The hormonal profile in women using combined monophasic oral contraceptive pills varies across the pill cycle: a temporal analysis of serum endogenous and exogenous hormones using liquid chromatography with tandem mass spectroscopy.

Oral contraceptive pills, of all types, are used by approximately 151 million women worldwide; however, a clear understanding of the concentrations of endogenous and exogenous hormones across a 28-day combination monophasic oral contraceptive pill pack is not well described. In our study of 14 female participants taking various combination monophasic oral contraceptive pills, we found significant fluctuations in endogenous and exogenous hormone levels throughout the pill cycle. Our analysis revealed significantly greater levels of ethinyl estradiol on the 20th and 21st days of active pill ingestion, compared with days 1-2 (active) and days 27-28 (inactive pill ingestion). Conversely, estradiol concentrations decreased during active pill consumption, while progestin and progesterone levels remained stable. During the 7 days of inactive pill ingestion, estradiol levels rose sharply and were significantly higher at days 27-28 compared with the mid and late active phase time points, while ethinyl estradiol declined and progestin did not change. These findings challenge the previous assumption that endogenous and exogenous hormones are stable throughout the 28-day pill cycle.NEW & NOTEWORTHY The results from this study have wide-ranging implications for research and treatment in women's health including considerations in research design and interpretation for studies including women taking oral contraceptives, the potential for more precise and personalized methods of dosing to reduce unwanted side effects and adverse events, and the potential treatment of a variety of disorders ranging from musculoskeletal to neurological with exogenous hormones.

Sex and gender differences in lower limb chronic exertional compartment syndrome: a systematic review.

OBJECTIVES: Chronic exertional compartment syndrome (CECS) is a cause of exertional leg pain and has been reported in varying frequencies in males and females. Currently, it is unclear whether there are significant sex and gender differences in lower-limb CECS. Delineating sex and gender differences is vital in determining the causes of CECS and best treatments. This systematic review aimed to determine the sex/gender distribution of CECS and to assess for sex and gender differences in CECS diagnosis and outcomes. METHODS: PubMed (Medline), Cochrane Library, and EMBASE databases were searched for studies that were published from January 2000-March 2022 and reported lower-limb CECS data in males and/or females. Data on CECS diagnosis (intracompartmental pressures) and outcomes (e.g. post-surgical return-to-sport, need for re-operation) with sex/gender breakdowns were extracted. The sex/gender distribution of CECS and prevalence of CECS by sex/gender were calculated. RESULTS: Forty-one studies were included in the systematic review; there were 27 retrospective reviews, 8 prospective studies, and 6 retrospective studies with prospective follow-ups. Thirty studies involved surgical populations. Sex/gender distribution of CECS was calculated using data from 24 studies; 51% were female. Prevalence of CECS was available in five studies and ranged widely for males (54%-73%) and females (43%-65%). Intracompartmental pressure data varied by sex/gender. Male athletes were more likely than female athletes to return to sport following surgery for CECS, but variations in all other post-surgical outcomes were observed between sexes and genders in the general population. CONCLUSION: Females represented 51% of the patients who were diagnosed with CECS among studies. Most CECS diagnosis and outcomes data varied by sex/gender, except for post-surgical outcomes data in athletes, which demonstrated that males had higher rates of return to sport than females. Future studies are needed to examine factors contributing to sex and gender differences in CECS diagnosis and outcomes.

Link Between the Female Athlete Triad and Gymnastics-Related Injury in Retired Collegiate Gymnasts.

