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BACKGROUND: Periprosthetic joint infection is a major complication of total joint arthroplasty, with treatment requiring a two-stage exchange procedure and 6 weeks of systemic antibiotics. However, depending on the infection site, intravenous delivery of antibiotics like vancomycin (VCM) can have poor tissue transferability, thus reducing their therapeutic effect. OBJECTIVE: This study demonstrates the 24-week in vivo release profile and antibacterial activity of VCM from calcium phosphate cement impregnated with VCM (CPC/VCM) and compares them with those from polymethylmethacrylate impregnated with VCM (PMMA/VCM). METHODS: Rats were implanted with the test specimens between the fascia and quadriceps. After implantation for 24 weeks, the test specimens were removed and residual VCM was extracted to calculate the concentration of VCM released into rat tissues. We also examined the antibacterial activity of releasable VCM from the removed test specimens by placing them directly onto the surface of agar. RESULTS: CPC/VCM released greater concentrations of VCM for a longer period of time within the 24 weeks than PMMA/VCM. Moreover, CPC/VCM released 1.4 to 26.1-fold more VCM than PMMA/VCM. Using Staphylococcus aureus, antibacterial activity was logarithmically correlated with VCM concentration across the entire concentration range tested (12.5–800 μg/mL). While the area within which inhibition was observed—the inhibition zone—for both CPC/VCM and PMMA/VCM formed and gradually shrank with time after implantation, that for CPC/VCM was significantly larger than that for PMMA/VCM in each week after implantation. CONCLUSION: CPC/VCM releases greater amounts of VCM with antibacterial activity for longer periods of time than PMMA/VCM, suggesting that CPC is effective for facilitating the release of antibiotics for local action in patients with established postoperative infection.

Age is a key factor in intervertebral disc (IVD) degeneration; however, the changes that occur in IVDs with age are not fully understood. Tissue-resident macrophages are critical for tissue homeostasis and are regulated by transforming growth factor- (TGF-) β. We examined changes in the proportion of resident macrophages in young versus aged mice and the role of TGF-β in regulating resident macrophages in IVDs. IVDs were harvested from 4-month (young) and 18-month-old (aged) C57BL/6J mice. The proportion of macrophages in IVDs was determined using flow cytometry ( n = 5 for each time point) and the expression of Cd11b, Cd206, and Tgfb genes, which encode CD11b, CD206, and TGF-β protein, respectively, using real-time PCR. To study the role of TGF-β in the polarization of resident macrophages, resident macrophages isolated from IVDs from young and aged mice were treated with recombinant TGF-β with and without a TGF-β inhibitor (SB431542). Additionally, SB431542 was intraperitoneally injected into young and aged mice, and Cd206 expression was examined using real-time PCR ( n = 10 for each time point). The proportion of CD11b+ and CD11b+ CD206+ cells was significantly reduced in aged versus young mice, as was Cd11b, Cd206, and Tgfb expression. TGF-β/IL10 stimulation significantly increased the expression of Cd206, an M2 macrophage marker, in disc macrophages from both young and aged mice. Meanwhile, administration of a TGF-β inhibitor significantly reduced Cd206 expression compared to vehicle control in both groups. Conclusion. Resident macrophages decrease with age in IVDs, which may be associated with the concomitant decrease in TGF-β. Our findings provide new insight into the mechanisms of age-related IVD pathology.

Ken Takata, Kentaro Uchida, Shotaro Takano, Manabu Mukai, Gen Inoue, Hiroyuki Sekiguchi, Jun Aikawa, Masayuki Miyagi, Dai Iwase, Masashi Takaso Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara City, Kanagawa, 252-0374, JapanCorrespondence: Kentaro UchidaDepartment of Orthopedic Surgery, Kitasato University School of Medicine, 1-15-1 Minami-Ku Kitasato, Sagamihara City, Kanagawa, 252-0374, JapanTel/Fax +81-042-778-9217Email kuchida@med.kitasato-u.ac.jpPurpose: Obesity is associated with the risk of developing knee osteoarthritis (KOA). Furthermore, synovial basic fibroblast growth factor (bFGF) is linked to the severity of KOA. We previously demonstrated that bFGF and mast cell (MC) marker expression were elevated in the synovial tissues (ST) of KOA patients with obesity. However, it remains unclear whether MCs contribute to bFGF expression and regulation.Patients and Methods: Radiographically diagnosed KOA patients (n=249) were assigned to groups based on the body mass index (BMI) classifications used by the World Health Organization: normal-weight (NW, BMI < 25 kg/m2, n=95), overweight (OW, BMI ≥ 25 and < 30, n=109) and obese (OB, ≥ 30 kg/m2, n=45). BFGF expression in the ST was examined using quantitative polymerase chain reaction and compared across the BMI groups. Additionally, BFGF and interleukin (IL) 13 expression were examined in freshly extracted MC-rich (THY-1-, CD3-, CD14-, and CD19-) and MC-poor (THY-1+, CD3+, CD14+, or CD19+) fractions from ST. Moreover, regulation of BFGF expression by IL-13 was studied in CD14-negative (fibroblast-rich) and CD14-positive (M&phis;-rich) and cells in culture.Results: BFGF expression was significantly higher in OB than in NW patients. Furthermore, although IL13 was significantly higher in the MC-rich than the MC-poor fraction, BFGF expression was comparable. Recombinant human IL-13 stimulated expression of BFGF in synovial fibroblast cells.Conclusion: BFGF expression is higher in the ST of KOA patients with obesity. Increased numbers of MCs may contribute to the elevated BFGF expression through IL-13 in KOA patients with obesity.Keywords: obesity, mast cell, osteoarthritis, BFGF, IL13, synovial tissues

Background Autologous vein wrapping (VW) is used in the treatment of recurrent chronic constriction neuropathy and traumatic peripheral nerve injury. However, use of autologous veins is limited by the inability to obtain longer veins of sufficient length for larger sites. Frozen allograft tissue has several advantages, including its availability for large grafts, avoidance of donor-site morbidity, and shorter operation time. Here, we investigated the effect of frozen vein wrapping (FVW) in Wistar rats as a model of sciatic nerve injury. Results The rats were grouped by treatment as (i) untreated after chronic constriction injury surgery (CCI; control group), (ii) treated with vein wrapping using freshly isolated vein (VW), and (iii) treated with vein wrapping using frozen vein (FVW). Mechanical allodynia was assessed with von Frey filaments on postoperative days (PODs) 1, 3, 5, 7, and 14. Gene expression of HO-1 was evaluated by quantitative polymerase chain reaction (qPCR). The response of heme oxygenase-1 gene, Hmox-1, expression to VW and FVW was assessed by RT-PCR. Both VW and FVW significantly increased withdrawal threshold levels compared to the untreated control group on POD 1, 3, and 5. Both VW and FVW also showed increased HO-1 expression compared to the CCI group. Conclusions FVW increased the withdrawal threshold similar to VW in a rat CCI model for short periods. Frozen vein wrapping using vein allograft without donor site morbidity may be an alternative therapeutic option.

