Is the increase in the number of total hip arthroplasties in Japan due to an aging society?

BACKGROUND: The number of total hip arthroplasty (THA) is increasing globally, including Japan. The Japanese Orthopaedic Association has been conducting a registry of joint replacement surgery, but there may be a gap between the reported numbers of THA in the registry and the actual number. This study aimed to investigate the exact number of THA and assess the trends in Japan using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB). METHODS: We downloaded data from 2014 to 2019 from the NDB Open Data. Data on primary THA were extracted, and we calculated the annual number and number for each 10-year age group and sex. We also compared the number and trends between elderly and non-elderly groups. RESULTS: During the study period, number of THAs increased by approximately 20,000, showing a continuous upward trend. The highest number of THAs were performed on patients in their 60s, except for the years 2014 and 2019. Comparison of the numbers in 2014 and 2019 by age group showed an increase in the number in patients in their 90s (by 2.05 times). There were significantly a greater number of elderly patients (P < 0.001). The number of THAs performed was higher in women than in men (P < 0.001). CONCLUSION: The number of THAs in Japan increased substantially from 2014 to 2019, despite a decrease in population. Significantly higher number of THAs were performed on elderly patients in Japan, which might be due to an aging society. The NDB data is highly valuable for epidemiological research in Japan, as it might enable the early detection of issues occurring during THA, facilitating their prompt integration into daily clinical practice.

Influence of broach surface design of a fully hydroxyapatite coated, double tapered stem on periprosthetic bone mineral density after total hip arthroplasty: a study based on the morphology of the proximal femur.

INTRODUCTION: This study aimed to compare the impact of different broach surface designs on post-operative clinical outcomes, bone reactions and changes in bone mineral density (BMD) in patients who underwent total hip arthroplasty (THA) using a fully hydroxyapatite coated and double tapered stem with either compaction shape (COM) or hybrid shape (HYB) broaches. MATERIALS AND METHODS: A retrospective analysis was conducted on 76 patients (100 hips) who underwent primary THA using the Avenir complete stem®. Patients were divided into two groups: the COM broach group (50 hips) and HYB broach group (50 hips). We evaluated clinical outcomes using the Japanese Orthopaedic Association hip scores one month before the surgery, and 12 and 24 months after the surgery. Radiographic findings, including stem alignment angles, radiolucent lines, spot welds, and cortical hypertrophy, were assessed. BMD around the stem in Gruen zones 1-7 was evaluated using dual-energy X-ray absorptiometry (DEXA) at 7 days, 12, and 24 months post-operatively. The Dorr classification was used to assess femoral morphology. RESULTS: There were no significant differences in clinical outcomes, radiographic findings, or BMD changes between the COM and HYB broach groups in the overall patient cohort. However, in Dorr type A femurs, the COM broach group demonstrated superior BMD superior preservation in zones 1 and 7 after 12 months and in zones 1, 6 and 7 after 24 months. Additionally, in Dorr type B femurs, significant BMD preservation was observed in zone 3 at 24 months in the COM broach group. CONCLUSIONS: This study suggests that the broach surface design of fully hydroxyapatite coated stems may influence periprosthetic BMD changes, especially in Dorr type A and B femurs. Surgeons should consider broach selection based on patient-specific femoral morphology to optimize BMD preservation in THA procedures using fully hydroxyapatite coated stems.

The necessity of suction drainage when intra-articular injection of tranexamic acid is used during primary total knee arthroplasty: a retrospective study.

