Difference in the anterior displacement of the tibial tuberosity relative to the proximal tibial fragment between opening wedge and closed wedge high tibial osteotomies.

INTRODUCTION: This study aimed to investigate the anterior-posterior (AP) displacement of the tibial tuberosity (TT) and to assess the difference between closed wedge and opening wedge high tibial osteotomies (OWHTO and CWHTO). METHODS: One hundred consecutive knees with osteoarthritis that underwent OWHTO (50 knees) or CWHTO (50 knees) were investigated retrospectively. The femorotibial angle (FTA) was measured on AP radiographs of the knee. AP displacement of the TT, posterior tibial slope (PTS), the modified Blackburne-Peel index (mBPI), and the modified Caton-Deschamps index (mCDI) were measured on lateral radiographs of the knee. RESULTS: Patients had a mean correction angle of 12.58 ± 2.84° and 18.98 ± 5.14° (P < 0.001), with a mean AP displacement of TT of 0.84 ± 2.66 mm and 7.78 ± 3.41 mm (P < 0.001) in OWHTO and CWHTO, respectively. The AP displacement of the TT per correction of 1° was significantly greater in CWHTO than in OWHTO (P < 0.001). A significant correlation was found between the correction angle and AP displacement of the TT in CWHTO (r = -0.523, P < 0.001), but not in OWHTO. The change of PTS per correction of 1° was significantly greater in OWHTO than in CWHTO (P < 0.001). The changes of mBPI and mCDI per correction of 1° were significantly greater in CWHTO than in OWHTO (P < 0.001 and P < 0.001, respectively). CONCLUSIONS: There was greater anterior displacement of the TT in CWHTO than in OWHTO, which was correlated with the correction angle. The results suggested that CWHTO would be better than OWHTO when a concomitant anteriorization of TT is required.

Comparison of the indications for high tibial osteotomy and double-level osteotomy for the correction of diverse lower-leg deformities in an Asian population with medial compartment osteoarthritis: a retrospective observational study.

PURPOSE: Double-level osteotomy (DLO) for knee osteoarthritis is becoming increasingly popular to achieve superior anatomical correction. This study aimed to compare the indication for open-wedge high tibial osteotomy (OWHTO) and DLO and to investigate preoperative bone morphology. METHODS: Data of 166 knees treated with osteotomy were evaluated. The weight-bearing line ratio, mechanical lateral distal femoral angle (mLDFA), and mechanical medial proximal tibial angle (mMPTA) were measured. Bone deformity assessment and osteotomy simulation were conducted. Normal values of mLDFA and mMPTA were defined as 85-90°. Bone deformity was classified into four patterns: femoral, tibial, both, and no deformity. Simulation was performed to achieve a postoperative weight-bearing line ratio of 62%. Distal femoral osteotomy (DFO) or OWHTO was performed to achieve an mLDFA of 85° or mMPTA of up to 95°. If the postoperative parameter remained outside the correctable limit, DLO was performed. Cases were classified according to the corrective surgery performed, and those that could not be corrected after DLO were classified into the uncorrectable group. RESULTS: Femoral, tibial, both, and no deformities were observed in 14.2%, 37.8%, 10.7%, and 33.9% of cases, respectively. No cases were classified into the DFO group; however, 53.6%, 38.1%, and 8.3% were classified into the OWHTO, DLO, and uncorrectable groups, respectively. CONCLUSION: Bone deformity differed among cases, and only one-third had tibial deformity. OWHTO and DLO were indicated in approximately 50% and 40% of cases, respectively. Our study results reinforce the importance of evaluating leg morphology before surgical planning to achieve acceptable alignment.

Evaluation of the Postoperative Risk of Deep Tissue Injury to the Lower Extremities Following Surgery in the Lithotomy Position.