The perioperative complication rate for spinal fusion in Duchenne muscular dystrophy (DMD) remains high and sometimes prolonged perioperative intensive care is needed. We investigated preoperative and intraoperative risk factors associated with prolonged intensive care unit (ICU) stay after posterior spinal fusion.We reviewed the records of 49 consecutive DMD patients who underwent posterior spinal fusion. Instrumentation was performed from T4 to L5 (46 cases) or to the ilium (3 cases). We recorded the preoperative Cobb angle and perioperative clinical data from patient records. Patients were divided into two groups (ICU stay 0 or 1 day, 2 days or longer). Chi-square and t tests were used for univariate analysis. Factors with p 0.05 in the univariate analysis were entered into a multilevel logistic regression analysis.The average age of patients at surgery was 14.2 years (range 11-20 years). Their preoperative Cobb angle was 79.2° (range 40°-154°). Average operative time was 325.3 min (range 225-507 min). The average estimated blood loss (EBL) was 1673.0 ml (range 500-3785 ml). Eight patients stayed in the ICU for 2 days or longer for postoperative monitoring and treatment. Univariate analysis found statistical difference between the two groups in preoperative Cobb angle, Thoracolumbar kyphosis, %VC, operation time, and EBL during surgery. After multiple logistic regression analysis, Cobb angle and EBL was identified as an independent factor. The patients with a larger Cobb angle and greater EBL had a higher rate of prolonged ICU stay in interquartile range-based comparison.The present study suggests the preoperative Cobb angle and intraoperative EBL could be predictors for postoperative course in posterior spinal fusion for DMD patients.

Introduction Intraoperative hypothermia is associated with perioperative complications such as blood loss and wound infection. Thus, perioperative heat retention methods to prevent perioperative hypothermia such as providing a warmed blanket and active patients' warming are important. Although major surgery and pediatric patient age are noted as risk factors, only a few studies focus on hypothermia as an intraoperative complication in pediatric scoliosis surgery. The aim of this study is to investigate the incidence of intraoperative hypothermia in pediatric scoliosis surgery and the associated preoperative risk factors. Methods We retrospectively reviewed the records of pediatric patients who underwent posterior spinal fusion at a single institution between 2015 and 2019. We recorded the background data, perioperative data, lowest recorded core temperature, and perioperative complications. Patients were divided into those whose temperature decreased below 36°C (Group H) and those who maintained a temperature of 36°C or greater (Group N) during surgery. We compared the two groups and performed multivariate analysis to identify preoperative risk factors for intraoperative hypothermia. Results A total of 103 patients underwent posterior spinal fusion; 56 for adolescent idiopathic scoliosis and 47 for neuromuscular scoliosis. Hypothermia was observed in 40 patients (38.8%). Group H had more non-adolescent idiopathic scoliosis (AIS) patients, lower mean body mass index, greater mean blood loss, greater number of fused vertebrae, larger preoperative Cobb angle, and lower initial core body temperature (immediately after induction of anesthesia). On multivariate analysis, a diagnosis of neuromuscular scoliosis, a lower body mass index, and a lower initial core body temperature were identified as independent risk factors for intraoperative hypothermia. Conclusions The incidence of hypothermia in pediatric posterior scoliosis surgery is 38.8%. Diagnosis of non-AIS, lower body mass index, and lower core body temperature at the time of anesthesia induction are preoperative risk factors for intraoperative hypothermia.

Introduction Spinal muscular atrophy (SMA) is defined as a neuromuscular disorder induced by progressive weakness of the skeletal muscle and is usually accompanied by progressive spinal deformity including scoliosis. The newly developed Nusinersen, which is the first approved drug worldwide for SMA, requires accurate intrathecal injection, which is sometimes difficult in patients with severe spinal deformity. Technical note For an accurate intrathecal approach in patients who have spinal fusion surgery to treat neuromuscular scoliosis, we have combined an L3 laminectomy with spinal correction and fusion surgery. Here, we review four cases of SMA in patients who underwent the additional L3 laminectomy during surgery to treat spinal scoliosis. A successful intrathecal approach was made using fluoroscopic guidance in all four patients, who were then administered with Nusinersen. Conclusions Our findings show that additional lumbar laminectomy during surgery for spinal scoliosis has effectively allowed for intrathecal injection of Nusinersen.

Introduction: There are few reports on body composition, particularly muscle mass, in patients with adolescent idiopathic scoliosis (AIS). The purpose of this study was to measure body composition including muscle mass and estimated bone mass of patients with AIS using bioelectrical impedance analysis (BIA) and to clarify the relationship between the degree of scoliosis and body composition. Methods: The subjects were 210 girls (mean age 14.0 years, range 10-18 years) whose body composition was evaluated using BIA (Tanita MC-780). Body mass index (BMI), percent body fat (%BF), lean muscle mass index (LMI: muscle mass/height^2), and estimated bone mass index (eBoneMI: estimated bone mass/height^2) were determined by age and compared with those of previous reports. We divided 111 subjects whose bone maturation was complete into two groups for comparison of body composition metrics: those with Cobb angle

Background Muscle weakness is associated with osteoarthritis pathology. A recent study demonstrated that measuring muscle volume using computed tomography (CT)-based analysis and comparing bilateral muscles in the same patient allowed for accurate evaluation of muscle volume in unilateral hip osteoarthritis (OA) patients. Here, we evaluated muscle volume using CT-based analysis and compared bilateral muscles in knee OA (KOA) patients. Methods CT images were obtained from 35 female radiographic KOA patients the day prior to total knee replacement surgery. Muscle volume (MV) was semi-automatically analyzed. Knee extension muscle strength (MS) was determined using a hand-held dynamometer. The severity of KOA patients’ clinical symptoms was examined using four domains of the Japanese Orthopedic Association (JOA) score. We compared the difference in MS (ΔMS) and MV (ΔMV) between the operated side (OS), which exhibited severe radiographic OA or severe pain, and the contralateral side (CS). Results JOA score was significantly lower in the OS than CS. MV and MS were also significantly lower in the OS than CS. There was no correlation between MV and MS or between MV and MS as a percentage of body weight on either side. However, ΔMV was positively correlated with ΔMS and pain on walking in the JOA. Conclusions We evaluated MV and MS using bilateral CT images of the legs of KOA patients. A reduction in MV was observed on the OS, and was correlated with a reduction in MS and pain on walking. Bilateral CT image analysis may be useful for evaluating the relationship between OA pathology and muscle atrophy.

