Peripheral Activation of Formyl Peptide Receptor 2/ALX by Electroacupuncture Alleviates Inflammatory Pain by Increasing Interleukin-10 Levels and Catalase Activity in Mice.

In the context of the electroacupuncture (EA) neurobiological mechanisms, we have previously demonstrated the involvement of formyl peptide receptor 2 (FPR2/ALX) in the antihyperalgesic effect of EA. The present study investigated the involvement of peripheral FPR2/ALX in the antihyperalgesic effect of EA on inflammatory cytokines levels, oxidative stress markers and antioxidant enzymes in an animal model of persistent inflammatory pain. Male Swiss mice underwent intraplantar (i.pl.) injection with complete Freund's adjuvant (CFA). Mechanical hyperalgesia was assessed with von Frey monofilaments. Animals were treated with EA (2/10 Hz, ST36-SP6, 20 minutes) for 4 consecutive days. From the first to the fourth day after CFA injection, animals received i.pl. WRW4 (FPR2/ALX antagonist) or saline before EA. Levels of inflammatory cytokines (TNF, IL-6, IL-4 and IL-10), antioxidant enzymes (catalase and superoxide dismutase), oxidative stress markers (TBARS, protein carbonyl, nitrite/nitrate ratio), and myeloperoxidase activity were measured in paw tissue samples. As previously demonstrated, i.pl. injection of the FPR2/ALX antagonist prevented the antihyperalgesic effect induced by EA. Furthermore, animals treated with EA showed higher levels of IL-10 and catalase activity in the inflamed paw, and these effects were prevented by the antagonist WRW4. EA did not change levels of TNF and IL-6, SOD and MPO activity, and oxidative stress markers. Our work demonstrates that the antihyperalgesic effect of EA on CFA-induced inflammatory pain could be partially associated with higher IL-10 levels and catalase activity, and that these effects may be dependent, at least in part, on the activation of peripheral FPR2/ALX.

Disparities in access to health care in adults with sinusitis in the United States.

BACKGROUND: Sinusitis can significantly decrease quality of life, is costly in both health care expenditure and lost productivity, and can lead to complications if treatment is delayed. Our objective was to explore disparities in health care access among adults with sinusitis based on sociodemographic factors. METHODS: A total of 32,994 participants (representing 244,838,261 US adults) who completed the 2016 National Health Interview Survey (NHIS) were analyzed, of whom 12.17% were diagnosed with sinusitis at least once in the prior 12 months. Multivariate regression analyses were performed. RESULTS: In regression analyses, female sex (odds ratio [OR], 2.00 [95% confidence interval (CI), 1.79-2.24]; p < 0.001) and older age groups were associated with increased odds of having sinusitis. Within the sinusitis cohort, Asian race (OR, 5.97 [95% CI, 1.61-22.12]; p = 0.008) and Hispanic ethnicity (OR, 6.97 [95% CI, 3.22-15.06]; p < 0.001) were associated with increased odds of obtaining foreign medications. Individuals with Medicaid had decreased odds of delaying care (OR, 0.37 [95% CI, 0.25-0.56]; p < 0.001) or not receiving care due to cost (OR, 0.40 [95% CI, 0.24-0.65]; p < 0.001), but increased odds of delaying care due to transportation barriers (OR, 4.64 [95% CI, 2.52-8.55]; p < 0.001). Uninsured individuals had higher odds for delaying care (OR, 4.97 [95% CI, 3.35-7.38]; p < 0.001) and not receiving care (OR, 5.46 [95% CI, 3.56-8.38]; p < 0.001) due to cost. Income >$100,000 was associated with a nearly 90% reduction in inability to obtain care due to cost (OR, 0.11 [95% CI, 0.05-0.21]; p < 0.001) and an over 99% reduction in inability to obtain care due to transportation issues compared with income < $35,000 (OR, 0.01 [95% CI, 0.00-0.04]; p< 0.001). CONCLUSION: Significant disparities in health care access based on race, health insurance status, and income exist among adults with sinusitis in the United States.

Perceptions of Respect Among Patients With Hearing Loss in the United States.

