Nacre-mimetic cerium-doped nano-hydroxyapatite/chitosan layered composite scaffolds regulate bone regeneration via OPG/RANKL signaling pathway.

Autogenous bone grafting has long been considered the gold standard for treating critical bone defects. However, its use is plagued by numerous drawbacks, such as limited supply, donor site morbidity, and restricted use for giant-sized defects. For this reason, there is an increasing need for effective bone substitutes to treat these defects. Mollusk nacre is a natural structure with outstanding mechanical property due to its notable "brick-and-mortar" architecture. Inspired by the nacre architecture, our team designed and fabricated a nacre-mimetic cerium-doped layered nano-hydroxyapatite/chitosan layered composite scaffold (CeHA/CS). Hydroxyapatite can provide a certain strength to the material like a brick. And as a polymer material, chitosan can slow down the force when the material is impacted, like an adhesive. As seen in natural nacre, the combination of these inorganic and organic components results in remarkable tensile strength and fracture toughness. Cerium ions have been demonstrated exceptional anti-osteoclastogenesis capabilities. Our scaffold featured a distinct layered HA/CS composite structure with intervals ranging from 50 to 200 µm, which provided a conducive environment for human bone marrow mesenchymal stem cell (hBMSC) adhesion and proliferation, allowing for in situ growth of newly formed bone tissue. In vitro, Western-blot and qPCR analyses showed that the CeHA/CS layered composite scaffolds significantly promoted the osteogenic process by upregulating the expressions of osteogenic-related genes such as RUNX2, OCN, and COL1, while inhibiting osteoclast differentiation, as indicated by reduced TRAP-positive osteoclasts and decreased bone resorption. In vivo, calvarial defects in rats demonstrated that the layered CeHA/CS scaffolds significantly accelerated bone regeneration at the defect site, and immunofluorescence indicated a lowered RANKL/OPG ratio. Overall, our results demonstrate that CeHA/CS scaffolds offer a promising platform for bone regeneration in critical defect management, as they promote osteogenesis and inhibit osteoclast activation.

Graphene-modified CePO4 nanorods effectively treat breast cancer-induced bone metastases and regulate macrophage polarization to improve osteo-inductive ability.

BACKGROUND: Breast cancer bone metastasis has become one of the most common complications; however, it may cause cancer recurrence and bone nonunion, as well as local bone defects. METHODS: Herein, In vitro, we verified the effect of bioscaffold materials on cell proliferation and apoptosis through a CCK8 trial, staining of live/dead cells, and flow cytometry. We used immunofluorescence technology and flow cytometry to verify whether bioscaffold materials regulate macrophage polarization, and we used ALP staining, alizarin red staining and PCR to verify whether bioscaffold material promotes bone regeneration. In vivo, we once again studied the effect of bioscaffold materials on tumors by measuring tumor volume in mice, Tunel staining, and caspase-3 immunofluorescence. We also constructed a mouse skull ultimate defect model to verify the effect on bone regeneration. RESULTS: Graphene oxide (GO) nanoparticles, hydrated CePO4 nanorods and bioactive chitosan (CS) are combined to form a bioactive multifunctional CePO4/CS/GO scaffold, with characteristics such as photothermal therapy to kill tumors, macrophage polarization to promote blood vessel formation, and induction of bone formation. CePO4/CS/GO scaffold activates the caspase-3 proteasein local tumor cells, thereby lysing the DNA between nucleosomes and causing apoptosis. On the one hand, the as-released Ce3+ ions promote M2 polarization of macrophages, which secretes vascular endothelial growth factor (VEGF) and Arginase-1 (Arg-1), which promotes angiogenesis. On the other hand, the as-released Ce3+ ions also activated the BMP-2/Smad signaling pathway which facilitated bone tissue regeneration. CONCLUSION: The multifunctional CePO4/CS/GO scaffolds may become a promising platform for therapy of breast cancer bone metastases.

Quercetin inhibits macrophage polarization through the p-38α/ß signalling pathway and regulates OPG/RANKL balance in a mouse skull model.