Background The aim of this study was to determine the incidence of deep tissue injury (DTI) and potential risk factors after surgery in the lithotomy position. Methods All patients who underwent surgery in the lithotomy position under general anesthesia at a single center between January 2017 and December 2021 were retrospectively evaluated. The medical records of these patients were reviewed, and patient demographic and clinical characteristics, surgical data, and occurrence of DTI were recorded. Results During the study period, 5146 patients, 2055 (39.9%) males and 3091 (60.1%) females, with a mean age of 57.3 ± 17.4 years, underwent surgery in the lithotomy position. Seven (0.14%) patients developed DTI on their calf following surgery. All presented with severe pain and swelling, requiring prolonged hospital stay. Multivariate analysis showed that male sex (odds ratio (OR): 11.43; 95% confidence interval (CI): 1.15-113.34, p = 0.037), higher BMI (OR: 1.32; 95% CI: 1.17-1.50, p = 0.0001), and longer operation time (OR: 1.01; 95% CI: 1.004-1.014, p = 0.0002) were independent risk factors for postoperative DTI. Optimal cut-off values for BMI and operation time were 23.5 kg/m2 (sensitivity = 100%; specificity = 64%) and 285 minutes (sensitivity = 100%; specificity = 90%), respectively. Conclusion Factors significantly associated with DTI include male sex, higher BMI, and prolonged operation time.

Bead-beating assay during synovial fluid DNA extraction improves real-time PCR accuracy for periprosthetic joint infection.

Polymerase chain reaction (PCR)-based genetic diagnosis is a rapid and sensitive method to diagnose periprosthetic joint infection (PJI). DNA extraction using bead beating is an effective method for collecting bacterial genes in Gram-positive bacteria. We compared the detection accuracy between the conventional and bead-beating DNA extraction assay. The detection rate improved from 86.7% using the conventional method to 95.6% using the bead-beating. Our results suggest that bead-beating during DNA extraction can improve the accuracy of PCR-based genetic diagnosis of PJI.

Hybrid Closed Wedge High Tibial Osteotomy Maintains the Leg Length After Surgery Compared With Open Wedge High Tibial Osteotomy.

BACKGROUND: This study aimed to assess the changes in leg length following open wedge high tibial osteotomy (OWHTO) and hybrid closed wedge high tibial osteotomy (h-CWHTO) and whether the change in leg length was associated with preoperative radiographic factors and the change in planned opening or closing width. METHODS: We retrospectively evaluated the data of patients who underwent OWHTO (n=57) and h-CWHTO (n=31) between 2016 and 2019. Standing full-length anteroposterior radiographs were obtained preoperatively and one year postoperatively. Changes in the lower leg and tibial length were measured using radiography, and the planned opening or closing width was decided via operative planning. Flexion contracture was examined preoperatively and one year postoperatively using a goniometer, and the correlation factors and changes in leg length were analyzed using Spearman's rank correlation. RESULTS: In the OWHTO group, the lower leg was significantly longer by a mean of 6.0±8.7 mm compared to that preoperatively (p<0.01); however, no significant difference was observed in the h-CWHTO group (mean, -0.56±11.6 mm) (p=0.788). In the OWHTO group, flexion contracture did not improve after surgery, however, in the h-CWHTO group, flexion contracture significantly improved from -7.1±7.0 degrees to -4.7±6.2 degrees postoperatively (p<0.01). No radiographic factors or bone opening or closing width were associated with changes in leg length in both groups. CONCLUSION: OWHTO led to a significant elongation of the lower leg while leg length was maintained post-h-CWHTO. However, the changes in leg length following both OWHTO and h-CWHTO were not predictable from preoperative radiographic factors or changes in bone width.

Preoperative prediction for periprosthetic bone loss and individual evaluation of bisphosphonate effect after total hip arthroplasty using artificial intelligence.

