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.

A novel primary stability test method for artificial acetabular shells considering vertical load during level walking and shell position.

Uncemented acetabular shell primary stability is essential for optimal clinical outcomes. Push-out testing, rotation testing, and lever-out testing are major evaluation methods of primary stability between the shell and bone. However, these test methods do not consider shell loads during daily activity and shell installation angle. This study proposes a novel evaluation method of acetabular shell primary stability considering load during level walking and acetabular installation angles such as inclination and anteversion. To achieve this, a novel primary stability test apparatus was designed with a shell position of 40° acetabular inclination and 20° anteversion. The vertical load, corresponding to walking load, was set to 3 kN according to ISO 14242-1, which is the wear test standard for artificial hip joints. The vertical load was applied by an air cylinder controlled by a pressure-type electro-pneumatic proportional valve, with the vertical load value monitored by a load cell. Torque was measured when angular displacement was applied in the direction of extension during the application of vertical load. For comparison, we also measured torque using the traditional lever-out test. The novel primary stability test yielded significantly higher primary stabilities; 5.4 times greater than the lever-out test results. The novel primary stability test failure mode was more similar to the clinical failure than the traditional lever-out test. It is suggested that this novel primary stability test method, applying physiological walking loads and extension motions to the acetabular shell, better reflects in vivo primary stability than the traditional lever-out test.

The Impact of Sarcopenia Risk on Postoperative Walking Independence in Older Adults Undergoing Total Joint Arthroplasty.

BACKGROUND AND PURPOSE: Sarcopenia is known to be associated with poor outcomes after arthroplasty; however, no study has reported the relationship between sarcopenia and postoperative walking independence. This study aimed to determine the impact of sarcopenia risk screening using the SARC-CalF questionnaire and calf circumference on the time to walk independently after total hip or knee arthroplasty in older patients. METHODS: We included 599 nonobese patients aged 65 years and older who underwent unilateral and primary total hip or knee arthroplasty. Preoperative sarcopenia risk was assessed using the SARC-CalF or calf circumference. The outcome of this study was the time to independent walking after surgery; it was calculated as the number of days from the date of surgery to the date when the patient was able to walk independently. The association between preoperative sarcopenia risk and time to independent walking after surgery was analyzed using Kaplan-Meier curves and Cox proportional hazards models. RESULTS: Among the 599 patients undergoing total joint arthroplasty, 175 (29.2%) were determined to be at risk of sarcopenia using SARC-CalF and 193 (32.2%) using calf circumference. The Kaplan-Meier curve showed that sarcopenia risk assessed by SARC-CalF or calf circumference was associated with a prolonged time to independent walking in patients undergoing hip arthroplasty (log-rank test, P < .001 and P < .001, respectively). In patients undergoing hip arthroplasty, the Cox proportional hazards model showed that SARC-CalF score of 11 points and greater or a calf circumference less than the cutoff was a risk factor for delayed time to independent walking (hazard ratios: 0.55 and 0.57, P < .001 and P = .001, respectively). There was no association between preoperative sarcopenia risk and postoperative time to independent walking in patients who underwent knee arthroplasty. CONCLUSIONS: Sarcopenia screening tools, such as SARC-CalF or calf circumference, should be useful for planning postoperative rehabilitation in older adults scheduled for hip arthroplasty. However, the accuracy of SARC-CalF or calf circumference measurement in patients scheduled for knee arthroplasty may be low.

Association of affected and non-affected side ability with postoperative outcomes in patients undergoing total hip arthroplasty.

BACKGROUND: Although several reports have examined the association between preoperative function and postoperative outcomes in patients undergoing total hip arthroplasty (THA), it is unclear whether the ability of the affected or non-affected side particularly impacts on outcomes. We aimed to investigate the association between affected and non-affected side ability and walking independence. METHODS: We prospectively enrolled 721 consecutive patients who underwent THA. Preoperatively, quadriceps isometric strength (QIS) and one-leg standing time (OLST) were measured. The endpoints were walking independence within 3, 5, 7, 10, and 14 days postoperatively. The associations between preoperative abilities and outcomes were examined using multivariate Cox hazard model, and the area under the curves (AUCs) for outcomes were compared. RESULTS: We analysed 540 patients after excluding patients who met the exclusion criteria. Both affected and non-affected QIS predicted walking independence within 3 (p = 0.006 and 0.001, respectively), 5, 7, 10, and 14 (both p < 0.001) days postoperatively. For OLST, only the affected side did not predict walking independence within 3 days postoperatively (p = 0.154 and 0.012, respectively), and both sides did at days 5 (p = 0.019 and <0.001, respectively), 7, 10, and 14 (both p < 0.001). The AUCs of the non-affected side ability for walking independence were significantly greater than those of the affected side on postoperative days 3 (0.66 vs. 0.73; p = 0.021) and 5 (0.67 vs. 0.71; p = 0.040), with no significant difference after day 7. CONCLUSIONS: Both sides abilities were associated with walking independence after THA, but non-affected side was found to be particularly crucial for early walking independence.

