Sex, military occupation and rank are associated with risk of anterior cruciate ligament injury in tactical-athletes.

INTRODUCTION: Anterior cruciate ligament (ACL) injury is common within the US military and represents a significant loss to readiness. Since recent changes to operational tempo, there has not been an analysis of ACL injury risk. The aim of this retrospective cohort study was to evaluate military occupation, sex, rank and branch of service on ACL injury risk in the US military from 2006 to 2018. METHODS: The Defense Medical Epidemiology Database was queried for the number of US tactical athletes with International Classification of Diseases diagnosis codes 717.83 (old disruption of ACL), 844.2 (sprain of knee cruciate ligament), M23.61 (other spontaneous disruption of ACL) and S83.51 (sprain of ACL of knee) on their initial encounter. Relative risk and χ2 statistics were calculated to assess sex and military occupation effects on ACL injury. A multivariable negative binomial regression model evaluated changes in ACL injury incidence with respect to sex, branch of service and rank. RESULTS: The study period displayed a significant decrease in the ACL injury rate at 0.18 cases per 1000 person-years or relative decrease of 4.08% each year (p<0.001) after averaging over the main and interactive effects of sex, rank and branch of service. The interaction effect of time with sex indicated a steeper decline in the incidence in men as compared with women. The risk of ACL injury by sex was modified by rank. The incidence among military personnel varied by occupation. CONCLUSION: Despite the decline among tactical athletes over time, rates of ACL injury remain much higher than the general US population. Sex, rank, branch of service and military occupation were found to be risk factors for ACL injury. It is critical for policy makers to understand the salient risk factors for ACL injury to guide proactive measures to prevent injury.

Does policy that provides choice in athletic footwear affect musculoskeletal injury risk in US Coast Guard recruits?

INTRODUCTION: Musculoskeletal injuries (MSKIs) are ubiquitous during initial entry military training, with overuse injuries the most common. A common injury mechanism is running, an activity that is integral to US Coast Guard (USCG) training and a requirement for graduation. The purpose of this study was to assess the effects of a policy that allowed for athletic footwear choice on risk of lower quarter MSKI in USCG recruits. METHODS: A retrospective cohort study was performed that included 1230 recruits (1040 men, 190 women) who trained under a policy that allowed self-selection of athletic footwear and 2951 recruits (2329 men, 622 women) who trained under a policy that mandated use of prescribed uniform athletic shoes and served as controls. Demographic data and physical performance were derived from administrative records. Injury data were abstracted from a medical tracking database. Unadjusted risk calculations and multivariable logistic regression assessing the effects of group, age, sex, height, body mass and 2.4 km run times on MSKI were performed. RESULTS: Ankle-foot, leg, knee and lumbopelvic-hip complex injuries were ubiquitous in both groups (experimental: 13.13 per 1000 person-weeks; control: 11.69 per 1000 person-weeks). Group was not a significant factor for any of the injuries assessed in either the unadjusted or adjusted analysis, despite widespread reports of pain (58.6%), perceived injury attribution (15.7%), perceived deleterious effect on performance (25.3%), general dissatisfaction (46.3%) and intended discontinuance of use following graduation (87.7%). CONCLUSION: MSKI continues to be a major source of morbidity in the recruit training population. The policy that allowed USCG recruits to self-select athletic footwear did not decrease or increase the risk of MSKI. While regulations pertaining to footwear choice did not influence injury outcomes, there was general dissatisfaction with the prescribed uniform athletic footwear conveyed by the recruits and widespread reports of discomfort, perceived deleterious effects from wear and intended discontinued use following training completion.

Prescribed footwear and orthoses are not prophylactic in preventing lower extremity injuries in military tactical athletes: a systematic review with meta-analysis.

INTRODUCTION: Military members are exposed to high cumulative physical loads that frequently lead to injury. Prescribed footwear and orthoses have been used to prevent injury. The purpose of this systematic review with meta-analysis was to assess if prescribed prophylactic footwear or foot orthoses reduced the risk of lower extremity injury in military tactical athletes. METHODS: MEDLINE, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature, SportDiscus, and Defense Technical Information Center databases were searched for randomised controlled trials published at any time that compared foot orthoses or prescribed footwear (to include shock-absorbing insoles and socks) with a placebo intervention or a no-treatment control. Methodological quality was assessed and the number of injuries, population at risk and duration of the study epoch were extracted and relative risk (RR) calculated. An omnibus meta-analysis was performed assessing all prescribed footwear and orthoses intervention studies, with subgroup analyses conducted on studies with similar interventions (ie, basketball athletic shoes, athletic shoes (prescribed by foot type), foot orthoses, shock-absorbing insoles, socks, tropical combat boots). RESULTS: Of 1673 studies identified, 22 were included. Three of eight studies that employed orthoses demonstrated significantly reduced overuse injuries compared with no-treatment controls (RR range: 0.34-0.68); one study showed neoprene insoles significantly decreased overuse injuries (RR: 0.75). There were no other significant effects in the individual studies and no protective effects observed in the omnibus meta-analysis or in the component subanalyses. CONCLUSIONS: Prescribed footwear and orthoses do not appear to have a prophylactic effect on lower quarter musculoskeletal injuries in military members and cannot be recommended at this time.

Changes in social isolation and loneliness following total hip and knee arthroplasty: longitudinal analysis of the English Longitudinal Study of Ageing (ELSA) cohort.