OBJECTIVES: To compare gymnastics-related injuries between former collegiate gymnasts who did and did not report components of the female athlete triad (Triad) during college, including disordered eating or menstrual irregularity. We hypothesized that athletes reporting these 2 triad symptoms would have higher rates of time loss injury and injuries requiring surgery. DESIGN: Retrospective case-control. SETTING: Online survey. PATIENTS: Four hundred seventy former collegiate gymnasts. INTERVENTIONS: Athletes completed online survey distributed through social media. MAIN OUTCOME MEASURES: Participants were grouped based on self-reported menstrual irregularity and disordered eating during college. We compared time loss injuries, injuries resulting in surgery, and injury locations between the groups using χ2 analyses. RESULTS: Seventy percent (n = 328) of participants in this study reported a time loss college injury without surgery, and 42% (n = 199) reported an injury during college that required surgical treatment. A significantly greater proportion of gymnasts with only disordered eating reported a time loss gymnastics injury (without surgery) compared with those who reported only menstrual irregularity during college (79% vs 64%; P =0 .03). A significantly greater proportion of the disordered eating-only group reported a spine injury compared with the menstrual irregularity-only group (P = 0.007) and the group who reported neither menstrual irregularity nor disordered eating (P = 0.006). CONCLUSIONS: College gymnasts who experienced disordered eating were more likely to experience a nonsurgical time loss injury while in college, as well as spine injury compared with those with menstrual irregularity. Sports medicine providers should be aware of the association between injuries and individual components of Triad in gymnasts beyond bone stress injuries.

Variability in Patient-Incurred Costs and Protocols of Regenerative Medicine Procedures for Musculoskeletal Conditions in the United States.

Background: The use of regenerative medicine as an "off label" treatment for musculoskeletal conditions has increased in recent years. However, the literature is sparse regarding the costs of these treatments to patients. Purposes: We sought to determine the patient-incurred costs for regenerative medicine treatments performed by physicians for musculoskeletal conditions in the United States, according to primary specialty, geographic region, practice setting, and years in practice. We also sought to characterize pre- and posttreatment protocols and image guidance use. Methods: We performed a cross-sectional study with data collection occurring between April 2020 and April 2021. It began with the distribution of an online survey through an email campaign by the American College of Sports Medicine to its members. Approximately 90 emails were sent by our research team as well. Throughout the year, various participant recruitment methods were used (through Twitter, for example). Survey data included physician demographics, practice/training information, types/costs of regenerative medicine treatments performed, and pre-/postprocedure protocols. Results: One hundred physicians who self-reported performing standalone regenerative medicine procedures participated in this online survey. According to the responses, the most common treatments performed were platelet-rich plasma (PRP; 100%), bone marrow concentrate (BMC; 41%), microfragmented adipose grafting (36%), prolotherapy (33%), and bone marrow aspirate (BMA; 21%) administered to the peripheral joints, tendons/muscles, ligaments, and/or spine. Overall, the respondents reported large variations in treatment costs to patients; BMA and BMC were the most expensive and had the largest ranges in costs for all anatomical locations. Costs for PRP were lower than those for BMA and BMC, with less variation. Physicians in private practice reported higher PRP, BMC, and BMA costs in the peripheral joints than those in academic settings. Most physicians recommended avoiding non-steroidal anti-inflammatory drugs pre- and postprocedure, and 74% recommended physical therapy postprocedure. Conclusions: Findings from a survey of physicians who provide regenerative medicine procedures as off-label treatment for musculoskeletal conditions suggest that there is variation in related patient-incurred costs. Future studies should explore associations between treatment costs and outcomes.

Intersection of surgical injuries and pain interference among former female collegiate gymnasts.

