Internal rotational patellar resection and patella alta induced patellar maltracking in total knee arthroplasty: intraoperative measurement of the patellofemoral pressure.

BACKGROUND: Anterior knee pain due to patellar maltracking following total knee arthroplasty (TKA) reduces patients' satisfaction. This study aimed to determine the patellofemoral pressure (PFP) in patients with favorable patellar tracking (FT) and impaired patellar tracking (IT) following TKA, the factors causing patellar maltracking, and the effect of lateral retinacular release (LRR) on patients with IT. METHODS: Forty-four patients with varus knee osteoarthritis undergoing cruciate-retaining TKA were enrolled. After component implantation, patients with a separation of ≥ 2 mm of the patellar medial facet from the medial femoral trochlea throughout knee range of motion were classified into the IT group; meanwhile, the others were classified into the FT group. PFP was measured intraoperatively in three phases: (1) with the resurfaced patella (RP); (2) with the resurfaced patella and knee (RPK); and (3) when LRR was performed in IT (post-LRR). The PFPs at 0°, 90°, 120°, and 135° knee flexion were compared between FT and IT using the Mann-Whitney U test. Pairwise comparison of the PFP in IT between RPK and post-LRR was performed using the Wilcoxon signed-rank test. Correlations between PFP and pre- and postoperative radiographic parameters, such as hip-knee-ankle angle, lateral distal femoral angle, medial proximal tibial angle, anterior femoral offset, Insall-Salvati ratio (ISR), patellar tilt, and patellar resection angle (PRA), were evaluated using Spearman's rank correlation coefficients. RESULTS: High lateral PFP in the knee flexion position led to patellar maltracking. Patients with IT (n = 24) had higher lateral and lower medial PFP than did patients with FT (n = 20) at 90°, 120°, and 135° knee flexion in RP and RPK. LRR in IT reduced the lateral PFP in the knee flexion position. PRA and ISR were correlated with the lateral PFP at no less than 90° in RP and RPK. CONCLUSIONS: This study demonstrated that internal rotational patellar resection, which resulted in a thick medial patellar remnant and a thin lateral counterpart, and patella alta were the causative factors of high lateral PFP, which induced patellar maltracking after TKA. Surgeons should avoid internal rotational patellar resection to achieve FT and perform LRR in patients with patellar maltracking.

Difficulty in Early Diagnosis of Bilateral Posterior Fracture-dislocation of the Shoulder Caused by an Electric Shock in a Walk-in Patient: A Case Report.

Introduction: Bilateral posterior fracture-dislocation of the shoulder is a very rare injury that is commonly missed. Almost 70% of bilateral posterior dislocations are due to convulsive seizures, with electric shocks accounting for < 5% of bilateral posterior shoulder dislocations. Case Report: The case of a walk-in patient, a 52-year-old man, with bilateral posterior fracture-dislocation of the shoulder caused by an electric shock is reported. Although he was initially admitted to the emergency department for observation of the potential complications of an electric shock, such as fatal arrhythmia and rhabdomyolysis, he subsequently consulted an orthopedic surgeon 4 days after the event due to persistent bilateral shoulder pain and was diagnosed using X-ray and computed tomography with bilateral posterior fracture-dislocation of the shoulder. Following open reduction and internal fixation 7 days after the injury, the upper limbs were fixed with shoulder braces at a slightly flexed and abducted position with neutral rotation for 3 weeks postoperatively followed by range of motion exercises. Twelve months after surgery, he had a Constant shoulder score of 94, an American Shoulder and Elbow Surgeon score of 100, and no shoulder re-dislocation or humeral head necrosis. Conclusion: In this walk-in patient, the diagnosis of bilateral posterior fracture-dislocation of the shoulder caused by an electric shock was delayed. We believe that understanding the mechanism of this type of injury will facilitate its early diagnosis.

The ICHI-FIXATOR® system, a novel wire-connected external fixator, demonstrates efficacy in managing intra-articular fractures involving the proximal phalanx of the big toe.