Aseptic loosening caused by wear particles is a common complication after total hip arthroplasty. We investigated the effect of the quercetin on wear particle-mediated macrophage polarization, inflammatory response and osteolysis. In vitro, we verified that Ti particles promoted the differentiation of RAW264.7 cells into M1 macrophages through p-38α/ß signalling pathway by using flow cytometry, immunofluorescence assay and small interfering p-38α/ß RNA. We used enzyme-linked immunosorbent assays to confirm that the protein expression of M1 macrophages increased in the presence of Ti particles and that these pro-inflammatory factors further regulated the imbalance of OPG/RANKL and promoted the differentiation of osteoclasts. However, this could be suppressed, and the protein expression of M2 macrophages was increased by the presence of the quercetin. In vivo, we revealed similar results in the mouse skull by µ-CT, H&E staining, immunohistochemistry and immunofluorescence assay. We obtained samples from patients with osteolytic tissue. Immunofluorescence analysis indicated that most of the macrophages surrounding the wear particles were M1 macrophages and that pro-inflammatory factors were released. Titanium particle-mediated M1 macrophage polarization, which caused the release of pro-inflammatory factors through the p-38α/ß signalling pathway, regulated OPG/RANKL balance. Macrophage polarization is expected to become a new clinical drug therapeutic target.

Ursolic acid loaded-mesoporous bioglass/chitosan porous scaffolds as drug delivery system for bone regeneration.

Bioglass scaffolds have great application potentials in orthopedics, and Ursolic acid (UA) can effectively promote in vivo new bone formation. Herein, we for the first time developed the mesoporous bioglass/chitosan porous scaffolds loaded with UA (MBG/CS/UA) for enhanced bone regeneration. The MBG microspheres with particle sizes of ~300 nm and pore sizes of ~3.9 nm were uniformly dispersed on the CS films. The mesoporous structure within the MBG microspheres and the hydrogen bonding between the scaffolds and UA drugs made the MBG/CS/UA scaffolds have controlled drug release performances. The as-released UA drugs from the scaffolds increased remarkably the alkaline phosphatase activity, osteogenic differentiation related gene type I collagen, runt-related transcription factor 2 expression, and osteoblast-associated protein expression. Moreover, the results of micro-CT images, histomorphological observations demonstrated that the MBG/CS/UA scaffolds improved new bone formation ability. Therefore, the MBG/CS/UA porous scaffolds can be used as novel bone tissue engineering materials.

Fabrication, characterization, and biocompatibility of ethyl cellulose/carbonated hydroxyapatite composite coatings on Ti6Al4V.

In order to improve the biocompatibility of metallic implants, bioactive components are often used as coatings so that a real bond with the surrounding bone tissue can be formed. We prepared ethyl cellulose/carbonated hydroxyapatite composite coatings (ECHCs) on Ti6Al4V substrates with carbonated hydroxyapatite coatings (CHACs) without ethyl cellulose as controls. The inorganic constituent on the CHACs and ECHCs is calcium-deficient carbonated hydroxyapatite with a flaky texture and a low degree of crystallinity. The flaky carbonated hydroxyapatite plates aggregate to form macropores with an aperture size of around 0.5-2.0 µm. The presence of ethyl cellulose provides superior morphology, contact angle, and biocompatibility characteristics. In comparison to CHACs, ECHCs exhibit a smoother, crack-free surface because the cracks are filled by ethyl cellulose. Moreover, the contact angle of ECHCs is 37.3°, greater than that of CHACs (13.0°). Surface biocompatibility was investigated by using human bone mesenchymal stem cells (hBMSCs). The attachment, spreadability, viability and proliferation of hBMSCs on ECHCs are superior to those on CHACs. Thus, the crack-free ECHCs have excellent biocompatibility and are appropriate for use as biological implants.

Strontium ranelate reduces cartilage degeneration and subchondral bone remodeling in rat osteoarthritis model.