BACKGROUND: Gymnastics is a competitive sport with numerous health benefits. However, few data exist that examine the lasting effects of injuries in retired gymnasts. OBJECTIVE: To examine pain interference among former collegiate gymnasts. Specifically, we focused on the relationship between gymnastics-related injuries sustained during middle/high school or college that required surgery and former collegiate gymnasts' current pain. We hypothesized that injuries requiring surgery would be associated with increased pain and reduced function after retirement. DESIGN: Cross-sectional survey. SETTING: An online questionnaire was distributed to former female collegiate gymnasts via social media. PARTICIPANTS: A total of 447 former female collegiate gymnasts completed the survey and were grouped according to whether they indicated an injury during their middle/high school or collegiate gymnastics career that required surgery. MAIN OUTCOME MEASURES: The association between current pain interference (Patient-Reported Outcomes Measurement Information System [PROMIS] scale) and injuries in middle/high school or college that resulted in surgery. Pain interference elements included current enjoyment of life, ability to concentrate, participation in day-to-day activities, enjoyment of recreational activities, ability to perform errands, and ability to socialize with others. RESULTS: Those who reported an injury that resulted in surgery (n = 260; mean current age ± SD = 32.8 ± 9.5 years) were younger than those who did not at the time of survey completion (n = 187; current age: 37.0 ± 11.0 years) and reported beginning gymnastics at an earlier age (4.4 ± 2.0 years vs. 5.1 ± 2.5 years; p = .001). There were no statistically significant differences between the groups on any PROMIS questions. In secondary analyses, we found a small but significant association between beginning gymnastics at an earlier age and the odds of requiring surgery (odds ratio = 1.11, 95% confidence interval [CI] = 1.02-1.21; p = .02). CONCLUSIONS: Most retired gymnasts reported a gymnastics-related injury that required surgery. Gymnasts who start gymnastics at a younger age were more likely to sustain an injury that required surgery, but surgery was not associated with higher levels of pain interference.

Health outcomes among former female collegiate gymnasts: the influence of sport specialization, concussion, and disordered eating.

Objective: Gymnastics is a popular sport with high injury rates, especially at the collegiate level. There is limited evidence, however, regarding the risks of early specialization in this sport, the rate of concussions in gymnasts, and the long-term effects of disordered eating in gymnasts. We sought to describe health-related outcomes of former collegiate gymnasts and the association with early sport specialization, concussion history, and disordered eating.Methods: We distributed an online survey through social media outlets. A total of 473 former female collegiate gymnasts completed the survey and were grouped according to early (<14 years) specialization, presence or absence of concussion history, and history of disordered eating. We determined the number of participants who had time-loss injuries, injuries requiring surgery, and injuries resulting in retirement. We also evaluated menstrual history, reasons for sport retirement, functional outcome measures, and mental health.Results: The median age of gymnastics specialization was 8 years [interquartile range = 6-11 years]. The proportion of injuries sustained during college did not significantly differ by specialization age. A significantly greater proportion of early specializers required surgery for college sports-related injuries (60% vs. 44%; p = 0.02). Forty-two percent of the respondents reported concussion history, and a greater proportion of those with concussion history reported seeking mental health treatment during college (32% vs. 23%; p = 0.03), and anxiety disorder diagnosis (16% vs. 9%; p = 0.01). Disordered eating history was reported by 34% of the respondents, and this group had a higher proportion of time-loss injury (78% vs 65%; p = 0.004), and osteoporosis (4% vs 0%; p = 0.003) during college, and worse current pain (11.5 vs 10.2; p = 0.007) and physical function (12.2 vs 11.0; p = 0.01) than those without disordered eating.Conclusion: Athletes and clinicians should be aware of the long-term effects of early specialization, concussions, and disordered eating in gymnastics as these issues are common in female collegiate gymnasts.

The Efficacy of Telehealth for the Treatment of Spinal Disorders: Patient-Reported Experiences During the COVID-19 Pandemic.

BACKGROUND: The use of telehealth saw a rapid surge during the early months of the COVID-19 pandemic. There remains little data on how effectively telehealth replicates traditional office visits in the treatment of spinal disorders and how telehealth is perceived by patients with spinal disorders. QUESTIONS/PURPOSES: We sought to evaluate patient satisfaction with telehealth visits as a platform for delivering care for the treatment of spinal pathology. METHODS: Patients undergoing a telehealth visit with providers specializing in the treatment of spinal disorders (one surgeon and two physiatrists) were provided with an anonymous, online survey. Data on patient satisfaction, effectiveness of the telehealth visit (in comparison with in-person visits), and clarity of communication were collected through 5-point Likert scales; visit characteristics and free-text responses were also collected. RESULTS: Eighty-four patients responded to the survey. Their attitudes were largely positive, with an overall mean patient satisfaction score of 4.79. Patients gave high scores for clarity of communication during the visit, and for satisfaction with the formulation of treatment plans and their ability to ask questions, they gave the lowest scores to the effectiveness of telemedicine in replacing an in-person visit and ease of interface navigation. CONCLUSIONS: The high overall patient satisfaction reported by our patients seeking care for a spinal pathology supports the growing body of evidence promoting the use of telehealth for orthopedic care. Further research is needed in a standardized telehealth examination of patients with spinal disorders.