Proximal phalanx fractures of the big toe involving angulation or dislocation of the articular surface require repositioning and fixation. We treated a patient with such a fracture using a novel wire-connected external fixator, the ICHI-FIXATOR® system. A 45-year-old male sustained an injury when slipping down the stairs and impacting his left big toe. Plain radiography and computed tomography revealed a proximal phalangeal fracture of the left big toe with dislocation of the articular surface and comminution. The surgical intervention was performed using 1.1-mm diameter C-wires and an external fixator. The patient regained ambulation and resumed work immediately after surgery. Four weeks postoperatively, all wires were removed on an outpatient basis. Eight months postoperatively, the patient experienced no pain during strenuous activities or exercises. This novel wire-connected external fixator provides reliable and secure fixation, facilitating a prompt return to normal daily activities. This technique may be an effective option for managing toe fractures.

Reverse Posterior Interosseous Artery Flap for Human Bite Injury to the Hand.

Bite injuries frequently occur on human hands. Human bite injuries to the hand may lead to an infection because of limited soft tissue protection and wound contamination. However, no studies have reported severe bite injuries on hands treated by flaps. We report a case of an 80-year-old woman diagnosed with a major neurocognitive disorder. The patient accidentally had a self-bite injury accompanied with an open metacarpal fracture. Debridement and fixation of the first metacarpal fracture were performed. Afterward, skin necrosis occurred gradually on the dorsum of the hand. Therefore, a reverse posterior interosseous artery (PIA) flap was used, and the postoperative course was uneventful. Given the high risk of infection, human bite injuries, particularly hand bites, should be treated immediately. Delayed treatment for such injuries may lead to extensive soft tissue defects requiring reconstruction with flaps.

A Lateral Fracture Line Affects Femoral Trochanteric Fracture Instability and Swing Motion of the Intramedullary Nail: A Biomechanical Study.

Background: An unstable trochanteric femoral fracture is a serious injury, with a 1-year mortality rate of 5.4% to 24.9%, for which there is currently no standard treatment method. The lag screw insertion site is one of the primary contact areas between the cortical bone and an intramedullary nail. We hypothesized that a posterolateral fracture causes intramedullary nail instability when the posterolateral fracture line interferes with lag screw insertion. The purpose of the present study was to investigate the effect of posterolateral fracture line morphology on intramedullary nail stability by simulating unstable trochanteric femoral fractures with a posterolateral fracture fragment. Methods: Eighteen custom-made synthetic osteoporotic bone samples were used in the present study. Nine samples had a posterolateral fracture line interfering with the lag screw insertion hole (Fracture A), and the other 9 had a fracture line 10 mm away from the hole (Fracture B). Cyclic loading (750 N) was applied to the femoral head 1,500 times. Movement of the end cap attached to the intramedullary nail was recorded. The amplitudes of motion in the coronal plane (coronal swing motion), sagittal plane (sagittal swing motion), and axial plane (total swing motion) were evaluated. The change in the neck-shaft angle was evaluated on photographs that were made before and after the test. Medial cortical displacement was measured before and after the test. Results: Two Fracture-A samples were excluded because the amplitude of sagittal swing motion was too large. The mean values for coronal, sagittal, and total swing motion were 1.13 ± 0.28 mm and 0.51 ± 0.09 mm (p < 0.001), 0.50 ± 0.12 mm and 0.46 ± 0.09 mm (p = 0.46), and 1.24 ± 0.24 mm and 0.69 ± 0.11 mm (p < 0.001) for Fractures A and B, respectively. The mean neck-shaft angle change was -8.29° ± 2.69° and -3.56° ± 2.35° for Fractures A and B, respectively (p = 0.002). The mean displacement of the medial cortex was 0.38 ± 1.12 mm and 0.12 ± 0.37 mm for Fractures A and B, respectively (p = 0.57). Conclusions: This study showed that an unstable trochanteric femoral fracture with a posterolateral fracture line that interferes with the lag screw insertion holes is a risk factor for increased intramedullary nail instability.

Differences in prevalence of self-reported oral hypofunction between older adult patients with rheumatoid arthritis and the general older population: A cross-sectional study using propensity score matching.

