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Bone & Joint Research
Vol. 7, Issue 3 | Pages 252 - 262
1 Mar 2018
Nishida K Matsushita T Takayama K Tanaka T Miyaji N Ibaraki K Araki D Kanzaki N Matsumoto T Kuroda R

Objectives

This study aimed to examine the effects of SRT1720, a potent SIRT1 activator, on osteoarthritis (OA) progression using an experimental OA model.

Methods

Osteoarthritis was surgically induced by destabilization of the medial meniscus in eight-week-old C57BL/6 male mice. SRT1720 was administered intraperitoneally twice a week after surgery. Osteoarthritis progression was evaluated histologically using the Osteoarthritis Research Society International (OARSI) score at four, eight, 12 and 16 weeks. The expression of SIRT1, matrix metalloproteinase 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5), cleaved caspase-3, PARP p85, and acetylated nuclear factor (NF)-κB p65 in cartilage was examined by immunohistochemistry. Synovitis was also evaluated histologically. Primary mouse epiphyseal chondrocytes were treated with SRT1720 in the presence or absence of interleukin 1 beta (IL-1β), and gene expression changes were examined by real-time polymerase chain reaction (PCR).


Bone & Joint Research
Vol. 6, Issue 5 | Pages 331 - 336
1 May 2017
Yamauchi R Itabashi T Wada K Tanaka T Kumagai G Ishibashi Y

Objectives

Ultraviolet (UV) light-mediated photofunctionalisation is known to improve osseointegration of pure titanium (Ti). However, histological examination of titanium alloy (Ti6Al4V), which is frequently applied in orthopaedic and dental surgery, has not yet been performed. This study examined the osseointegration of photofunctionalised Ti6Al4V implants.

Methods

Ti and Ti6Al4V implants were treated with UV light, and the chemical composition and contact angle on the surfaces were evaluated to confirm photofunctionalisation. The implants were inserted into femurs in rats, and the rats were killed two or four weeks after the surgery. For histomorphometric analysis, both the bone–implant contact (BIC) ratio and the bone volume (BV) ratio were calculated from histological analysis and microcomputed tomography data.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_9 | Pages 16 - 16
1 May 2017
Furumatsu T Inoue H Miyazawa S Tanaka T Fujii M Ozaki T
Full Access

Background

Meniscus repair can restore the function of torn meniscus in anterior cruciate ligament (ACL)-reconstructed knees. However, few reports investigate the relationship between concurrent meniscus repair with ACL reconstruction and postoperative meniscal position. This study aimed to evaluate the size of the medial meniscus in patients who underwent ACL reconstruction and concomitant all-inside medial meniscus repair.

Methods

This study received the approval of our Institutional Review Board. Twenty patients underwent ACL reconstruction and concurrent medial meniscus repair of a peripheral longitudinal tear using the FasT-Fix meniscal repair device. Medial tibial plateau length (MTPL) and width (MTPW) were determined by radiographic images. We evaluated the Lysholm score, anteroposterior instability (difference in KT-2000 arthrometer measurement), meniscal healing, and magnetic resonance imaging (MRI)-based medial meniscal length (MML) and width (MMW). The healing status of repaired medial meniscus was assessed by 2nd-look arthroscopy.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_8 | Pages 14 - 14
1 Apr 2017
Tanaka T Furumatsu T Miyazawa S Fujii M Inoue H Ozaki T
Full Access

Background

Hyaluronan (HA) promotes extracellular matrix (ECM) production and inhibits the activity of matrix degrading enzymes in chondrocytes. The meniscus is composed of the avascular inner and vascular outer regions. Inner meniscus cells have a chondrocytic phenotype compared with outer meniscus cells. In this study, we examined the effect of HA on chondrocytic gene expression in human meniscus cells.

Methods

Human meniscus cells were prepared from macroscopically intact lateral meniscus. Inner and outer meniscus cells were obtained from the inner and outer halves of the meniscus. The proliferative activity of meniscus cells was evaluated by WST-1 assay in the presence or absence of HA (MW = 600–1200 kDa; Seikagaku). Gene expression of SOX9, COL2A1, and COL1A1 was assessed by a quantitative real-time PCR analysis. The effect of HA on the gene expression and cellular proliferation was investigated under the treatment of interleukin (IL)-1α. Meniscal samples perforated by a 2-mm-diameter punch were maintained for 3 weeks in HA-supplemented media. Cultured meniscal samples were evaluated by histological analyses.


Bone & Joint Research
Vol. 6, Issue 2 | Pages 108 - 112
1 Feb 2017
Itabashi T Narita K Ono A Wada K Tanaka T Kumagai G Yamauchi R Nakane A Ishibashi Y

Objectives

The surface of pure titanium (Ti) shows decreased histocompatibility over time; this phenomenon is known as biological ageing. UV irradiation enables the reversal of biological ageing through photofunctionalisation, a physicochemical alteration of the titanium surface. Ti implants are sterilised by UV irradiation in dental surgery. However, orthopaedic biomaterials are usually composed of the alloy Ti6Al4V, for which the antibacterial effects of UV irradiation are unconfirmed. Here we evaluated the bactericidal and antimicrobial effects of treating Ti and Ti6Al4V with UV irradiation of a lower and briefer dose than previously reported, for applications in implant surgery.

Materials and Methods

Ti and Ti6Al4V disks were prepared. To evaluate the bactericidal effect of UV irradiation, Staphylococcus aureus 834 suspension was seeded onto the disks, which were then exposed to UV light for 15 minutes at a dose of 9 J/cm2. To evaluate the antimicrobial activity of UV irradiation, bacterial suspensions were seeded onto the disks 0, 0.5, one, six, 24 and 48 hours, and three and seven days after UV irradiation as described above. In both experiments, the bacteria were then harvested, cultured, and the number of colonies were counted.