Musculoskeletal Consequences of COVID-19.

Coronavirus disease 2019 (COVID-19) is an emerging pandemic disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although the majority of patients who become infected with SARS-CoV-2 are asymptomatic or have mild symptoms, some patients develop severe symptoms that can permanently detract from their quality of life. SARS-CoV-2 is closely related to SARS-CoV-1, which causes severe acute respiratory syndrome (SARS). Both viruses infect the respiratory system, and there are direct and indirect effects of this infection on multiple organ systems, including the musculoskeletal system. Epidemiological data from the SARS pandemic of 2002 to 2004 identified myalgias, muscle dysfunction, osteoporosis, and osteonecrosis as common sequelae in patients with moderate and severe forms of this disease. Early studies have indicated that there is also considerable musculoskeletal dysfunction in some patients with COVID-19, although long-term follow-up studies have not yet been conducted. The purpose of this article was to summarize the known musculoskeletal pathologies in patients with SARS or COVID-19 and to combine this with computational modeling and biochemical signaling studies to predict musculoskeletal cellular targets and long-term consequences of the SARS-CoV-2 infection.

Sex Differences in Common Sports Injuries.

Common sports injuries include bone stress injuries (BSIs), anterior cruciate ligament (ACL) injuries, and concussions. Less commonly recognized are the specific sex differences in epidemiology, risk factors, and outcomes of these conditions by sex. An understanding of these factors can improve their clinical management, from prescribing appropriate prehabilitation to guiding postinjury rehabilitation and return to play. This narrative review summarizes the sex differences in the diagnosis and management of BSIs, ACL injuries, and concussions. Although BSIs are more common in female athletes, risk factors for both sexes include prior injury and relative energy deficiency in sport (RED-S). Risk factors in female athletes include smaller calf girth, femoral adduction, and higher rates of loading. Female athletes are also at greater risk for developing ACL injuries in high school and college, but their injury rate is similar in professional sports. Increased lateral tibial slope, smaller ACL size, and suboptimal landing mechanics are additional risk factors more often present in female athletes. Male athletes are more likely to have ACL surgery and have a higher rate of return to sport. Concussions occur more commonly in female athletes; however, female athletes are also more likely to report concussions. Male athletes more commonly sustain concussion through contact with another player. Female athletes more commonly sustain injury from contact with playing equipment. Managing post-concussion symptoms is important, and female athletes may have prolonged symptoms. An understanding of the sex-specific differences in these common sports injuries can help optimize their prehabilitation and rehabilitation. LEVEL OF EVIDENCE: IV.

Systematic review of the relationships between objectively measured physical activity and health indicators in school-aged children and youth.

Moderate-to-vigorous physical activity (MVPA) is essential for disease prevention and health promotion. Emerging evidence suggests other intensities of physical activity (PA), including light-intensity activity (LPA), may also be important, but there has been no rigorous evaluation of the evidence. The purpose of this systematic review was to examine the relationships between objectively measured PA (total and all intensities) and health indicators in school-aged children and youth. Online databases were searched for peer-reviewed studies that met the a priori inclusion criteria: population (apparently healthy, aged 5-17 years), intervention/exposure/comparator (volumes, durations, frequencies, intensities, and patterns of objectively measured PA), and outcome (body composition, cardiometabolic biomarkers, physical fitness, behavioural conduct/pro-social behaviour, cognition/academic achievement, quality of life/well-being, harms, bone health, motor skill development, psychological distress, self-esteem). Heterogeneity among studies precluded meta-analyses; narrative synthesis was conducted. A total of 162 studies were included (204 171 participants from 31 countries). Overall, total PA was favourably associated with physical, psychological/social, and cognitive health indicators. Relationships were more consistent and robust for higher (e.g., MVPA) versus lower (e.g., LPA) intensity PA. All patterns of activity (sporadic, bouts, continuous) provided benefit. LPA was favourably associated with cardiometabolic biomarkers; data were scarce for other outcomes. These findings continue to support the importance of at least 60 min/day of MVPA for disease prevention and health promotion in children and youth, but also highlight the potential benefits of LPA and total PA. All intensities of PA should be considered in future work aimed at better elucidating the health benefits of PA in children and youth.

