Comparison of percutaneous compression plate to parallel screws in the treatment of nondisplaced femoral neck fractures in elderly patients: a prospective, randomized study.

BACKGROUND: The optimal internal fixation for non-displaced femoral neck fractures remains controversial. This study aimed to compare the clinical results of the percutaneous compression plate (PCCP) with parallel screws (PS) in treating femoral neck fractures in elderly patients. MATERIALS AND METHODS: A total of 218 patients who underwent internal fixation were randomized to receive either a percutaneous compression plate (PCCP group) or parallel screws (PS group) using a computerized random sequence generator which was used to assign the order of randomization. Patients were assessed by the operating time, intraoperative blood loss, hemoglobin level drop, postoperative hospital stay, the time to full weight-bearing, reduction quality, fracture healing time, Harris hip score, and postoperative complications. RESULTS: There was no significant difference between PCCP and PS groups regarding operative time, intraoperative blood loss, hemoglobin level drop, postoperative hospital stays, reduction quality, and Harris hip score (p > 0.05). The time to full weight-bearing and the fracture healing time in the PCCP group were shorter than those in the PS group (p < 0.05). The overall complication rates were slightly lower in the PCCP compared to the PS patients, but there was no significant difference (p > 0.05). However, the implant failure rate was significantly higher in the PS group compared to the PCCP group (p < 0.05). CONCLUSIONS: The present study suggests that the PCCP is superior to the parallel screws fixation in the treatment of non-displaced elderly femoral neck fractures in terms of earlier full weight-bearing, shorter fracture healing time, and lower implant failure rate. Therefore, it may be a better therapeutic strategy for non-displaced femoral neck fractures in elderly patients.

Correction: Preparation and characterizations of an injectable and biodegradable high-strength iron-bearing brushite cement for bone repair and vertebral augmentation applications.

Correction for 'Preparation and characterizations of an injectable and biodegradable high-strength iron-bearing brushite cement for bone repair and vertebral augmentation applications' by Luguang Ding et al., Biomater. Sci., 2023, 11, 96-107, https://doi.org/10.1039/D2BM01535H.

Ectoderm mesenchymal stem cells promote osteogenic differentiation of MC3T3-E1 cells by targeting sonic hedgehog signaling pathway.

BACKGROUND: Despite their high repair capability, bone defects still present a major challenge in orthopedic tissue engineering. Osteoblast differentiation is central to the treatment of bone defects. METHODS AND RESULTS: We used nasal mucosal-derived ectoderm mesenchymal stem cells (EMSCs) to promote osteogenic differentiation by co-culturing MC3T3-E1 cells. Our results showed that MC3T3-E1/EMSCs co-culture upregulated bone-related proteins and transglutaminase 2 (TG2) and increased alkaline phosphatase (ALP) activity and bone nodule formation relative to controls. Furthermore, our results showed that EMSC-derived sonic hedgehog (Shh) accounted for the enhanced MC3T3-E1 differentiation because inhibiting Shh signaling substantially reduced osteogenic differentiation. CONCLUSION: Altogether, these results suggest that EMSCs differentiated into osteoblast cells and supported MC3T3-E1 differentiation. Thus, EMSCs may be a promising cell source for treating bone-related diseases.

Preparation and characterizations of an injectable and biodegradable high-strength iron-bearing brushite cement for bone repair and vertebral augmentation applications.

Brushite cements have good osteoconductive and resorbable properties, but the low mechanical strength and poor injectability limit their clinical applications in load-bearing conditions and minimally invasive surgery. In this study, an injectable brushite cement that contains monocalcium phosphate monohydrate (MCPM) and ß-tricalcium phosphate (ß-TCP) as its solid phase and ammonium ferric citrate (AFC) solution as the aqueous medium was designed to have high mechanical strength. The optimized formulation achieved a compressive strength of 62.8 ± 7.2 MPa, which is above the previously reported values of hand-mixing brushite cements. The incorporation of AFC prolonged the setting times and greatly enhanced the injectability and degradation properties of the cements. In vitro and in vivo experiments demonstrated that the brushite cements exhibited good biocompatibility and bone regeneration capacity. The novel brushite cement is promising for bone healing in load-bearing applications.