BACKGROUND: Suction drainages are commonly used after total knee arthroplasty (TKA) procedures; however, their use is somewhat controversial. Recently, some reports have claimed that the administration of tranexamic acid (TXA) may prevent postoperative bleeding following TKAs. Although numerous studies have reported regarding different dosages, timings of administration, or drain clamping times for intravenous and intra-articular TXA injections (IA-TXAs), few have examined whether suction drainage is necessary when TXA is administered. In this study, we compared using suction drainage without TXA administration and IA-TXA without suction drainage and aimed to examine the need for suction drainage during IA-TXA. METHODS: This retrospective study was conducted on 217 patients who had received TKA for osteoarthritis; 104 were placed on suction drainage after TKA without TXA (Group A), whereas the remaining 113 received IA-TXA immediately after surgery without suction drainage (Group B). Our clinical evaluation included assessments of the need for transfusion, presence of postoperative complications, incidence of deep vein thrombosis (DVT), and changes in hemoglobin (Hb), hematocrit (Hct), and D-dimer levels. RESULTS: No significant differences were observed in terms of postoperative complications and preoperative Hb, Hct, or D-dimer levels between the two groups. Although the prevalence of DVT was significantly higher in Group B (p < 0.05), all cases were asymptomatic. Hb and Hct levels were significantly lower in Group A than in Group B at 1, 3, 7, and 14 days postoperatively (p < 0.05), although none of the cases required blood transfusions. D-dimer levels were significantly higher in Group A than in Group B at 1 and 3 days postoperatively (p < 0.05). CONCLUSION: Suction drainage might not be necessary when IA-TXA is administered after TKA procedures.

Fibrocyte Phenotype of ENTPD1+CD55+ Cells and Its Association with Pain in Osteoarthritic Synovium.

Osteoarthritis (OA) is a prevalent degenerative joint disorder characterized by cartilage erosion, structural changes, and inflammation. Synovial fibroblasts play a crucial role in OA pathophysiology, with abnormal fibroblastic cells contributing significantly to joint pathology. Fibrocytes, expressing markers of both hematopoietic and stromal cells, are implicated in inflammation and fibrosis, yet their marker and role in OA remain unclear. ENTPD1, an ectonucleotidase involved in purinergic signaling and expressed in specific fibroblasts in fibrotic conditions, led us to speculate that ENTPD1 plays a role in OA pathology by being expressed in fibrocytes. This study aimed to investigate the phenotype of ENTPD1+CD55+ and ENTPD1-CD55+ synovial fibroblasts in OA patients. Proteomic analysis revealed a distinct molecular profile in ENTPD1+CD55+ cells, including the upregulation of fibrocyte markers and extracellular matrix-related proteins. Pathway analysis suggested shared mechanisms between OA and rheumatoid arthritis. Correlation analysis revealed an association between ENTPD1+CD55+ fibrocytes and resting pain in OA. These findings highlight the potential involvement of ENTPD1 in OA pain and suggest avenues for targeted therapeutic strategies. Further research is needed to elucidate the underlying molecular mechanisms and validate potential therapeutic targets.

Trends in hip preservation surgery in Japan from 2014 to 2019 with a focus on hip arthroscopic surgery.

Secondary hip osteoarthritis due to hip dysplasia is common among Japanese populations. This study aimed to investigate the number of hip preservation surgeries performed in Japan and assess trends, by age and sex, from 2014 to 2019, focusing on hip arthroscopic surgery, based on the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB). We downloaded the files 'Number of calculations by division, sex, and age group' under 'operation (code K)' from 2014 to 2019 from the NDB Open Data Japan database. Data on hip preservation surgeries were extracted, including the number for each surgical procedure and its incidence per year, calculated as the number of surgeries performed for each 10-year age group and by sex, regarding hip arthroscopic surgery. Overall, 14 891 hip preservation surgeries were performed in Japan over the study period, with pelvic osteotomy being the most common procedure. Although the incidence of hip preservation surgeries decreased from 2014 to 2019, there was a specific 1.54-fold higher incidence in hip arthroscopic procedures in 2019 compared to 2014. Hip arthroscopic labral repair was performed more frequently than synovectomy. The highest incidence of hip arthroscopic surgery was in the 40- to 49-years age group, with no difference in incidence between sexes (P = 0.951). In Japan, pelvic osteotomy was performed more often as a hip preservation surgery than hip arthroscopic surgery. Although hip arthroscopic surgery was developed in Japan, its use has not increased from 2017 to 2019.

In Vivo Kinematic Analysis of the Axial Shoulder Rotation in the Standing and Supine Positions Using 3D/2D Registration and Electromyography.