AIM: To investigate whether strontium ranelate (SR), a new antiosteoporotic agent, could attenuate cartilage degeneration and subchondral bone remodeling in osteoarthritis (OA). METHODS: Medial meniscal tear (MMT) operation was performed in adult SD rats to induce OA. SR (625 or 1800 mg·kg(-1)·d(-1)) was administered via gavage for 3 or 6 weeks. After the animals were sacrificed, articular cartilage degeneration was evaluated using toluidine blue O staining, SOX9 immunohistochemistry and TUNEL assay. The changes in microarchitecture indices and tissue mineral density (TMD), chemical composition (mineral-to-collagen ratio), and intrinsic mechanical properties of the subchondral bones were measured using micro-CT scanning, confocal Raman microspectroscopy and nanoindentation testing, respectively. RESULTS: The high-dose SR significantly attenuated cartilage matrix and chondrocyte loss at 6 weeks, and decreased chondrocyte apoptosis, improved the expression of SOX9, a critical transcription factor responsible for the expression of anabolic genes type II collagen and aggrecan, at both 3 and 6 weeks. Meanwhile, the high-dose SR also significantly attenuated the subchondral bone remodeling at both 3 and 6 weeks, as shown by the improved microarchitecture indices, TMD, mineral-to-collagen ratio and intrinsic mechanical properties. In contrast, the low-dose SR did not significantly change all the detection indices of cartilage and bone at both 3 and 6 weeks. CONCLUSION: The high-dose SR treatment can reduce articular cartilage degeneration and subchondral bone remodeling in the rat MMT model of OA.

Calcineurin/NFAT pathway mediates wear particle-induced TNF-α release and osteoclastogenesis from mice bone marrow macrophages in vitro.

AIM: To investigate the roles of the calcineurin/nuclear factor of activated T cells (NFAT) pathway in regulation of wear particles-induced cytokine release and osteoclastogenesis from mouse bone marrow macrophages in vitro. METHODS: Osteoclasts were induced from mouse bone marrow macrophages (BMMs) in the presence of 100 ng/mL receptor activator of NF-κB ligand (RANKL). Acridine orange staining and MTT assay were used to detect the cell viability. Osteoclastogenesis was determined using TRAP staining and RT-PCR. Bone pit resorption assay was used to examine osteoclast phenotype. The expression and cellular localization of NFATc1 were examined using RT-PCR and immunofluorescent staining. The production of TNFα was analyzed with ELISA. RESULTS: Titanium (Ti) or polymethylmethacrylate (PMMA) particles (0.1 mg/mL) did not significantly change the viability of BMMs, but twice increased the differentiation of BMMs into mature osteoclasts, and markedly increased TNF-α production. The TNF-α level in the PMMA group was significantly higher than in the Ti group (96 h). The expression of NFATc1 was found in BMMs in the presence of the wear particles and RANKL. In bone pit resorption assay, the wear particles significantly increased the resorption area and total number of resorption pits in BMMs-seeded ivory slices. Addition of 11R-VIVIT peptide (a specific inhibitor of calcineurin-mediated NFAT activation, 2.0 µmol/L) did not significantly affect the viability of BMMs, but abolished almost all the wear particle-induced alterations in BMMs. Furthermore, VIVIT reduced TNF-α production much more efficiently in the PMMA group than in the Ti group (96 h). CONCLUSION: Calcineurin/NFAT pathway mediates wear particles-induced TNF-α release and osteoclastogenesis from BMMs. Blockade of this signaling pathway with VIVIT may provide a promising therapeutic modality for the treatment of periprosthetic osteolysis.

Mesoporous bioactive glass as a drug delivery system: fabrication, bactericidal properties and biocompatibility.

Implant-associated infection remains a difficult medical problem in orthopaedic surgery. Here, we report on the fabrication of gentamicin-loaded mesoporous bioactive glass (Gent-MBG) for use as a controlled antibiotic delivery system to achieve the sustained release of antibiotics in the local sites of bone defects. The high surface area and mesoporous structure of MBG enable higher drug loading efficiency (79-83 %) than non-mesoporous biological glass (NBG) (18-19 %). Gent-MBG exhibits sustained drug release for more than 6 days, and this controlled release of gentamicin significantly inhibits bacterial adhesion and prevents biofilm formation by S. aureus (ATCC25923) and S. epidermidis (ATCC35984). Biocompatibility tests with human bone marrow stromal cells (hBMSCs) indicate that MBG has better biocompatibility than NBG. Therefore, Gent-MBG can be used as a controlled drug delivery system to prevent and/or treat orthopedic peri-implant infections.

Berberine inhibits lipopolysaccharide- and polyethylene particle-induced mouse calvarial osteolysis in vivo.