Micro-RNA-124-5p promotes insulin producing cell differentiation through regulating transcriptional factor NKX6.1.

Aims: Differentiating human embryonic stem cells into pancreatic ß cells has been proposed as a practical approach to managing diabetes. There have been several protocols attempting to generate ß-like cells or insulin-producing cells (IPCs), but their low efficiency is a common issue. The expression level of Nkx6.1 is crucial for maintaining pancreatic ß cell identity, while the proportion of PDX1 and Nkx6.1 double positive cells were not satisfied in the present protocols, leading to relative low efficiency in the differentiation into IPCs. This study aims to identify the mechanism underlying the regulation of Nkx6.1 during IPC differentiation and provide new insights for diabetes therapy. Methods: In the current study, human embryonic stem cell (hESC) line H1 was used to perform IPC specifications. Immunofluorescence, flow cytometry, and qPCR were conducted to analyze gene expression. In addition, insulin and C-peptide were measured through glucose-stimulated insulin secretion (GSIS) assays and ELISA. Results: We found that the transcription factor NKX6.1, a crucial inducer of early pancreatic development and IPC generation, was downregulated by micro-RNA-124-5p (miR-124-5p) in hESCs during IPC differentiation. Also, we observed that miR-124-5p was upregulated and bound to the 3' untranslated region (3' UTR) of NKX6.1 in pancreatic progenitor (PP), which subsequently suppressed PP differentiation. Moreover, inhibiting miR-124-5p induced the generation of IPCs. Conclusion: The current study results demonstrated an important role for miR-124-5p in regulating NKX6.1 expression, which appears to be a practical strategy for producing IPCs.

Enhanced Bone Regeneration Using a ZIF-8-Loaded Fibrin Composite Scaffold.

In the present study, fibrin-based biomaterials made of zeolite imidazole framework-8 (ZIF-8) and fibrin gel (Z-FG) are fabricated with the aim of enhancing skull regeneration. X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet (UV)-vis spectrophotometry, Fourier transform infrared spectroscopy, and rheometry are used to characterize ZIF-8 and Z-FG. The influences of ZIF-8 on the physical properties of fibrin gel (e.g., porosity, modulus, and in vitro biodegradation) are investigated, and the effect of ZIF-8 concentration on fibrin gel properties in vitro is determined by seeding ectomesenchymal stem cells (EMSCs) over Z-FG. EMSC osteogenic differentiation reveals higher expression of bone-related proteins and higher calcium deposition and alkaline phosphatase activity, indicating that Z-FG may be a good osteoinductive biomaterial. Furthermore, these results show that the piezochannel and yes-associated protein (YAP) signaling pathway are involved in the differentiation process. In addition, the in vivo results demonstrate that Z-FG increases bone formation in critical-sized calvarial defects in rats. Thus, the developed composite scaffold may be a suitable biomaterial for skull tissue-engineering applications.

Enhanced Osseointegration of Titanium Implants by Surface Modification with Silicon-doped Titania Nanotubes.