Background There has been no report comparing shoulder kinematics and muscle activities during axial shoulder rotation in different positions. The purpose of this study was to investigate differences in shoulder kinematics and muscle activities during axial shoulder rotation in healthy subjects between standing and supine positions using three-dimensional/two-dimensional (3D/2D) registration techniques and electromyography (EMG). Methods Eleven healthy males agreed to participate in this study. We recorded the fluoroscopy time during active shoulder axial rotation with a 90° elbow flexion in both standing and supine positions, simultaneously recording surface EMG of the infraspinatus, anterior deltoid, posterior deltoid, and biceps brachii. Three-dimensional bone models were created from CT images, and shoulder kinematics were analyzed using 3D/2D registration techniques. Muscle activities were evaluated as a ratio of mean electromyographic values to 5-sec maximum voluntary isometric contractions.  Results Scapular kinematics during axial shoulder rotation in the supine position showed similar patterns with those in the standing position. The scapula was more posteriorly tilted and more downwardly rotated in the supine posture than in standing (P < 0.001 for both). Acromiohumeral distance (AHD) in the supine posture was significantly larger than in standing. Muscle activities showed no significant differences between postures except for biceps (P < 0.001). Discussion Shoulder kinematics and muscle activities during axial rotation were similar in pattern between standing and supine postures, but there were shifts in scapular pose and AHD. The findings of this study suggest that posture may be an important consideration for the prescription of optimal shoulder therapy following surgery or for the treatment of shoulder disorders.

Management of Antithrombotic Drugs before Elective Spine Surgery: A Nationwide Web-Based Questionnaire Survey in Japan.

Introduction: The number of patients on antithrombotic drugs for coronary heart disease or cerebrovascular disease has been increasing with the aging of society. We occasionally need to decide whether to continue or discontinue antithrombotic drugs before spine surgery. The purpose of this study is to understand the current perioperative management of antithrombotic drugs before elective spine surgery in Japan. Methods: In 2021, members of the Japanese Society for Spine Surgery and Related Research (JSSR) were asked to complete a web-based questionnaire survey that included items concerning the respondents' surgical experience, their policy regarding discontinuation or continuation of antithrombotic drugs, their reasons for decisions concerning the management of antithrombotic drugs, and their experience of perioperative complications related to the continuation or discontinuation of these drugs. Results: A total of 1,181 spine surgeons returned completed questionnaires, giving a response rate of 32.0%. JSSR board-certified spine surgeons comprised 75.1% of the respondents. Depending on the management policy regarding antithrombotic drugs for each comorbidity, approximately 73% of respondents discontinued these drugs before elective spine surgery, and about 80% also discontinued anticoagulants. Only 4%-5% of respondents reported continuing antiplatelet drugs, and 2.5% reported continuing anticoagulants. Among the respondents who discontinued antiplatelet drugs, 20.4% reported having encountered cerebral infarction and 3.7% reported encountering myocardial infarction; among those who discontinued anticoagulants, 13.6% reported encountering cerebral embolism and 5.4% reported encountering pulmonary embolism. However, among the respondents who continued antiplatelet drugs and those who continued anticoagulants, 26.3% and 27.2%, respectively, encountered an unexpected increase in intraoperative bleeding, and 10.3% and 8.7%, respectively, encountered postoperative spinal epidural hematoma requiring emergency surgery. Conclusions: Our findings indicate that, in principle, >70% of JSSR members discontinue antithrombotic drugs before elective spine surgery. However, those with a discontinuation policy have encountered thrombotic complications, while those with a continuation policy have encountered hemorrhagic complications.

Expression of Apelin in Rotator Cuff Tears and Examination of Its Regulatory Mechanism: A Translational Study.

