Risk factors for contralateral total knee arthroplasty after unilateral total knee arthroplasty.

BACKGROUND: Little attention has been focused on risk factors for undergoing bilateral total knee arthroplasty (TKA) after primary unilateral TKA among patients with knee osteoarthritis (OA). This study investigated the differences in characteristics between groups with and without additional TKA for the contralateral knee among patients with knee OA who underwent primary unilateral TKA. METHODS: Seventy-six patients who underwent primary unilateral TKA were included in this study. We defined patients who underwent additional TKA for the contralateral knee within one year of the primary TKA as a bilateral TKA group, and patients who did not undergo bilateral TKA as a unilateral TKA group. Femorotibial angle (FTA), percentage of mechanical axis (%MA), Kellgren-Lawrence (KL) grade, range of motion, Japan Orthopaedic Association (JOA) score, 10 m-walking time, C-reactive protein, estimated glomerular filtration rate, and serum albumin levels were selected as independent variables including covariates of age, sex, and body mass index for predicting bilateral TKA. We compared differences in variables between the two groups using the t-test or Mann-Whitney U-test and general linear models. A multivariate stepwise logistic regression model was also used to determine which variables correlated with bailateral TKA. RESULTS: In pairwise comparisons, the KL grade, FTA, %MA, JOA score, and knee flexion angle in the contralateral knee were significantly worse in the bilateral TKA group than in the unilateral TKA group after controlling for covariates (P < 0.01, respectively). A stepwise logistic regression revealed that significant contributors to undergoing the contralateral TKA were FTA (OR = 1.47, P < 0.001) and knee flexion angle (OR = 0.96, P = 0.022) of the contralateral knee. CONCLUSIONS: Severe varus deformity and limitations of flexion in the contralateral knee were found to be risk factors for undergoing additional TKA within one year of primary unilateral TKA among patients with knee OA.

Correlation Between Gut Microbiome Composition and Acute Pain Perception in Young Healthy Male Subjects.

OBJECTIVE: Recently, there has been growing interest in the gut-brain axis because it is emerging as a player influencing the health status of the host human. It is a known fact that the gut microbiome (GM) through the gut-brain axis has been implicated in numerous diseases. We previously reported that stool condition was associated with pain perception. Stool consistency and constipation are known to be associated with GM composition. Thus, we imagine that GM composition could influence pain perception. The aim of this study was to investigate the correlations between GM composition and pain perception and psychological states in young healthy male subjects. SUBJECTS: A total of 42 healthy young male volunteers completed the present study. METHODS: The volunteers' pain perceptions were assessed by pressure pain threshold, current perception threshold, temporal summation of pain, and conditioned pain modulation, and a questionnaire on psychological state was obtained. During the current perception threshold examination, we used 5, 250, and 2,000 Hz to stimulate C, Aδ, and Aß fibers. In addition, GM composition was evaluated by using 16S rRNA analysis. RESULTS: Pressure pain threshold showed a significant and negative correlation with Bacteroidetes phylum, in contrast to a significant and positive correlation with Firmicutes phylum. Current perception threshold of Aδ and Firmicutes phylum showed a significant correlation. There was a negative correlation between anxiety state and Bifidobacterium genus. In contrast, there was no significant correlation between psychological states and pain perceptions. CONCLUSION: The present study showed that acute pain perception was associated with GM composition in young healthy males.

Pain Catastrophizing Is Independently Associated with Quality of Life in Patients with Severe Hip Osteoarthritis.