INTRODUCTION: Despite great progress made in developing orthopedic implants, the development of titanium (Ti) implants with ideal early osseointegration remains a big challenge. Our pilot study has demonstrated that Si-TiO2 nanotubes on the surface of Ti substrates could enhance their osteogenic activity. Hence, in this study, we aim to comprehensively evaluate the effects of silicon-doped titania (Si-TiO2) nanotubes on the osseointegration property of Ti implants. MATERIALS AND METHODS: The Ti implants were surface modified with Si-TiO2 nanotubes through in situ anodization and Si plasma immersion ion implantation (PIII) method. Three groups were divided as Ti implants (Ti), Ti modified with TiO2 nanotubes (TiO2-NTs) and Ti modified with Si-TiO2 nanotubes (Si-TiO2-NTs). The morphology of Si-TiO2 nanotubes was observed by scanning electron microscope. The growth and osteogenic differentiation of MC3T3-E1 cells on the Ti implants were evaluated. Further, the pull-out tests and in vivo osseointegration ability evaluation were performed after implanting the screws in the femur of Sprague Dawley rats. RESULTS: The Si-TiO2 nanotubes could be seen on the surface of Ti implants. The MC3T3-E1 cells could grow on the surface of Ti, TiO2-NTs and Si-TiO2-NTs, and showed fast proliferation rate on the Si-TiO2-NTs. Moreover, the production of some osteogenesis-related proteins (ALP and Runx2) at one week and calcium deposition at four week was also enhanced in Si-TiO2-NTs rather than other groups. In vivo osseointegration results showed that Si-TiO2 nanotube-modified Ti screws had higher pullout force at two and four weeks as well as enhanced new bone formation at six weeks compared to bare Ti screws and Ti screws modified with TiO2 nanotubes alone. DISCUSSION: The modification of Si-TiO2-NTs on the Ti substrate could generate a nanostructured and hydrophilic surface, which can promote cell growth. Moreover, the existence of the TiO2 nanotubes and Si element also can improve the in vitro osteogenic differentiation of MC3T3-E1 cells and early bone formation around the implanted screws. Together, findings from this study show that surface modification of Ti implants with Si-TiO2 nanotubes could enhance early osseointegration and therefore has the potential for clinical applications.

Nanomaterials for oncotherapies targeting the hallmarks of cancer.

An increasing amount of evidence has demonstrated the diverse functionalities of nanomaterials in oncotherapies such as drug delivery, imaging, and killing cancer cells. This review aims to offer an authoritative guide for the development of nanomaterial-based oncotherapies and shed light on emerging yet understudied hallmarks of cancer where nanoparticles can help improve cancer control. With this aim, three nanomaterials, i.e. those based on gold, graphene, and liposome, were selected to represent and encompass metal inorganic, nonmetal inorganic, and organic nanomaterials, and four oncotherapies, i.e. phototherapies, immunotherapies, cancer stem cell therapies, and metabolic therapies, were characterized based on the differential hallmarks of cancer that they target. We also view physical plasma as a cocktail of reactive species and carrier of nanomaterials and focus on its roles in targeting the hallmarks of cancer provided with its unique traits and ability to selectively induce epigenetic and genetic modulations in cancer cells that halt tumor initiation and progression. This review provides a clear understanding of how the physico-chemical features of particles at the nanoscale contribute alone or create synergistic effects with current treatment modalities in combating each of the hallmarks of cancer that ultimately leads to desired therapeutic outcomes and shapes the toolbox for cancer control.

Comparison of the short-term outcomes of robot-assisted minimally invasive, video-assisted minimally invasive, and open esophagectomy.

BACKGROUND: The development of minimally invasive surgery has initiated many changes in the surgical treatment of esophageal cancer (EC) patients. The aim of this study was to compare the short-term outcomes of robotic-assisted minimally invasive esophagectomy (RAMIE), video-assisted minimally invasive esophagectomy (VAMIE), and open esophagectomy (OE). METHODS: Our study included patients who had undergone McKeown esophagectomy at Tianjin Medical University Cancer Institute and Hospital between January 2016 and December 2018. We analyzed clinical baseline data, as well as perioperative and pathological outcomes. RESULTS: A total of 312 cases met the inclusion criteria (OE: 77, VAMIE: 144, RAMIE: 91). The OE group had a greater number of late-stage patients as well as those who received the neo-adjuvant therapy, compared with the other two groups (P=0.001). The procedure time in the OE group was also shorter by approximately 20 minutes (P=0.021). Total blood loss was significantly lower in the two MIE groups (P=0.004) than in the OE group. There were no differences in the total number of dissected lymph nodes between the three groups (OE: 24.09±10.77, VAMIE: 23.07±10.18, RAMIE: 22.84±8.37, P=0.680). Both the lymph node number (P=0.155) and achievement rate (P=0.190) in the right recurrent laryngeal nerve (RLN) area were comparable between the three groups. However, in the left RLN area, minimally invasive approaches resulted in a higher number of harvested lymph nodes (P=0.032) and greater achievement rate (P=0.018). Neither MIE procedure increased the incidence of postoperative complications. CONCLUSIONS: Minimally invasive surgery could guarantee the quality of bilateral RLN lymphadenectomy without increasing postoperative complications, especially in RAMIE patients. The rational choice of different surgical approaches would improve both safety and oncological outcomes for patients.