Increase in TPSB2 and TPSD1 Expression in Synovium of Hip Osteoarthritis Patients Who Are Overweight.

While research suggests that increasing body mass index (BMI) is a risk factor for hip osteoarthritis (HOA), the mechanisms of this effect are not fully understood. Tryptases are among the main proteases found in mast cells (MCs) and contribute to OA pathology. TPSB2, which encodes ß-tryptase, is increased in the synovium of overweight and obese knee OA patients. However, it remains unclear whether tryptase in the synovium of HOA is increased with increasing BMI. Here, we investigated tryptase genes (TPSB2 and TPSD1) in the synovium of overweight HOA patients. Forty-six patients radiographically diagnosed with HOA were allocated to two groups based on BMI, namely normal (<25 kg/m2) and overweight (25-29.99 kg/m2). TPSB2 and TPSD1 expression in the synovium of the two groups was compared using real-time polymerase chain reaction. To compare TPSB2 and TPSD1 expression in MCs between the groups, we isolated the MC-rich fraction (MC-RF) and MC-poor fraction (MC-PF), extracted using magnetic isolation. TPSB2 and TPSD1 expression was increased in the overweight group compared with the normal group. Expression of both genes in the MC-RF was significantly higher than that in MC-PF in both groups. However, TPSB2 and TPSD1 expression levels in the MC-RF did not differ between the groups. Tryptase genes were highly expressed in the synovium of overweight HOA patients. Further investigation to reveal the role of tryptase in the relationship between increasing BMI and HOA pathology is required.

Effect of Devised Simultaneous Physical Function Improvement Training and Posture Learning Exercises on Posture.

Poor posture in young adults and middle-aged people is associated with neck and back pain which are among the leading causes of disability worldwide. Training posture maintenance muscles and learning about ideal posture are important for improving poor posture. However, the effect of using both approaches simultaneously has not been verified, and it is unclear how long the effects persist after the intervention. Forty female university students were randomly and evenly assigned to four groups: physical function improvement training, posture learning, combination, and control groups. Four weeks of intervention training was conducted. Postural alignment parameters were obtained, including trunk anteroposterior inclination, pelvic anteroposterior inclination, and vertebral kyphosis angle. Physical function improvement training for improving crossed syndrome included two types of exercises: "wall-side squatting" and "wall-side stretching". The posture learning intervention consisted of two types of interventions: "standing upright with their back against the wall" and "rolled towel". A multiple comparison test was performed after analysis of covariance to evaluate the effect of each group's postural change intervention on postural alignment. Only the combination group showed an effective improvement in all posture alignments. However, it was found that a week after the 4-week intervention, the subjects' postures returned to their original state.

Reliability and validity of ultrasonographic automated length measurement system for assessing talofibular anterior instability in acute lateral ankle sprain.

Ankle joint instability after acute lateral ankle sprain (LAS) is an important factor for deciding treatment strategies. Nevertheless, the degree of ankle joint mechanical instability as a criterion for making clinical decisions is unclear. This study examined the reliability and validity of an Automated Length Measurement System (ALMS) in ultrasonography for assessing real-time anterior talofibular distance. Using a phantom model, we tested whether ALMS could detect two points within a landmark following movement of the ultrasonographic probe. Furthermore, we examined whether ALMS was comparable with the manual measurement method for 21 patients with an acute LAS (42 ankles) during the reverse anterior drawer test. Using the phantom model, ALMS measurements showed excellent reliability, with errors below 0.4 mm and with a small variance. The ALMS measurement was comparable to manually measured values (ICC = 0.53-0.71, p < 0.001) and detected differences in talofibular joint distances between unaffected and affected ankles of 1.41 mm (p < 0.001). ALMS shortened the measurement time by one-thirteenth for one sample compared to the manual measurement (p < 0.001). ALMS could be used to standardize and simplify ultrasonographic measurement methods for dynamic joint movements without human error in clinical applications.

Effects of perioperative exercise therapy combined with nutritional supplementation on functional recovery after fast-track total hip arthroplasty.