Purpose The mechanisms governing evidence that obesity is a risk factor for osteoarthritis (OA) are not well understood. We previously reported an increase in mast cell (MC) marker expression in the osteoarthritic synovial membrane (SM) of patients with obesity. We hypothesized that an enzyme produced by MC, β-tryptase, may be increased in the SM of obese patients with knee OA and contribute to synovial inflammation. This study investigated the expression of the β-tryptase encoding gene, TPSB2, in the SM of obese patients with knee OA and β-tryptase-mediated regulation of IL-1β in synovial cells. Patients and Methods A total of 216 patients radiographically diagnosed with knee OA were grouped according to the World Health Organization's body mass index classifications: normal weight (NW

Macrophages, particularly M1 macrophages, produce proinflammatory cytokines and contribute to the degenerative process in injured intervertebral discs (IVDs). We previously showed that macrophages in both intact and injured IVDs increased following IVD injury. Resident macrophages and macrophages recruited from the peripheral blood have distinct roles in tissue. However, it remains to be determined whether increased macrophages derive from resident or recruited macrophages. We investigated the origin of M1 macrophages in injured IVDs using green fluorescent protein (GFP) transgenic bone marrow chimeric mice. The M1 macrophage marker, CD86, increased in both disc-derived resident macrophages and bone marrow-derived macrophages (BMMs) after lipopolysaccharide/interferon γ stimulation in vitro. Following IVD injury, the proportion of cells positive for the CD86 ligand, the F4/80 antigen, and the surface glycoprotein CD11b (CD86+ CD11b+ F4/80+) significantly increased in GFP+ populations at days 3, 7, and 14. In contrast, CD86+ CD11b+ F4/80+ cells in GFP- populations significantly increased on day 3, and thereafter decreased on days 7 and 14. The proportion of CD86+ CD11b+ F4/80+ cells in the GFP+ populations was significantly higher than that in the GFP- populations at days 1, 3, 7, and 14. Monocyte chemoattractant protein-1 expression in disc-derived macrophages, but not in BMMs, increased following interleukin-1β stimulation. Our results suggest M1 macrophages following IVD injury originate from recruited macrophages. Resident macrophages may behave differently in IVD injury. The role of resident macrophages needs to be clarified. Further investigation is needed.

In the current study, multivariate analyses were performed to determine factors associated with low back pain (LBP) in patients with osteoporosis. Aging, high bone turnover, obesity, low trunk muscle mass, spinal global sagittal malalignment, and a high number of previous vertebral fractures were potential independent risk factors of pain-related disorders, gait disturbance, or ADL deficit due to LBP. PURPOSE Patients with osteoporosis often experience low back pain (LBP) even in the absence of acute fractures. This study identifies factors that may affect questionnaires about LBP. METHODS The data of 491 patients with osteoporosis were retrospectively reviewed. Data included patient age, sex, body mass index (BMI), bone mineral density of the lumbar spine, tartrate-resistant acid phosphatase 5b level (TRACP5b), trunk muscle mass, sagittal vertical axis (SVA), previous vertebral fractures, secondary osteoporosis, controlling nutritional status score, pain-related disorders and gait disturbance scores from the Japanese Orthopedic Association Back Pain Evaluation questionnaire (JOABPEQ), and Oswestry disability index (ODI) scores for activities of daily living (ADL) deficit. Patients with scores of 100 for each subsection of the JOABPEQ, or an ODI scores

Background Recently, Oblique lumbar interbody fusion (OLIF) is commonly indicated to correct the sagittal and coronal alignment in adult spinal deformity (ASD). Endplate fracture during surgery is a major complication of OLIF, but the detailed location of fracture in vertebral endplate in ASD has not yet been determined. We sought to determine the incidence and location of endplate fracture and subsidence of the OLIF cage in ASD surgery, and its association with fusion status and alignment. Methods We analyzed 75 levels in 27 patients were analyzed using multiplanar CT to detect the endplate fracture immediately after surgery and subsidence at 1 year postoperatively. The prevalence was compared between anterior and posterior, approach and non-approach sides, and concave and convex side. Their association with fusion status, local and global alignment, and complication was also investigated. Results Endplate fracture was observed in 64 levels (85.3%) in all 27 patients, and the incidence was significantly higher in the posterior area compared with the anterior area (85.3 vs. 68.0%, p=0.02) of affected vertebra in the sagittal plane. In the coronal plane, there was no significant difference in incidence between left (approach) and right (non-approach) sides (77.3 and 81.3%, respectively), or concave and convex sides (69.4 and 79.6%) of wedged vertebra. By contrast, cage subsidence at 1 year postoperatively was noted in 14/75 levels (18.7%), but was not associated with endplate fracture. Fusion status, local and global alignment, and complications were not associated with endplate fracture or subsidence. Conclusion Endplate fracture during OLIF procedure in ASD cases is barely avoidable, possibly induced by the corrective maneuver with ideal rod counter and cantilever force, but is less associated with subsequent cage subsidence, fusion status, and sustainment of corrected alignment in long fusion surgery performed even for elderly patients.

BACKGROUND: Impaired fracture healing results in extensive and prolonged disability and long-term pain. Previous studies reported that nerve growth factor (NGF) was expressed during fracture healing and that anti-NGF antibody improves physical activity associate with facture pain. However, NGF expression levels in delayed or non-union are not fully understood. OBJECTIVE: We compared chronological changes in NGF in the callus of young mice after femur fracture with those in aged mice after femur fracture as a model of bone fracture in the elderly. METHODS: We used young (age 8 weeks) and aged (age 10 months) male C57BL/6J mice. A fracture was generated in the femur. At 5, 7, 10, 14, 17, and 21 days after creation of a fracture, mRNA expression levels of Col2a1, Col10a1, NGF were evaluated using quantitative PCR. We examined NGF protein expression levels and localization in the callus at day 14 using ELISA and immunohistochemistry, respectively. RESULTS: Expression of NGF in the callus after femur fracture in aged mice was significantly greater than that in young mice at days 5, 7, 10, 17, and 21 days. NGF protein levels in the callus of aged mice were also significantly higher than that in young mice. Immunohistochemical staining showed that NGF was heavily expressed in hypertrophic chondrocytes in the callus in aged mice. CONCLUSIONS: It is suggested that delayed Col2a1 and Col10a1 expression reflects delayed chondrocyte formation and delayed chondrocyte maturation in aged mice and that higher NGF expression in aged mice at day 14 may be associated with the presence of remaining hypertrophic chondrocytes in callus with delaying endochondral ossification.

