Repeat-dose intravenous tranexamic acid further decreases blood loss in total knee arthroplasty.

PURPOSE: Tranexamic acid (TXA) reduces blood loss in patients undergoing total knee arthroplasty (TKA). However, few studies have reported the optimum timing and dosage for administration of TXA. The purpose of this study was to evaluate the effect of repeat-dose TXA on blood loss during TKA and the necessity of autologous blood donation or postoperative autotransfusion. METHODS: We enrolled 78 patients with primary osteoarthritis undergoing cemented TKAs. Consecutive patients were divided into three groups, as follows: control group (n = 31), single-TXA group (n = 21) in whom TXA (1,000 mg) was intravenously administered 10 min before deflation of the tourniquet, and twice-TXA group (n = 26) in whom TXA (1,000 mg) was intravenously administered 10 min before deflation of the tourniquet and 3 h after the operation. We measured the volume of drained blood after the operation. Haemoglobin (Hb) levels were measured at days 1, 4 and 7 postoperation. Venous thromboembolic events (VTE) were screened using compression ultrasonography at enrollment and 1 and 7 days after operation. RESULTS: The mean volume of drained blood after the operation was lower in the twice-TXA group than in the single-TXA (p < 0.001) and control (p < 0.0001) groups. No significant differences were observed in the incidence of VTE between these groups. CONCLUSION: Administration of TXA twice reduced postoperative blood loss after TKA, and TXA was not associated with the risk of deep-vein thrombosis (DVT) or pulmonary embolism (PE). Further, administration of TXA twice may eliminate the need for blood transfusion during TKA.

Association between Breakfast Meal Categories and Timing of Physical Activity of Japanese Workers.

BACKGROUND: Breakfast is the most important meal of the day and has been associated with longevity. Regular breakfast consumers often have a healthy lifestyle, including a healthy diet and regular physical activity. METHODS: We examined the association between breakfast type, chronotype (morningness-eveningness), and physical activity in 3395 Japanese workers using a cross-sectional web survey. RESULTS: Participants who ate Japanese breakfasts showed an early chronotype, while those who ate breakfast cereal exhibited a later chronotype. Physical activity was positively associated with adopting a Japanese breakfast style. Japanese breakfast eaters performed physical activities from 6:00-9:00 compared with other breakfast eaters. CONCLUSION: Our findings suggest that eating a Japanese breakfast is associated with an earlier chronotype (morningness) and higher physical activity.

Expression of dominant negative TGF-ß receptors inhibits cartilage formation in conditional transgenic mice.

Although transforming growth factor-ß (TGF-ß) signaling has been implicated in cartilage formation in various studies, the exact role played by TGF-ß in this process remains controversial. TGF-ß signals are transduced through TGF-ß type II receptor (TGF-ßRΙΙ) and type I receptor (ALK5). Col2a1-Cre-mediated deletion of Tgfbr2 did not cause obvious defects in long bone formation, suggesting that TGF-ß signals are dispensable for normal cartilage formation in the stage of condensing mesenchymal cells and chondrocytes or that related molecules can compensate for the lack of TGF-ßRΙΙ. In the present study, we established a conditional transgenic mouse in which a dominant negative form of TGF-ßRII (dnTGF-ßRII) is expressed in condensing mesenchymal cells and chondrocytes in limbs using the Cre/loxP system. Recombination at loxP sites and expression of dnTgfbr2 were monitored by the disappearance of LacZ expression. The conditional transgenic mice expressing dnTgfbr2 developed hypoplastic cartilage. The phenotype was much more severe than that of Col2a1-Cre-mediated Tgfbr2 conditional knockout mice, although the pattern of dnTgfbr2 expression appears similar to the pattern of Tgfbr2 deletion. These phenotypic differences suggest that the signaling through TGF-ß receptors is complex in cartilage.

Association between Irregular Meal Timing and the Mental Health of Japanese Workers.

Breakfast skipping and nighttime snacking have been identified as risk factors for obesity, diabetes, and cardiovascular diseases. However, the effects of irregularity of meal timing on health and daily quality of life are still unclear. In this study, a web-based self-administered questionnaire survey was conducted involving 4490 workers (73.3% males; average age = 47.4 ± 0.1 years) in Japan to investigate the association between meal habits, health, and social relationships. This study identified that irregular meal timing was correlated with higher neuroticism (one of the Big Five personality traits), lower physical activity levels, and higher productivity loss. Irregular meal timing was also associated with a higher incidence of sleep problems and lower subjective health conditions. Among health outcomes, a high correlation of irregular meal timing with mental health factors was observed. This study showed that irregularity of meal timing can be explained by unbalanced diets, frequent breakfast skipping, increased snacking frequency, and insufficient latency from the last meal to sleep onset. Finally, logistic regression analysis was conducted, and a significant contribution of meal timing irregularity to subjective mental health was found under adjustment for other confounding factors. These results suggest that irregular meal timing is a good marker of subjective mental health issues.

Outcome of double-bundle ACL reconstruction using hamstring tendons.