Combinations of physical activity, sedentary behaviour and sleep: relationships with health indicators in school-aged children and youth.

The purpose of this systematic review was to determine how combinations of physical activity (PA), sedentary behaviour (SB), and sleep were associated with important health indicators in children and youth aged 5-17 years. Online databases (MEDLINE, EMBASE, SPORTdiscus, CINAHL, and PsycINFO) were searched for relevant studies examining the relationship between time spent engaging in different combinations of PA, SB, and sleep with the following health indicators: adiposity, cardiometabolic biomarkers, physical fitness, emotional regulation/psychological distress, behavioural conduct/pro-social behaviour, cognition, quality of life/well-being, injuries, bone density, motor skill development, and self-esteem. PA had to be objectively measured, while sleep and SB could be objectively or subjectively measured. The quality of research evidence and risk of bias for each health indicator and for each individual study was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. A total of 13 cross-sectional studies and a single prospective cohort study reporting data from 36 560 individual participants met the inclusion criteria. Children and youth with a combination of high PA/high sleep/low SB had more desirable measures of adiposity and cardiometabolic health compared with those with a combination of low PA/low sleep/high SB. Health benefits were also observed for those with a combination of high PA/high sleep (cardiometabolic health and adiposity) or high PA/low SB (cardiometabolic health, adiposity and fitness), compared with low PA/low sleep or low PA/high SB. Of the 3 movement behaviours, PA (especially moderate- to vigorous-intensity PA) was most consistently associated with desirable health indicators. Given the lack of randomized trials, the overall quality of the available evidence was low.

Influence of Menstrual Cycle and Oral Contraceptive Phase on Spinal Excitability.

BACKGROUND: Rates of musculoskeletal injury differ substantially between the genders, with females more likely to experience conditions such as anterior cruciate ligament (ACL) injuries than males in the same sports. Emerging evidence suggests a significant hormonal contribution. Most research has focused solely on how hormonal fluctuations affect connective tissue, but a direct link between hormonal shifts, ligamentous laxity, and ACL injury has not been borne out. There is also evidence to suggest that sex hormones can modulate the central nervous system, but how this affects neuromuscular control is not well understood. OBJECTIVE: To determine whether changes in sex hormone concentrations would alter spinal excitability, measured across the menstrual and oral contraceptive pill cycle. We hypothesized that spinal excitability would fluctuate across the menstrual cycle (with increased excitability during the periovulatory phase due to peak estradiol concentration), but that there would be no fluctuation in oral contraceptive users. DESIGN: This was a prospective cohort study. SETTING: The study took place at a biomechanics laboratory at a rehabilitation hospital. PARTICIPANTS: A total of 30 healthy women aged 18-35 who were similar in age, body composition, and exercise-training status were included. Fifteen of the women were eumenorrheic and nonusers of oral contraceptives (nonusers), and 15 of the women were taking oral contraceptives (users). MAIN OUTCOME MEASURES: H-reflex (Hmax/Mmax ratio), serum estradiol, and progesterone concentrations were measured at 3 time points during the menstrual and contraceptive pill cycle. RESULTS: The H-reflex (Hmax/Mmax ratio) remained stable across the menstrual and contraceptive pill cycle. Spinal excitability was lower in the users compared with the nonusers across all testing sessions, but this was not statistically significant. CONCLUSIONS: Our results suggest that acute fluctuations of endogenous estradiol and progesterone do not modulate spinal excitability. However, long-term exposure to exogenous estrogen and progesterone (oral contraceptives) might have an impact on spinal excitability and neuromuscular control. Further research is necessary to better understand the potential differential effect of endogenous and exogenous sex hormones on spinal excitability.