Background The rotator cuff undergoes natural degeneration with age, leading to age-related rotator cuff tear; however, the precise mechanism remains unclear. Transforming growth factor-beta (TGF-β) concentrations rise with age and TGF-β contributes to the pathophysiology of skeletal muscle. TGF-β has also been shown to suppress expression of the myokine, apelin, in skin fibroblasts. We hypothesized that TGF-β expression in the rotator cuff changes with age and regulates apelin expression, thereby contributing to rotator cuff degeneration. Methods We used quantitative reverse-transcription polymerase chain reaction (Q-RT-PCR) to measure the expression of apelin and tendon-related genes (Tnmd, Col1a1, and Col3a1) in the rotator cuff of young (12 weeks), adult (24 weeks), and old (48 weeks) rats. Using Q-RT-PCR and enzyme-linked immunosorbent assay, we also measured Tgfb mRNA and TGF-β protein levels, respectively. Furthermore, we used Q-RT-PCR to measure apelin mRNA levels in rotator cuff-derived cells after treatment with 0 (control) and 10 ng/mL recombinant TGF-β. Results Apelin mRNA levels were significantly lower in old compared to young and adult rats. Similarly, tendon-related genes, Tnmd, Col1a1, and Col3a1, were significantly lower in adult and old rats than young rats. In contrast, Tgfb mRNA and TGF-β protein were significantly higher in old compared to young rats. Stimulation with exogenous TGF-β significantly decreased Apelin mRNA expression compared to control. Conclusions TGF-β regulates apelin expression in the rotator cuff and may play a key role in the degenerative pathology of the rotator cuff with age.

Expression of CD163, a scavenger receptor specifically expressed by monocytes and macrophages, is elevated in the synovial tissue of patients with knee osteoarthritis (OA) compared with healthy controls. However, the association between CD163 expression in the synovium and pain in OA patients is unclear. We investigated the correlation between synovial CD163 expression and resting and active pain levels in patients with hip osteoarthritis (HOA). To investigate the possible contribution of CD163+ subsets to pain pathogenesis, we compared pain-related cytokine expression and M1/M2 macrophage marker expression in CD163+ and CD163- cells. We performed flow cytometric analysis to study the CD163+ cell population. We also examined pain-related cytokine expression and M1/M2 macrophage marker expression on CD163+ CD14high and CD163+ CD14low cells using cell sorting. Synovial CD163 expression significantly correlated with resting pain levels (p = 0.006; R = 0.321), but not active pain levels (p = 0.155; R = 0.169). Expression of the M1 macrophage marker CD80 was significantly higher in CD163+ than CD163- cells (p = 0.010), as was the expression of M2 macrophage markers CD206 and IL10 (CD206, p = 0.014; IL10, p = 0.005), and TNFA and IL1B (TNFA, p = 0.002; IL1B, p = 0.001). TNFA expression was significantly higher in CD163+ CD14low than CD163+ CD14high cells, while IL1B, IL10, and CD206 expression were comparable among these subsets. Our findings suggest that CD163 expression is associated with higher resting pain scores. As TNF-α plays a role in the pain process, CD163+ CD14low cells expressing TNFA may be a potent contributor to the pathogenesis of resting pain in HOA.

Background:Bone marrow-derived monocytes/macrophages are recruited into synovial tissue, where they contribute to synovial inflammation in osteoarthritis through inflammatory cytokine production. Recent studies have suggested that V-Set and transmembrane domain-containing 4 (VSTM4) and its fragment, peptide Lv, exhibit immunosuppressive activity on T cells and vascular endothelial growth factor (VEGF)-like activity, respectively. Given that evidence suggests that VEGF may play a role in macrophage function, we investigated peptide Lv-mediated regulation of inflammatory cytokines in bone marrow macrophages (BMMs) and synovial inflammation.Method:To investigate the effects of peptide Lv, BMMs were stimulated with vehicle, LPS, or LPS + peptide Lv, andTnfa, Il1b, Il6, andIfngexpression were evaluated using quantitative PCR (qPCR). TNF-α and IFN-γ production was measured using ELISA. To examine the effect of peptide Lv deficiency on macrophages and synovitis,peptide Lv-deficient mice were generated using genome editing. LPS-inducedTnfaandIfngexpression and TNF-α and IFN-γ production were evaluated in BMM isolated from wild-type andpeptide Lv-deficient mice. Additionally,TnfaandIfngexpression levels were compared between wild-type andpeptide Lv-deficient mice before and after knee injury.Results:Peptide Lv suppressed the LPS-mediated elevation in TNF-α and IFN-γ. LPS stimulation significantly increased TNF-α and IFN-γ production in BMM derived frompeptide Lv-deficient mice compared to wild-type mice. Synovial TNF-α expression in the injured knee was elevated inpeptide Lv-deficient compared to wild-type mice.Conclusion:Peptide Lv suppressed TNF-α in macrophages and plays a role in synovial inflammation. Thus, peptide Lv may be a useful therapeutic target for synovitis.

Introduction Elderly patients with osteoporosis often complain of back pain associated with pathological vertebral fractures caused by abnormal spinal alignment. Few reports evaluate the relationships among muscle mass, bone mineral density (BMD), sagittal spinal alignment, and low back pain. We hypothesized that decreasing muscle mass in elderly patients with osteoporosis could cause spinal alignment abnormalities. The aim of the current study were to compare the characteristics between spinal sagittal normal alignment and malalignment and to evaluate the relationships between sagittal spinal alignment and muscle mass in elderly patients with osteoporosis. Methods Fifty patients aged 75 years or more (mean age = 80.5 years) with osteoporosis were included in this study. We evaluated the sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence minus lumbar lordosis (PI-LL), the number of vertebral fractures (N of VFs), BMD by dual-energy X-ray absorptiometry, and trunk and skeletal muscle mass using bioelectrical impedance. Low back pain was evaluated using the Oswestry Disability Index (ODI). Corrected trunk muscle mass (trunk muscle mass index, TMI) and corrected limb muscle mass (skeletal mass index, SMI) also were measured. Patients were divided into two groups for comparison: a ‘normal’ group and a sagittal spinal ‘malalignment’ group. Multiple regression analysis was carried out to evaluate the relationship between spinal sagittal parameters and muscle mass. Results Comparisons between normal and malalignment groups for SVA, N of VFs, BMI, and SMI showed significantly higher in the malalignment group versus the normal group (p < 0.05). N of VFs, BMI, and TMI, for PT, and BMI, TMI, SMI, and ODI scores for PI-LL showed significantly higher in the malalignment group versus the normal group (p < 0.05). There were significantly more vertebral fractures in the malalignment group than in the normal group (p < 0.05). However, there were no significant differences of pure muscle mass between the two groups. When adjusted by BMD and the number of vertebral fractures, SMI and TMI were positively correlated to PI-LL and SVA (p < 0.05). Conclusion Elderly patients with osteoporosis and a sagittal spinal malalignment had more vertebral fractures and a higher risk of low back pain than patients with normal spinal alignment. Patients with a sagittal spinal malalignment who were independent and maintained their activities of daily living (ADL) showed high BMI and maintained muscle mass, independent of BMD and the N of VFs, contrary to our hypothesis.