Hearing loss is a common condition that can lead to disability and significantly impact the quality of life. However, as the literature investigating the relationship between hearing loss and patients' perception of respect within the clinical setting is lacking, we performed a retrospective, cross-sectional analysis of the 2017 National Health Interview Survey to elucidate this interaction. After weights were applied, 16,295,495 patients (mean age: 63.79, standard error: 0.28) with hearing loss were identified. Multivariable logistic regression analyses found that those with self-reported hearing loss were less likely to report being treated with respect by their healthcare providers (odds ratio [OR], 0.766; [95% confidence interval, CI: 0.691-0.848]) and less likely to be asked about their beliefs/opinions about the care that they received (OR, 0.842; [95% CI: 0.774-0.916]), indicating a possible disparity in care. Further investigation is needed to examine how this patient population is treated and how providers can create a more inclusive environment.

Vestibular Vertigo and Disparities in Healthcare Access Among Adults in the United States.

OBJECTIVE: Vertigo and dizziness have a high lifetime prevalence with significant impacts on daily life. We sought to explore differences in access to and ability to afford care among adults with vestibular vertigo by race/ethnicity, income, and insurance type. DESIGN: This is a cross-sectional study using the 2016 National Health Interview Survey. A total of 32,047 adults who completed the 2016 National Health Interview Survey Balance Supplement were analyzed. We used a previously validated definition of vertigo defined as (1) positional vertigo, (2) rotational vertigo, or (3) recurrent dizziness with nausea and either oscillopsia or imbalance. We examined several self-reported measures of healthcare utilization and access. RESULTS: Among adults with vestibular vertigo, African Americans had significantly increased odds of delayed care due to lack of transportation; Hispanic ethnicity was associated with decreased odds of skipping medication doses and asking a doctor for a lower-cost medication. Adults with public insurance had significantly lower odds of reporting delayed care due to worry about cost, not receiving medical care due to cost, and delayed filling of a prescription, but had greater odds of reporting delayed care due to lack of transportation. Lack of insurance and lower income were associated with increased odds of delaying and not receiving care due to cost. CONCLUSION: These findings demonstrate significant differences in access to care among adults with vestibular vertigo in the United States based on race, income, and health insurance status.

Revision Rates of Septoplasty in the United States.

Background: Large-scale studies characterizing septoplasty revision rates are lacking. Objectives: To identify rates of septoplasty revision in the United States. Methods: Patients undergoing initial septoplasty between January 1, 2007 and December 31, 2013 were identified using the IBM® MarketScan® Commercial Database. Patients were excluded if they had nasal vestibular stenosis, rhinoplasty, or costal cartilage grafts for the initial surgery, or did not have either septoplasty, nasal vestibular stenosis, rhinoplasty, and/or costal cartilage grafts for the second surgery. Results: 295,236 patients received an initial septoplasty, and 3213 (1.1%) patients underwent a revision. Among the revision group, 178 (5.4%) patients received a septorhinoplasty, among which 13 (7.3%) required a costal cartilage graft. Older patients were less likely to need revision surgery (RS). Patients in the Northeast and West were significantly more likely than patients in the Midwest to undergo RS. Insurance plans such as comprehensive and point-of-service were associated with greater odds of RS, whereas others such as high-deductible health plans were associated with lower odds. Conclusion: Septoplasty revision rates are relatively low at 1.1% but influenced by age, region, and insurance plan.

Difference in Perception of Nasal Aesthetic Appearance Between Surgeons and Rhinoplasty Patients: A Single-Center Perspective.

BACKGROUND: Patient satisfaction is an essential outcome measure after a rhinoplasty. Yet it is not known whether the opinions of rhinoplasty patients and surgeons on nasal aesthetic appearance differ. OBJECTIVES: The aim of this study was to determine the differences between patients and surgeons in their perception of nasal aesthetic appearance. METHODS: A retrospective cohort of 300 patients seen in consultation for cosmetic, functional, or combined cosmetic and functional rhinoplasty at a single tertiary care center from June 2017 to June 2020 was studied. Based on preoperative patient images, 6 surgeons with varying levels of expertise assessed nasal aesthetics utilizing a modified Standardized Cosmesis and Health Nasal Outcomes Survey for nasal cosmesis (SCHNOS-C). These scores were then compared to the patient-reported SCHNOS-C scores. RESULTS: The cosmetic, functional, and combined subgroups consisted of 100 patients each. The mean [standard deviation] age was 35.4 [13.7] years and 64% were women. The modified SCHNOS-C scores were well-correlated among the 6 surgeons but showed only weak correlations of 0.07 to 0.20 between patient-reported scores and scores assessed by the surgeons. Compared with the surgeon's scores, patients in the cosmetic subgroup perceived their nasal aesthetic problems to be more severe whereas the those in the functional subgroup perceived their nasal aesthetic problems to be milder compared with the surgeons' assessment. CONCLUSIONS: Our findings suggest that patients and surgeons perceive nasal cosmesis differently. This difference should be considered carefully when planning rhinoplasty or assessing its outcome.

