated preoperatively and at first year follow-up of post-THA operation. RESULTS: The mean age of the patient was 46.8 (range 25-60) years. 194 cases (78.5%, 276 hips) were alcohol-induced ONFH. There is significant decrease (p = 0.026) in sexual relationship impairment on the 0-8 scale from pre-THA (5.3 ± 0.7) to post-THA (2.3 ± 0.4). There is no significant difference for effect on sexual function (p = 0.14) between pre-THA (2.3 ± 0.4) and post-THA (1.8 ± 0.3). There is significant improvement (p = 0.018) in overall sexual satisfaction degree of patients on the 1-5 scale from pre-THA (2.7 ± 0.2) to post-THA (4.7 ± 0.6), but no significant increase for sexual partner. CONCLUSION: ONFH has impaired relationships with partner and overall sexual satisfaction degree of the male patients; THA has improved significantly relationships with partner and overall sexual satisfaction degree of the male patients, but no effect on sexual function of the patients and overall sexual satisfaction degree of sexual partner.

[Effects of posterior tibial slope on non-contact anterior cruciate ligament rupture and stability of anterior cruciate ligament rupture knee].

OBJECTIVE: To retrospectively explore the correlation between anterior cruciate ligament (ACL)-ruptured knees, stability of ACL-rupture knee and posterior tibial slope (PTS). METHODS: From January 2008 to October 2012, 150 knees with ACL rupture underwent arthroscopic surgery for ACL reconstruction. A control group was established for subjects undergoing arthroscopic surgery without ACL rupture during the same period. PTS was measured on a digitalized lateral radiograph. Lachman and mechanized pivot shift tests were performed for assessing the stability of knee. RESULTS: There was significant difference (P = 0.007) in PTS angle between the patients with ACL rupture (9.5 ± 2.2 degrees) and the control group (6.6 ± 1.8 degrees). Only among females, increased slope of tibial plateau had effect on the Lachman test. There was a higher positive rate of pivot shift test in patients of increased posterior slope in the ACL rupture group. CONCLUSION: Increased posterior tibial slope (>6.6) appears to contribute to non-contact ACL injuries in females. And the changes of tibial slope have no effect upon the Lachman test. However, large changes in tibial slope affect pivot shift.

Lesion size changes in osteonecrosis of the femoral head: a long-term prospective study using MRI.

Osteonecrosis of the femoral head (ONFH) is one of the intractable diseases. It is controversial whether the lesion size assessed by magnetic resonance imaging (MRI) can change over time without any operative treatment. In this study, we used MRI to observe the lesion size changes of ONFH induced by corticosteroid administration in severe acute respiratory syndrome (SARS) patients. The study included 51 SARS patients (84 hips) with early-stage ONFH who did not receive any operative treatment and were diagnosed by MRI. All of the patients underwent MRI follow-ups. Each patient was evaluated on the basis of the lesion volume on MRI at every follow-up for further comparisons. At the first MRI scan, the mean lesion volume was 10.12 +/- 8.05 cm(3) (range: 0.39-41.62 cm(3)). At the mid-term follow-up (2.5 years), the mean lesion volume was 7.82 +/- 7.59 cm(3) (range: 0.11-39.65 cm(3)). At the final follow-up (five years), complete regression of the lesion was observed in six hips, and the mean lesion volume was 5.67 +/- 6.58 cm(3) (range: 0.00-31.47 cm(3)). Overall, the lesion volume was reduced by >15% in 80 hips, and only four hips with relatively larger lesion volumes showed no apparent reductions. The reduction in lesion size of ONFH observed on MRI is a slow, discontinuous and time-dependent process.

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.

[Study on the relationship between sclerosis rim and bone morphogenetic proteins of osteonecrosis of the femoral head].