Epigenetic profiles capturing breast cancer stemness for triple negative breast cancer control.

Aim: Triple-negative breast cancers (TNBCs) contain a higher percentage of breast cancer stem cells (BCSCs) than the other subtypes and lack effective yet safe-targeted therapies. We would like to unveil genes relevant to the therapeutic control of breast cancer stemness at the epigenetic level. Methods: We sequenced the transcriptome of BCSCs isolated from TNBCs, identified genes differentially expressed in these cells and subjected to DNA methylation and established the Bayesian network as well as interactions out of them. Results & conclusion: We presented a core epigenetic BCSC gene panel consisting of eight genes that can be used for BCSCs and TNBCs identification, and revealed the dominant roles of FOXA1 and GATA3 in orchestrating breast cancer heterogeneity and stemness.

Synergistic effects of titania nanotubes and silicon to enhance the osteogenic activity.

In this study, titania nanotubes (TNTs) incorporating silicon (Si) were formed on Ti disks using anodization and electron beam evaporation (EBE) technology to improve the osteogenic activity. The amount of Si was exquisitely adjusted by controlling the duration of EBE to optimize the biofunctionality. As the Si was incorporated, the samples exhibited hydrophilic surfaces. Long lasting and controllable Si release was observed from the EBE-modified samples without cytotoxicity. Moreover, initial cell adhesion, spreading, proliferation and osteogenic differentiation of MC3T3-E1 cells were evaluated. The results showed a notable enhancement of spreading, osteogenesis and differentiation of cells on silicon-coated TNTs (Si-TNTs). In particular, samples with highest amount of silicon (∼5.93% Si) displayed greatest augmentation of ALP activity, osteogenic-related gene expression and mineralization compared to the others in the present study. It was indicated that the modification with TNTs and appropriated Si content resulted in enhanced osteoblastic spreading, proliferation and differentiation, and therefore has the potential for future applications in the field of orthopedics.

Delayed total hip arthroplasty after failed treatment of acetabular fractures: an 8- to 17-year follow-up study.

BACKGROUND: Delayed total hip arthroplasty (THA) is a reliable procedure following failed treatment of acetabular fractures. The aim of the present study was to evaluate the influence of the type of fracture treatment and modern ceramic bearing on the clinical outcomes of delayed THA. METHODS: Between January 1997 and January 2008, 33 patients (33 hips) underwent cementless THA after failed acetabular fractures. Twenty-one were initially treated by open reduction internal fixation (ORIF) and 12 had non-ORIF. Joint articulation was either conventional metal-on-polyethylene (MOP) or ceramic-on-ceramic (COC). Intraoperative measures and preoperative and follow-up clinical, radiological, and functional outcomes were compared between the ORIF and non-ORIF groups. RESULTS: Surgery duration, blood loss, and transfusion requirement were greater in the ORIF group than in the non-ORIF group (p < 0.05). Significant improvement in Harris Hip Scores was seen post-surgery in both groups. However, a significant difference in the mean Harris Hip Score was not observed between the two groups (p = 0.57). Six patients in the ORIF group required acetabular reconstructive procedures to address bony defects compared to seven patients in the non-ORIF group (p = 0.09). The rate of anatomical restoration was 58.3% (7/12) in the non-ORIF group and 42.9% (9/21) in the ORIF group (p = 0.12). Radiolucent lines were observed in the MOP group and none in the COC group. Overall survival rate was similar in both groups (p = 0.85): 89.3% in the ORIF group and 87.5% in the non-ORIF group. CONCLUSION: Delayed THA with previous acetabular fractures is a challenging procedure. Initial fracture treatment does not influence the outcome of delayed THA, and modern ceramic bearing has promising results in the long-term follow-up.