Septoplasty Revision Rates in Pediatric vs Adult Populations.

Importance: Although septal deviations are highly prevalent in the pediatric population and pediatric septoplasties are garnering more discussion, to date, there are no large-scale studies characterizing pediatric septoplasty revision rates. Objective: To identify rates of pediatric septoplasty revision in the US. Design, Setting, and Participants: This retrospective, observational cohort study used administrative claims data from the IBM MarketScan Commercial Database (which contains inpatient and outpatient data for millions of patients and dependents covered by employer-sponsored private health insurance in the US) to identify patients undergoing septoplasty between January 1, 2007, and December 31, 2016. Patients 18 years or younger were included in the study as the pediatric cohort, and patients aged 19 to 65 years were included as the adult cohort for comparison. Patients were excluded if the initial surgery included rhinoplasty, nasal vestibular stenosis, or costal cartilage grafts or if the second surgery did not have nasal vestibular stenosis, septoplasty, rhinoplasty, and/or cartilage grafts. Main Outcomes and Measures: Outcomes included septoplasty revision rate, septoplasty-to-rhinoplasty conversion rate, and associated risks for revision surgery. Collected data were analyzed between January 1 and July 30, 2022. Results: A total of 24 322 pediatric patients (mean [SD] age, 15.7 [2.5] years; 15 121 boys [62.2%]) who underwent an initial septoplasty were identified, of whom 704 (2.9%) received a revision. In the adult cohort of 286 218 patients (mean [SD] age, 41.4 [12.2] years; 162 893 [56.9%] men), 3081 individuals (1.1%) received a revision. Within the pediatric revision group, 66 patients (9.4%) received a rhinoplasty vs 162 (5.3%) in the adult revision group. All pediatric age groups had higher revision rates than the adult population, with the 9- to 13-year-old group having the highest rates of revision (118 of 2763 [4.3%]). Patients in the West and Northeast, along with those with point of service and health maintenance organization health plans, were more likely to receive a revision. Conclusion and Relevance: The findings of this cohort study suggest that pediatric patients are more likely to receive a revision surgery than their adult counterparts. Furthermore, pediatric patients are more likely than adults to receive a rhinoplasty as their revision surgery. These findings provide valuable information that may be used to inform clinical decision-making, although further research is needed to better identify the causes for pediatric septoplasty revision.

The Cost of Return to Play Protocols in Collegiate Athletes Recovering from Coronavirus Disease 2019.

INTRODUCTION/PURPOSE: SARS-CoV-2 infection (COVID-19) can result in myocarditis. Protocols were developed to allow competitive athletes to safely return to play (RTP) after a COVID-19 infection, but the financial impact of these protocols is unknown. Our objective was to determine the differential cost of post-COVID-19 RTP protocols for competitive collegiate athletes. METHODS: This multicenter retrospective cohort study of clinical evaluation of 295 athletes after COVID-19 infection was performed at four institutions with three RTP protocols. Costs were calculated using adjusted Center for Medicare and Medicaid Services pricing. All athletes underwent electrocardiogram and clinical evaluation. A tiered approach performed cardiac imaging and biomarker analysis for major symptoms. A universal transthoracic echocardiogram (TTE) approach performed TTE and biomarkers for all athletes. A universal exercise stress echocardiogram (ESE) approach performed ESE and biomarkers for all athletes. RESULTS: The cost per athlete was $632.51 ± 651.80 ($44,908 total) in tiered group (n = 71), $1,072.30 ± 517.93 ($87,928 total) in the universal TTE group (n = 82), and $1357.38 ± 757.05 ($192,748 total) in the universal ESE group (n = 142) (P < 0.001). Extrapolated national costs for collegiate athletes would be $39 to 64 million higher for universal imaging approaches versus a tiered approach. Only seven athletes had probable/possible myocarditis with no significant difference between approaches. CONCLUSIONS: Cardiac screening in collegiate athletes after COVID-19 infection resulted in significant cost to the health care system. A tiered-based approach was more economical, and a universal exercise echocardiogram group detected slightly more myocardial abnormalities by cardiac magnetic resonance imaging. The clinical consequences of these approaches are unknown.