OBJECTIVE: To examine the association between rheumatoid arthritis (RA) and oral hypofunction (OHF) using propensity score matching (PSM) to adjust for differences between older adults with RA and the general older adult population. METHODS: We conducted a cross-sectional survey among 189 older adults with RA in 2019 (mean age, 71.9 ± 3.6) and 47 178 independent older adult residents in 2016 (mean age, 71.6 ± 4.0), respectively. The questionnaire covered information on socio-demographic characteristics and OHF for both groups. Age, sex, educational level and smoking history were used to determine PSM. Prevalence ratios (PRs) and 95% confidence intervals (CIs) of self-reported OHF (fewer remaining teeth, decreased masticatory function, deterioration of swallowing function and oral dryness) were estimated using Poisson regressions. RESULT: OHF was observed in 44.4% of patients with RA and 27.5% of residents. Before PSM, the prevalence of OHF among patients with RA was higher than that of residents (PR, 1.75; 95% CI, 1.50-2.05). After PSM, there were 189 patients with RA and residents, and the prevalence of OHF among patients with RA was still higher (PR, 1.61; 95% CI, 1.22-2.13). Poisson regression showed that the prevalence of 19 or fewer teeth (PR, 1.06; 95% CI, 0.82-1.36), difficulties eating tough foods (PR, 1.18; 95% CI, 0.90-1.55), difficulties swallowing tea or soup (PR, 1.77; 95% CI, 1.19-2.63), and dry mouth (PR, 2.79; 95% CI, 1.90-4.07) was higher among patients with RA than residents. CONCLUSION: Compared with the general older adult population, patients with RA have a higher prevalence of self-reported OHF.

Transforming Growth Factor-ß Induces Interleukin-6 Secretion from Human Ligamentum Flavum-Derived Cells through Partial Activation of p38 and p44/42 Mitogen-Activated Protein Kinases.

STUDY DESIGN: This experimental study was performed using human ligamentum flavum-derived cells (HFCs). PURPOSE: To investigate the intracellular signaling mechanism of interleukin-6 (IL-6) secretion in transforming growth factor-ß (TGF- ß)-stimulated HFCs. OVERVIEW OF LITERATURE: Lumbar spinal stenosis (LSS) is a prevalent disease among the elderly, characterized by debilitating pain in the lower extremities. Although the number of patients with LSS has increased in recent years, the underlying pathomechanism remains unclear. Clinical examinations typically rely on magnetic resonance imaging to diagnose patients, revealing ligamentum flavum hypertrophy. Some studies have suggested an association between ligamentum flavum hypertrophy and inflammation/fibrosis, and expression of TGF-ß and IL-6 has been observed in surgically obtained ligamentum flavum samples. However, direct evidence linking TGF-ß and IL-6 expression in HFCs is lacking. METHODS: HFCs were obtained from patients with LSS who had undergone decompression surgery. The cells were stimulated with TGF-ß and pretreated with either the p38 mitogen-activated protein (MAP) kinase inhibitor SB203580 or the p44/42 MAP kinase inhibitor FR180204. IL-6 secretion in the cell culture medium and IL-6 messenger RNA (mRNA) expression levels were analyzed using an enzyme-linked immunoassay and real-time polymerase chain reaction, respectively. RESULTS: TGF-ß administration resulted in a dose- and time-dependent stimulation of IL-6 release. Treatment with SB203580 and FR180204 markedly suppressed TGF-ß-induced IL-6 secretion from HFCs. Moreover, these inhibitors suppressed IL-6 mRNA expression in response to TGF-ß stimulation. CONCLUSIONS: Our findings indicate that TGF-ß induces IL-6 protein secretion and gene expression in HFCs through the activation of p38 or p44/42 MAP kinases. These results suggest a potential association between IL-6-mediated inflammatory response and tissue hypertrophy in LSS, and we provide insights into molecular targets for therapeutic interventions targeting LSS-related inflammation through our analysis of the MAP kinase pathway using HFCs.

Nontuberculous mycobacteriosis oligoarthritis of the right hand misdiagnosed as rheumatoid arthritis: A case report.

Infection with Mycobacterium marinum has several different clinical presentations. Most commonly, it appears as a solitary papulonodular lesion on an extremity. A rare presentation of osteoarticular M. marinum involving multiple small joints and tenosynovitis of the hand, which was misdiagnosed as rheumatoid arthritis, is reported. The patient was initially treated for seronegative rheumatoid arthritis but failed to respond to methotrexate. Magnetic resonance imaging showed arthritis and tenosynovitis. Subsequently, synovial biopsy led to histological and microbiological diagnosis. Antimycobacterial treatment should be started promptly in such cases. The combined use of rifampicin, ethambutol, and clarithromycin appears to be effective, and debridement is indicated in patients with deep-seated infections.