[Effectiveness of total hip arthroplasty in the treatment of involved hips in patients with ankylosing spondylitis].

Objective: To summarize the mid- to long-term effectiveness of total hip arthroplasty (THA) in the treatment of the involved hips in patients with ankylosing spondylitis (AS), and to investigate its influencing factors. Methods: Between March 1999 and May 2011, 32 patients (42 hips) with AS and involved hip underwent THA. There were 26 males and 6 females with a mean age of 39 years (range, 20-78 years). The disease duration ranged from 2 to 41 years, with a median of 10 years. Metal-on-polyethylene bearings were used in 19 hips, and ceramic-on-ceramic bearings in 23 hips. The diameter of prosthetic femoral head was 36 mm in 15 hips and was 28 mm in 27 hips; and all the prostheses were fixed biologically. The Harris score, visual analogue scale (VAS) score, and total range of motion (ROM) of the hip were compared between at pre- and post-operation to evaluate the effectiveness. The DeLee zone was used for describing acetabular prosthesis, the Gruen zone for describing femoral prosthesis, and the Brooker criterion for evaluating the heterotopic ossification. Results: Healing of incision by first intention was achieved in all patients after operation. There was no complication of anesthetic accident, infection, or neurovascular injury. Twenty-nine cases (39 hips) were followed up 5-17 years (mean, 9 years). Anterior dislocation of hip joint occurred in 2 hips of 24 hips (28 mm diameter), but did not in 15 hips (36 mm diameter). At last follow-up, the Harris score, VAS score, and the total hip ROM were significantly improved ( P<0.05). The shorter the disease duration was, the higher postoperative Harris score and the greater postoperative total hip ROM would be ( P<0.05); the bigger diameter of prosthetic femoral head was, the greater postoperative total hip ROM would be ( P<0.05). All the acetabular components and femoral stems were well fixed at last follow-up. The osteolysis rate around the acetabular cup in the metal-on-polyethylene bearing group (50%, 9/18) was higher than that in the ceramic-on-ceramic bearing group (0, 0/21). No prosthetic loosening was observed in 2 groups. Seven hips were found to have heterotopic ossification, including 5 hips of Brooker grade I and 2 hips of Brooker grade II. Conclusion: THA is an effective method to treat involved hips in patients with AS; especially for patients having shorter duration of the disease, THA shows better effectiveness when the bigger diameter of prosthetic femoral head and ceramic-on-ceramic bearing are used.

[Percutaneous vertebroplasty and open vertebroplasty for metastatic spinal tumor].