Background Female patients with osteoarthritis report more severe knee pain compared to men. However, the mechanism underlying sex differences in pain remains unclear. We previously found that calcitonin gene-related peptide (CGRP) was expressed in synovial tissue and that this localization may play a role in pain associated with knee osteoarthritis (KOA). Several animal studies have shown that the expression of CGRP and its receptor (receptor activity modifying protein 1, RAMP1) differs by sex. Here, we investigated synovial CGRP and RAMP1 expression in male and female patients with KOA. Methods Synovial tissue (ST) was harvested from male and female subjects (n=30 each) with radiographically confirmed unilateral Kellgren/Lawrence grade 3-4 KOA during total knee arthroplasty. Patients’ subjective pain severity was scored on a 0 to 10 cm visual analog scale (VAS). We compared the expression of CGRP and RAMP1 in ST from men and women and examined the correlation between mRNA levels of CGRP and RAMP1 and pain severity. Results Synovial expression of CGRP and RAMP1 was significantly elevated in women compared to men (CGRP, P=0.017; RAMP1, P=0.028). While CGRP expression was positively correlated with pain severity in females (ρ=0.443, P=0.014), no correlation was observed in men (ρ=-0.021, P=0.913). RAMP1 expression was not correlated with pain severity in either men or women (male, ρ=-0.114, P=0.939; female, ρ=-0.047, P=0.807). Conclusion CGRP and RAMP1 expression levels differ between men and women. Differential CGRP levels may suggest the presence of different pain mechanisms in men and women with KOA.

Spinal sagittal malalignment due to vertebral fractures (VFs) induces low back pain (LBP) in patients with osteoporosis. This study aimed to elucidate spinal sagittal malalignment prevalence based on VF number and patient characteristics in individuals with osteoporosis and spinal sagittal malalignment. Spinal sagittal alignment, and VF number were measured in 259 patients with osteoporosis. Spinal sagittal malalignment was defined according to the SRS-Schwab classification of adult spinal deformity. Spinal sagittal malalignment prevalence was evaluated based on VF number. In patients without VFs, bone mineral density, bone turnover markers, LBP scores and health-related quality of life (HRQoL) scores of normal and sagittal malalignment groups were compared. In 205 of the 259 (79.2%) patients, spinal sagittal malalignment was detected. Sagittal malalignment prevalence in patients with 0, 1, or ≥2 VFs was 72.1%, 86.0%, and 86.3%, respectively. All LBP scores and some subscale of HRQoL scores in patients without VFs were significantly worse for the sagittal malalignment group than the normal alignment group (p &lt, 0.05). The majority of patients with osteoporosis had spinal sagittal malalignment, including ≥70% of patients without VFs. Patients with spinal sagittal malalignment reported worse LBP and HRQoL. These findings suggest that spinal sagittal malalignment is a risk factor for LBP and poor HRQoL in patients with osteoporosis.

Macrophages produce proinflammatory cytokines in injured intervertebral discs (IVDs). We recently showed that macrophage-derived inflammatory cytokines contribute to the production of pain-related factors. However, the mechanism by which macrophages are recruited to injured IVDs has not been fully clarified. Here, we examined the expression dynamics of the chemokine CCL2 in a mouse IVD injury model and the mechanisms of its regulation. The percentage of macrophages increased from day 1 after injury and persisted up until day 28. At 1 and 3 days after injury, the expression of both Ccl2 messenger RNA (mRNA) and CCL2 protein was elevated in the IVD injury group, after which expression decreased to basal levels. Consistent with the increase in CCL2 expression, Ccr2 and Tnfa expression and various types of macrophages were also immediately elevated following disc injury. Further, tumor necrosis factor-α (TNF-α) stimulated Ccl2 mRNA and CCL2 protein expression in IVD cells in vitro. The expressions of M1 (Cd86 and Nos2) and M2a (Ym1) macrophage markers were all significantly elevated from day 1 following injury in injured compared with control mice. Meanwhile, the expression of Cd206 (M2a and M2c marker) was significantly elevated on days 3, 7, 14, and 28 following injury. These results suggest that in IVD injury, TNF-α stimulates CCL2, which, in turn, mediates the recruitment of macrophages with the recruited macrophages subsequently differentiating into M1 and M2 subtypes. CCL2 signaling may, therefore, play an important role in IVD pathology via macrophage recruitment. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:895-901, 2020.

Background. Previous studies suggest the presence of an association of vascular endothelial growth factor (VEGF) with osteoarthritis (OA) severity and pain in patients with knee OA. VEGF expression in human synovial fibroblasts (SFs) is induced by transforming growth factor-beta (TGFβ). However, the signaling pathway governing TGFβ-mediated regulation of VEGF in SFs has not been identified. Methods. OA patients who underwent total knee arthroplasty had their synovial tissue (SYT) extracted and the constituent SFs cultured. The cells were stimulated with culture medium (control), human recombinant TGFβ (hrTGFβ), hrTGFβ + ALK5 inhibitor SB505124, hrTGFβ + transforming growth factor activating kinase 1 (TAK1) inhibitor (5Z)-7-oxozeaenol, or hrTGFβ + p38 inhibitor SB203580 for 6 h. VEGF mRNA expression in SFs was examined using real-time polymerase chain reaction and VEGF protein production in the cell supernatant was examined using enzyme-linked immunosorbent assay. Additionally, phosphorylated levels of SMAD2 and p38 were examined using western blotting. Results. ALK5 (SB505124) and TAK1 (5Z-oxozeaenol) inhibitors completely suppressed TGFβ-induced VEGF mRNA expression and VEGF protein production. Both SB505124 and 5Z-oxozeaenol also suppressed SMAD2 and p38 phosphorylation. The p38 inhibitor (SB203580) partially inhibited TGFβ-mediated VEGF mRNA and VEGF protein production. Conclusion. TGFβ-mediated regulation of VEGF expression and VEGF protein production in the SYT of OA patients occurs through both the canonical and noncanonical pathway.