BACKGROUND: The combination of exercise therapy combined with nutritional supplementation (Nutr) is widely used for frail or sarcopenic older persons. However, the effects of Nutr in elderly patients after fast-track total hip arthroplasty (THA) are unknown. This study examined the effects of perioperative Nutr on muscle strength, functional performance, and quality of life (QOL) in frail elderly women after fast-track THA. METHODS: A total of 58 frail elderly women aged 65-80 years scheduled for unilateral primary THA were randomly allocated to two groups: the physical exercise (Ex) combined with Nutr (Ex + Nutr; n = 29) group, and the Ex alone (Ex; n = 29) group. Protein and vitamin D supplements were provided daily from 4 weeks preoperatively to 8 weeks postoperatively (12 weeks) to the patients in the Ex + Nutr group, whereas the Ex group did not receive any supplements. Surgery and postoperative rehabilitation programmes during intervention were identical in both groups. Hip abductor and knee extensor muscle strength, functional performance (Timed Up & Go test, Harris Hip Score), and QOL (Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire) were assessed at baseline and at 12 weeks (8 weeks postoperatively). RESULTS: After the intervention, hip abductor muscle strength on the contralateral leg and knee extensor muscle strength on both sides significantly improved in the Ex + Nutr group compared to the Ex group (p = 0.03, 0.01, and 0.01, respectively). However, hip abductor muscle strength on the operated side did not differ significantly between the groups (p = 0.23). There were no significant differences in functional performance and QOL. CONCLUSION: Ex + Nutr does not have an additional effect on the improvement of hip abductor strength, functional performance, and QOL compared to Ex alone after fast-track THA. However, significant improvements were observed in the strength of some muscles after fast-track THA. TRIAL REGISTRATION: UMIN 000042964. THE IRB APPROVAL: This study was approved by the Mirai Iryo Reesearch Center (approval number TGE1602-115).

Prevalence of frailty and associated factors among community-dwelling older adults after total hip arthroplasty.

OBJECTIVE: To evaluate the prevalence of frailty and associated factors among community-dwelling older adults who have undergone total hip arthroplasty (THA). MATERIALS AND METHODS: This study, which employed a cross-sectional, observational design, was conducted between April and November 2020. The participants were older adults (⩾65 years) who had undergone primary THA at the study hospital. Based on Fried's modified phenotype, frailty was stratified into 3 degrees according to the presence of 3 or more of the following components: weight loss, weakness, exhaustion, low activity level, and slow walking speed. Multinomial logistic regression was used to analyse the associations of frailty with its potential risk factors. RESULTS: The data of 518 participants were analysed. The overall prevalence of frailty and prefrailty was 11.4% and 51.0%, respectively. The multinomial logistic regression analysis showed that calf circumference (odds ratio [OR] 0.716, 95% confidence interval [CI], 0.611-0.839; p < 0.001), fall history (OR 2.435, 95% CI, 1.114-5.322; p = 0.026), hip abductor muscle strength (OR 0.962, 95% CI, 0.938-0.987; p = 0.003), knee extensor muscle strength (OR 0.980, 95% CI, 0.964-0.996; p = 0.013), and Timed Up and Go test (TUG) performance (OR 1.802, 95% CI, 1.458-2.228; p < 0.001) were associated with frailty. CONCLUSIONS: Frailty was highly prevalent in community-dwelling older adults after THA. Further, its potential associations with calf circumference, hip abductor and knee extensor muscle strength, TUG performance, and fall history highlight the significance of these factors for interventions.

Increased Synovial CD14 mRNA Expression and Proportion of CD14high Subsets in Early-Stage Hip Osteoarthritis: Propensity Matched Score Analysis.

The pathophysiology of early-stage hip osteoarthritis (EOA) is not fully understood. Although a previous study in an age-unmatched cohort reported that the number of macrophages was increased in knee EOA compared to late OA (LOA), it remained unclear whether increased macrophages in EOA accurately reflect EOA pathology. We investigated the differences in CD14 expression levels between EOA and LOA using age-unmatched and -matched cohorts. Synovial tissues were obtained from 34 EOA (Tönnis grades 0 and 1) and 80 LOA (Tönnis grades 2 and 3) patients. To correct for differences in demographics between patients with LOA and EOA, we also created propensity score-matched cohorts (16 EOA and 16 LOA). CD14 expression and its association with pain was estimated in LOA and EOA before and after propensity matching. We performed flow cytometry on tissues from the 16 patients, with 8 from each group, to assess for CD14+ subsets in the cells. The CD14 expression in EOA was higher than that in LOA both before and after propensity matching. The proportion of CD14high subsets in EOA was higher than that in LOA. The CD14 expression was associated with pain in EOA before matching. However, no difference was observed between the pain and CD14 expression after matching in EOA. The increased CD14 expression and the proportion of CD14high subsets may be important features associated with hip EOA pathology. To accurately compare early and late OA, the analysis of a propensity score-matched cohort is necessary.