OBJECTIVES: To analyze retrospectively the formation and histological changes of sclerosis rim in patients with osteonecrosis of the femoral head (ONFH), and to study the relationship between bone morphogenetic proteins (BMP4) and sclerosis rim, so as to acquire experimental and theoretical basis on individualized treatment for ONFH patients. METHODS: From November 2005 to November 2007, 184 hips of steroid-induced ONFH inpatients were collected. The mean age was (47 ± 7) years, the patients were divided into high (more than 54 years old), middle (40 - 54 years old) and low (less than 40 years old) age groups. Their clinical data were analyzed retrospectively according to gender and age. Parts of the femoral heads were selected for the study, including 18 hips in high age group, 11 hips in low age group and 20 hips in middle age group. Each 10 hips were selected with or without sclerosis rim. The femoral heads were cut along middle coronal plane, their weight-bearing and non-weight-bearing areas were used for the study. The specimens were processed by routine HE staining and picric acid-Sirius red staining and electron microscopy preparation and immunohistochemistry stain. The average optical density of BMP4 protein was calculated by image analysis software. RESULTS: The trabecular of sclerosis rim was thickening and disorder. But its osteocytes were normal and with high secretion. The ratio of sclerosis rim was 71.4% (105/147) in middle age ONFH patients, which was significantly higher than the low age group patients (45.5%, 5/11) and high age group patients (38.5%, 10/26) (P < 0.01). The optical density of BMP4 in middle age ONFH patients was 0.32 ± 0.14, which was significantly higher than the low age group 0.20 ± 0.17 and high age patients 0.19 ± 0.27 (P < 0.05). The optical density was 0.16 ± 0.11 in ONFH patients without sclerosis rim, which was significantly lower than with sclerosis rim (0.28 ± 0.13) (P < 0.01). The time from hip pain to joint replacement in patients with sclerosis rim was (49 ± 11) months, and (15 ± 2) months without sclerosis rim. There was significant difference between the two groups (P < 0.01). CONCLUSIONS: The formation of sclerosis rim is positively related to the expression of BMP4, and high expression of BMP maybe promote the formation of sclerosis rim.

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.

Local Administration of Bisphosphonate-soaked Hydroxyapatite for the Treatment of Osteonecrosis of the Femoral Head in Rabbit.

BACKGROUND: Systemic administration of bisphosphonates has shown promising results in the treatment of osteonecrosis of the femoral head (ONFH). However, few studies have evaluated the efficacy of local zoledronate (ZOL) administration in the treatment of ONFH. The purpose of this study was to investigate whether local administration of bisphosphonate-soaked hydroxyapatite (HA) could improve bone healing in an experimental rabbit model of ONFH. METHODS: This experimental study was conducted between October 2014 and June 2015. Forty-five rabbits underwent simulated ONFH surgery. Immediately following surgery, they were divided into three groups: model (untreated, n = 15), HA (treated with HA alone, n = 15), and HA + ZOL (treated with HA soaked in a low-dose ZOL solution, n = 15). Histological, immunohistochemical, and quantitative analyses were performed to evaluate bone formation and resorption 2, 4, and 8 weeks after surgery. RESULTS: Gross bone matrix and hematopoietic tissue formation were observed in the HA + ZOL group 4 weeks after surgery. The immunohistochemical staining intensities for 5-bromodeoxyuridine, runt-related transcription factor 2, osteocalcin, osteopontin, and osteoprotegerin were significantly higher in the HA + ZOL group than that in the model (P < 0.001, P< 0.001, P< 0.001, P< 0.001, and P = 0.018, respectively) and HA groups (P = 0.003, P = 0.049, P< 0.001, P = 0.020, and P = 0.019, respectively), whereas receptor activator of the nuclear factor-κB ligand staining intensity was significantly lower in the HA + ZOL group than that in the model and HA groups (P = 0.029 and P = 0.015, respectively) 4 weeks after surgery. No significant differences in bone formation or bone resorption marker expression were found between the three groups 2 or 8 weeks after surgery (P > 0.05). CONCLUSIONS: Local administration of HA soaked in a low-dose ZOL solution increased new bone formation while inhibiting bone resorption in an animal model of ONFH, which might provide new evidence for joint-preserving surgery in the treatment of ONFH.

The (PrS/HGF-pDNA) multilayer films for gene-eluting stent coating: Gene-protecting, anticoagulation, antibacterial properties, and in vivo antirestenosis evaluation.