OBJECTIVE: To explore the clinical application and therapeutic effect of percutaneous vertebroplasty(PVP) and open vertebroplasty for metastatic spinal tumor. METHODS: The clinical data of 126 patients with metastatic spinal tumor underwent surgery and obtained follow-up from January 2012 to March 2016 were retrospectively analyzed. These 126 cases were divided into two groups according to different operative methods. The metastatic tumor of 43 cases encroached vertebral canal oppressing spinal cord and nerve root, they were treated with open operation(open vertebroplasty group);and other 83 cases without obviously spinal cord or nerve root compression, or unfit for open operation, were treated with PVP (percutaneous vertebroplasty group) . VAS score, ECOG and Frankel grade were used to evaluate the pain and neurofunction in two groups.All out-hospital patients were followed up every 3 months for 1 time. X-ray, CT, MRI were examined in follow-up. RESULTS: A total of 112 vertebrae underwent PVP with the median surgical time of 50 min;VAS scores decreased significantly at 2 days after operation, which maintained till 1 month later; ECOG grade at 1 month decreased significantly;44 of 112 vertebrae suffered from asymptomatic bone cement leakage, no complications such as nerve injury or pulmonary embolism was found; the median survival time was 16 months. While for open vertebroplasty group, the median surgical time was 160 min and blood loss was 1 000 ml; postoperative VAS scores and ECOG grade at 1 month decreased significantly. Postoperative Frankel grade of 36 patients got improvement in 41 patients with spinal cord functional disturbance(87.8%); and 29 of 40 patients with incompleteness out of motor function were full recovery(76.3%); 12 cases (27.9%) occurred complications and the median survival time was 11 months. CONCLUSIONS: The different vertebroplasty treatments can be selected for patients with metastatic spinal tumor, which can relieve the pain, improve the nerve function, reconstruct the spinal stabilization, maintain the local control and raise the life quality.

Hemiarthroplasty versus internal fixation in super-aged patients with undisplaced femoral neck fractures: a 5-year follow-up of randomized controlled trial.

INTRODUCTION: There were higher rates of revision, complication, non-union, delayed union, and poorer functional outcomes reported in super-aged patients of undisplaced femoral neck fractures treated with internal fixation. Therefore, we designed this randomized comparative study aiming to compare the effectiveness and long-term follow-up results of hemiarthroplasty (HA) with that of multiple cannulated screws (MCS). MATERIALS AND METHODS: Eligible participants were randomly assigned into two groups for different methods of operation (hemiarthroplasty group and internal fixation group). The related indexes and data of two groups were collected for comparative analysis during the average follow-up period of 38.68 ± 28.24 months. RESULTS: There were only two patients performed reoperation in HA group, and the reoperation rate of HA group (5.41%, 2/37) was significantly lower than that of IF group (21.4%, 9/41) (P value = 0.000). The comparison of survival curves for reoperation showed significant differences between two groups (P value = 0.031).The results of Cox proportional hazards model suggested that only operation method significantly affected the occurrence of reoperation (P value = 0.049). The results of survival analysis showed that there was no significant difference in survival time between two groups (P value = 0.682). And in the Cox proportional hazards model, only age significantly affected the occurrence of death (P value = 0.000). The average Harris scores of two groups were all above 75 points, and there was no significant difference in Harris scores between the two groups (P value greater than 0.05). But in the early term follow-up, the excellent and good rate of hip joint function in HA group was significantly higher than that in IF group (P value less than 0.05). CONCLUSIONS: Hemiarthroplasty with less postoperative complications, low reoperation rate and better function recovery in early stage provide a good choice for the treatment of super-aged patients with nondisplaced femoral neck fracture.

[APPLICATION AND EFFECTIVENESS OF BIOLOGICAL TYPE ACETABULAR CUP IN ADULT Crowe TYPE IV DEVELOPMENTAL DYSPLASIA OF THE HIP].