Sports activity participation and subjective health status of patients after total hip arthroplasty via the anterolateral-supine approach: a case series study.

BACKGROUND: No reports have been published about participation in sports activity and subjective health status after total hip arthroplasty via the anterolateral approach in the supine position (ALS-THA) in Japanese patients. This study assessed sports activity participation and subjective health status, as well as factors potential associated with these variables, in patients who underwent ALS-THA. METHODS: Of 698 patients who underwent total hip arthroplasty at our institution between 2013 and 2018, questionnaires were sent to 355 patients under 80 years old who had undergone ALS-THA and 242 responded. Patients were asked about their subjective health status, participation in sports activity, the EuroQol 5-dimensions 5-level (EQ-5D-5L), the University of California Los Angeles (UCLA) activity scale score and the Forgotten Joint Score (FJS). Patient characteristics and hospitalization information were also collected. Patients' subjective health status was categorized as "healthy" or "unhealthy". Univariate and multivariate logistic regression analyses were performed to determine factors associated with participation in sports activity after ALS-THA and a "healthy" status. RESULTS: The pre- and postoperative sports activity participation rates were 54.0% and 57.8%, respectively. Most patients (76.8%, n = 182) were considered "healthy". Age (P = .019) and UCLA activity score (P < .001) were significantly associated with sports activity after ALS-THA. FJS (P = .002) and EQ-5D-5L (P = .004) were significantly associated with a "healthy" status. CONCLUSION: Patients participating in sports activity after ALS-THA are older and have higher UCLA activity scores and patients considered "healthy" have higher FJS and EQ-5D-5L scores.

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.

Tenodesis with bone marrow venting under local anesthesia for recalcitrant lateral epicondylitis: results of 2 years of follow-up.

Hypothesis: We hypothesized that the treatment of recalcitrant lateral epicondylitis requires accurate identification of the painful area to promote remodeling of the degenerated extensor insertion and to stabilize the tendon origin during tendon healing. Thus, we performed tenodesis with bone marrow venting under local anesthesia for recalcitrant lateral epicondylitis. Methods: Twenty patients (21 elbows) were treated with bone marrow venting at the painful area of the lateral epicondyle of the elbow and tenodesis using 2 soft anchors lateral to the capitellum (immediately distal to the painful area) and were followed up for ≥2 years. Patients were assessed using the numerical rating scale for pain and the Quick Disabilities of the Arm, Shoulder, and Hand questionnaire, and objective evaluation included active range of motion. Results: The mean preoperative and postoperative pain scores were 7.5 and 0.5, respectively, indicating significant pain relief (P < .001). The mean preoperative and postoperative Quick Disabilities of the Arm, Shoulder, and Hand questionnaire scores were 44.2 and 1.0, respectively (P < .001). Two elbows had a slightly positive Thomsen test at the final visit. No recurrence of intra-articular symptoms induced by synovial fringe impingement was observed. Patients experienced more pain at the bone-tendon junction of extensors than at the tendon parenchyma. Conclusion: Tenodesis with bone marrow venting under local anesthesia was effective for subjective patient satisfaction and positive clinical outcomes at ≥2 years of follow-up in patients with recalcitrant lateral epicondylitis. Intra-articular symptoms can be improved by stabilization of the lateral soft tissue without treatment for intra-articular lesions.

Internal Validation of a Risk Scoring System for Venous Thromboembolism After Total hip or Knee Arthroplasty.

We developed a computerized clinical decision support system (CCDSS) for venous thromboembolism (VTE) risk assessment. We aimed to demonstrate its relevance and evaluate associations between risk level and VTE incidence in patients undergoing total hip/knee arthroplasty. In this case-control study, VTE was confirmed using ultrasonography/computed tomography angiography in 1098 adults at a tertiary care hospital over five years (2013-2018). Postoperative VTE incidence was classified into three risk levels (moderate, high, and highest). The overall VTE incidence was 11.7%, which increased with a risk level of 0%, 5.8%, and 12.8% in moderate-risk, high-risk, and highest-risk patients, respectively. Highest-risk patients were significantly more likely to develop VTE than high-risk patients (odds ratio [OR] 2.4; 95% confidence interval [CI] 1.2-5.5; p = 0.01). VTE development was more likely in patients with risk scores ≥4 relative to those with risk scores of 2-3 (OR 1.8; 95% CI 1.2-2.7; p = 0.003) and -1 to 1 (OR 3.3; 95% CI 1.6-7.7; p < 0.001). This study indicates that risk level and VTE incidence are associated; our scoring system appears useful for patients undergoing total hip/knee arthroplasty.