Vascular gene-eluting stents (GES) is a promising strategy for treatment of cardiovascular disease. Very recently, we have proved that the (protamine sulfate/plasmid DNA encoding hepatocyte growth factor) (PrS/HGF-pDNA) multilayer can serve as a powerful tool for enhancing competitiveness of endothelial cell over smooth muscle cell, which opens perspectives for the regulation of intercellular competitiveness in the field of interventional therapy. However, before the gene multilayer films could be used in vascular stents for real clinical application, the preservation of gene bioactivity during the industrial sterilization and the hemocompatibility of film should be taken into account. Actually, both are long been ignored issues in the field of gene coating for GES. In this study, we demonstrate that the (PrS/HGF-pDNA) multilayer film exhibits the good gene-protecting abilities, which is confirmed by using the industrial sterilizations (gamma irradiation and ethylene oxide) and a routine storage condition (dry state at 4°C for 30 days). Furthermore, hemocompatible measurements (such as platelet adhesion and whole blood coagulation) and antibacterial assays (bacteria adhesion and growth inhibition) indicate the good anticoagulation and antibacterial properties of the (PrS/HGF-pDNA) multilayer film. The in vivo preliminary data of angiography and histological analysis suggest that the (PrS/HGF-pDNA) multilayer coated stent can reduce the in-stent restenosis. This work reveals that the (PrS/HGF-pDNA) multilayer film could be a promising candidate as coating for GES, which is of great potential in future clinic application.

Relationship between preservation of the lateral pillar and collapse of the femoral head in patients with osteonecrosis.

It is difficult to predict if and when the femoral head will collapse and whether the collapse can be minimized. This study examined the final outcome of early-stage osteonecrosis of the femoral head (ONFH) using magnetic resonance imaging to verify the relationship between preservation of the lateral pillar and collapse of the femoral head. A midcoronal section of the femoral head was divided into 3 pillars (medial, central, and lateral) on a T1-weighted image. According to the site of necrosis on the lateral pillar, the necrosis was divided into 3 types: I, the necrosis occupies the central and medial pillars, and the lateral pillar is preserved; II, the necrosis partially occupies the lateral pillar; and III, the necrosis totally occupies the lateral pillar. One group of 87 patients (127 hips) with Association for Research on Osseous Circulation (ARCO) stage I ONFH underwent nonoperative treatment and were followed for 3 to 8 years (average, 6.2 years). Another group of 42 patients (72 hips) with ARCO stage I ONFH underwent debridement and impacted bone graft and were followed for 5 to 9 years (average, 7.1 years). In both groups, the more preserved the lateral pillar, the less collapse occurred. The authors concluded that whether ONFH progressed to collapse is determined by preservation of the lateral pillar. The lateral pillar is the keystone for maintaining the sphere of the femoral head and its preservation.

Construction of degradable multilayer films for enhanced antibacterial properties.

Infections associated with medical devices have become a major concern. The adhesion of bacteria to the devices' surfaces during the initial 24 h is believed to be a "decisive period" for implant-associated infections, which pose key challenges to optimal antiadhesion of microbes in this period. Herein, we have designed and constructed a (heparin/chitosan)10-(polyvinylpyrrolidone/poly(acrylic acid))10 [(HEP/CHI)10-(PVP/PAA)10] multilayer film by layer-by-layer self-assembly. Assembly of the underlying (HEP/CHI)10 multilayer film is based on electrostatic interactions, showing the properties of contact killing of bacteria. Deposition of the top (PVP/PAA)10 multilayer film is based on hydrogen bond interactions. The PAA molecules are then cross-linked to form anhydride groups by thermal treatment at 110 °C for 16 h. Therefore, it shows a top-down degradable capability in the determined period, leading to almost no adhesion of bacteria in 24 h. Our system combining the adhesion resistance and the contact killing properties shows an enhanced antibacterial capability through targeting the "decisive period" of implantation may have great potential for applications in medical implants, tissue engineering, etc.

Efficacy of multimodal cocktail periarticular injection with or without steroid in total knee arthroplasty.