BACKGROUND: Wear particle-induced osteolysis could lead to the aseptic loosening of implants. Studies have suggested that endotoxins, such as lipopolysaccharides (LPS), may be the primary causes of wear particle-mediated osteolysis, and that osteolysis may originate from subclinical levels of bacterial infection. However, effective therapies against wear particles and gram-negative bacterial or LPS-induced bone resorption are limited. MATERIALS AND METHODS: In the current study, the effect of berberine on LPS- and polyethylene (PE) particle-induced osteolysis in vivo was investigated using a mouse calvarial model. Osteoclast number per bone perimeter and eroded surface per bone surface were measured. RESULTS: Berberine (10 mg/kg), injected either simultaneously with LPS or 3 d after LPS (25 mg/kg) treatment, blocked LPS-induced osteoclast recruitment and bone resorption in the mouse calvarial model. A daily single-dose of berberine (10 mg/kg), injected either simultaneously with PE particles or 4 d after treatment with PE particles, blocked PE particle-induced osteoclast recruitment and bone resorption. Berberine treatment markedly decreased LPS and PE particle-induced osteoclast recruitment and bone resorption in the murine calvarial model. CONCLUSION: These results suggest that berberine may have therapeutic effect for osteolysis induced by wear particles and LPS in gram-negative bacteria.

Efficacy of zoledronic acid in treatment of teoarthritis is dependent on the disease progression stage in rat medial meniscal tear model.

AIM: To investigate whether the stage of osteoarthritis (OA) progression influenced the efficacy of the third-generation bisphosphonate zoledronic acid in a rat medial meniscal tear model. METHODS: Medial meniscal tear (MMT) was surgically induced in adult male Sprague Dawley rats. Zoledronic acid (ZOL, 100 µg/kg, sc, twice a week) was administered starting immediately, early (from 4 weeks) or late (from 8 weeks) after OA induction. The degeneration of articular cartilage was evaluated with toluidine blue O staining. Subchondral bone remodeling was evaluated with X-ray micro-CT scanning. Joint pain was measured with respect to weight-bearing asymmetry. Calcitonin gene-related peptide (CGRP) expression in dorsal root ganglia (DRGs) was examined using immunofluorescence analysis. The afferent neurons in DRGs innervating the joint were identified by retrograde labeling with fluorogold. RESULTS: Progressive cartilage loss was observed during 12 weeks after OA induction. Subchondral bone remodeling manifested as increased bone resorption at early stage (4 weeks), but as increased bone accretion at advanced stages (8 weeks). Immediately and early ZOL administration significantly improved subchondral microstructural parameters, attenuated cartilage degeneration, reduced weight-bearing asymmetry and CGRP expression, whereas the late ZOL administration had no significant effects. CONCLUSION: The stage of OA progression influences the efficacy of ZOL in treating joint degeneration and pain. To obtain the maximum efficacy, bisphosphonate treatment should be initiated in rat with early stages of OA pathogenesis.

Nickel-titanium shape-memory sawtooth-arm embracing fixator for periprosthetic femoral fractures.

PURPOSE: We reviewed data to determine outcomes for 21 consecutive Vancouver type B1 or type C periprosthetic fractures that we treated between 2001 and 2008 using a nickel-titanium shape-memory sawtooth-arm embracing fixator. METHODS: The study participants were 12 men and 9 women (mean age, 70.8 years; range, 42-85 years). The average duration of follow-up monitoring was 39.7 months (range, 1-78 months). In five cases, cables and screws were used for further stabilisation. No bone grafting was performed for any of the patients. RESULTS: Results were satisfactory, except for one patient who died one month after surgery from a cause unrelated to arthroplasty. Bone union was achieved in the remaining 20 cases within an average of 5.25 months. No implant failures or malunions occurred in any of the patients. The average Harris hip score at the final follow-up examination was 79.3 points. CONCLUSIONS: Our results show that the embracing fixator is a valid alternative treatment for Vancouver type B1 or type C periprosthetic femoral fractures.

Open Reduction and Internal Fixation by Volar Locking Plates and the "Poking Reduction" Technique in Distal Radius Fractures with Displaced Dorsal Ulnar Fragments: A Retrospective Study.