Trainee involvement in transforaminal epidural steroid injections associated with increased incidence of vasovagal reactions.

OBJECTIVES: To evaluate whether trainee involvement (resident and fellow) during transforaminal epidural steroid injections (TFESI) results in greater rates of vasovagal reactions. DESIGN: Retrospective study on consecutive patients. SETTING: Single academic medical center with multiple attending physicians and trainees. PARTICIPANTS: A total of 2642 consecutive subjects undergoing 4482 TFESI were analyzed from March 8, 2004, to January 30, 2009. MAIN OUTCOME MEASURES: The Pearson χ(2) test was used to determine the relationship between vasovagal reactions and level of trainee involvement. RESULTS: A total of 4482 TFESIs were performed, with 157 (3.5%) of procedures complicated by a vasovagal reaction. An attending physician performed 2884 (64.3%) procedures without trainee involvement, with only 79 (2.7%) vasovagal reaction noted. A fellow was involved in 723 (16.1%) procedures, with 30 (4.1%) noted to have a vasovagal reaction. A resident was involved in 875 (19.5%) procedures, with 48 (5.5%) having a vasovagal reaction. Overall, trainees were involved in 1598 (35.7%) cases, of which 78 (4.9%) were complicated by vasovagal reaction. When a trainee was involved in the case, there was a greater incidence of vasovagal episodes (P < .001, χ(2) = 16.047). Although there was a trend towards greater vasovagal rates with residents over fellows, this did not reach statistical difference. CONCLUSIONS: Vasovagal reactions can occur with spine injection procedures and may result in premature procedure termination or other adverse events. Although this retrospective study has significant potential for bias, it appears that trainee involvement in a TFESI is associated with a greater incidence of vasovagal reaction (P < .001, χ(2) = 16.047).

A mediastinal mass presenting with unilateral periscapular and arm pain.

We describe a case of a patient with mediastinal lymphoma who presented with arm and scapular pain, which is an atypical referral pattern for pain originating from the mediastinum. We use this case as a platform to discuss mediastinal pain referral patterns and the importance of maintaining a broad differential diagnosis of arm and scapular pain, especially when symptoms atypical of pure neuromusculoskeletal structural disease are present.

Comparative effectiveness of lumbar transforaminal epidural steroid injections with particulate versus nonparticulate corticosteroids for lumbar radicular pain due to intervertebral disc herniation: a prospective, randomized, double-blind trial.

BACKGROUND: Lumbar transforaminal epidural injections are commonly utilized to treat radicular pain due to intervertebral disc herniation. OBJECTIVE: This study aims to determine if there was a major difference in effectiveness between particulate and nonparticulate corticosteroids for acute radicular pain due to lumbar disc herniation. DESIGN: A multicenter, double blind, prospective, randomized trial on 78 consecutive subjects with acute uni-level disc herniation resulting in unilateral radicular pain. All subjects received a single level transforaminal epidural steroid injection with either dexamethasone or triamcinolone. Repeat injections were allowed as determined by the blinded physician and subjects. Primary outcomes included: number of injections received, surgical rates, and categorical pain scores at 2 weeks, 3 months, and 6 months. Secondary outcomes included mean Oswestry Disability Index. RESULTS: Both triamcinolone and dexamethasone resulted in statically significant improvements in pain and function at 2 weeks, 3 months, and 6 months, without clear differences between groups. The surgical rates were comparable with 14.6% of the dexamethasone group and 18.9% of the triamcinolone group receiving surgery. There was a statistically significant difference in the number of injections received, with 17.1% of the dexamethasone group receiving three injections vs only 2.7% of the triamcinolone group. CONCLUSIONS: Transforaminal epidural corticosteroid injections are an effective treatment for acute radicular pain due to disc herniation, and frequently only require 1 or 2 injections for symptomatic relief. Dexamethasone appears to possess reasonably similar effectiveness when compared with triamcinolone. However, the dexamethasone group received slightly more injections than the triamcinolone group to achieve the same outcomes.