OBJECTIVES: Inflammatory mediators play important roles in the pain associated with rotator cuff tears (RCTs), but their underlying mechanisms are unclear. Apelin, a neuropeptide, is upregulated under inflammatory conditions and possibly contributes to pain induced by rotator cuff tears. This translational study aimed to examine apelin expression and regulation by tumor necrosis factor alpha (TNF-α) in patients with RCT and in rat RCT models. METHODS: Synovial tissues were harvested from the glenohumeral joints of the shoulders in 46 patients who underwent arthroscopic Bankart repair for recurrent shoulder dislocations (RSDs) or arthroscopic rotator cuff repair for RCTs. The harvested tissues were extracted and processed by reverse transcriptase-polymerase chain reaction (RT-PCR). Rats underwent sham or RCT surgery; the rotator cuff tissues were extracted 1, 7, 14, 28, and 56 days after surgery and analyzed for mRNA expression levels of the TNF-α and apelin using RT-PCR. The cultured rotator cuff cells (RCCs) were stimulated with TNF-α to examine their role in the regulation of apelin expression. RESULTS: Apelin expression was higher in the RCT group than in the RSD group and significantly correlated with pain intensity. In rats, the expression was also higher in RCT. Apelin expression significantly increased during the acute and chronic phases in rats. CONCLUSIONS: In cultured RCCs, apelin mRNA levels significantly increased after TNF-α stimulation. Apelin levels were regulated by TNF-α and were highly expressed in patients with RCT and rats in RCT models. Thus, apelin may be a new pain management target for RCTs.

Medermycin Inhibits TNFα-Promoted Inflammatory Reaction in Human Synovial Fibroblasts.

Synovial inflammation plays a crucial role in the destruction of joints and the experience of pain in osteoarthritis (OA). Emerging evidence suggests that certain antibiotic agents and their derivatives possess anti-inflammatory properties. Medermycin (MED) has been identified as a potent antibiotic, specifically active against Gram-positive bacteria. In this study, we aimed to investigate the impact of MED on TNFα-induced inflammatory reactions in a synovial cell line, SW-982, as well as primary human synovial fibroblasts (HSF) using RNA sequencing, rtRT-PCR, ELISA, and western blotting. Through the analysis of differentially expressed genes (DEGs), we identified a total of 1478 significantly upregulated genes in SW-982 cells stimulated with TNFα compared to the vehicle control. Among these upregulated genes, MED treatment led to a reduction in 1167 genes, including those encoding proinflammatory cytokines such as IL1B, IL6, and IL8. Pathway analysis revealed the enrichment of DEGs in the TNF and NFκB signaling pathway, further supporting the involvement of MED in modulating inflammatory responses. Subsequent experiments demonstrated that MED inhibited the expression of IL6 and IL8 at both the mRNA and protein levels in both SW982 cells and HSF. Additionally, MED treatment resulted in a reduction in p65 phosphorylation in both cell types, indicating its inhibitory effect on NFκB activation. Interestingly, MED also inhibited Akt phosphorylation in SW982 cells, but not in HSF. Overall, our findings suggest that MED suppresses TNFα-mediated inflammatory cytokine production and p65 phosphorylation. These results highlight the potential therapeutic value of MED in managing inflammatory conditions in OA. Further investigations utilizing articular chondrocytes and animal models of OA may provide valuable insights into the therapeutic potential of MED for this disease.

Efficacy and Safety of Beta-Tricalcium Phosphate/Polylactic-Co-Glycolic Acid for Implantation of Bone Defects.

INTRODUCTION: Bone defects are often observed after surgery for fractures and bone tumors. Their treatment is technically difficult and sometimes results in negative clinical and economic outcomes. To repair bone defects, a bone graft is implanted by selecting a transplant material from an autologous or artificial bone. Each method has its advantages and disadvantages. Compared to the gold standard of autologous bone graft, bone graft substitutes are not limited by the amount of harvested graft and avoid complications at the donor site. ORB-03 is a new cotton-like bone graft substitute composed of beta-tricalcium phosphate (ß-TCP) and a bioabsorbable polymer, polylactic-co-glycolic acid (PLGA). ORB-03 is easy to mold and can fill various bone defect shapes, and its three-dimensional microfiber scaffold can enhance the differentiation of osteoblasts and promote osteogenesis. We investigated the efficacy, ease of handling, and safety of ORB-03 as a bone graft substitute. A multicenter, open-label, single-group study was conducted at six institutions. METHODS: Between July 2018 and August 2019, 60 patients with bone defects caused by fracture, benign tumors, or an iliac donor site from bone harvesting were enrolled in this study; 54 patients were finally included for the safety analysis and 48 patients for the image analysis. During surgery, ORB-03 was mixed with the patient's blood and molded into a bone defect. To evaluate the efficacy of ORB-03, radiography and computed tomography (CT) were performed at intervals until 24 weeks after surgery. RESULTS: The effective rate and its accurate bilateral 95% confidence interval (CI) were calculated based on the efficacy criteria at 24 weeks postoperatively. The ease with which ORB-03 could be handled in surgery was evaluated. Adverse events that occurred after surgery were evaluated, and those associated with ORB-03 were examined. Bone fusion was good in all cases, and the radiography and CT effective rates were 100.0% and 91.5%, respectively. Handling was easy in all cases. There were four adverse events, none of which were clinically problematic. CONCLUSIONS: ORB-03 was found to be easy to handle, safe, and effective as a bone graft substitute for bone defects.