OBJECTIVE: Pain catastrophizing is an important pain-related variable, but its impact on patients with osteoarthritis is uncertain. The aim of the current study was to determine whether pain catastrophizing was independently associated with quality of life (QOL) in patients with osteoarthritis of the hip. DESIGN: Cross-sectional study conducted between June 2017 and February 2018. SETTING: Tertiary center. SUBJECTS: Seventy consecutively enrolled patients with severe hip osteoarthritis who had experienced pain for six or more months that limited daily function, and who were scheduled for primary unilateral total hip arthroplasty. METHODS: QOL was measured using the EuroQOL-5 Dimensions questionnaire, the Japanese Orthopedic Association Hip Disease Evaluation Questionnaire, and a dissatisfaction visual analog scale. Covariates included pain intensity, pain catastrophizing, range of hip motion, and gait speed. The variables were subjected to multivariate analysis with each QOL scale. RESULTS: The median age was 68 years, and the median Pain Catastrophizing Scale score was 26. In multiple regression analysis, pain catastrophizing, pain intensity in both hips, pain intensity on the affected side, hip flexion on the affected side, and gait speed were independently correlated with QOL. CONCLUSIONS: Pain catastrophizing was independently associated with each QOL scale in preoperative patients with severe hip osteoarthritis. Pain catastrophizing had either the strongest or second strongest effect on QOL, followed by pain intensity.

Randomized open-label [corrected] non-inferiority trial of acetaminophen or loxoprofen for patients with acute low back pain.

BACKGROUND: Current worldwide clinical practice guidelines recommend acetaminophen as the first option for the treatment of acute low back pain. However, there is no concrete evidence regarding whether acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) is more effective for treating acute low back pain (LBP) in Japan. The present study aimed to investigate whether acetaminophen treatment for acute musculoskeletal pain was comparable with loxoprofen (a traditional NSAID in Japan) treatment. METHODS: Of the 140 patients with acute LBP who visited out-patient hospitals, 127 were considered eligible and were randomly allocated to a group taking acetaminophen or one taking loxoprofen. As primary outcome measure, pain intensity was measured using a 0-10-numeric rating scale (NRS). Moreover, pain disability, pain catastrophizing, anxiety, depression, and quality of life, as well as adverse events, were assessed as secondary outcomes. The primary outcome was tested with a noninferiority margin (0.84 on changes in pain-NRS), and the secondary outcomes were compared using conventional statistical methods at week 2 and week 4. RESULTS: Seventy patients completed the study (acetaminophen: 35, loxoprofen: 35). The dropout rates showed no significant difference between the two medication-groups. We found that the mean differences of changes in pain-NRS from baseline to week 2 or 4 between the two medication groups were not statistically beyond the noninferiority margin (mean [95% confidence interval]: -0.51 [-1.70, 0.67], at week 2 and -0.80 [-2.08, 0.48] at week 4). There were no consistent differences between the two medication groups in terms of secondary outcomes. CONCLUSIONS: The results suggest that acetaminophen has comparable analgesic effects on acute LBP, based on at least a noninferiority margin, compared with loxoprofen at 4 weeks. Acetaminophen seems to be a reasonable first-line option for patients with acute LBP in Japan.

Analysis of follow-up data from an outpatient pain management program for refractory chronic pain.

BACKGROUND: Numerous reports indicate that multifaceted pain management programs based on cognitive-behavioral principles are associated with clinically meaningful long-term improvements in chronic pain. However, this has not yet been investigated in Japan. This study investigated the effects of a multifaceted pain management program in Japanese patients with chronic pain, both immediately after the program and 6 months thereafter. METHODS: A total of 96 patients, 37 male and 59 female (mean age 63.8 years) experiencing treatment difficulties and suffering from intractable pain for more than 6 months were enrolled in the study. The programs were conducted with groups of 5-7 patients who met weekly for 9 weeks. Weekly sessions of approximately 2 h in duration incorporating a combination of lectures and exercise were conducted. Several measures related to pain and physical function were assessed at the start of the program, the end of the program, and 6 months after completion of the program. The resulting data were analyzed via Wilcoxon signed-rank test, and 'r' estimated by effect size was also assessed. RESULTS: Of the 96 initial participants, 11 dropped out during the program and 85 completed it. Thereafter, we evaluated 62 subjects at 6 months after the program, while 23 could not be evaluated at that time-point. Pain intensity upon moving, catastrophizing scores, and pain disability scores showed good improvements at the 6-month follow-up, with large efficacy (r > 0.5). Moving capacity and 6-min walking distance also showed good improvements with large efficacy, both at the end of the program and at the 6-month follow-up (r > 0.5). CONCLUSIONS: A multifaceted pain-management program based on cognitive-behavioral principles was effective in Japanese patients with chronic pain, resulting in improved long-term clinical outcomes.