Aims: This study was designed to develop a model for predicting bone mineral density (BMD) loss of the femur after total hip arthroplasty (THA) using artificial intelligence (AI), and to identify factors that influence the prediction. Additionally, we virtually examined the efficacy of administration of bisphosphonate for cases with severe BMD loss based on the predictive model. Methods: The study included 538 joints that underwent primary THA. The patients were divided into groups using unsupervised time series clustering for five-year BMD loss of Gruen zone 7 postoperatively, and a machine-learning model to predict the BMD loss was developed. Additionally, the predictor for BMD loss was extracted using SHapley Additive exPlanations (SHAP). The patient-specific efficacy of bisphosphonate, which is the most important categorical predictor for BMD loss, was examined by calculating the change in predictive probability when hypothetically switching between the inclusion and exclusion of bisphosphonate. Results: Time series clustering allowed us to divide the patients into two groups, and the predictive factors were identified including patient- and operation-related factors. The area under the receiver operating characteristic (ROC) curve (AUC) for the BMD loss prediction averaged 0.734. Virtual administration of bisphosphonate showed on average 14% efficacy in preventing BMD loss of zone 7. Additionally, stem types and preoperative triglyceride (TG), creatinine (Cr), estimated glomerular filtration rate (eGFR), and creatine kinase (CK) showed significant association with the estimated patient-specific efficacy of bisphosphonate. Conclusion: Periprosthetic BMD loss after THA is predictable based on patient- and operation-related factors, and optimal prescription of bisphosphonate based on the prediction may prevent BMD loss.

Increased Wnt5a/ROR2 signaling is associated with chondrogenesis in meniscal degeneration.

The aim of the present study was to investigate the association between chondrogenic differentiation and Wnt signal expression in the degenerative process of the human meniscus. Menisci were obtained from patients with and without knee osteoarthritis (OA), and degeneration was histologically assessed using a grading system. Immunohistochemistry, real-time polymerase chain reaction (PCR), and Western blot analysis were performed to examine the expressions of chondrogenic markers and of the components of Wnt signaling. Histological analyses showed that meniscal degeneration involved a transition from a fibroblastic to a chondrogenic phenotype with the upregulation of SOX9, collagen type II, collagen type XI, and aggrecan, which were associated with increased Wnt5a and ROR2 and decreased TCF7 expressions. OA menisci showed significantly higher expressions of Wnt5a and ROR2 and significantly lower expressions of AXIN2 and TCF7 than non-OA menisci on real-time PCR and Western blot analysis. These results potentially demonstrated that increased expression of Wnt5a/ROR2 signaling promoted chondrogenesis with decreased expression in downstream Wnt/ß-catenin signaling. This study provides insights into the role of Wnt signaling in the process of meniscal degeneration, shifting to a chondrogenic phenotype. The findings suggested that the increased expression of Wnt5a/ROR2 and decreased expression of the downstream target of Wnt/ß-catenin signaling are associated with chondrogenesis in meniscal degeneration.

Differences in Diagnostic Sensitivity of Cultures Between Sample Types in Periprosthetic Joint Infections: A Systematic Review and Meta-Analysis.

BACKGROUND: Differences between the bacterial culture results of the preoperative fluid, intraoperative tissue, and sonication fluid of implants in the diagnosis of periprosthetic joint infection (PJI) are important issues in clinical practice. This study aimed to identify the differences in pooled diagnostic accuracy between culture sample types for diagnosing PJI by performing a systematic review and meta-analysis. METHODS: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. A comprehensive literature search of PubMed, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library databases was performed. Data extraction and study assessment using the quality assessment of diagnostic accuracy studies were performed independently by two reviewers. The pooled sensitivity, specificity, summary receiver operating characteristic curve, and area under the summary receiver operating characteristic curve were estimated for each sample type. RESULTS: There were thirty-two studies that were included in the analysis after screening and eligibility assessment. The pooled sensitivities of preoperative fluid, intraoperative tissue, and sonication fluid for the diagnosis of PJI were 0.63 (95% confidence interval [CI] 0.56 to 0.70), 0.71 (95% CI 0.63 to 0.79), and 0.78 (95% CI 0.68 to 0.85), while the specificities were 0.96 (95% CI 0.93 to 0.98), 0.92 (95% CI 0.86 to 0.96), and 0.91 (95% CI 0.83 to 0.95), respectively. The area under the curves for preoperative fluid, intraoperative tissue, and sonication fluid were 0.86, 0.88, and 0.90, respectively. CONCLUSIONS: Sonication fluid culture demonstrated better sensitivity compared with the conventional culture method, and preoperative fluid culture provided lower sensitivity in diagnosing PJI.

Physical Therapy May Not Be Successful for Patients With Cam-Type Femoroacetabular Impingement Syndrome and May Result in Insufficient Hip Range of Motion When Femoral Anteversion Is Less Than 16° and α-Angle Is Greater Than 65°.