Low back pain (LBP) is a major public health problem that adversely affects the quality of life (QOL) of workers. The etiology of LBP is considered to be multi-factorial with individual, physical, and psychosocial factors contributing to its development and persistence. Although prevention of LBP in workers in the workplace is very important, only a small number of studies have assessed the risk factors and epidemiology of LBP among Japanese factory workers who stand as part of their job. This cross-sectional study investigated the prevalence of LBP in 691 factory employees who conducted their work while standing. Health-related QOL was evaluated using the Roland-Morris Disability Questionnaire (RDQ) to quantify the severity of LBP with the aim of identifying risk factors for LBP among workers who stand as part of their work in an electronics manufacturing company. We observed that the prevalence of LBP lasting for at least 48 hours within a week was 20.0% among participants, with female employees and those with a prior history of LBP having a significantly increased risk of developing LBP. The distribution of the RDQ score showed a negative regression curve among the employees, which was different from the normal distribution pattern reported previously in Japanese patients with LBP. These findings suggest that prolonged standing among factory workers poses an increased risk for LBP.

Several nerve conduits have been investigated for their potential as alternative sources of autografts for bridging neural gaps. However, autologous nerve transplants remain the most effective for nerve repair. We examined clinically approved nerve conduits containing collagen and polyglycolic acid (PGA-c) combined with collagen-binding basic fibroblast growth factor (bFGF) containing a polycystic kidney disease (PKD) domain and collagen binding domain (CBD) (bFGF-PKD-CBD) in a rat 15-mm sciatic nerve critical-size defect model. The treatment groups were: PGA-c immersed in phosphate-buffered saline (PBS) (PGA-c/PBS group), bFGF (PGA-c/bFGF group), or bFGF-PKD-CBD (PGA-c/bFGF-PKD-CBD group), and no treatment (Defect group). Gait and histological analyses were performed. Four weeks after treatment, the recovery rate of the paw print area was significantly greater in the PGA-c/bFGFPKD-CBD group than the PGA-c/PBS and PGA-c/bFGF groups. Mean intensity of paw prints was significantly greater in the PGA-c/bFGF-PKD-CBD group than the PGA-c/PBS and Defect groups. Swing time was significantly greater in the PGA-c/PBS, PGA-c/bFGF, and PGA-c/bFGF-PKD-CBD groups than the Defect group. At 8 weeks, all three parameters were significantly greater in the PGA-c/PBS, PGA-c/bFGF, and PGA-c/bFGF-PKD-CBD groups than the Defect group. Regenerated myelinated fibers were observed in 7/8 (87.5%) rats in the PGA-c/bFGF-PKD-CBD group after 8 weeks, and in 1/8 (12.5%) and 3/8 (37.5%) rats in the PGA-c/PBS and PGA-c/bFGF groups, respectively. PGA-c/bFGF-PKD-CBD composites may be promising biomaterials for promoting functional recovery of long-distance peripheral nerve defects in clinical practice.

Background Basic fibroblast growth factor (bFGF) has been applied for periodontal regeneration. However, the application depends on bone defect morphology because bFGF diffuses rapidly from defect sites. In a previous study, collagen‐binding bFGF (CB‐bFGF) has been shown to enhance bone formation by collagen‐anchoring in the orthopedic field. The aim of this study is to demonstrate the efficacy of CB‐bFGF with collagen scaffolds in bone regeneration of horizontal bone defect. Methods Cell proliferation activity and collagen binding activity of CB‐bFGF was confirmed by WST‐8 assay and collagen binding assay, respectively. The retention of CB‐bFGF in the collagen sheet (CS) was measured by fluorescence imaging. The rat horizontal alveolar bone defect model was employed to investigate the efficacy of CB‐bFGF with collagen powder (CP). After 4 and 8 weeks, the regenerative efficacy was evaluated by microcomputed tomography, histological, and immunohistochemical analyses. Results CB‐bFGF had a comparable proliferation activity to bFGF and a collagen binding activity. CB‐bFGF was retained in CS longer than bFGF. At 8 weeks postoperation, bone volume, bone mineral content, and new bone area in CB‐bFGF/CP group were significantly increased compared with those in other groups. Furthermore, epithelial downgrowth was significantly suppressed in CB‐bFGF/CP group. At 4 weeks, the numbers of osteocalcin, proliferating cell nuclear antigen, and osteopontin‐positive cells at the regeneration site in CB‐bFGF/CP group were greater than those in other groups. Conclusions CB‐bFGF/CP effectively promoted bone regeneration of horizontal bone defect possibly by sustained release of bFGF. The potential of CB‐bFGF composite material for improved periodontal regeneration in vertical axis was shown.

Purpose: While research suggests that obesity is a risk factor for knee osteoarthritis (KOA), the mechanisms are not fully understood. Mast cell (MC) numbers are increased in the osteoarthritic synovium and in the adipose tissue of obese individuals. We hypothesized that MC numbers are increased in the synovium of obese KOA patients. This study investigated MC marker and MC-generated cytokine/growth factor expression in the synovium of obese KOA patients. Patients and methods: Patients radiographically diagnosed with KOA (male: 38, female: 132) were allocated to three groups based on their body mass index (BMI): normal (

Purpose: Bursal inflammation is thought to be a major cause of pain in degenerative rotator cuff tears (RCTs). While the expression of proinflammatory mediators, such as COX-2, TNF-α, IL-1β, and IL-6, is crucial for the pathophysiology of osteoarthritis (OA), their role in degenerative RCTs remains unknown. The aim of this study was to determine the expression of COX-2 and proinflammatory mediators in the development of RCT-induced pain by comparing their levels in patients with hip OA or RCTs. Methods: We included samples obtained from 31 shoulders of 31 patients with RCTs and samples from 30 hips of 27 patients with hip OA. The mRNA levels of COX-2, TNF-α, IL-1β, and IL-6 were determined using RT-PCR, and were compared between the subacromial bursa and hip joints. We also analyzed IL-1β-induced COX-2 expression in the subacromial bursa and synovial blast of the hip. Results: COX-2, IL-1β, and IL-6 expression levels were significantly lower in the subacromial bursa of RCTs than in hip OA samples, while no significant difference was observed for TNF-α. No significant difference in the fold increase was observed between subacromial bursa and hip OA samples, even though IL-1β-induced COX-2 expression increased in both samples. Conclusion: Our findings suggest that the main mechanism underlying pain development differs between patients with RCTs and those with hip OA.

Background Nerve growth factor (NGF) plays a key role in osteoarthritic pain and low back pain. Rotator cuff tear (RCT) is often associated with severe shoulder pain. However, the role of NGF in RCT remains to be fully understood. Methods Rats were divided into sham and RCT groups. The rotator cuff was harvested from the sham and RCT groups on various days for reverse transcription-polymerase chain reaction analysis of Tnfa, Ngf, Il1b, and Cox2 expression. Rotator cuffs from the sham and RCT groups were also harvested at 1 and 14 days for enzyme-linked immunosorbent assay and immunohistochemistry to assess NGF protein levels and localization. Rotator cuff–derived cells were stimulated with rat recombinant tumor necrosis factor (TNF)-α to investigate the involvement of TNF-α in the regulation of NGF expression. Results Tnfa and Ngf messenger RNA levels increased within 1 day in the RCT group. Notably, Tnfa and Ngf upregulation persisted for up to 56 days after the RCT surgery, while Il1b and Cox2 expression was significantly reduced. NGF levels in the RCT group were significantly higher than those in the sham operation group on days 1 and 14. Certain inflammatory cells and synovial-like cells lining the surface of the laminated tears were NGF-positive on days 1 and 14, respectively. Ngf messenger RNA levels increased significantly in rotator cuff–derived cells after TNF-α stimulation. Conclusion NGF levels are continuously elevated in RCT, which is mainly regulated by TNF-α. NGF may thus represent a potential target for therapies that modulate RCT pain.