Locomotive syndrome is associated not only with physical capacity but also degree of depression.

BACKGROUND: Reports of locomotive syndrome (LS) have recently been increasing. Although physical performance measures for LS have been well investigated to date, studies including psychiatric assessment are still scarce. Hence, the aim of this study was to investigate both physical and mental parameters in relation to presence and severity of LS using a 25-question geriatric locomotive function scale (GLFS-25) questionnaire. METHODS: 150 elderly people aged over 60 years who were members of our physical-fitness center and displayed well-being were enrolled in this study. Firstly, using the previously determined GLFS-25 cutoff value (=16 points), subjects were divided into two groups accordingly: an LS and non-LS group in order to compare each parameter (age, grip strength, timed-up-and-go test (TUG), one-leg standing with eye open, back muscle and leg muscle strength, degree of depression and cognitive impairment) between the groups using the Mann-Whitney U-test followed by multiple logistic regression analysis. Secondly, a multiple linear regression was conducted to determine which variables showed the strongest correlation with severity of LS. RESULTS: We confirmed 110 people for non-LS (73%) and 40 people for LS using the GLFS-25 cutoff value. Comparative analysis between LS and non-LS revealed significant differences in parameters in age, grip strength, TUG, one-leg standing, back muscle strength and degree of depression (p < 0.006, after Bonferroni correction). Multiple logistic regression revealed that functional decline in grip strength, TUG and one-leg standing and degree of depression were significantly associated with LS. On the other hand, we observed that the significant contributors towards the GLFS-25 score were TUG and degree of depression in multiple linear regression analysis. CONCLUSIONS: The results indicate that LS is associated with not only the capacity of physical performance but also the degree of depression although most participants fell under the criteria of LS.

One-year results of voluntary-based supervised exercise or treatment at orthopedic clinic for radiographic severe knee osteoarthritis.

[Purpose] In this study, we investigated the efficacy of supervised physical exercise or conventional treatment on symptomatic knee osteoarthritis with severe morphological degeneration. [Subjects] Sixty-six patients with severe radiographic knee osteoarthritis were enrolled. [Methods] Participants were separated into two groups: in one group patients conducted physical exercise under supervision; while in the other group they were treated by conventional clinical methods for one year. Participants filled out two types of questionnaires; the Japanese Knee Osteoarthritis Measure and the Pain Disability Assessment Scale at baseline and one year following enrollment in the study. Two-way repeated measures analysis of variance was used to examine the effects over time and by group for a total of 43 participants; consisting of an exercise group (n=20) and a clinical group (n=23) excluding 23 dropouts. [Results] Analysis did not show a significant time-course effect or interaction between time-course and the groups in both questionnaires. On the other hand, there were significant group effects in both questionnaires with an advantage in the exercise group. [Conclusion] These results indicate that patients with knee osteoarthritis under supervised exercise conditions are more likely to maintain a better clinical outcome at one-year follow-up, despite the severe morphological degeneration in their knees.

Dorsal root ganglion pulsed radiofrequency for the management of intractable vertebral metastatic pain: a case series.

OBJECTIVE: Metastatic bone pain is characteristic of cancer pain and is a form of refractory cancer pain, as the pain includes not only nociceptive but also neuropathic pain. Although some drugs are effective in the management of painful bone metastases, pain while moving is one of the most refractory forms of pain. Although pulsed radiofrequency (RF) dramatically reduces neuropathic pain, chronic pain, and vertebral metastatic pain, the number of cases reported in these studies was very small (five or less). DESIGN: Case report. SETTING: Single pain center. PATIENTS: Fifteen patients suffering from intractable vertebral metastatic pain. INTERVENTIONS: Dorsal root ganglion (DRG) pulsed RF. OUTCOME MEASURES: A numerical rating scale (NRS) of pain at rest and while moving. RESULTS: Almost all patients experienced sound pain relief after the pulsed RF treatment. There were no severe side effects reported. CONCLUSION: DRG pulsed RF procedure provided sound pain relief for patients with intractable vertebral metastatic pain. Metastatic bone pain is characteristic of cancer pain and is a form of refractory cancer pain, as the pain includes not only nociceptive but also neuropathic pain. Although some drugs are effective in the management of painful bone metastases, pain while moving is one of the most refractory forms of pain. DRG pulsed RF procedure provided sound pain relief for patients with intractable vertebral metastatic pain.