PURPOSE: To identify factors associated with insufficient range of motion (ROM) improvement after the posterior pelvic tilt change in cam-type femoroacetabular impingement syndrome. METHODS: Preoperative computed tomography images from 71 consecutive patients with femoroacetabular impingement syndrome treated with arthroscopic cam resection were evaluated. Using a dynamic computer simulation program, 3-dimensional models with a 10° posterior pelvic tilt from the supine functional pelvic plane (baseline) were created by computed tomography models. Patients were divided into 2 groups: those who experienced >10° (effective group) and ≤10° (ineffective group) improvements in internal rotation at 90° flexion after a 10° posterior pelvic tilt. Demographic characteristics; preoperative range of internal rotation at 90° flexion; and radiographic parameters, including Tönnis grade, lateral center-edge angle, acetabular roof obliquity angle, central acetabular anteversion, cranial acetabular anteversion, femoral anteversion, and α angle, were compared in the 2 groups. Univariate and multivariable logistic regression analyses were performed to evaluate factors associated with insufficient ROM improvement following a 10° posterior pelvic tilt. RESULTS: The 71 patients included 58 men and 13 women, of mean age 41.4 ± 14.6 years. Posterior pelvic tilt was effective in 13 hips and ineffective in 58. Univariate analysis showed that preoperative range of internal rotation at 90°flexion, femoral anteversion, and α angle differed significantly in the 2 groups. Multivariable analysis showed that femoral anteversion <16° (odds ratio 7.4; 95% confidence interval 1.6-35; P = .012) and α angle >65° (odds ratio 6.7; 95% confidence interval 1.2-37; P = .027) were significant factors associated with insufficient ROM improvement after posterior pelvic tilt. CONCLUSIONS: Physical therapy may not be successful for patients with cam-type femoroacetabular impingement syndrome and may result in insufficient hip ROM when femoral anteversion is less than 16° and α-angle is greater than 65°. CLINICAL RELEVANCE: Patients with a prominent cam-type deformity and lower anterior femoral anteversion are at high risk of clinical failure following improvement in pelvic mobility by conservative treatment alone and are likely to benefit from surgery for cam deformity.

Prior hip arthroscopy increases the risk of dislocation, reoperation, and revision after hip arthroplasty: An updated meta-analysis and systematic review.

BACKGROUND: The indications for hip arthroscopy have been increasing, as have been the number of patients undergoing total hip arthroplasty (THA) after hip arthroscopy. Several matched cohort studies have assessed the impact of prior hip arthroscopy on THA, but conflicting results have been observed. The purpose of this study was to evaluate the influence of prior arthroscopy on subsequent THA. METHODS: This systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 checklist. PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Library were searched to identify relevant studies. Dichotomous variables were summarized qualitatively as a meta-analysis of pooled odds ratios (ORs) and 95% confidence intervals (CIs), and continuous variables were summarized as standardized mean differences and 95% CIs. P-values <0.05 were considered statistically significant. The risk of bias was evaluated for each study, as was publication bias. RESULTS: In patients who underwent hip arthroscopy prior to THA, the ORs for dislocation, reoperation, and revision were 2.02 (P = 0.01), 1.66 (P = 0.01), and 2.15 (P = 0.001), respectively. There were no significant between-group differences in the Harris Hip Score (HHS; P = 0.40), WOMAC (P = 0.069), FJS-12 (P = 0.77), estimated blood loss (P = 0.48), and surgical time (P = 0.16). CONCLUSIONS: Prior hip arthroscopy is a risk for postoperative dislocation, reoperation, or revision after conversion THA. However, prior hip arthroscopy has no effect on patient-reported outcomes, or operative factors such as surgical time and blood loss.

Shelf acetabuloplasty may inhibit range of motion: A computer simulation analysis.