A biomechanical analysis of the effect of hydroxyapatite augmentation for trochanteric femoral fractures.

Hydroxyapatite (HA) augments are used to treat trochanteric femoral fractures. However, the efficacy of HA augmentation has not been fully described in trochanteric femoral fracture surgery. In total, 85 patients were enrolled in the present study; all had trochanteric femoral fractures between January 2016 and October 2020, 45 with HA (HA group) and 40 without HA (N group). The intraoperative lag screw insertion torque was directly measured and the amount of lag screw telescoping with and without HA augmentation after surgery was analyzed. Maximum lag screw insertion torque (max-torque), bone mineral density in the opposite femoral neck (n-BMD), tip apex distance (TAD) of the lag screw, radiographic findings including fracture union, the amounts of lag screw telescoping and occurrence of complications were evaluated. A total of 12 patients were excluded if they were aged under 60 years old, had ipsilateral surgery and disorders in the hip joint, TAD of the lag screw ≥26 mm on postoperative radiographs and had measurement errors. A total of 73 fractures could be analyzed: HA group (n=36) and N group (n=37). Max-torque/n-BMD ratios were higher in the HA group compared with in the N group (7.23±2.71 vs. 5.93±1.91 g/cm2·N·m; P=0.04). The amounts of lag screw telescoping in the HA group were smaller compared with the N group (1.41±2.00 vs. 2.58±2.34; P=0.05). Evaluation of screw insertion torque showed maximum screw insertion torque correlated well with n-BMD in both groups, HA (R=0.57; P<0.01) and N group (R=0.64; P<0.01). No correlation was found between maximum screw insertion torque and TAD in both groups, HA (R=-0.10; P=0.62) and N group (R=0.02; P=0.93). All fractures were radiographically united without any complications. These results support the effectiveness of HA augmentation, indicating higher resistance against rotational instability and reduced lag screw telescoping in trochanteric femoral fracture treatment.

Median Nerve Recovery and Morphological Change on MRI at 24 Months after Open Carpal Tunnel Release.

Background: This study aimed to investigate the relationship between postoperative clinical results and long-term morphological changes in patients with carpal tunnel syndrome (CTS) as observed on magnetic resonance imaging (MRI) before and after open carpal tunnel release (OCTR). Methods: We retrospectively analysed data for 28 hands that had undergone OCTR with at least 24 months of follow-up data. Two-point discrimination (2PD) test results were examined for the first three fingers, as were the distal motor latency (DML) and sensory conduction velocity (SCV) of the median nerve. We also calculated the cross-sectional area (CSA) of the carpal tunnel and the distance from the median nerve to the volar carpal bone at the hamate and the pisiform levels using MRI images. Variables were compared before and 24 months after OCTR. Results: Significant improvements in all variables were observed, including average 2PD scores (Finger I: 13.1 ± 6.2 vs. 7.7 ± 4.3, p < 0.01, Finger II: 11.9 ± 6.6 vs. 7.0 ± 3.5, p < 0.01, Finger III: 13.6 ± 6.1 vs. 7.8 ± 4.5, p < 0.01), average DML (8.3 ± 3.3 vs. 4.3 ± 0.6 m/s, p < 0.01), average SCV (30.8 ± 11.0 vs. 41.3 ± 5.3 m/s, p < 0.01), CSA of the carpal tunnel (hamate level: 194.9 ± 30.6 vs. 254.2 ± 47.6 mm2, p < 0.01, pisiform level: 244.2 ± 46.5 vs. 274.7 ± 75.1 mm2, p = 0.01) and the distance between the median nerve and volar carpal bone (hamate level: 8.7 ± 1.4 vs. 11.2 ± 1.6 mm, p < 0.01, pisiform level: 11.8 ± 1.7 vs. 13.8 ± 2.5 mm, p < 0.01). Conclusions: Our results demonstrate that OCTR is successful in achieving long-term decompression and recovery of the median nerve in patients with CTS. Level of Evidence: Level III (Therapeutic).