The muscle stretch reflex throughout the menstrual cycle.

INTRODUCTION: The significant sex disparity in sports-related knee injuries may be due to underlying differences in motor control. Although the development of sex-specific movement patterns is likely multifactorial, this study specifically focuses on the potential modulatory role of sex hormones. PURPOSE: This study aimed to investigate the muscle stretch reflex (MSR) across the menstrual cycle. We hypothesized that the MSR would fluctuate throughout the menstrual cycle and that the lowest response would correspond with peak concentrations of estrogen. METHODS: Nineteen healthy women age 18-35 yr participated in this study: 8 eumenorrheic women and 11 women taking oral contraceptives. Serum estradiol and progesterone concentrations, anterior knee laxity (AKL), and the MSR response of the quadriceps muscles were measured three times during the menstrual cycle. RESULTS: The MSR response of the rectus femoris (RF) varied significantly across the menstrual cycle in both groups. Specifically, the RF MSR response was 2.4 times lower during the periovulatory phase when compared with the luteal phase (P = 0.007). The same trend was seen in the vastus medialis, but this did not reach statistical significance (P = 0.070). The MSR response of the vastus lateralis did not change significantly across the menstrual cycle (P = 0.494). A mixed model comparison did not show an association between endogenous concentrations of estradiol and progesterone, exposure to hormonal contraceptives or AKL, and the MSR response for any muscle. CONCLUSIONS: Our results demonstrate that the RF MSR response varies throughout the menstrual cycle with the lowest response around the time of ovulation. Additional research is needed to clarify the exact relationship between sex hormones, AKL, and MSR response and to determine the specific origin of the change along the monosynaptic reflex arc.

Vasovagal rates in flouroscopically guided interventional procedures: a study of over 8,000 injections.

OBJECTIVE: To determine the rate of vasovagal (vv) complications in fluoroscopically guided interventional procedures. DESIGN: Retrospective case series analysis of prospectively collected data from March 8, 2004 to January 30, 2009. SETTING: A single academic medical center. SUBJECTS: Four thousand one hundred eighty-three subjects undergoing 8,010 consecutive injections. OUTCOME MEASURES: Pearson's chi-square test was used to determine the relationship between categorical variables. RESULTS: A total of 8,010 injections, including epidural steroid injections, radiofrequency nerve ablations, medial branch blocks, hip injections, knee injections, and glenohumeral injections were performed. Overall vv reaction rate was 2.6%, with 0.8% of procedures resulting in early terminated due to vv reaction. Peripheral joint injections had a vv rate of 0.2%, all occurring in hip injections. Transforaminal epidural steroid injections had a vv rate of 3.5%. Diagnostic blocks of the medial branches had the highest rate of vv (5.1%). Other predictors of vv reactions were identified including preprocedure pain score visual analog scale <5 (P = 0.004), male gender (P < 0.001), and age less than 65 years old (P < 0.001). CONCLUSIONS: vv reactions have an overall low occurrence rate (2.6%) in interventional procedures ranging from 0% in peripheral knee and shoulder injections to 5.1% in medial branch blocks. Conservative treatment of vv reaction and willingness to terminate procedures resulted in no serious adverse events related to vv reaction in 8,010 procedures.

Role of sex hormones in the development of osteoarthritis.

Women older than 50 years have a considerably higher prevalence of osteoarthritis than men of the same age group. Although several factors have been proposed, there is some evidence that sex hormones influence the development of osteoarthritis. This article will focus on the basic science and clinical evidence that describe the current state of knowledge regarding the relationship between sex hormones and the development of osteoarthritis.