Inverse association of des-acyl ghrelin with worksite blood pressure in overweight/obese male workers.

BACKGROUND: Job strain, defined as a combination of high job demands and low job control, has been reported to elevate blood pressure (BP) during work. Meanwhile, a recent experimental study showed that ghrelin blunted the BP response to such mental stress. In the present study, we examined the hypothesis that des-acyl ghrelin may have some beneficial effects on worksite BP through modulating the BP response to work-related mental stress, i.e., job strain. METHODS: Subjects were 34 overweight/obese male day-shift workers (mean age 41.7 ± 6.7 years). No subjects had received any anti-hypertensive medication. A 24-h ambulatory BP monitoring was recorded every 30 min on a regular working day. The average BP was calculated for Work BP, Morning BP, and Home BP. Job strain was assessed using the short version of the Japanese Job Content Questionnaire. RESULTS: Des-acyl ghrelin showed significant inverse correlations with almost all BPs except Morning SBP, Morning DBP, and Home DBP. In multiple regression analysis, des-acyl ghrelin inversely correlated with Work SBP after adjusting for confounding factors. Des-acyl ghrelin was also negatively associated with BP changes from Sleep to Morning, Sleep to Work, and Sleep to Home. CONCLUSIONS: Des-acyl ghrelin was inversely associated with Worksite BP, suggesting a unique beneficial effect of des-acyl ghrelin on Worksite BP in overweight/obese male day-shift workers.

Predictive factors for the outcome of multidisciplinary treatments in chronic low back pain at the first multidisciplinary pain center of Japan.

[Purpose] Multidisciplinary treatments are recommended for treatment of chronic low back pain. The aim of this study was to show the associations among multidisciplinary treatment outcomes, pretreatment psychological factors, self-reported pain levels, and history of pain in chronic low back pain patients. [Subjects and Methods] A total of 221 chronic low back pain patients were chosen for the study. The pretreatment scores for the 10-cm Visual Analogue Scale, Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale, Short-Form McGill Pain Questionnaire, Pain Disability Assessment Scale, pain drawings, and history of pain were collected. The patients were divided into two treatment outcome groups a year later: a good outcome group and a poor outcome group. [Results] One-hundred eighteen patients were allocated to the good outcome group. The scores for the Visual Analogue Scale, Pain Disability Assessment Scale, and affective subscale of the Short-Form McGill Pain Questionnaire and number of nonorganic pain drawings in the good outcome group were significantly lower than those in the poor outcome group. Duration of pain in the good outcome group was significantly shorter than in the poor outcome group. [Conclusion] These findings help better predict the efficacy of multidisciplinary treatments in chronic low back pain patients.

The effects of exercise therapy for the improvement of jaw movement and psychological intervention to reduce parafunctional activities on chronic pain in the craniocervical region.

PURPOSE: Apparent organic abnormalities are sometimes not identified among patients suffering from chronic pain in the craniocervical region. In some cases, parafunctional activities (PAs) are recognized. PAs are nonfunctional oromandibular activities that include jaw clenching and bruxism, but are considered as factors that contribute to craniomandibular disorders (CMDs). It is now recognized that PAs and CMDs influence musculoskeletal conditions of the upper quarter. Exercise therapy (ET) to improve jaw movement and psychological intervention (PI) to reduce PAs are useful for PAs and CMDs. We hypothesized that ET and PI would be effective for craniocervical pain without organic abnormalities. METHODS: Thirty-nine subjects suffering from craniocervical chronic pain were allocated into 3 groups: The control group received only pharmacological treatment; the ET group received jaw movement exercise (JME); and the ET-PI group received JME and PI. Pain and jaw movement were evaluated using a numerical rating scale (NRS). RESULTS: After interventions, the NRS scores were significantly lower in the ET-PI group, compared with those in the other groups. Jaw movement improved 100% in the ET group, 92% in the ET-PI group, and 0% in the control group. CONCLUSION: A combination of jaw exercise and psychological intervention to reduce parafunctional activities is more effective than jaw exercise alone for the improvement of craniocervical pain without apparent organic abnormalities.