Widespread myofascial dysfunction and sensitisation in women with endometriosis-associated chronic pelvic pain: A cross-sectional study.

BACKGROUND: Chronic pelvic pain persists in some women with endometriosis even after lesion removal and optimized hormonal treatment. OBJECTIVE: Characterize the presence and distribution of pain, myofascial dysfunction and sensitisation beyond the pelvis in women with endometriosis-associated chronic pelvic pain. METHODS: Cross-sectional study of 30 women prior to participation in a clinical trial. Evaluation included pain-focused abdominopelvic gynaecologic examination with the identification of pelvic floor muscle spasm. Neuro-musculoskeletal examination assessed paraspinal allodynia and hyperalgesia bilaterally and myofascial trigger points in 13 paired muscles. Pressure-pain thresholds were measured over interspinous ligaments and trigger points. Women completed the body territories element of the Body Pain Index. RESULTS: All women had a pelvic floor muscle spasm that they self-identified as a major focus of pain. Twenty of 30 women described their pelvic pain as focal. However, all demonstrated widespread myofascial dysfunction with low pressure-pain thresholds and trigger points in over two-thirds of 26 assessed regions. Widespread spinal segmental sensitisation was present in 17/30, thoracic in 21/30 and lumbosacral/pelvic in 18/30. Cervical sensitisation manifested as low pressure-pain thresholds with 23/30 also reporting recurrent, severe headaches and 21/30 experiencing orofacial pain. Those reporting diffuse pelvic pain were more likely to have widespread (p = .024) and lumbosacral/pelvic (p = .036) sensitisation and report over 10 painful body areas (p = .009). CONCLUSIONS: Women with endometriosis-associated chronic pelvic pain often have myofascial dysfunction and sensitisation beyond the pelvic region that may be initiated or maintained by on-going pelvic floor spasm. These myofascial and nervous system manifestations warrant consideration when managing pain in this population. Clinicaltrials.gov identifier: NCT01553201. SIGNIFICANCE: Women with endometriosis often have pelvic pain persisting after surgery despite hormonal therapies and these women have regional pelvic sensitisation and myofascial dysfunction. Pelvic floor muscle spasm is a major pain focus in this population. Sensitisation and myofascial dysfunction are widespread, beyond the pelvic region. On-going pelvic floor spasm may initiate or maintain sensitisation. Myofascial/sensitisation manifestations warrant consideration when managing pain in this population.

Increase in Lactate Without Change in Nutritive Blood Flow or Glucose at Active Trigger Points Following Massage: A Randomized Clinical Trial.

OBJECTIVE: To investigate changes in nutritive blood flow as well as interstitial glucose and lactate within an active myofascial trigger point (MTrP) following massage. DESIGN: Randomized, placebo-controlled trial. SETTING: Subjects were recruited from the general population; procedures were conducted at a research center affiliated with a university hospital. PARTICIPANTS: Adults (N=25) (18-49y old) with episodic or chronic tension-type headache and an active MTrP in the upper trapezius muscle. INTERVENTIONS: Subjects were randomized to receive a single trigger point (TrP) release massage or sham ultrasound (US) treatment at an active MTrP in the upper trapezius muscle. Microdialysis was used to continuously sample interstitial fluid from the MTrP before, during, and for 60 minutes following intervention. MAIN OUTCOME MEASURES: The primary outcome measure was nutritive blood flow within the MTrP as measured by microdialysis ethanol clearance; secondary measures included dialysate glucose, dialysate lactate, and subject discomfort with the procedures. Pressure-pain threshold (PPT) was determined to assess treatment effectiveness. RESULTS: There was no treatment effect of TrP release massage on nutritive blood flow (P=.663) or dialysate glucose (P=.766). The interaction for lactate was significant indicating that dialysate lactate increased for TrP release massage vs sham US (P=.04); maximum lactate increase over baseline was observed at 60 minutes after TrP release massage (P=.007, 0.128 µM, 95% confidence interval 0.045-0.212). Pain evoked by probe placement into an active MTrP was low. An interaction effect on PPT was significant (P=.005). CONCLUSION: TrP release massage of an active MTrP affected anaerobic metabolism as represented by an increase in dialysate lactate without change in nutritive blood flow or dialysate glucose. The lack of a treatment effect on blood flow is discussed.