Shelf acetabuloplasty has been performed in patients with developmental dysplasia of the hip (DDH); however, the appropriate position of the shelf has not been determined, particularly with respect to avoiding range of motion (ROM) loss. The aim of this study was to investigate the frequency of ROM inhibition and the influence of 3D position of the shelf following actual shelf acetabuloplasty and virtual surgery using computer simulation analysis. Computed tomography data from 15 patients with DDH who underwent shelf acetabuloplasty were collected between August 2019 and February 2022. The three-dimensional models of a hip joint were constructed using Zed Hip®. Maximal internal rotation (MIR) at 45° and 90° flexion was measured in each patient. The frequency and position of ROM inhibition was determined in a real postoperative model virtually. In addition, a second analysis using virtual acetabuloplasty was performed. Upon placing the shelf, three patterns were provided for the following four parameters: height, coronal inclination, center-edge angle (CEA), and anteroposterior position. The predictors for ROM inhibition were analyzed using a logistic regression model. In the actual postoperative model, a limitation of MIR at 90° and 45° of flexion occurred in 60% and 66.7% of patients, respectively. A higher CEA and anterior position are major factors limiting MIR. The analysis of the virtual shelf acetabuloplasty model revealed that anterior position and CEA were significant factors causing ROM inhibition. As for clinical significance, the results of the current study indicated the optimal location of the shelf to avoid iatrogenic impingement after shelf acetabuloplasty.

Long-term Experience on Breast Cancer-related Lymphedema in the Coastal Area of Fukushima, Japan After the 2011 Triple Disaster.

BACKGROUND/AIM: Disasters can jeopardize breast cancer care and Japan's triple disaster in 2011 (earthquake, tsunami, and nuclear accident) is no exception. However, detailed information is lacking regarding the care of breast cancer related lymphedema (BCRL) following the disaster. We aimed to explore the process by which local patients become aware of BCRL, the problems faced, and the support they require. We also aimed to clarify the effects of the 2011 disaster on experiences related to lymphedema in the target population. PATIENTS AND METHODS: Patients who developed BCRL after breast cancer treatment were recruited from Iwaki city, a municipality located in the southern coastal region of Fukushima (N=16). In-depth, semi-structured, face-to-face interviews were conducted, and the obtained data were appraised using thematic analysis. RESULTS: Five themes related to BCRL were identified: 1) the process of becoming aware of BCRL, 2) troubles or worries/concerns due to BCRL, 3) information sources regarding BCRL management, 4) strategies to cope with BCRL, and 5) the adverse impacts of the 2011 disaster on BCRL management. CONCLUSION: Except for the disaster context, the themes are in line with those of previous studies conducted in the non-disaster context. Nonetheless, there were limited but non-negligible adverse effects of the 2011 disaster on long-term local BCRL management. The findings of this study demonstrate the necessity for individualizing coping strategies against BCRL among healthcare professionals in the Fukushima coastal area and beyond.

Accuracy of Albumin, Globulin, and Albumin-Globulin Ratio for Diagnosing Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis.

Periprosthetic joint infection (PJI) is one of the most intractable orthopedic diseases, partly because of the difficulty in differentiating septic from aseptic conditions. We aimed to evaluate and consolidate the diagnostic accuracy of the quantitative assessment of serum albumin (Alb), globulin (Glb), and albumin-globulin ratio (AGR), alone or in combination with the inflammatory marker, C-reactive protein (CRP), for PJI. We searched the PubMed, CINAHL, and Cochrane Library databases for studies that quantitatively measured Alb, Glb, or AGR for the diagnosis of PJI up until the 30 April 2023. A total of 2339 patients were included from 10 studies, including 845 patients with a definitive diagnosis of PJI and 1494 with non-PJI. The pooled sensitivity, specificity, and area under the curve (AUC) in the summary receiver-operating characteristic curve were as follows: 0.625, 0.732, and 0.715 for Alb; 0.815, 0.857, and 0.887 for Glb; 0.753, 0.757, and 0.875 for AGR; 0.788, 0.837, and 0.876 for CRP; 0.879, 0.890, and 0.917 for the CRP-Alb ratio; and 0.845, 0.855, and 0.908 for the CRP-AGR ratio. Serum Alb, Glb, and AGR levels are feasible and accurate diagnostic markers for PJI, and the combination of these markers with CRP levels may potentially improve preoperative serum diagnostic accuracy. Future prospective studies are required to verify these findings because of the small numbers of included studies.