Pulsed radiofrequency treatment within brachial plexus for the management of intractable neoplastic plexopathic pain.

We report on the use of pulsed radiofrequency (RF) within the plexus for the management of intractable pain in three patients with metastatic or invasive plexopathy. The patients were a 38-year-old woman with a history of breast cancer 6 years earlier whose computed tomography (CT) scans revealed a mass lesion at the infraclavicular part of the right brachial plexus, a 68-year-old man diagnosed with advanced lung cancer whose CT scans revealed a bone metastasis in the right humerus invading the axillary region of the right brachial plexus, and a 67-year-old woman diagnosed with advanced lung cancer whose CT scans revealed a bone metastasis in the left humerus invading the axillary region of the left brachial plexus. Ultrasound-guided pulsed RF was performed within the interscalene brachial plexus. During the follow-up period, their intractable pain was moderately controlled.

Intravenous lidocaine and magnesium for management of intractable trigeminal neuralgia: a case series of nine patients.

Most patients suffering from trigeminal neuralgia (TN) benefit from medical therapy, for example carbamazepin, gabapentin, and pregabalin, individually or in combination. Nonetheless, some patients experience severe and intractable pain despite such medication, or the medication eliminates their pain but they experience intolerable side effects sufficient to warrant discontinuation. Intravenous magnesium and lidocaine have been used for management of intractable neuropathic pain. We treated nine patients with TN by using an intravenous infusion of a combination of 1.2 g magnesium and 100 mg lidocaine for 1 hour, once a week for 3 weeks. All patients experienced sound pain relief after the combined intravenous infusion therapy. Two patients experienced short and mild dizziness after the therapy, but no severe side effects were reported.

Associations between Degenerative Lumbar Scoliosis Structures and Pain Distribution in Adults with Chronic Low Back Pain.

BACKGROUND: This study aimed to investigate the location and distribution of pain in adults with chronic low back pain (LBP) with degenerative lumbar scoliosis (DLS) according to coronal deformities. METHODS: We enrolled 100 adults with chronic LBP and DLS, dividing them into two groups, a right-convex DLS group (n = 50) and a left-convex DLS group (n = 50). Dominant pain location was analyzed by dividing it into three parts-left side, right side, and center-and pain areas were identified using the pain drawing method; then, a heat map was created for each group. An association between pain location and convex side was analyzed as the primary outcome. Additionally, we assessed pain characteristics and radiological parameters, such as the curve structure and degree of degeneration. We used the Mann-Whitney U test or the chi-squared test to compare the clinical characteristics of the two groups, and generalized linear models were utilized to determine which variables were associated with pain severity or pain area. RESULTS: The results indicated that there was no significant difference between the two groups in terms of the association between the curve structure, pain severity and location. In multivariate analysis, although we did not find any variables associated with pain severity, we observed that age and a left-convex DLS were negatively correlated with pain area among all participants. The heat map demonstrated that individuals with chronic LBP frequently experienced pain in the central lumbar region, regardless of the coronal curve structure. CONCLUSIONS: Our findings suggest that degenerative coronal lumbar deformities may not have a specific pain pattern associated with a curved structure.

Predictors of high-cost patients with acute whiplash-associated disorder in Japan.