OBJECTIVE: To investigate the clinical and radiological outcomes of distal radius fractures (DRFs) with displaced dorsal ulnar fragments treated with volar locking plate (VLP) and the "poking reduction" technique. METHODS: Between January 2014 and January 2019, 78 unilateral DRFs with displaced dorsal ulnar fragment (AO type C3) treated with VLP were conducted. According to the reduction technique of the dorsal ulnar fragment, the patients were divided into the conventional reduction (CRG) group (33 patients, 14 males and 19 females, mean age 57.2 ± 12.1 years old) and the "poking reduction" (PRG) group (45 patients, 11 males and 34 females, mean age 60.1 ± 12.4 years old). According to the AO classification, there were 21 cases of C3.1 and 12 of C3.2 in the CPG group, 27 cases of C3.1 and 18 of C3.2 in the PRG group. Clinical and radiographic data were extracted from the electronic medical record system. These data were reviewed for clinical outcomes (range of motion, grip strength), radiological outcomes (volar tilt, radial inclination, radial height, step of articular surface), and postoperative complications. The final functional recovery was evaluated by the disabilities of the arm, shoulder, and hand (DASH) score. RESULTS: The mean duration of follow-up was 27 months (range from 12 to 56). The average operation time and intraoperative blood loss did not significantly differ between groups (p > 0.05). Postoperative CT examination showed that the step of articular surface in CPG group (0.8 ± 0.3 mm) was larger than that in PRG group (0.5 ± 0.2 mm) (p < 0.001). The DASH score did not significantly differ between groups (26.1 ± 4.6 in CRG and 24.7 ± 4.0 in PRG, p > 0.05) at 3 months postoperatively. At 6 months and 12 months postoperatively, the DASH score was better in PRG group (11.8 ± 2.5 and 10.4 ± 2.0) than in CRG group (13.6 ± 2.7 and 12.2 ± 2.5) (p = 0.004, p = 0.001, respectively). At 12 months postoperatively, wrist range of motion did not significantly differ between groups (p > 0.05). There was no significant difference in radiological parameters between the two groups (p > 0.05). The incidence of complications was higher in the CRG group (7/33) than in the PRG group (2/45) (p = 0.009). CONCLUSION: The "poking reduction" technique is a wise option for reduction of dorsal ulnar fragment in DRFs. This innovative technique could restore smoothness of the radiocarpal joint effectively, and the dorsal ulnar fragment could be fixed effectively combined with the volar plate.

The utility of digital templating in Total Hip Arthroplasty with Crowe type II and III dysplastic hips.

With the superiority of digital imaging, conventional preoperative acetate templating is gradually being replaced by digital templating in total hip arthroplasty (THA). The purpose of this study was to assess the utility of digital templating for patients with Crowe type II and III dysplastic hips. In this study, 41 THA patients with Crowe type II or III dysplastic hips and 48 THA patients with other primary diseases were retrospectively reviewed. All patients were fitted with cementless prostheses in 2008. For the THA patients with dysplastic hips, we attempted to restore their hip centres to the position of the true acetabulum. Digital templating was the method chosen to achieve hip centre restoration. The prosthesis prediction accuracy (within ± one size using digital templating) was 20 (48.8%) for the cup size and 30 (73.2%) for the stem size. Meanwhile, for patients with other primary diseases, the accuracy for the cup size within ± one size was 34 (70.8%) and for the stem size accuracy was within ± one size in 38 (79.2%). Between the two patient groups, there was a significant difference in the predicted cup size. In patients with dysplastic hips, the low accuracy of the predicted cup size may have resulted from difficulty in predicting the vertical location of the hip centre. Despite this limitation, preoperative planning using digital templating is a convenient technique for THA patients with Crowe type II and III dysplastic hips.

[Comparison of surgical effects between extension and flexion type of distal radius fracture].