In situ-formed hyaluronan gel/BMP-2/hydroxyapatite composite promotes bone union in refractory fracture model mice.

BACKGROUND: A combination of synthetic porous materials and BMP-2 has been used to promote fracture healing. For bone healing to be successful, it is important to use growth factor delivery systems that enable continuous release of BMP-2 at the fracture site. We previously reported that in situ-formed gels (IFGs) consisting of hyaluronan (HyA)-tyramine (TA), horseradish peroxidase and hydrogen peroxide enhance the bone formation ability of hydroxyapatite (Hap)/BMP-2 composites in a posterior lumbar fusion model. OBJECTIVE: We examined the effectiveness of IFGs-HyA/Hap/BMP-2 composites for facilitating osteogenesis in refractory fracture model mice. METHODS: After establishing the refractory fracture model, animals were either treated at the site of fracture with Hap harboring BMP-2 (Hap/BMP-2) or IFGs-HyA with Hap harboring BMP-2 (IFGs-HyA/Hap/BMP-2) (n = 10 each). Animals that underwent the fracture surgery but did not receive any treatment were considered the control group (n = 10). We determined the extent of bone formation at the fracture site according to findings on micro-computed tomography and histological studies four weeks following treatment. RESULTS: Animals treated with IFGs-HyA/Hap/BMP-2 demonstrated significantly greater bone volume, bone mineral content and bone union than those treated with vehicle or IFG-HyA/Hap alone. CONCLUSIONS: IFGs-HyA/Hap/BMP-2 could be an effective treatment option for refractory fractures.

Posterior Spinal Fusion Surgery for Neuromuscular Disease Patients with Severe Scoliosis Whose Cobb Angle Was over 100 Degrees.

Background and objectives: Patients with neuromuscular diseases usually have progressive neuromuscular scoliosis (NMS), requiring invasive surgery. Some patients present with severe scoliosis at the time of consultation and are difficult to treat. Posterior spinal fusion (PSF) surgery combined with anterior release and pre- or intraoperative traction would be effective for severe spinal deformities but would be invasive. This study aimed to evaluate the outcomes of PSF-only surgery for patients with severe NMS with a Cobb angle > 100°. Materials and Methods: Thirty NMS patients (13 boys and 17 girls; mean age 13.8 years) who underwent PSF-only surgery for scoliosis with a Cobb angle > 100° were included. We reviewed the lower instrumented vertebra (LIV), duration of surgery, blood loss, perioperative complications, preoperative clinical findings, and radiographic findings, including Cobb angle and pelvic obliquity (PO) in the sitting position pre- and postoperatively. The correction rate and correction loss of the Cobb angle and PO were also calculated. Results: The mean duration of surgery was 338 min, intraoperative blood loss was 1440 mL, preoperative %VC was 34.1%, FEV1.0 (%) was 91.5%, and EF was 66.1%. There were eight cases of perioperative complications. The Cobb angle and PO correction rates were 48.5% and 42.0%, respectively. We divided the patients into two groups: the L5 group, in which the LIV was L5, and the pelvis group, in which the LIV was the pelvis. The duration of surgery and PO correction rate in the pelvis group were significantly higher than those in the L5 group. Conclusions: Patients with severe NMS demonstrated severe preoperative restrictive ventilatory impairments. PSF surgery without anterior release or any intra-/preoperative traction showed satisfactory outcomes, including acceptable scoliosis correction and improved clinical findings, even in patients with extremely severe NMS. Instrumentation and fusion to the pelvis for severe scoliosis in patients with NMS showed good PO correction and low correction loss of Cobb angle and PO, but a longer duration of surgery.