BACKGROUND: Multimodal cocktail periarticular injection (MCPI) with a large volume of low concentration local anesthetics, adrenaline, and anti-inflammatory agents such as non-steroidal anti-inflammatory drug or steroids have shown good pain control and improvement in range of motion after surgery. This study compares the efficacy of pain control after total knee arthroplasty, using multimodal cocktail periarticular injection with steroid or without steroid. METHODS: This is a prospective, double-blinded, randomized and control study. Seventy-two patients with osteoarthritis that met clinical criteria for total knee arthroplasty were recruited into the study, and were randomized to receive either multimodal cocktail periarticular injection with steroid or without steroid. Pain was assessed by visual analogue scale (VAS) at preoperative and postoperative at rest, and during activity. The range of motion was recorded preoperatively and postoperatively. The amount of daily and cumulative morphine consumption were measured by patient-controlled analgesia in the first 72 hours postoperatively. The duration of celecoxib usage was also recorded at the last follow-up. RESULTS: There were no differences between the non-steroid and steroid groups with regard to VAS at rest and during activity, or range of motion, at any postoperative observation time. The postoperative Knee Society Knee Score in the steroid group improved significantly as compared with that in non-steroid group at the one-month (84.1±13.1 and 65.9±12.1; P < 0.0045), three-month follow-up (90.2±16.3 and 72.5±16.6; P < 0.0027), but after postoperative six-month the Knee Society Knee Score showed no significant difference between the groups. There was no significant difference in consumption of the morphine about daily or total consumption within 72 hours between the two groups. The duration of celecoxib usage in patients in the steroid group was significantly shorter than that in the non-steroid group ((7.2±0.7) compared with (10.5±1.9) weeks; P = 0.012). CONCLUSION: The patients who received the steroid injection had faster rehabilitation and less non-steroidal antiinflammatory drugs consumption.

Surface-mediated functional gene delivery: an effective strategy for enhancing competitiveness of endothelial cells over smooth muscle cells.

The non-biorecognition of general biomaterials and inherent biospecificity of biological systems pose key challenges to the optimal functions of medical devices. In this study, we constructed the surface-mediated functional gene delivery through layer-by-layer self-assembly of protamine sulfate (PrS) and plasmid DNA encoding hepatocyte growth factor (HGF), aiming at specific enhancing endothelial cells (EC) compeititiveness over smooth muscle cells (SMC). Characterizations of the (PrS/HGF-pDNA) multilayered films present the linear buildup with homogeneous and flat topographical feature. The amount of DNA can be easily controlled. By using these multilayered films, both human umbilical vein endothelial cells (HUVEC) and human umbilical artery smooth muscle cells (HUASMC) can be directly transfected when they contact with the multilayered films. On transfection, increasing secretion of HGF has been detected in both HUVEC and HUASMC culture, which leads to selective promotion of HUVEC proliferation. In the co-culture experiment, we also exhibit the promoted and hindered growth of HUVEC and HUASMC, respectively, which could be attributed to the inverse influence of HUVEC on HUASMC. These results collectively demonstrate that our system can be served as a powerful tool for enhancing competitiveness of EC over SMC, which opens perspectives for the regulation of intercellular competitiveness in the field of interventional therapy.

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.

Fast and long-acting antibacterial properties of chitosan-Ag/polyvinylpyrrolidone nanocomposite films.

Infection associated with medical devices is one of the most frequent complications of modern medical biomaterials. Preparation of antibacterial films on the medical devices is a great challenge owing to bactericidal efficiency, long acting and biocompatibility. In this study, silver nanoparticles (Ag NPs) doped chitosan/polyvinylpyrrolidone (PVP) films were successfully prepared by dip coating method. The nanocomposite films with spherical Ag NPs (diameters in 10-50 nm) were stable after being immersed in PBS for 35 days. Through regulating the concentration of AgNO3, the nanocomposite films showed good cell compatibility. The nanocomposite films could eliminate 100% Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8739) in 5 min and had favorable long-acting antibacterial property. The increase of PVP amount obviously enhanced anti-adhesion activity of the nanocomposite film. Such nanocomposite films can be expected to have good potential in biomaterials applications.

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.