OBJECTIVE: To compare therapeutic effects of internal fixation with volar locking plate in treating extension and flexion type of distal radius fracture (DRF). METHODS: From January 2015 to June 2018, 103 patients with DRF were retrospectively analyzed. According to original fracture displacement direction, patients were divided into extension fracture(Colles) group and flexion fracture (Smith) group. In Colles fracture group, there were 24 males and 44 females aged from 20 to 79 years old with an average of (59.0±13.4) years old;according to AO classification, 9 patients of type A2, 13 patients of type A3, 16 patientsof type C1, 17 patients of type C2 and 13 patients of type C3;the time from injury to operation ranged from 2 to 9 days with an average of (3.9±0.8) days. In Smith fracture group, there were 15 males and 20 females, aged from 27 to 87 years old with an average of (60.1±15.3) years old;according to AO classification, 4 patienst of A2, 7 patients of A3, 14 patients of C1, 5 patients of C2 and 5 patients of C3;the time from injury to operation ranged from 2 to 6 days with an average of (4.1±0.9) days. Operation time, fracture healing time and postoperative complications were recorded between two groups. Disabilities of arm, shoulder and hand (DASH) score at 6 and 8 weeks, 6 and 8 months were used to evaluate functional recovery of affected limbs during each follow up. Volar tilt, radial inclination and radius height were measured at 8 months after operation. Mayo score was measured at 8 months after operation to evaluate recovery of limb function. RESULTS: All patients were followed up for 8 to 30 months with an average of (14.8±4.3) months, and no difference in follow up between two groups (P> 0.05). There were no statistical differences in operation time, fracture healing time and postoperative complications between two groups(P>0.05). DASH score at 6 and 12 weeks in Colles fracture group were (37.24±5.08) and (19.68±4.55), while in Smith fracture group were (39.05±4.79) and (23.44±4.21);Colles fracture group was better than that of Smith fracture group (P<0.001);while there were no differences in DASH score at 6 and 8 months between two groups (P>0.05). Volar tilt of Smith fracture group (11.1±3.1)° was better than that of Colles fracture group (8.6±4.1) °, and there were no significant difference in radial inclination and radius height between two groups(P>0.05). Also there was no significant difference in Mayo score between two group(P>0.05). CONCLUSION: Patients with Colles fracture and Smith fracture could receive good reduction and fixation through volar locking plate. The radiographic parameters of both groups recovered satisfactorily after operation. Recovery of volar tilt of Smith fracture group is better than that of Colles fracture group, and early recovery function of Colles fracture group is better than that of Smith group, but there is no significant difference in long-term wrist joint function and incidence of postoperative complications between two groups.

Post-Marketing Surveillance of Qishe Pill () Use for Management of Neck Pain in a Chinese Patient Cohort to Determine its Safety, Tolerability and Effectiveness.

OBJECTIVE: To evaluate the safety and effectiveness of Qishe Pill () on neck pain in real-world clinical practice. METHODS: A multi-center, prospective, observational surveillance in 8 hospitals across Shanghai was conducted. During patients receiving 4-week Qishe Pill medication, Visual Analogue Scale (VAS) and Neck Disability Index (NDI) assessments have been used to assess their pain and function, while safety monitoring have been observed after 2 and 4 weeks. RESULTS: Results from 2,023 patients (mean age 54.5 years) suggest that the drug exposure per unit of body mass was estimated at 3.41 ± 0.62 g/kg. About 8.5% (172/2,023) of all participants experienced adverse events (AEs), while 3.8% (78/2,023) of all participants experienced adverse reaction. The most common AEs were gastrointestinal events and respiratory events. The VAS score (pain) and NDI score (function) significantly decreased after 4-week treatment. An effect-quantitative analysis was also conducted to show that the normal clinical dosage may be consider as 3-4 g/kg, at which dosage the satisfactory pain-relief effect may achieve by 40-mm reduction in VAS. CONCLUSION: These findings showed that patients with cervical radiculopathy who received Qishe Pill experienced significant improvement on pain and function. (Registration No. NCT01875562).

Tetracyclines inhibit rat osteoclast formation and activity in vitro and affect bone turnover in young rats in vivo.