Current clinical, radiological and treatment perspectives of patellofemoral pain syndrome.

Anterior knee pain in active young adults is commonly related to patellofemoral pain syndrome, which can be broadly classified into patellar malalignment and patellar maltracking. Imaging is performed to further elucidate the exact malalignment and maltracking abnormalities and exclude other differentials. This article details the role of the stabilizers of the patellofemoral joint, findings on conventional and multimodality imaging aiding in patellofemoral pain syndrome diagnosis and characterization, and current perspectives of various treatment approaches.

Relating Chronic Pelvic Pain and Endometriosis to Signs of Sensitization and Myofascial Pain and Dysfunction.

Chronic pelvic pain is a frustrating symptom for patients with endometriosis and is frequently refractory to hormonal and surgical management. While these therapies target ectopic endometrial lesions, they do not directly address pain due to central sensitization of the nervous system and myofascial dysfunction, which can continue to generate pain from myofascial trigger points even after traditional treatments are optimized. This article provides a background for understanding how endometriosis facilitates remodeling of neural networks, contributing to sensitization and generation of myofascial trigger points. A framework for evaluating such sensitization and myofascial trigger points in a clinical setting is presented. Treatments that specifically address myofascial pain secondary to spontaneously painful myofascial trigger points and their putative mechanisms of action are also reviewed, including physical therapy, dry needling, anesthetic injections, and botulinum toxin injections.

Beneficial Effects of Dry Needling for Treatment of Chronic Myofascial Pain Persist for 6 Weeks After Treatment Completion.

BACKGROUND: Dry needling is an effective treatment for reducing pain associated with active myofascial trigger points (a-MTrPs) in the short term. The duration of the benefits of this treatment have not been fully assessed. OBJECTIVE: To determine whether the benefits of dry needling (DN) of a-MTrPs are sustained 6 weeks posttreatment. DESIGN: Follow-up of a prospective study. SETTING: University. PARTICIPANTS: A total of 45 patients (13 male and 32 female) with cervical pain >3 months and a-MTrPs in the upper trapezius who completed 3 DN treatments and who were evaluated 6 weeks posttreatment. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Primary outcomes were changes from baseline to follow-up in scores for the verbal analogue scale (VAS), Brief Pain Inventory (BPI), and MTrP status. MTrPs were rated as active (spontaneously painful), latent (painful only on compression), and nonpalpable nodule. Responders were patients whose MTrP status changed from active to latent or nonpalpable nodule (resolved). Secondary outcomes were pain pressure threshold (PPT), Profile of Mood States, Oswestry Disability Index (ODI), MOS 36-Item Short-Form Health Survey (SF-36), and cervical range of motion. RESULTS: Pain measures remained significantly improved 6 weeks posttreatment (P < .003), as did the SF-36 physical functioning score (0.01) and ODI (P = .002). Side bending and PPT for subjects with unilateral MTrPs had sustained improvement (P = .002). The number of subjects with sustained MTrP response at 6 weeks was significant (P < .001). Comparing responders to nonresponders, the changes in VAS and BPI were statistically significant (P = .006, P = .03) but the change in PPT was not. Patients with higher baseline VAS scores had a higher risk of not responding to DN; those with a greater drop in VAS score from baseline had a higher probability of sustained response. A 1-unit decrease in VAS at baseline resulted in a 6.3-fold increase in the odds of being a responder versus a nonresponder (P = .008). CONCLUSIONS: In this study, there was sustained reduction of pain scores after completion of DN, which is more likely with a greater drop in VAS score. Patients with higher baseline VAS scores are less likely to respond to DN. Early intervention toward significant pain reduction is likely to be associated with sustained clinical response. LEVEL OF EVIDENCE: IV.