Fixation of intra-articular calcaneal fractures: A comparative study of the postoperative outcome between HA/PPLA screws and locking plates.

Background: Forged unsintered hydroxyapatite and poly l-lactic acid (F-u-HA/PLLA) screw is bioactivite, bioabsorbable, and radiopaque with high mechanical strength. Its efficacy has been previously demonstrated in the treatment of lateral humeral condylar, lateral tibial condylar, ankle, and patellar fractures. However, studies on its efficacy in treatment of calcaneal fractures is lacking. This study aimed to compare the postoperative results of F-u-HA/PLLA screw fixation and locking plate fixation for intra-articular calcaneal fractures. Methods: From January 2013 to December 2019, 47 closed intra-articular fractures treated with either F-u-HA/PLLA screws (group S, 18 feet in 17 patients) or locking plates (group P, 29 feet in 28 patients) in a single trauma center were retrospectively reviewed. The sinus tarsi approach was used in both groups. The time to bone union, step-off, varus deformity, Bohler's angle, and width and height of the calcaneus were assessed after surgery. Ankle joint range of motion (ROM) and postoperative complications were also assessed. Results: All fractures were successfully treated. The Kaplan-Meier curves of the two groups showed similar trends. The log-rank test showed no significant difference in the time to bone union between the two groups (p = 0.48). In the Cox proportional hazards model adjusted for preoperative width and Bohler's angle, the hazard ratio for bone union was not statistically significant (HR: 1.13, 95%CI: 0.50-2.56, p = 0.78). Other variables included step-off (group S: 2.0 vs group P: 2.2 mm, p = 0.84), varus deformity (2.0° vs. 3.0°, p = 0.7), Gissane's angle (103.5° vs 104.0°, p = 0.84), width (38.0 vs 34.8 mm, p = 0.12), height (42.1 vs 44.0 mm, p = 0.07), and ankle ROM degrees (dorsal flexion, 20.0° vs. 20.0°, p = 0.13; plantar flexion 40.0° vs 40.0°, p = 0.56), which were not significantly different between groups P and S. The Bohler's angle was smaller in group S than in group P (20.5° vs 27.0°, p < 0.01). No skin necrosis or infection was observed in either group. Conclusion: Postoperative results of F-u-HA/PLLA screw fixation using the sinus tarsi approach for intra-articular calcaneal fractures were as good as those of locking plate fixation.

IL-1ß promotes osteoclastogenesis by increasing the expression of IGF2 and chemokines in non-osteoclastic cells.

Bone remodeling mediated by bone-forming osteoblasts (OBs) and bone-resorbing osteoclasts (OCs) maintains bone structure and function. Excessive OC activation leads to bone-destroying diseases such as osteoporosis and bone erosion of rheumatoid arthritis (RA). Differentiation of OCs from bone marrow cells (BMCs) is regulated by the bone microenvironment. The proinflammatory cytokine interleukin (IL)-1ß reportedly enhances osteoclastogenesis and plays important roles in RA-associated bone loss. The present study investigated the effect of IL-1ß on OC formation via microenvironmental cells. Treating mouse BMCs with IL-1ß in the presence of receptor activator of NF-κB ligand and macrophage colony-stimulating factor increased the number of OCs. Real-time RT-PCR revealed increased expression of the IL-1ß, IL-1RI, and IL-1RII genes in non-OCs compared with OCs. Removing CD45- cells which cannot differentiate into OCs, from mouse BMCs reduced the IL-1ß-mediated enhancement of osteoclastogenesis. IL-1ß treatment upregulated the expression of inducible nitric oxide synthase, insulin-like growth factor 2 (IGF2), and the chemokines stromal cell derived factor 1, C-X3-C motif ligand 1 (CX3CL1), and CXCL7 in non-OCs. Neutralizing antibodies against these chemokines and IGF2 suppressed osteoclastogenesis in the presence of IL-1ß. These results suggest that IL-1ß enhances osteoclastogenesis by upregulating IGF2 and chemokine expression in non-OCs.

Influence of concomitant methotrexate use on the clinical effectiveness, retention, and safety of abatacept in biologic-naïve patients with rheumatoid arthritis: Post-hoc subgroup analysis of the ORIGAMI study.