An experiment was designed to investigate whether systemic administration of tetracyclines (TCs) as bone fluorochrome labels could interfere with bone modeling in vivo and inhibit osteoclast formation and activity in vitro. Cell cultures of rat bone marrow macrophages revealed that TC and oxytetracycline inhibited osteoclastogenesis and bone resorption and stimulated apoptosis. Forty rats in five groups were treated with saline, calcein green, alizarin red S, TC, or oxytetracycline. Their tibias were used for histomorphometric analysis, including bone static, dynamic, and resorption parameters in the tibial proximal metaphysis. No significant differences in bone volume per tissue volume, trabecular number, trabecular thickness, trabecular separation, bone formation rate per bone surface, mineralizing surface, or mineral apposition rate were observed. TC or oxytetracycline decreased eroded surface, number of osteoclasts per bone perimeter, and osteoclast surface per bone surface by about 50%. The results demonstrated that TC and oxytetracycline inhibit rat osteoclast formation and activity in vitro, and histomorphometric parameters involved in bone turnover may be affected by the use of oxytetracycline and TC as fluorescent bone labels in vivo.

Changes in Alignment of Ipsilateral Knee on Computed Tomography after Total Hip Arthroplasty for Developmental Dysplasia of the Hip.

OBJECTIVE: To assess the changes in alignment of ipsilateral knee joint after total hip arthroplasty (THA) for patients with developmental dysplasia of the hip (DDH). METHODS: Thirty-four patients with DDH (38 hips) who underwent THA between February and December 2008 were included in the study: 4 men and 30 women with a mean age of 56.2 years. According to Crowe classification, 11 patients were grade I, 12 were grade II, 9 were grade III, and 6 were grade IV. Computed tomography scans were performed from the anterior superior iliac spine to the tibial tubercle before surgery and at last follow-up. Femoral anteversion angle, leg lengthening, and knee alignment, including patellar tilt angle, lateral patellar displacement, and tibiofemoral rotation angle, were measured on computed tomography scans, and their relationships were analyzed. RESULTS: The mean follow-up period was 51.5 months (range, 39-70 months). There were no intraoperative fractures, and no infections occurred during the follow-up period. One patient developed deep venous thrombosis and another suffered from femoral nerve palsy. The mean preoperative Harris Hip Score was 48.9 ± 7.5 and improved to 91.2 ± 8.3 by the last follow-up (P < 0.001). There was no sign of prosthetic loosening in all hips. Postoperatively, mean leg lengthening was 26.08 ± 21.81 mm (P < 0.001), femoral anteversion decreased 9.03° ± 12.80° (P < 0.001), and patellar tilt, lateral patellar displacement, and tibiofemoral rotation increased by 3.58° ± 4.96° (P < 0.001), 1.78 ± 3.36 mm (P = 0.002), and 2.56° ± 3.37° (P < 0.001), respectively. Postoperative increase in patellar tilt and lateral patellar displacement had significant linear relationships with the decrease in femoral anteversion (r = 0.621, P < 0.001 and r = 0.437, P = 0.0037, respectively). These results revealed that patellofemoral alignment would change more with the decrease in femoral anteversion. Postoperative increase in external rotation of the tibia had significant positive linear relationships with leg lengthening (r = 0.34, P = 0.037) and the decrease in femoral anteversion (r = 0.693, P < 0.001). These results revealed that the external rotation of the proximal tibia would increase with the leg lengthening or the decrease of femoral anteversion. Postoperative changes in patellar tilt and lateral patellar displacement had no significant linear relationships with leg lengthening (P = 0.795 and P = 0.082, respectively). CONCLUSIONS: Total hip arthroplasty for DDH could induce changes in alignment of ipsilateral patellofemoral and tibiofemoral joints, with increases in patellar tilt and displacement, and increases in external rotation of the tibia. These secondary alterations still existed at medium-term follow-up after surgery, which should be considered during THA for patients with DDH. Extended follow-up is necessary to evaluate long-term changes in the knee joint.

[Clinical study of lumbar fusion by hybrid construct of stem cells technique and biodegradable material].