OBJECTIVE: To investigate the application and effectiveness of the biological type acetabular cup(diameter < 44 mm) in adult Crowe type IV developmental dysplasia of the hip (DDH). METHODS: Between April 2001 andAugust 2013, biological type acetabular cup was used in total hip arthroplasty for the treatment of Crowe type IV DDH in16 cases (20 hips). There were 3 males and 13 females, aged 31-69 years (mean, 49 years). Unilateral hip was involved in 12cases, and bilateral hips in 4 cases. The patients showed pain of the hip joint and inequality of lower limb (shortening ofaffected limb 1.8-6.0 cm in length, 3.5 cm on average). Acetabular deformity, the relationship and the severity of femoralhead dislocation were comfirmed on the X-ray films. The preoperative Harris score was 34.0 ± 6.9. RESULTS: All patientsachieved healing of incision by first intention, with no complication of infection or neurovascular injury. Sixteen caseswere followed up 4-12 years (mean, 7.5 years). At 2 weeks after operation, dislocation occurred in 2 cases, and were fixedwith plaster for 3 weeks after reduction of the hip. Postoperative X-ray films showed complete reduction of femoral head;the average acetabular coverage of the cup of the weight-bearing area was 98.5% (range, 98.2%-99.1%). The cup from theRanawat triangle was 4.6-7.0 mm (mean, 5.8 mm) in medial shifting, and was 4.5-7.9 mm (mean, 6.2 mm) in elevation,it located at cup lateral surface area inside the iliopectineal line and the Kohler line (< 40%); the cup abduction angle was(45 ± 5)degrees, and the anteversion angle was (10 ± 5)degrees. The other patients had no prosthesis loosening except 1 patient havingextensive acetabular prosthesis loosening because of acetabular osteolysis at 12 years after operation. The hip Harris scorewas significantly improved to 85.0 ± 7.5 at 1 year after operation (t = 14.34, P = 0.01). CONCLUSION: The acetabular grindingprocess to retain enough bone combined with a small cup of-biological prosthesis treating adult Crowe type IV DDH has theadvantages of satisfactory coverage and initial acetabular fixation, so good early and mid-term effectiveness can be obtained.

Mid term results of total hip arthroplasty using polyethylene-ceramic composite (Sandwich) liner.

BACKGROUND: Ceramic-on-ceramic (COC) couplings are an attractive alternative bearing surfaces that have been reported to eliminate or reduce problems related to polyethylene wear debris. However, the material in total hip arthroplasty (THA) remains one of the major concern regarding the risk of fracture. The present study aims at reporting the fracture rate of bearings in a series of COC THAs with the use of a sandwich liner and attempt to detect the relative risk factors, the possible cause and assess the clinical results. MATERIALS AND METHODS: We retrospectively evaluated 153 patients (163 hips) using the sandwich liner COC THA between 2001 and 2009. Patient assessment was based on demographic factors, including age, weight, gender and body-mass index (BMI). All patients were evaluated clinically and radiographically or using computed tomography viz-a-viz dislocation, osteolysis, periprosthetic fracture, infection, loosening and implant fracture. RESULTS: Three ceramic sandwich liners fracture (1.84%) were observed at an average of 7.3 years' followup. The factors which were found to be non-significant to the ceramic liner fracture, included age (P = 0.205), weight (P = 0.241), gender (P = 0.553), BMI (P = 0.736), inclination (P = 0.199) and anteversion (P = 0.223). The overall survival was 91.4% at 12-year with revision as the endpoint. Other complications included osteolysis in 4 (2.45%), dislocation in one and periprosthetic fracture in one. In no hip aseptic loosening of the implants was seen. CONCLUSIONS: Our experience with the ceramic-polyethylene sandwich liner acetabular component has been disappointing because of the high rate of fracture and osteolyis. We have discontinued the use of this device and recommend the same.

Silicon-Doped Titanium Dioxide Nanotubes Promoted Bone Formation on Titanium Implants.

While titanium (Ti) implants have been extensively used in orthopaedic and dental applications, the intrinsic bioinertness of untreated Ti surface usually results in insufficient osseointegration irrespective of the excellent biocompatibility and mechanical properties of it. In this study, we prepared surface modified Ti substrates in which silicon (Si) was doped into the titanium dioxide (TiO2) nanotubes on Ti surface using plasma immersion ion implantation (PIII) technology. Compared to TiO2 nanotubes and Ti alone, Si-doped TiO2 nanotubes significantly enhanced the expression of genes related to osteogenic differentiation, including Col-I, ALP, Runx2, OCN, and OPN, in mouse pre-osteoblastic MC3T3-E1 cells and deposition of mineral matrix. In vivo, the pull-out mechanical tests after two weeks of implantation in rat femur showed that Si-doped TiO2 nanotubes improved implant fixation strength by 18% and 54% compared to TiO2-NT and Ti implants, respectively. Together, findings from this study indicate that Si-doped TiO2 nanotubes promoted the osteogenic differentiation of osteoblastic cells and improved bone-Ti integration. Therefore, they may have considerable potential for the bioactive surface modification of Ti implants.