OBJECTIVES: We performed post-hoc analyses of the ORIGAMI study to investigate whether concomitant methotrexate (MTX) influences the clinical outcomes of abatacept in biologic-naïve patients with rheumatoid arthritis. METHODS: Enrolled patients (n = 325) were divided into two groups according to whether abatacept was prescribed without (MTX-) or with (MTX+) concomitant MTX. We compared the changes in Simplified Disease Activity Index (SDAI), Disease Activity Score-28 with C-reactive protein (DAS28-CRP), and Japanese Health Assessment Questionnaire (J-HAQ) through to 52 weeks of treatment, the abatacept retention rate, and safety. RESULTS: At Week 52, the mean SDAI (8.9 vs. 8.8), DAS28-CRP (2.6 vs. 2.6), and J-HAQ (0.92 vs. 0.91) scores were comparable in the MTX- (n = 129) and MTX+ (n = 150) groups. Multivariable logistic regression revealed no significant association between MTX use and SDAI (low disease activity) or J-HAQ (minimum clinically important difference). The abatacept retention rates, estimated using the Kaplan-Meier method, were 73.2% and 66.7% in the MTX- and MTX+ groups, respectively. Adverse events occurred in 47.5% (of 139) and 52.2% (of 159) of patients in the MTX- and MTX+ groups, respectively. CONCLUSION: The effectiveness and safety of abatacept appeared comparable with or without concomitant MTX in this real-world clinical setting.

An Analysis of the Femoral Drilling Angle to Avoid Tunnel Collision during Double-Bundle Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction on the Knee.

Concomitant anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction has been reported as an effective technique for providing rotational control of the knee. However, the intraoperative risk of collision with an ACL tunnel during the drilling for the femoral ALL tunnel has been described. The purpose of this study was to investigate the various femoral drilling procedures to avoid tunnel collisions during combined double-bundle ACL and ALL reconstruction. Nine cadaveric knees were used in this study. ACL drilling was performed through the anteromedial portal to footprints of the posterolateral bundle at 120° (PL120) and 135° (PL135) knee flexion and the anteromedial bundle at 120° (AM120) and 135° (AM135) knee flexion. ALL drilling was performed at 0° (Cor0-ALL) and 30° (Cor30-ALL) coronal angles using a Kirschner wire (K-wire). The distance between the ALL footprint and ACL K-wire outlets, axial angles of ALL K-wires colliding with ACL K-wires, and distances from the ALL footprint to the collision point were measured. From these values, the safe zone, defined as the range of axial angles in which no collisions or penetrations occurred, was identified by simulation of tunnels utilized for reconstruction grafts in each drilling procedure. The point-to-point distance from the ALL footprint to the K-wire outlet was significantly greater in the AM120 than the AM135 (13.5 ± 3.1, 10.8 ± 3.2 mm; p = 0.048) and in the PL135 than the PL120 (18.3 ± 5.5, 16.1 ± 6.5 mm; p = 0.005) conditions, respectively. During an ACL drilling combination of PL135/AM120, a safe zone of > 45° in Cor30-ALL was identified. With a narrow safe zone during the PL135/AM120 combination only, the risk of femoral tunnel collisions in combined double-bundle ACL and ALL reconstruction is high. AM drilling at 120° and PL drilling at > 135° knee flexion, combined with ALL drilling at 30° coronal angle and > 45° axial angle, may reduce this risk.

Evaluation of lower extremity gait analysis using Kinect V2® tracking system.