The objective of this article is to describe the clinical outcome of the transitional double-bundle procedure for anatomical ACL reconstruction. Subjects included 78 patients (average age 25 years) who had undergone ACL reconstruction with the transitional double-bundle procedure with multi-stranded hamstring tendons. The femoral socket for the anteromedial (AM) graft was created at 5-6 mm from the mid-sagittal line of the intercondylar notch at 2:00 or 10:00, and that for the posterolateral (PL) graft was drilled adjacent to the AM socket at 3:00 or 9:00. For the tibial side, two tunnels were made at the center of the footprint of the AM and PL bundles of the normal ACL. Patients were evaluated at 24 months or longer postoperatively based on the IKDC Knee Examination Form. Subjectively, 32 knees (41%) were graded as normal; 41 (53%), as nearly normal; 4 (5%), as abnormal; and 1 (1%) as graft rupture by re-injury. The average side-to-side difference in anterior laxity at manual maximum force with the KT-2000 arthrometer was 0.9 mm +/- 1.2. Seventy patients (93%) had a range between -1 mm and 2 mm. In conclusion the transitional double-bundle ACL reconstruction provided a satisfactory outcome after a short-term follow-up.

VAC Therapy Direct to the Medullary Cavity for Chronic Tibial Osteomyelitis.

BACKGROUND: Vacuum-assisted wound closure (VAC) is useful for difficult wound beds, although sites where bleeding or infection is expected are usually regarded as problematic for this therapy. This report outlines the treatment of chronic tibial osteomyelitis (Cierny- Mader type III) due to mixed infection with Nocardia spp and Bacteroi- des fragilis by postoperative VAC therapy direct to the medullary cavity, followed by wound coverage with a gastrocnemius myocutaneous skin flap. CASE REPORT: A 64-year-old man developed chronic left tibial os- teomyelitis after a work injury. The nonviable tissues were debrided, including a sequestrum. Nocardia spp and B. fragilis were isolated from surgical bone specimens, and chronic tibial osteomyelitis due to mixed infection was diagnosed. Postoperatively, VAC therapy was performed directly to the open medullary cavity of the tibia and sub- sequently covered the residual soft tissue defect with a gastrocnemius myocutaneous flap. DISCUSSION: The authors could not find any English literature on VAC therapy direct to the medullary cavity combined with transplantation of a myocutaneous flap for osteomyelitis. Nocardia spp can cause a variety of infections, among which osteomyelitis occupies a relatively small percentage. CONCLUSION: This case raises the possibil- ity of treating chronic tibial osteomyelitis caused by mixed infection with Nocardia spp and B. fragilis by applying postoperative VAC ther- apy directly to the medullary cavity and covering the residual wound with a gastrocnemius myocutaneous flap.

Intra-articular corrective osteotomy for malunited Hoffa fracture: A case report.

Hoffa fracture, an isolated coronal plane fracture of the posterior aspect of the femoral condyle, is known as an unstable, intra-articular fracture, and therefore, operative treatment is recommended. However, insufficient open reduction or failure of fixation may lead to malunion. We performed intra-articular corrective osteotomy for a malunited Hoffa fracture in a 31-year-old man and obtained good functional and radiographic results. This report suggests that intra-articular corrective osteotomy for malunited Hoffa fracture offers a good outcome and should be considered as salvage treatment.

Smad7 Inhibits chondrocyte differentiation at multiple steps during endochondral bone formation and down-regulates p38 MAPK pathways.

Bone morphogenetic proteins (BMPs) play critical roles at various stages in endochondral bone formation. In vitro studies have demonstrated that Smad7 regulates transforming growth factor-beta and BMP signals by inhibiting Smad pathways in chondrocytes. However, the in vivo roles of Smad7 during cartilage development are unknown. To investigate distinct effects of Smad7 at different stages during chondrocyte differentiation, we generated a series of conditional transgenic mice that overexpress Smad7 in chondrocytes at various steps of differentiation by using the Cre/loxP system. We generated Col11a2-lacZ(floxed)-Smad7 transgenic mice and mated them with three types of Cre transgenic mice to obtain Smad7(Prx1), Smad7(11Enh), and Smad7(11Prom) conditional transgenic mice. Smad7(Prx1) mice overexpressing Smad7 in condensing mesenchymal cells showed disturbed mesenchymal condensation associated with decreased Sox9 expression, leading to poor cartilage formation. Smad7(11Enh) mice overexpressing Smad7 in round chondrocytes showed decreased chondrocyte proliferation rates. Smad7(11Prom) mice overexpressing Smad7 in flat chondrocytes showed inhibited maturation of chondrocytes toward hypertrophy. Micromass culture of mesenchymal cells showed that BMP-induced cartilaginous nodule formation was down-regulated by overexpression of Smad7, but not Smad6. Overexpression of Smad7, but not Smad6, down-regulated the phosphorylation of p38 MAPKs. Our data provide in vivo evidence for distinct effects of Smad7 at different stages during chondrocyte differentiation and suggest that Smad7 in prechondrogenic cells inhibits chondrocyte differentiation possibly by down-regulating BMP-activated p38 MAPK pathways.

Low-intensity pulsed ultrasound increases bone ingrowth into porous hydroxyapatite ceramic.

Synthetic porous ceramic made of hydroxyapatite (HA) has been used as a bone graft substitute. In the present study we investigated whether low-intensity pulsed ultrasound (LIPUS) accelerates bone ingrowth into the pores of HA ceramic. Application of LIPUS did not mechanically weaken porous ceramic that was immersed in water in vitro. In vivo experiments using rabbits showed that LIPUS application for 2 weeks significantly increased osteoblast number and bone area in the central part of the porous HA ceramic implanted in the femoral condyle in comparison with similarly implanted HA ceramic that was not exposed to LIPUS. LIPUS application for 3 weeks significantly increased mineralized tissue volume and mineral content in the porous HA ceramic. Wound healing assays revealed increased migration of MC3T3-E1 cells as a result of LIPUS treatment, partly accounting for the increased osteoblast number. Use of porous HA ceramic combined with LIPUS may be a promising treatment for filling large bone defects in a clinical setting.