[CLINICAL OBSERVATION OF ROTATING-PLATFORM PROSTHESIS FOR VALGUS KNEE DEFORMITY].

OBJECTIVE: To investigate the effectiveness of rotating-platform prosthesis for valgus knee deformity in total knee arthroplasty (TKA). METHODS: A retrospective analysis was made on the clinical date of 25 cases (28 knees) of valgus deformity undergoing primary TKA by using Gemini MK II rotating-platform prosthesis. There were 6 males (7 knees) and 19 females (21 knees), aged from 47 to 82 years, with an average age of 64.8 years. The unilateral knee was involved in 22 cases and the bilateral knees in 3 cases. The causes included osteoarthritis in 20 cases (22 knees), rheumatoid arthritis in 4 cases (5 knees), and traumatic arthritis in 1 case (1 knee). The disease duration was 2-22 years (mean, 10.4 years). The main clinical symptoms were arthralgia combined with limited movement. According to the Keblish grade, there were 13 knees of mild deformity, 11 knees of moderate deformity, and 4 knees of severe deformity. RESULTS: All incisions healed by first intension. No complications of infection, cutaneous necrosis, deep venous thrombosis, and pulmonary embolism occurred. The postoperative follow-up duration was 12-60 months (mean, 25.4 months). Medial instability and palsies of nervus peroneus communis occurred in 1 and 2 cases respectively, and all were cured after symptomatic treatment. No patellar and polysthylene insert dislocation, prosthetic loosening or infection was observed. The Hospital for Special Surgery (HSS) score, femoral tibial angle, maximun flexion and extension angles, knee range of motion, and patellar score were significantly improved at last follow-up when compared with preoperative ones (P<0.01). CONCLUSIONS: The rotating-platform prosthesis for valgus deformity can obtain satisfactory effectiveness, but it requires precise soft tissue balancing technology, and the long-term effectiveness remains further observation.

Ceramic-on-ceramic bearings total hip arthroplasty in young patients.

BACKGROUND: The results of ceramic-on-ceramic (CoC) total hip arthroplasty (THA) in younger patients were not univocal. This study aims to evaluate the results of CoC bearing THA in patients younger than 50 years. METHODS: A total of 90 younger patients performed CoC THAs during March 2003 and May 2008 were included in this study. Hip function and activity were evaluated with Harris hip score and University of California Los Angeles activity score. We had discussed survival rates, radiological findings of component loosening or osteolysis, and ceramic-related complications in these patients. RESULTS: The mean Harris hip score increased from 46.3 ± 12.0 points (range, 28-70 points) before surgery to 92.5 ± 5.6 points (range, 78-100 points) at the final follow-up. The mean preoperative University of California Los Angeles activity score was 4.2 ± 1.1 points (range, 2-6 points), which improved to a mean of 7.2 ± 1.3 points (range, 4-10 points). At the time of the last follow-up, there was found to be 1 occurrence of hip dislocation, 1 squeaking, and 2 "sandwich" ceramic liners fractured during normal activity of daily living. No hips showed osteolysis or required revision for aseptic loosening. Kaplan-Meier survivorship with revision due to loosening or osteolysis was 100% and with revision due to ceramic fracture was 97.3% (95% confidence interval, 93.7%-100%) at a mean of 9.4 years. CONCLUSIONS: This study with the use of CoC bearings THAs in younger patients have shown promising results and higher rate of survivorship without evidence of osteolysis.