Novel Use of Ultrasound Elastography to Quantify Muscle Tissue Changes After Dry Needling of Myofascial Trigger Points in Patients With Chronic Myofascial Pain.

OBJECTIVES: To compare a mechanical heterogeneity index derived from ultrasound vibration elastography with physical findings before and after dry-needling treatment of spontaneously painful active myofascial trigger points in the upper trapezius muscle. METHODS: Forty-eight patients with chronic myofascial pain enrolled in a prospective interventional trial of 3 weekly dry-needling treatments for active myofascial trigger points. Trigger points were evaluated at baseline and at treatment completion using palpation, the pressure-pain threshold, and the mechanical heterogeneity index. Thirty patients were reevaluated at 8 weeks. Trigger points that "responded" changed to tissue that was no longer spontaneously painful, with or without the presence of a palpable nodule. Trigger points that "resolved" changed to tissue without a palpable nodule. The mechanical heterogeneity index was defined as the proportion of the upper trapezius muscle that appeared mechanically stiffer on elastography. Statistical significance for comparisons was determined at P < .05. RESULTS: Following 3 dry needle treatments, the mechanical heterogeneity index decreased significantly for the 38 myofascial trigger points (79% of 48) that responded to treatment. Among these, the baseline mechanical heterogeneity index was significantly lower for the 13 trigger points (27% of 38) that resolved, but the decrease after 3 dry needle treatments did not reach significance. The pressure-pain threshold improved significantly for both groups. At 8 weeks, the mechanical heterogeneity index decreased significantly for the 22 trigger points (73% of 30) that responded and for the 10 (45% of 22) that resolved. The pressure-pain threshold improvement was significant for trigger points that responded but did not reach significance for resolved trigger points. CONCLUSIONS: The mechanical heterogeneity index identifies changes in muscle tissue properties that correlate with changes in the myofascial trigger point status after dry needling.

Torsional Fracture of the Humerus after Subpectoral Biceps Tenodesis with an Interference Screw: A Biomechanical Cadaveric Study.

BACKGROUND: Humeral fracture following subpectoral biceps tenodesis has been previously reported; however, there are no published biomechanical studies reporting the resulting torsional strength of the humerus. Our purpose was to determine if there is an increased risk of humerus fracture after subpectoral biceps tenodesis with an interference screw and to determine if screw size is also a factor. We hypothesized that limbs receiving the procedure would have reduced failure torque and rotation under external rotation compared to untreated controls and that the larger screw size would result in inferior mechanical properties compared to the smaller. METHODS: Twenty matched pairs of embalmed cadaveric humeri were subjected to subpectoral biceps tenodesis using either a 6.25 or 8.0mm interference screw, with the untreated contralateral limb serving as a control. Each humerus was mechanically tested in torsional external rotation to failure. FINDINGS: Maximum torque and rotation to failure were reduced in the tenodesis group compared to controls; however, there was no difference between screw sizes. When both screw sizes were combined into a single group, paired t-tests also showed similar differences. INTERPRETATION: Based on our experiment, there is an increased risk for humerus spiral fracture when subjected to torsional external rotation after subpectoral biceps tenodesis with an interference screw compared to an intact humerus; however, there is not a significant difference between a 6.25mm and 8.0mm screw. Surgeons may elect to use alternative fixation methods in patients at high risk (e.g., overhead throwing athletes, etc.) for torsional loads and fracture.

Myofascial Trigger Points Then and Now: A Historical and Scientific Perspective.

The intent of this article is to discuss the evolving role of the myofascial trigger point (MTrP) in myofascial pain syndrome (MPS) from both a historical and scientific perspective. MTrPs are hard, discrete, palpable nodules in a taut band of skeletal muscle that may be spontaneously painful (i.e., active) or painful only on compression (i.e., latent). MPS is a term used to describe a pain condition that can be acute or, more commonly, chronic and involves the muscle and its surrounding connective tissue (e.g. fascia). According to Travell and Simons, MTrPs are central to the syndrome-but are they necessary? Although the clinical study of muscle pain and MTrPs has proliferated over the past two centuries, the scientific literature often seems disjointed and confusing. Unfortunately, much of the terminology, theories, concepts, and diagnostic criteria are inconsistent, incomplete, or controversial. To address these deficiencies, investigators have recently applied clinical, imaging (of skeletal muscle and brain), and biochemical analyses to systematically and objectively study the MTrP and its role in MPS. Data suggest that the soft tissue milieu around the MTrP, neurogenic inflammation, sensitization, and limbic system dysfunction may all play a role in the initiation, amplification, and perpetuation of MPS. The authors chronicle the advances that have led to the current understanding of MTrP pathophysiology and its relationship to MPS, and review the contributions of clinicians and researchers who have influenced and expanded our contemporary level of clinical knowledge and practice.