A Comparison of the Minimum Inhibitory Concentration of Antibiotics in Staphylococcus Species Isolated From Orthopedic and Respiratory Medicine Infections.

INTRODUCTION: Antibiotic susceptibility is very important for the successful treatment of orthopedic infections, particularly for implant-related infections. While the minimum inhibitory concentrations (MICs) of Staphylococcus species were well investigated for the isolates from the respiratory tract, investigations for orthopedic pathogens are very limited. We investigated the antibiotic MIC values of Staphylococcus species isolated from orthopedic infections and compared them with those of respiratory medicine isolates used as a control. METHODS: The MICs of vancomycin (VCM), arbekacin (ABK), teicoplanin (TEIC), linezolid (LZD), and rifampicin (RFP) of a total of consecutive 259 (89 orthopedic and 170 respiratory) Staphylococcus speciesisolated in our laboratory from January 2013 to July 2016 were retrospectively reviewed. Differences between the MICs of each antibiotic in orthopedic and respiratory samples were determined. RESULTS: The number of methicillin-sensitive Staphylococcus aureus (MSSA) with a VCM MIC of <0.5 µg/mL among respiratory isolates was significantly higher than that among orthopedic isolates, while those with a MIC of 2 µg/mL were significantly lower (P = 0.0078). The proportion of methicillin-resistant coagulase-negative staphylococci (MRCNS) isolates with a VCM MIC of 2 µg/mL was significantly higher in orthopedic samples than that of methicillin-resistant Staphylococcus aureus (MRSA) (P < 0.001) in respiratory isolates. The proportion of MRCNS orthopedic isolates with an RFP MIC of >2 µg/mL was significantly higher (P = 0.0058) than that of other orthopedic staphylococci. CONCLUSIONS: The VCM MICs of Staphylococcus species from orthopedic infections were higher than those of respiratory samples, particularly MRCNS from implant-related samples.

Predictors of conversion surgery after conservative treatment for pyogenic spondylitis.

BACKGROUND: Patient demographic and clinical characteristics may be factors associated with the success of conservative treatment for pyogenic spondylitis. The ability of imaging findings at initial diagnosis to predict patient outcomes remains unclear. The aim of this study was to investigate the risk factors associated with conversion surgery after conservative treatment for pyogenic spondylitis, with a special focus on the initial computed tomography (CT) findings. METHODS: This study enrolled 35 patients with pyogenic spondylitis who underwent CT and magnetic resonance imaging (MRI) at diagnosis and were followed-up for more than 6 months. Patients were diagnosed by MRI, and the degree of bone destruction was assessed on CT cross-sectional images. Vertebral body destruction was classified as grades 0 (almost normal), 1 (endplate irregularity), 2 (vertebral body destruction not involving the posterior wall), and 3 (destruction involving the posterior wall). Patients were divided into four groups based on grade of bone destruction and their clinical characteristics were compared. RESULTS: 1, 11, 11, and 12 patients were classified as grades 0, 1, 2, and 3, respectively. Univariate analysis showed no significant differences in the demographic and clinical characteristics of the four groups. Eighteen (51.4 %) patients had been treated surgically, with the rate of surgical treatment being significantly higher in patients with grade 3 (83.3 %) than in those with grades 0 + 1 (25 %) and grade 2 (45.5 %) (P < 0.05). Multivariate analysis showed that epidural abscess on MRI (odds ratio [OR] 10.8, 95 % confidence interval [CI] 1.68-69.7), grade 3 bone destruction on CT (OR 3.97, 95 % CI 1.21-13.0), and C-reactive protein (CRP) improvement rate after 1 week of treatment (OR 0.95, 95 % CI 0.91-0.99) were risk factors for surgery. CONCLUSIONS: Early surgical treatment should be considered for patients with pyogenic spondylitis who present with an epidural abscess on MRI and bone destruction extending to the posterior wall on CT at the time of diagnosis.

Novel Local Antifungal Treatment for Fungal Periprosthetic Joint Infection With Continuous Local Antibiotic Perfusion: A Surgical Technique.