Intraoperative Blood Loss at Different Surgical-Procedure Stages during Posterior Spinal Fusion for Idiopathic Scoliosis.

Background and Objectives: Several predictive factors have been reportedly associated with intraoperative total blood loss (TBL) during posterior spinal fusion (PSF) for idiopathic scoliosis (IS). To reduce TBL, preoperative factors and interoperative factors are considered important. However, there are few reports that have evaluated bleeding patterns according to surgical stages. This study aimed to elucidate bleeding patterns at different surgical stages and determine the predictive factors for TBL during PSF surgery in patients with IS. Materials and Methods: Preoperative data, radiographic parameters, and intraoperative data of patients undergoing PSF for IS were retrospectively collected. We divided the patients into six stages: stage 1, exposure; stage 2, implant placement; stage 3, release; stage 4, correction; stage 5, bone grafting; and stage 6, closure; then we reviewed the blood loss and bleeding speed. Multiple-regression analysis was performed to generate a predictive formula for blood loss using preoperative and intraoperative factors, including blood loss at stage 1, as explanatory variables. Results: Forty-five patients (mean age: 17.6 years) were included. The mean operative time and TBL were 287.9 min and 756.5 mL, respectively. Blood loss was the highest at stage 3, followed by stage 4. Bleeding speed was the highest at stage 4, followed by stage 3. Bleeding speeds at stages 3 and 4 were significantly higher than those at stages 1 and 2. Preoperative Cobb angle, activated partial thromboplastin time (aPTT), number of fused vertebrae, and blood loss at stage 1 were significant contributing factors. Conclusions: Blood loss and bleeding speed during the release and correction stages were high. Specifically, bleeding speed significantly increased during and after the release procedure. The preoperative Cobb angle, aPTT, number of fixed vertebrae, and blood-loss volume during PSF were significantly associated with TBL. Our findings would be helpful for reducing TBL in patients undergoing PSF for IS.

Residual Neuropathic Pain in Postoperative Patients With Cervical Ossification of Posterior Longitudinal Ligament.

STUDY DESIGN: A prospective multi-institutional observational study. OBJECTIVE: To investigate and identify risk factors for residual neuropathic pain after surgery in patients with cervical ossification of posterior longitudinal ligament (c-OPLL). SUMMARY OF BACKGROUND DATA: Patients with c-OPLL often require surgery for numbness and paralysis of the extremities; however, postoperative neuropathic pain can considerably deteriorate their quality of life. METHODS: Out of 479 patients identified from multicenter c-OPLL registries between 2014 and 2017, 292 patients who could be followed up for 2 years postoperatively were reviewed, after excluding patients with nervous system comorbidities. Demographic details; medical history; radiographic factors including the K-line, spinal canal occupancy rate of OPLL, cervical kyphosis angle, and presence of spinal cord myelomalacia; preoperative Japanese Orthopaedic Association (JOA) score; surgical procedure (fusion or decompression surgery); postoperative neurological deterioration; and the visual analogue scale for pain and numbness in the upper extremities (U/E) or trunk/lower extremities (L/E) at baseline and at 2 years postoperatively were assessed. Patients were grouped into residual and non-residual groups based on a postoperative visual analogue scale ≥40 mm. Risk factors for residual neuropathic pain were evaluated by multiple logistic regression analysis. RESULTS: The prevalence of U/E and L/E residual pain in postoperative c-OPLL patients was 51.7% and 40.4%, respectively. The U/E residual group had a poor preoperative JOA score and longer illness duration, and fusion surgery was more common in the residual group than in non-residual group. The L/E residual group was older with a poorer preoperative JOA score. On multivariate analysis, risk factors for U/E residual pain were long illness duration and poor preoperative JOA score, whereas those for L/E residual pain were age and poor preoperative JOA score. CONCLUSIONS: The risk factors for residual spinal neuropathic pain after c-OPLL surgery were age, long duration of illness, and poor preoperative JOA score. LEVEL OF EVIDENCE: IV.