Yoshihisa Ohashi,1 Kensuke Fukushima,1 Kentaro Uchida,1 Tomohisa Koyama,1 Maho Tsuchiya,1 Hiroki Saito,1 Katsufumi Uchiyama,2 Naonobu Takahira,3 Gen Inoue,1 Masashi Takaso1 1Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara City, Kanagawa, 252-0374, Japan; 2Department of Patient Safety and Healthcare Administration, Kitasato University School of Medicine, Sagamihara City, Kanagawa, 252-0374, Japan; 3Department of Rehabilitation, Kitasato University School of Allied Health Sciences, Sagamihara City, Kanagawa, 252-0374, JapanCorrespondence: Kensuke FukushimaDepartment of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara City, Kanagawa, 252-0374, JapanTel +81-42-778-9343Fax +81-42-778-5850Email kenfu@r4.dion.ne.jpBackground: In patients with hip osteoarthritis (OA), pain at rest, unlike pain on activity, is due to pain mechanisms that cannot be explained by nociceptive pain. However, it remains unclear whether central sensitization (CS) is one of the causes of exacerbated pain at rest in patients with hip OA. Therefore, we investigated the differences in causative factors and postoperative course of total hip arthroplasty (THA) between preoperative pain at rest and on activity in patients with hip OA.Methods: In total, 120 patients (125 hips, 22 men and 98 women, aged 64.5± 1.0 years) with hip OA were included. Preoperative pain at rest and on activity and CS were assessed using the visual analog scale (VAS) and CS Inventory (CSI), respectively. Postoperative assessments were evaluated using the Japanese Orthopedic Association Hip Disease Evaluation Questionnaire (JHEQ); pain, satisfaction, function, and mental scores were evaluated 6 and 12 months after THA.Results: Multivariate regression analysis indicated the CSI score as affecting VAS for pain at rest (β=0.067, P=0.002) but not VAS for pain on activity (β=0.036, P=0.073). VAS for pain at rest had a weak negative correlation with satisfaction and pain scores at both 6 and 12 months after THA (satisfaction, r=− 0.309, − 0.278; pain, r=− 0.202, − 0.22). VAS for pain on activity was not correlated with JHEQ. The CSI score had a weak or moderate negative correlation with three scores other than the function score at both 6 and 12 months after THA (satisfaction, r=− 0.266, − 0.213; pain, r=− 0.332, − 0.203, mental, r=− 0.427, − 0.370). The function score was weakly correlated with the CSI score only 6 months after THA (function, r=− 0.231, − 0.190).Conclusion: A higher level of preoperative pain at rest, a CS-related symptom, may affect postoperative pain persistence and dissatisfaction in patients with hip OA.Keywords: central sensitization, pain at rest, postoperative pain, hip osteoarthritis, total hip arthroplasty

Background Intervertebral disc (IVD) degeneration is a major cause of low back pain (LBP). Following disc injury, nerve growth factor (NGF) concentrations rise in IVDs, and anti-NGF therapy has been shown to attenuate LBP in humans. Increased levels of tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) in degenerative IVDs and in in vitro studies suggest that these factors promote NGF production. However, whether these factors regulate NGF in vivo remains unclear. Thus, we studied NGF regulation in a mouse model of IVD injury. Methods After inducing IVD injury, we examined mRNA levels of Tnfa, Tgfb, and Ngf in IVDs from control and IVD-injured mice across 7 days. To do this, we used magnetic cell separation to isolate CD11b ( +) (macrophage-rich) and CD11b (-) (IVD cell-rich) cell fractions from injured IVDs. To study the effect of TNF-α on Ngf expression, we examined Ngf expression in injured IVDs from C57BL/6 J and Tnfa-knockout (KO) mice (C57BL/6 J background). To study the effect of TGF-β on Ngf expression, C57/BL6J mice were given an intraperitoneal injection of either the TGF-β inhibitor SB431542 or DMSO solution (vehicle) one and two days before harvesting IVDs. Results mRNA expression of Tnfa, Tgfb, and Ngf was significantly increased in injured IVDs. Tnfa was predominantly expressed in the CD11b ( +) fraction, and Tgfb in the CD11b (-) fraction. Ngf expression was comparable between CD11b ( +) and CD11b (-) fractions, and between wild-type and Tnfa-KO mice at post-injury day (PID) 1, 3, and 7. SB431542 suppressed TGF-β-mediated Ngf expression and NGF production in vitro. Further, administration of SB431542 significantly reduced Ngf expression in IVDs such that levels were below those observed in vehicle-treated animals at PID3 and PID7. Conclusion A TGF-β inhibitor reduced Ngf expression in a mouse model of IVD injury, suggesting that TGF-β may regulate NGF expression in vivo.

Osteoarthritis (OA) is a chronic degenerative musculoskeletal disease that causes articular cartilage degeneration and chronic pain. Research into OA animal models suggests that elevated NGF levels in the synovium contribute to pain and central sensitization (CS). However, it is unclear whether synovial NGF contributes to CS in patients with OA. We investigated the association between synovial NGF expression and clinical assessments of pain and CS in hip OA (hOA) patients. We also aimed to identify which cells in the synovium of hOA patients express NGF. Sixty-six patients who received total hip replacement and a diagnosis of hOA were enrolled. We measured NGF mRNA expression in synovial samples obtained from 50 patients using qPCR and analyzed the correlation of NGF expression with the CS inventory (CSI) score and Japanese Orthopaedic Association (JOA) score, a clinical scoring system for OA. To identify the synovial cells expressing NGF, we analyzed NGF mRNA expression in CD14+ and CD14- cells, which represent macrophage-rich and fibroblast-rich fractions, respectively, extracted from 8 patients. To further identify which macrophage subtypes express NGF, we examined NGF mRNA expression in CD14high and CD14low cells sorted from 8 patients. Synovial NGF mRNA expression was negatively correlated with JOA score but positively correlated with CSI score (JOA pain, r = − 0.337 , P = 0.017 ; CSI score, r = 0.358 , P = 0.011 ). Significantly greater levels of NGF were observed in CD14- cells compared to CD14+ cells ( P = 0.036 ) and in CD14high cells compared to CD14low cells ( P = 0.008 ). In conclusion, synovial NGF expression is correlated with the degree of pain and CS in hOA patients. NGF is predominantly expressed in synovial fibroblasts. Further, CD14high synovial macrophages expressed higher levels of NGF. Our results may provide a novel NGF-targeted therapeutic strategy for hOA pain.