OBJECTIVE: To explorer the effectiveness of enriched bone marrow stem cells technique for lumbar fusion. METHODS: With the randomization and control principles, 2 graft materials [Enrichment bone marrow mesenchymal stem cells hybridized with beta-tri calcium phosphate (composite graft group), autologous iliac crest bone graft (autograft group)] were compared in posterior lumbar fusion procedures. 56 patients with degenerative disc disease, lumbar instability or spinal stenosis, were included. The volume of cells suspension in pre- and post-enrichment and the number of nucleated cells (NCs) were identified. The number of osteoprogenitor cells was estimated by counting the colony-forming units which express alkaline phosphatase (CFUs/ALP+). Then the efficiency of the enrichment was evaluated. Clinical follow-up with roentgenogram and Oswestry scale scores was performed for outcome evaluation. RESULTS: (249 +/- 31) ml bone marrow per patient from bilateral iliac crests was aspirated peri-operatively. About (43 +/- 11) ml enriched bone marrow was collected. The number of NCs was concentrated from (15.9 +/- 3.3) x 10(6)/ml to (44.1 +/- 10.8) x 10(6)/ml, CFUs/ALP+ was significantly increased from (118 +/- 86)/ml to(486 +/- 305)/ml. The follow-up was about (26.3 +/- 7.5) months. There was no significant differences in age, gender, disease and fusion segments between the two groups. The fusion rate was 93.3% and 96.2% for composite graft group and autograft group, respectively (chi2 = 0.2146, P = 0.6432). There was no difference in operation time between the two group (t = 0.5243, P = 0.6022), but blood loss in composite graft group was more than that in autograft group (t = 6.4664, P < 0.01). Cell salvage for auto-transfusion could transfuse back half of the blood loss during operation. No hematoma or chronic soreness in the bone marrow donor sites of composite graft group occurred, but a little exudation or moderate swelling in the wound happened in 4 cases which disappeared under medical treatment. Meanwhile, 15.4% patients had hematoma in the iliac bone donor site and 26.9% patients had chronic soreness, but no case had wound problem in autograft group. As for Oswestry scale scores, there was no significant difference between the two groups. CONCLUSIONS: The enrichment technique of autologous bone marrow stem cells can greatly increase the concentration of MSCs. It is a rapid and safe method used peri-operatively. The composite material of enriched MSCs and porous beta-TCP is a good bone substitute in posterior spinal fusion.

Titanium particle­mediated osteoclastogenesis may be attenuated via bidirectional ephrin­B2/eph­B4 signaling in vitro.

The present study investigated the role of bidirectional ephrin­B2/erythropoietin­producing human hepatocellular receptor 4 (ephB4) signaling in the regulation of wear particle­mediated osteoclastogenesis in vitro. Mouse bone marrow macrophages (BMMs) were induced into osteoclasts by receptor activator of nuclear factor­κB ligand (RANKL, 50 ng/ml). EphB4­Fc, an osteoblast membrane surface receptor (4 µg/ml), was used to stimulate the ephrin­B2 ligand of osteoclasts in the presence and absence of titanium (Ti). Tartrate­resistant acid phosphatase (TRAP) staining was used to detect the number of osteoclasts, and phalloidin staining was used to examine the cytoskeletons of the osteoclasts. A bone pit absorption experiment was used to measure osteoclast function. Reverse transcription quantitative polymerase chain reaction and western blot analysis were used to examine osteoclastogenesis. ELISAs were used to detect the production of inflammatory factors. The data demonstrated that Ti significantly promoted the differentiation of BMMs into mature osteoclasts in the presence of RANKL and significantly promoted expression of the ephrin­B2, nuclear factor of activated T­cells 1 (NFATc1), TRAP, Fos proto­oncogene, AP­1 transcription factor subunit (C­FOS), and matrix metalloproteinase 9 (MMP9) genes. Phalloidin and TRAP staining revealed that following the addition of ephB4­Fc, the number, size and cytoskeletal elements of osteoclasts were significantly decreased compared with those in the titanium particle group without ephB4­Fc. Compared with the titanium particle group, the bone pit absorption experiment revealed significantly decreased absorption pit areas in the titanium particle+ephB4­Fc group. The expression of the NFATc1, TRAP, C­FOS and MMP9 genes was markedly decreased in the ephB4­Fc group; however, the expression of the ephrin­B2 gene was increased compared with the Ti particle group without ephB4­Fc after 5 days. Production of inflammatory cytokines was inhibited by Ti particles through bidirectional signals. Addition of ephB4­Fc inhibited the osteoclast­mediated formation of Ti particles via bidirectional ephrin­B2/ephB4 signaling. Activation of this bidirectional signaling pathway may be a potential clinical treatment for osteolysis surrounding prostheses.