Effect of spheroid size on gene expression profiles of a mouse mesenchymal stem cell line in spheroid culture.

BACKGROUND: Mesenchymal stem cell (MSC)-based therapies offer potential for bone repair. MSC spheroid cultures may harbor enhanced therapeutic potential over MSC monolayers through increased secretion of trophic factors. However, the impact of spheroid size on trophic factor expression is unclear. OBJECTIVE: We investigated the effect of spheroid size on trophic factor-related gene expression. METHODS: KUM10, a murine MSC line was used. RNA-seq was used to screen the transcriptional profiles of MSC monolayer and spheroid cultures. Differentially expressed genes identified in RNA-seq were evaluated by q-PCR in cultures of 5 × 104 (S group), 5 × 105 (M group), 5 × 106 (L group) cells/well. RESULTS: Comparison of expression levels between KUM10 monolayer and spheroid cultures identified 2140 differentially expressed genes, of which 1047 were upregulated and 1093 were downregulated in KUM10 spheroids. Among these, 12 upregulated genes (Bmp2, Fgf9, Fgf18, Ngf, Pdgfa, Pdgfb, Tgfb1, Vegfa, Vegfc, Wnt4, Wnt5a, Wnt10a) were associated with secretory growth factors. Of these, expression of Fgf9, Fgf18, Vegfa and Vegfc was elevated in the L group, and Pdgfb and Tgfb1 was elevated in the S group. CONCLUSIONS: Spheroid size may impact trophic factor expression. Our results will be useful for future studies assessing the utility of MSC spheroids for treating bone injury.

Trunk flexibility using a sit-and-reach test after surgery for adolescent idiopathic scoliosis.

PURPOSE: Spinal fusion reduces flexibility, but we do not have detailed knowledge that accounts for growth or sex differences. We sought to determine trunk flexibility pre- and postoperatively in patients with adolescent idiopathic scoliosis (AIS). METHODS: We included data from 109 patients with AIS in this retrospective, single-center observational study. Patients had performed a sit-and-reach (SR) test preoperatively, and 1 and 2 years postoperatively, and measurements were standardized to Z scores according to age and sex. The patient data were divided into three groups according to the level of lower instrumented vertebra (LIV): (1) Group A (fusion above L2); (2) Group B (fusion to L2), and (3) Group C (fusion to L3 or L4). The change in the Z score for various levels was determined and compared. RESULTS: The preoperative Z score for all patients was -0.622. At 2 years postoperatively, the Z score in Groups A and B was not significantly different from the preoperative score; in Group C, the Z score decreased by 1 year postoperatively, improved during the second year, but remained significantly lower than the preoperative score. Our study was the first to assess trunk flexibility using the SR test in patients with scoliosis. CONCLUSIONS: Preoperatively, patients with AIS had lower SR test Z-scores than the general population, indicating a lower trunk flexibility in these patients. At 2 years after surgery in these patients, trunk flexibility had returned to preoperative levels when LIV was at L2 or above, but when LIV was at L3 or L4, trunk flexibility was less than it was preoperatively. LEVEL OF EVIDENCE: Prognostic Level II: retrospective study.

Mild inflammation persists in the glenohumeral joint of patients with shoulder instability: Cross-sectional study.