Ultrasonic characterization of the upper trapezius muscle in patients with chronic neck pain.

Myofascial trigger points (MTrPs) are palpable, tender nodules in taut bands of skeletal muscle that are painful on compression. MTrPs are characteristic findings in myofascial pain syndrome (MPS). The role of MTrPs in the pathophysiology of MPS is unknown. Localization, diagnosis, and clinical outcome measures of painful MTrPs can be improved by objectively characterizing and quantitatively measuring their properties. The goal of this study was to evaluate whether ultrasound imaging and elastography can differentiate symptomatic (active) MTrPs from normal muscle. Patients with chronic (>3 months) neck pain with spontaneously painful, palpable (i.e., active) MTrPs and healthy volunteers without spontaneous pain (having palpably normal muscle tissue) were recruited for this study. The upper trapezius muscles in all subjects were imaged, and the echotexture was analyzed using entropy filtering of B-mode images. Vibration elastography was performed by vibrating the muscle externally at 100 Hz. Color Doppler variance imaging was used to quantify the regions of color deficit exhibiting low vibration amplitude. The imaging measures were compared against the clinical findings of a standardized physical exam. We found that sites with active MTrPs (n = 14) have significantly lower entropy (p < 0.05) and significantly larger nonvibrating regions (p < 0.05) during vibration elastography compared with normal, uninvolved muscle (n = 15). A combination of both entropy analysis and vibration elastography yielded 69% sensitivity and 81% specificity in discriminating active MTrPs from normal muscle. These results suggest that active MTrPs have more homogeneous texture and heterogeneous stiffness when compared with normal, unaffected muscle. Our methods enabled us to improve the imaging contrast between suspected MTrPs and surrounding muscle. Our results indicate that in subjects with chronic neck pain and active MTrPs, the abnormalities are not confined to discrete isolated nodules but instead affect the milieu of the muscle surrounding palpable MTrPs. With further refinement, ultrasound imaging can be a promising objective method for characterizing soft tissue abnormalities associated with active MTrPs and elucidating the role of MTrPs in the pathophysiology of MPS.

Reliability of the dial test using a handheld inclinometer.

PURPOSE: The primary purpose of this study was to investigate the intra-tester and inter-tester reliability of the dial test using a handheld digital inclinometer. Additionally, we examined the responsiveness of the test, and side-to-side differences for meaningful comparison. MATERIALS/METHODS: Twenty-four healthy subjects (22.5 ± 2.8 years) participated in the study. The dial test was performed on both knees at 30° and 90° of knee flexion with the subject supine. While maintaining a neutral position of the ankle, an inclinometer was positioned parallel to the medial border of the foot to quantify external rotation of the tibia. Two examiners performed the dial test in a blinded manner. The minimal detectable change across repeated measures and side-to-side difference was calculated. RESULTS: Intra-tester reliability for examiner 1 (E1) was 0.83 at 30° knee flexion and 0.89 at 90° knee flexion. Reliability values for examiner 2 (E2) were 0.86 at 30° and 0.87 at 90° knee flexion. Inter-tester reliability was 0.74 at 30° and 0.83 at 90°. The minimal detectable change (MDC) for E1 at 30° was ±9.4° and ±7.4° at 90°. For E2, the MDC value was ±9.1° at 30° and ±8.3° at 90°. Ninety-five percent limits of agreement for side-to-side difference was 16.1° and 11.3° ° for E1 at 30° and 90° and for E2 13.9° at 30° and 14.1° at 90°. CONCLUSIONS: This instrumented dial test using a handheld digital inclinometer to measure external rotation can be performed with acceptable reliability in the clinical setting. A difference of 10° between two measurements on the same knee suggests that a meaningful change has occurred. For right to left comparison, differences greater than 15° suggest clinical significance. LEVEL OF EVIDENCE: III.