A novel device for lower leg intermittent pneumatic compression synchronized with active ankle exercise for prevention of deep vein thrombosis.

OBJECTIVE: Intermittent pneumatic compression devices (IPCDs) and active ankle exercises have been shown to be efficacious in preventing venous thromboembolism (VTE) by increasing venous flow velocity and volume. However, IPCDs are expensive and require electricity; therefore, they cannot be used in the event of power loss. We developed a non-powered device that provides lower leg intermittent pneumatic compression synchronized with AAEs (LISA) and compared its efficacy with AAEs alone in increasing the peak velocity in the femoral vein. METHODS: The study population consisted of 20 healthy younger men and 20 healthy older men who performed AAE every 2 s in a sitting posture under four conditions: AAE with LISA (AAE+LISA), AAE alone (AAE), AAE with IPCD, and AAE with a graduated compression stocking. RESULTS: The PVs under all conditions were significantly higher than those at rest. The PVs in the AAE+LISA condition were significantly higher than those in the AAE alone condition in both younger and older groups (both p < .001). CONCLUSIONS: AAE with LISA significantly increased the PV, suggesting that LISA might be useful for preventing DVT.

Venous thromboembolism risk factors and usefulness of a risk scoring system in lower limb orthopedic surgery: A case-control study in Japan.

ABSTRACT: We previously developed a computerized clinical decision support system based on national consensus guidelines and previous studies. This system was used to assess the risk of venous thromboembolism. In this study, we examined the risk factors for venous thromboembolism in patients who underwent lower limb orthopedic surgery using our risk scoring system, to investigate the association between the total risk score and the occurrence of venous thromboembolism.We retrospectively evaluated the records of 649 patients who underwent lower limb orthopedic surgery at a tertiary care center in Japan between January 2015 and August 2018. Venous thromboembolism was confirmed using ultrasonography or computed tomography angiography. The computerized clinical decision support system was used throughout the hospitalization period. Independent risk factors for postoperative venous thromboembolism were identified using logistic regression analysis.Age (≥68 years) was significantly associated with an increased risk of venous thromboembolism (adjusted odds ratio: 1.06, 95% confidence interval: 1.03-1.09; P < 0.001). Furthermore, the Cochran-Armitage trend test revealed a significant positive correlation between the total risk score and the occurrence of venous thromboembolism (P < 0.001).Our risk scoring system may be used preoperatively to determine the need for venous thromboembolism prophylaxis. This study suggests that age (≥68 years) may be a risk factor for venous thromboembolism after lower limb orthopedic surgery. Additional studies are needed to validate these results.

Correlation between CD163 expression and resting pain in patients with hip osteoarthritis: Possible contribution of CD163+ monocytes/macrophages to pain pathogenesis.

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

Prevalence of locomotive syndrome in Japanese patients more than 10 years after total hip arthroplasty: A cross-sectional cohort study.

BACKGROUND: Locomotive syndrome (LS) is a high risk condition that requires nursing care. It is important to investigate the prevalence of and factors related to LS to maintain a healthy life expectancy for patients; however, only a few reports have focused on the relationship between LS and total hip arthroplasty (THA). The purpose of this study was to evaluate the prevalence of LS and to identify factors associated with LS in patients more than 10 years after THA. METHODS: This is a cross-sectional cohort study. Patients were assessed via a mail survey that included items regarding demographic data, cardiometabolic and motor disorders, the incidence of falls, physical activity level, and the 25-question Geriatric Locomotive Function Scale (GLFS-25) questionnaire. LS was defined as having a score ≥16 on the GLFS-25, and the respondents were categorized into two groups: an LS group and a non-LS group. The prevalence of LS was calculated in each gender and age group. Differences in variables between the groups were determined using the unpaired t-test and chi-squared test. RESULTS: A total of 593 patients were included in the study (mean age, 70.4 years; 525/593 females). According to the GLFS-25, 164 patients (27.7%; 21.1% men and 28.8% women) were classified as having LS, which increased with age. In addition, compared with the non-LS group, the LS group had a significantly higher prevalence of motor diseases, cardiometabolic diseases, and falls and significantly lower levels of activity. CONCLUSION: These findings suggest that the prevalence of LS in patients more than 10 years after THA is 27.7%. The result suggest that the prevalence of LS in patients more than 10 years after THA is similar to the prevalence of LS in the general elderly population. Furthermore, LS is related to not only motor diseases but also cardiometabolic diseases.