Objective: Approximately two-thirds of patients with history of shoulder dislocation may develop osteoarthritis (OA) of the glenohumeral joint. However, the biochemical mechanisms underlying the association between dislocation and OA are largely unknown. This study aimed to investigate macrophage markers and inflammatory cytokine expression associated with shoulder instability (SI) in comparison to rotator cuff tears (RCTs). Design: This study included 30 patients with SI and 30 patients with RCTs. Synovial membrane samples were harvested from the rotator interval during the arthroscopic anatomical repair for both groups. The localization of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, and cluster of differentiation (CD) 68 in synovial membranes was determined by immunohistochemistry. Transcript-level expressions of the inflammatory cytokines (TNFA and IL1B) and macrophage markers pan-CD68 and -M1 (CD80 and CD86) were quantified. CD80 and CD86 expression in macrophages from the SI group was confirmed using flow cytometry. Results: TNF-α, IL-1ß, and CD68 were expressed in the synovial lining layer of the synovial tissue in both groups. In addition, the mRNA expressions of TNFA, IL1B, CD68, and CD80 were significantly higher in the SI group compared to the RCT group (P â€‹= â€‹0.012, 0.014, 0.022, 0.003, respectively). In samples from the SI group, 96.3% of CD68+/CD14+ macrophages were CD86-positive, whereas 2.5% of CD68+/CD14+/CD86+ cells were CD80-positive. Conclusions: Patients with SI had higher mRNA levels of TNFA, IL1B, CD68, and CD80 than those with RCTs. These findings may partially explain the biochemical mechanism underlying the frequent development and progression of osteoarthritis in patients with SI.

Is bone marrow oedema in patients with labral tear an indicator of hip pain?

BACKGROUND: Hip labral tear (LT) causes various degrees of hip pain, for which there are few objective measures. Bone marrow oedema (BME), characterized by a diffuse, widely spreading change in the bone marrow, is observed in some patients with LT. However, its pathological role has not been fully understood. The purpose of this study was to investigate the prevalence of BME on hip magnetic resonance imaging (MRI) in patients with LT and to determine whether BME was an objective indicator of hip pain. METHODS: In total, 84 patients with LT who underwent MRI scanning under the same conditions were included. We determined the presence or absence of BME and its size on MRI and evaluated the relationships between BME and sex, age, and pain and total scores on the modified Harris hip score (MHHS). In addition, we collected data on surgical treatments such as hip arthroscopy within a one-year follow-up period and examined whether the presence of BME affected the course of therapy. RESULTS: BME was found in 34.5% of patients. MHHS pain and total scores were significantly lower in patients with BME (MHHS pain score: non-BME vs. BME ≤ 1 cm: p = 0.022, non-BME vs. BME > 1 cm: p < 0.001; MHHS total score: non-BME vs. BME ≤ 1 cm: p = 0.131, non-BME vs. BME > 1 cm: p = 0.027). The presence of BME did not differ between patients who did and did not undergo surgery during follow-up (p = 0.563). CONCLUSION: BME on MRI in patients with LT might be an indicator of hip pain and hip joint dysfunction.

Differences in outcomes after total hip arthroplasty for osteoarthritis between patients with and without central sensitivity syndromes other than fibromyalgia.

We investigated the differences in outcomes after total hip arthroplasty (THA) for hip osteoarthritis (HOA) between patients with and without central sensitivity syndromes (CSSs) other than fibromyalgia (FM). After excluding two patients with FM, we compared the clinical data of 41 patients with CSSs and 132 patients without CSSs. Clinical data included scores on the central sensitization inventory, visual analog scale for pain (VAS pain), and Japanese Orthopedic Association Hip Disease Evaluation Questionnaire (JHEQ). VAS pain was significantly higher at 3 and 6 months after THA in patients with CSSs than in those without CSSs (3 and 6 months, P < 0.001). Satisfaction, pain, and mental JHEQ scores were lower in patients with CSSs than in those without CSSs (satisfaction, P < 0.001; pain, P = 0.011; mental, P = 0.032). Multiple regression analyses indicated that one and ≥ 2 CSS diagnoses significantly impacted the satisfaction score (one CSS, ß = - 0.181, P = 0.019; ≥ 2 CSSs, ß = - 0.175, P = 0.023). Two or more CSSs were the only factor influencing the pain score (ß = - 0.175, P = 0.027). Pain in patients with CSSs reflects central sensitization, which may adversely affect post-operative outcomes. Surgeons should pay attention to patients with a history of CSSs diagnoses who undergo THA for HOA.