Fungal periprosthetic joint infections are one of the most intractable orthopedic disorders. Continuous local antibiotic perfusion allows direct administration of the antifungal agent micafungin into the local infection area at biofilm-disruptive concentrations, while controlling the dead space in addition to conventional treatment. Although the appropriate use of continuous local antibiotic perfusion requires familiarity with the characteristics of local antibiotic perfusion, it is a versatile treatment modality that can improve the clinical outcomes of fungal periprosthetic joint infection in combination with conventional treatment methods.

Bevacizumab promotes tenogenic differentiation and maturation of rat tendon-derived cells in vitro.

Previous work suggested that tenogenic differentiation of tendon stem/progenitor cells (TSPCs) was suppressed by upregulated expression of the angiogenic marker vascular endothelial growth factor (VEGF). The purpose of this study was to test the hypothesis that anti-VEGF antibody, bevacizumab, promotes in vitro tenogenic differentiation and maturation of two distinct types of TSPCs, tendon proper-derived cells (TDCs), and paratenon-derived cells (PDCs) originating from rat Achilles tendon. TDCs and PDCs were isolated from the tendon proper and the paratenon of rat Achilles tendons. TDCs and PDCs were cultured for 3 days on plates with or without VEGF. TDCs and PDCs were also cultured in collagen gel matrix, and the blocking effect of VEGF was examined by the addition of 100 ng/mL of bevacizumab. Effects of bevacizumab on tenogenic differentiation were assessed using real-time PCR, immunofluorescent staining, and western blotting. VEGF significantly attenuated expression of the Tnmd gene in both PDCs and TDCs (P<0.05). Expressions of the Scx, Tnmd, and Col1a1 genes were significantly upregulated by the addition of bevacizumab (P<0.05). Immunofluorescent staining showed that the percentage of tenomodulin-positive PDCs and TDCs was significantly higher with bevacizumab treatment than in control cultures (P<0.05). Western blotting showed that bevacizumab suppressed pVEGFR-2 protein expression in both PDCs and TDCs. Bevacizumab promoted the in vitro tenogenic differentiation and maturation of two distinct TSPCs derived from rat Achilles tendon. Since the previous studies demonstrated that TSPCs have a potential to contribute to tendon repair, attenuating VEGF levels in TSPCs by administration of bevacizumab is a novel candidate therapeutic option for promoting tendon repair.

The influence of COVID-19 epidemic on the number of orthopaedic surgeries in Japan.

BACKGROUND: There is limited data on the impact of COVID-19 epidemic on the number of orthopaedic surgeries in Japan. METHODS: We conducted a nationwide hospital survey asking for the monthly number of orthopaedic surgeries performed at each facility from January 2019 to June 2021. Those facilities that had performed at least 100 surgeries in 2019 were included for analyses. The facilities were further grouped by prefecture and by hospital characteristics. A brief health economic evaluation was also performed. Risk ratios were compared using univariate analyses with P < 0.05 considered statistically significant. RESULTS: Questionnaire was sent to 1988 hospitals with 1671 hospitals (84%) responding. The survey data indicated a total number of orthopaedic surgeries decreased in 2020 compared to 2019 (1,061,541 vs 1,119,955 P < 0.01), and also for the first six months of 2021 compared to the same period in 2019 (530,388 vs 550,378 P < 0.01). In 2020, over 50% of all facilities in nearly all of the prefectures saw a decline in surgical procedures. The risk of incurring more than a 25% decease in the number of surgeries was significantly higher in 2020 for class I designated medical institutions compared to those that were not designated for any types of infectious diseases among the institutions with a tertiary emergency medical center in 2020 (crude risk ratio 2.9: 95% CI 1.2-7.4, p = 0.02) and in 2021 (crude risk ratio 4.7: 95% CI 1 0.9-12.1, p < 0.01). The estimated total nationwide decrease of revenue were in the range of approximately ¥29.2 to ¥116.8 billion per year for orthopaedic surgeries alone. CONCLUSION: There was a statistically significant decrease in the number of orthopaedic surgeries in Japan. The magnitude of the decline varied by prefectures and hospital characteristics, with the greater impact imposed on medical institutions with higher classification functions. The estimated immediate health economic impact was sizable.