INTRODUCTION: Microsoft Kinect V2® (Kinect) is a peripheral device of Xbox® and acquires information such as depth, posture, and skeleton definition. In this study, we investigated whether Kinect can be used for human gait analysis. METHODS: Ten healthy volunteers walked 20 trials, and each walk was recorded by a Kinect and infrared- and marker-based-motion capture system. Pearson's correlation and overall agreement with a method of meta-analysis of Pearson's correlation coefficient were used to assess the reliability of each parameter, including gait velocity, gait cycle time, step length, hip and knee joint angle, ground contact time of foot, and max ankle velocity. Hip and knee angles in one gait cycle were calculated in Kinect and motion capture groups. RESULTS: The coefficients of correlation for gait velocity (r = 0.92), step length (r = 0.81) were regarded as strong reliability. Gait cycle time (r = 0.65), minimum flexion angle of hip joint (r = 0.68) were regarded as moderate reliability. The maximum flexion angle of the hip joint (r = 0.43) and maximum flexion angle of the knee joint (r = 0.54) were regarded as fair reliability. Minimum flexion angle of knee joint (r = 0.23), ground contact time of foot (r = 0.23), and maximum ankle velocity (r = 0.22) were regarded as poor reliability. The method of meta-analysis revealed that participants with small hip and knee flexion angles tended to have poor correlations in maximum flexion angle of hip and knee joints. Similar trajectories of hip and knee angles were observed in Kinect and motion capture groups. CONCLUSIONS: Our results strongly suggest that Kinect could be a reliable device for evaluating gait parameters, including gait velocity, gait cycle time, step length, minimum flexion angle of the hip joint, and maximum flexion angle of the knee joint.

Insulin-like growth factor 2 promotes osteoclastogenesis increasing inflammatory cytokine levels under hypoxia.

Osteoporosis is caused by an imbalance in bone remodeling due to abnormal osteoclast (OC) formation and activation. Hypoxia at the site of inflammation promotes OC formation and activation in various species, including humans. We previously reported that insulin-like growth factor 2 (IGF2) plays an important role in osteoclastogenesis under hypoxia. In our present study, we focused on the mechanism of osteoclastogenesis in regard to IGF2 signaling under hypoxia. We confirmed that the addition of IGF2 promoted osteoclastogenesis under normoxic conditions. Conversely, IGF2-neutralizing antibodies inhibited osteoclastogenesis under both normoxic and hypoxic conditions. IGF2 addition increased levels of phosphorylated Akt (Thr308 and Ser473) and NF-κB (Ser536), indicating activation of the Akt-NF-κB pathway. IGF2 also increased the expression of inducible nitric oxide synthase, which promotes osteoclastogenesis via nitric oxide production. Expression levels of genes encoding inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6, were upregulated, indicating that IGF2 promotes osteoclastogenesis by increasing the expression of inflammatory cytokines via activation of the Akt-NF-κB pathway. These results suggest that IGF2 is a promising therapeutic target for osteoporosis and rheumatoid arthritis.

The Janus kinase inhibitor (baricitinib) suppresses the rheumatoid arthritis active marker gliostatin/thymidine phosphorylase in human fibroblast-like synoviocytes.

Gliostatin/thymidine phosphorylase (GLS/TP) is known to have angiogenic and arthritogenic activities in the pathogenesis of rheumatoid arthritis (RA). The novel oral Janus kinase (JAK) inhibitor baricitinib has demonstrated high efficacy in RA. However, the effect of baricitinib on fibroblast-like synoviocytes (FLSs), a key component of invasive synovitis, has not been still elucidated. This study investigated whether GLS/TP production could be regulated by JAK/signal transducers and activators of transcription (STAT) signaling in FLSs derived from patients with RA. FLSs were cultured and stimulated by interferon (IFN)γ in the presence of baricitinib. Expression levels of GLS/TP were determined using reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and immunocytochemistry. Phosphorylation of STAT proteins was investigated by Western blot. In cultured FLSs, GLS/TP mRNA and protein levels were significantly induced by treatment with IFNγ and these inductions were suppressed by baricitinib treatment. Baricitinib inhibited IFNγ-induced STAT1 phosphorylation, while JAK/STAT activation played a pivotal role in IFNγ-mediated GLS/TP upregulation in RA. These results suggested that baricitinib suppressed IFNγ-induced GLS/TP expression by inhibiting JAK/STAT signaling, resulting in the attenuation of neovascularization, synovial inflammation, and cartilage destruction.

Impact of social support on severity of depressive symptoms by remission status in patients with rheumatoid arthritis.