Background Labral tear can be the initiating factor in the onset of hip osteoarthritis (HOA). However, the physiopathology of labral tear is not fully understood. Our aim was to compare synovial tissue inflammatory cytokine levels between patients with labral tear and late-stage HOA. Methods Synovial tissue from sites showing the greatest inflammation was harvested from 106 hips from 100 subjects during hip surgery. RNA was extracted, and levels of TNFA, IL1B, IL6 and COX2 mRNA were compared among all patients using real-time PCR. Additionally, we examined whether femoroacetabular impingement (FAI) was associated with elevated levels of inflammatory cytokines in patients with labral tear. To analyze the effects of TNF-α on inflammatory mediators in hip synovial tissue, synovial fibroblasts were extracted from hip synovial tissue of patients with labral tear and late-stage HOA (n = 5 each). Mononuclear cells were extracted from synovial tissue, cultured for 7 days, and stimulated with control or 10 ng/mL human recombinant TNF-α for 1 day. mRNA was extracted from stimulated cells and IL1B, IL6, and COX2 levels were determined using real-time PCR. Results TNFA, IL1B, and COX2 expression in synovial tissue were significantly higher in patients with labral tear than late-stage HOA (TNFA, p IL1B, p COX2, p = 0.001). There were no differences in expression between patients with labral tear with and without FAI (TNFA, p = 0.546; IL1B, p = 0.559; IL6, p = 0.599; COX2, p = 0.124). Compared to vehicle control, TNF-α stimulation significantly elevated IL1B, IL6, and COX2 expression in synovial fibroblasts collected from patients with labral tear and late-stage HOA (IL1B, p = 0.043 and p = 0.043; IL6, p = 0.043 and 0.043; COX2, p = 0.043 and p = 0.080, respectively). Conclusions TNFA, IL1B, and COX2 expression were elevated in the synovial tissue of patients with labral tear. Further investigations are needed to reveal the relationship between inflammatory cytokine levels and various aspects of labral tear pathology, including pain and the onset and progression of OA.

Introduction: Intra-articular lidocaine injections have been used to confirm the hip pathology and may predict the efficacy of arthroscopic surgery. We have routinely performed the injections as a surgical indicator. The aim of this study was to assess the duration and effectiveness of these diagnostic intra-articular lidocaine injections on groin pain in patients with labral tears involving early osteoarthritis. Methods: A total of 113 patients were included in this study. All patients received one injection of 10 ml of 1% lidocaine into the hip joint under fluoroscopy. The duration and effectiveness of the injection were assessed 2 weeks after the injection and at a minimum of 1 year of follow-up. The effect of the injection was graded as 0: unchanged or worse; 1: an effect only on the day of injection; 2: the effect lasted a few days; 3: the effect lasted about a week; and 4: symptom remission. In addition, we recorded whether hip arthroscopic surgery was eventually performed. Results: The effect was rated as 0 in 19 patients (16.8%), as 1 in 30 patients (26.5%), as 2 in 38 patients (33.6%), as 3 in 13 patients (11.5%), and as 4 in 13 patients (11.5%). Seventy-two patients (63.7%) underwent hip arthroscopic surgery. No relationship with patients’ characteristics was found. Conclusion: In total, 83% of patients experienced some effect of the lidocaine injection. Furthermore, 11.5% of patients experienced complete remission of their symptoms.

Background There are many reports of Achilles tendon lengthening procedures for equinus deformity of the ankle. We previously modified an Achilles tendon lengthening to prevent overextension with a locking mechanism suture before performing a sliding lengthening. The purpose of this study was to compare the biomechanical properties of the locking mechanism suture with sliding lengthening (L-SL) and Z-lengthening (ZL) using a rabbit model. Methods Thirty-six male Japanese white rabbits were assigned to two groups - half undergoing the L-SL technique and half undergoing the ZL technique on the flexor hallucis longus (FHL) tendon. Six rabbits in each group were sacrificed at one week, three weeks, and six weeks postoperatively and evaluated, while five rabbits underwent radiographical and biomechanical evaluation and one underwent histological evaluation. Results In extension length, L-SL was significantly lower than ZL one week postoperatively. In the L-SL group, elongation one week postoperatively was significantly lower than that three and six weeks postoperatively. In the ultimate failure load, L-SL was significantly higher than ZL one and three weeks after lengthening. In the L-SL group, the ultimate failure load one week postoperatively was significantly lower than that three and six weeks postoperatively. In the ZL group, there were significant differences at all time points. Conclusion L-SL had higher mechanical property in vivo.

Introduction The coronavirus disease 2019 (COVID-19) epidemic beginning December 2019 in China has now become a worldwide pandemic. With the need to develop an approach to manage orthopaedic surgeries, we aimed to evaluate the most current data on all the surgical cases in our department including the results of the reverse-transcriptase polymerase chain reaction (RT-PCR) assay for infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods The monthly number of surgical cases from 2016 were reviewed, and compared the numbers of surgical cases both in elective and emergency surgery during the pandemic with the pre-pandemic period. The results of RT-PCR for SARS-CoV-2 in 94 orthopaedic surgery cases from May 13 to June 30, 2020, and clinical signs/symptoms, and laboratory data of 48 consecutive cases within a month from May 13 were also evaluated. Results The mean monthly number of surgeries from January to May 2020 was significantly lower than the mean number in 2019 (73.8 vs 121.9, respectively, p=0.01). The proportion of emergency surgeries in all surgeries performed in May 2020 was 35.5%, which is significantly more than the mean rate of 20.4% in 2019 (p=0.04). Hip arthroplasties and spine surgeries showed the greatest reduction, at greater than 80% and 65%, respectively. Although none of the 94 patients were positive for SARS-CoV-2, 66.7% showed signs/symptoms typical of COVID-19. The most frequent signs/symptoms were production of nasal mucus (25.5%), followed by dry cough (19.1%); and fatigue, headache, and dizziness (17.0% each). The incidence of abnormal values, which are commonly noted in COVID-19 patients, were eosinopaenia 37.5%; lymphopaenia 18.8%; thrombocytopaenia 8.3%; and elevated prothrombin time 10.4%. Conclusions Our results show that our RT-PCR negative patients showed signs/symptoms and abnormal laboratory values typical of COVID-19, indicating surgeons should be aware of these abnormalities in patients and the need to rule out COVID-19 before proceeding with surgery.