INTRODUCTION: The proportion of neck injuries due to traffic accidents is increasing. Little is known about high-cost patients with acute whiplash-associated disorder (WAD). The present study aimed to investigate whether time to first visit for conventional medicine, multiple doctor visits, or alternative medicine could predict high-cost patients with acute WAD in Japan. METHODS: Data from a compulsory, no-fault, government automobile liability insurance agency in Japan between 2014 and 2019 were used. The primary economic outcome was the total cost of healthcare per person. Treatment-related variables were assessed based on the time to first visit for conventional and alternative medicine, multiple doctor visits, and visits for alternative medicine. Patients were categorized according to total healthcare cost (low, medium, and high cost). The variables were subjected to univariate and multivariate analysis to compare high-cost and low-cost patients. RESULTS: A total of 104,911 participants with a median age of 42 years were analyzed. The median total healthcare cost per person was 67,366 yen. The cost for consecutive medicine, for consecutive and alternative medicine, and total healthcare costs were significantly associated with all clinical outcomes. Female sex, being a homemaker, a history of WAD claim, residential area, patient responsibility in a traffic accident, multiple doctor visits, and visits for alternative medicine were identified as independent predictive factors for a high cost in multivariate analysis. Multiple doctor visits and visits for alternative medicine showed large differences between groups (odds ratios 2673 and 694, respectively). Patients with multiple doctor visits and visits for alternative medicine showed a significantly high total healthcare cost per person (292,346 yen) compared to those without (53,587 yen). CONCLUSIONS: A high total healthcare cost is strongly associated with multiple doctor visits and visits for alternative medicine in patients with acute WAD in Japan.

Evaluating the Relationship Between Acute Pain Perception and Gut Microbiota Among Female University Students in Japan: A Prospective Cohort Study.

The gut microbiota (GM) plays an important role in gut-brain communication, and the 'gut-brain axis' has attracted much attention as a factor influencing human host health. We previously reported that pain perception may be associated with GM composition in males. The aim of this study was to investigate the relationship between GM composition and pain perception among 42 healthy female university students in Japan. Pain perception was evaluated by pressure pain threshold (PPT), current perception threshold (CPT), temporal summation of pain (TSP), conditioned pain modulation (CPM), and a questionnaire on psychological state. CPT was stimulated at 5, 250, and 2,000 Hz, which reflected the thresholds of the C, Aδ, and Aß fibers, respectively. Also, GM composition was estimated using 16S rRNA analysis. The lower alpha diversity was associated with, the lower PPT (rs = 0.330, P < 0.05) and CPT of 2000 Hz (re = 0.339, P < 0.05). Furthermore, alpha diversity was identified as an explanatory variable for PPT (ß = 0.424, P < 0.01) and TSP (ß = -0.317, P < 0.05), alpha diversity and state anxiety for CPT of 2000 Hz (ß = 0.321, P < 0.05), and state anxiety for CPT of 250 Hz (ß = 0.320, P < 0.05). However, there was no relationship between the rate of major phylum and pain perception.

Two Key Symptoms for Detecting Vertebral Compression Fracture among Elderly People with Acute Low Back Pain.

Introduction: This study aimed to investigate whether difficulties in some motions concomitant with increased spinal loads would distinguish between patients with and without fresh vertebral compression fractures (VCFs) in elderly patients with acute low back pain. Methods: Of the 85 screened patients aged 65 years and older, 80 eligible participants were enrolled. Participants were asked about difficulties (none, slightly, and extreme) in getting up and rolling over and then divided into the VCF group or the non-VCF group after imaging examinations. A logistic regression model was used to determine whether the following variables were associated with the presence of fresh VCFs: age, sex, pain duration, pain severity, and difficulties in getting up and rolling over. Then, a multivariate stepwise logistic regression model was used to determine which variable correlated with the presence of fresh VCFs. Subsequently, we created a key symptom score for the presence of fresh VCFs, and discrimination of fresh VCFs was tested using the receiver operating characteristic (ROC) curve. Results: In the multivariate logistic regression analysis, difficulties in getting up (p<0.05) and rolling over (p<0.01) were associated with VCFs after controlling for age, sex, and pain severity. As we weighted with 0, 1, or 2 to assess the severity of key symptoms, the score ranged from 0 to 4. The ROC curve showed that scoring of the two key symptoms significantly discriminated participants with or without VCFs with an area under curve=0.88 (p<0.001). A score of 2 on the key symptom score showed a sensitivity of 97%, and a score of 4 showed a specificity of 95% for fresh VCFs. Conclusions: The results indicate that there may be specific symptoms in elderly patients with fresh VCFs. Scoring of the two key symptoms may be useful for screening fresh VCFs in this population.