OBJECTIVES: We aimed to examine the psychosocial characteristics of patients with rheumatoid arthritis (RA) by remission status and determine the impacts of social support on severity of depressive symptoms. METHODS: We enrolled RA patients aged 40-79 years who visited university hospitals' outpatient clinics. Severity of depressive symptoms (Beck Depression Inventory-II), physical disability (Health Assessment Questionnaire), and support were evaluated. Furthermore, RA disease activity was evaluated by 28-point Disease Activity Score (DAS28) calculation. The independent impacts of instrumental and emotional social support on depressive symptoms by remission status defined as DAS28 score < 2.6 were estimated by multivariable regression analysis. RESULTS: This study included 360 RA patients. In the remission group, emotional support showed a statistically significant negative impact on depressive symptoms, whereas instrumental support had an extremely limited contribution to severity of depressive symptoms. In the non-remission group, instrumental support showed a negative tendency of impact on severity of depressive symptoms, whereas emotional support had a wide range of influence. CONCLUSIONS: Favourable association between emotional support and depressive symptoms is confirmed only among RA patients in remission status. The influence of emotional support in non-remission patients and that of instrumental support regardless of remission status are inconclusive.

Diagnosis of medial meniscal ramp lesion is difficult by pre-operative magnetic resonance imaging evaluation and needs a methodical arthroscopic exploration.

BACKGROUND: Meniscal ramp lesion (RL) is the peripheral lesion of the posterior horn of the medial meniscus (PHMM) associated with anterior cruciate ligament (ACL) tear. The purpose of this study was to evaluate the accuracy of pre-operative magnetic resonance imaging (MRI) evaluation in diagnosing RL and to identify whether the difficulty in diagnosis differs depending on the location of RL. METHODS: ACL-injured patients undergoing ACL reconstruction from January 2017 to January 2019 were enrolled. A methodical arthroscopic exploration to identify RL was conducted intra-operatively using three steps, namely, the anterior visualization step, the inter-condylar visualization step, and the posteromedial step. The location of the RLs was evaluated and classified into two types as follows: Red-red zone (RR) - a meniscal tear of the red-red zone of the PHMM. Menisco-capsular junction (MCJ) - a lesion at the menisco-capsular junction of the PHMM, which is more peripheral than RR. Furthermore, the accuracy of 1.5-T MRI evaluation to diagnose RL by two testers using sagittal proton-density fat-saturated images was calculated. RESULTS: Of the 81 patients enrolled, 11 had RL: 5 cases each were at the MCJ and RR, and 1 case was at both locations. The sensitivity of MRI for detecting RL was 27.3-45.5%, whereas the specificity was 84.3-95.7% in total. The sensitivity of MRI in detecting RL at the RR and MCJ was 40.0-80.0%, 0-20.0%, respectively. The intra-observer reliability of the MRI evaluation was moderate (κ coefficient: 0.40-0.46), while the inter-observer reliability was fair to moderate (κ coefficient: 0.27-0.41). CONCLUSIONS: A low sensitivity of the MRI in detecting RL at the MCJ was observed, and the reliability of the MRI evaluation for diagnosis of RL was not high. Therefore, methodical arthroscopic exploration is essential to diagnose RL even when it is not suspected on pre-operative MRI.

The Inducible Nitric Oxide Synthase Pathway Promotes Osteoclastogenesis under Hypoxic Culture Conditions.

Bone homeostasis depends on the balance between bone resorption by osteoclasts (OCs) and bone formation by osteoblasts. Bone resorption can become excessive under various pathologic conditions, including rheumatoid arthritis. Previous studies have shown that OC formation is promoted under hypoxia. However, the precise mechanisms behind OC formation under hypoxia have not been elucidated. The present study investigated the role of inducible nitric oxide synthase (iNOS) in OC differentiation under hypoxia. Primary bone marrow cells obtained from mice were stimulated with receptor activator of NF-κB ligand and macrophage colony-stimulating factor to induce OC differentiation. The number of OCs increased in culture under hypoxia (oxygen concentration, 5%) compared with that under normoxia (oxygen concentration, 20%). iNOS gene and protein expression increased in culture under hypoxia. Addition of an iNOS inhibitor under hypoxic conditions suppressed osteoclastogenesis. Addition of a nitric oxide donor to the normoxic culture promoted osteoclastogenesis. Furthermore, insulin-like growth factor 2 expression was significantly altered in both iNOS inhibition experiments and nitric oxide donor experiments. These data might provide clues to therapies for excessive osteoclastogenesis under several hypoxic pathologic conditions, including rheumatoid arthritis.