OBJECTIVE: To determine the prevalence and change in social isolation and loneliness in people before and after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in England. DESIGN: The English Longitudinal Study of Ageing (ELSA) dataset, a prospective study of community-dwelling older adults, was used to identify people who had undergone primary THA or TKA because of osteoarthritis. Social isolation was assessed using the ELSA Social Isolation Index. Loneliness was evaluated using the Revised University of California, Los Angeles (UCLA) Loneliness Scale. The prevalence of social isolation and loneliness were calculated and multilevel modelling was performed to assess the potential change of these measures before arthroplasty, within a two-year operative-recovery phase and a following two-year follow-up. RESULTS: The sample consisted of 393 people following THA and TKA. The prevalence of social isolation and loneliness changed from 16.9% to 18.8% pre-operative to 21.8% and 18.9% at the final post-operative follow-up respectively. This was not a statistically significant change for either measure (P = 0.15; P = 0.74). There was a significant difference in social isolation at the recovery phase compared to the pre-operative phase (P = 0.01), where people following arthroplasty reported an increase in social isolation (16.9-21.4%). There was no significant difference between the assessment phases in respect to UCLA Loneliness Scale score (P ≥ 0.74). CONCLUSIONS: Given the negative physical and psychological consequences which social isolation and loneliness can have on individuals following THA or TKA, clinicians should be mindful of this health challenge for this population. The reported prevalence of social isolation and loneliness suggests this is an important issue.

Measurements of skeletal muscle mass and power are positively related to a Mediterranean dietary pattern in women.

The age-related loss of skeletal muscle and function are risk factors for osteoporosis and fractures. We found that higher adherence to the Mediterranean diet score was significantly associated with greater fat-free mass and leg explosive power suggesting a role for the Mediterranean Diet in prevention of loss of muscle outcomes. INTRODUCTION: The loss of skeletal muscle mass, strength, and function with age are contributing risk factors for the onset of sarcopenia, frailty, osteoporosis, fractures, and mortality. Nutrition may affect the progression and trajectory of these changes in skeletal muscle but the role of the micronutrient-rich Mediterranean diet (MD) has hardly been investigated in relation to these muscle outcomes. METHODS: We examined associations between the MD score (MDS) and FFM% (fat-free mass / weight × 100), FFMI (fat-free mass/height2), hand grip strength, and leg explosive power (LEP, watts/kg) in a cross-sectional study in 2570 women aged 18-79 years from the TwinsUK study. Measurements of body composition were made using dual-energy X-ray absorptiometry and dietary intake assessed by a food frequency questionnaire. FFM%, FFMI, grip strength, and LEP were compared across quartiles of the MDS after adjustment for covariates, with CRP measured in a subgroup (n = 1658). RESULTS: Higher adherence to the MDS was positively associated with measurements of muscle outcomes, with significant differences of 1.7 % for FFM% and 9.6 % for LEP (P trend <0.001), comparing extreme quartiles of intake, but not with grip strength or CRP concentrations. CONCLUSIONS: For the first time in a northern European population, we have observed significant positive associations between the MDS and FFM% and LEP in healthy women that are potentially clinically relevant, independent of the factors known to influence muscle outcomes. Our findings emphasize the potential role for overall diet quality based on the MD in the prevention of age-related loss of skeletal muscle outcomes.

The surgical treatment of rheumatoid arthritis: a new era?

There has been an in increase in the availability of effective biological agents for the treatment of rheumatoid arthritis as well as a shift towards early diagnosis and management of the inflammatory process. This article explores the impact this may have on the place of orthopaedic surgery in the management of patients with rheumatoid arthritis.

Prednisolone combined with adjunctive immunosuppression is not superior to prednisolone alone in terms of efficacy and safety in giant cell arteritis: meta-analysis.

To conduct a meta-analysis of published data of the effectiveness of drug treatment in giant cell arteritis (GCA) to provide evidence to support the optimal use of glucocorticoids (GCs) and adjunct therapy. MEDLINE, CENTRAL and EMBASE searches were used to identify randomised control trials on the treatment of GCA. Studies included were trials in which: (1) the participants were classified as having GCA by the 1990 ACR criteria or biopsy proven disease; (2) parallel-group randomised control of at least 16 weeks duration had been conducted with at least 20 participants; (3) the design included either alternative adjunct immunosuppressant regimens, alternative GCs dosing or routes of administration; and (4) outcome data was included on either relapse rates or rates of infection. One thousand eight hundred thirty-six articles were retrieved, of which only 37 met the primary inclusion criteria. Sixteen of these studies reported some information about the GCs or adjuvant regimen used. Only ten studies were of sufficient quality to be included in the meta-analysis. Together these comprised 638 participants of which 72 % were female. Three studies compared various GCs regimens, with two comparing IV GCs, the latter showing a marginal benefit with respect to relapse (risk ratio (RR) = 0.78, 95 % CI = 0.54 to 1.12) but a greater risk of infection (RR = 1.58, 95 % CI = 0.90 to 2.78). Another three used methotrexate as an adjunctive agent and showed marginal benefit with respect to relapse (RR = 0.85, 95 % CI = 0.66 to 1.11). The remaining four trials compared prednisolone to dapsone, infliximab, adalimumab and hydroxychloroquine, respectively. There are various clinical trials of varying quality. The results from this meta-analysis show that the use of adjunct agents is not associated with improved outcome.

A higher alkaline dietary load is associated with greater indexes of skeletal muscle mass in women.

UNLABELLED: Conservation of muscle mass is important for fall and fracture prevention but further understanding of the causes of age-related muscle loss is required. This study found a more alkaline diet was positively associated with muscle mass in women suggesting a role for dietary acid-base load in muscle loss. INTRODUCTION: Conservation of skeletal muscle is important for preventing falls and fractures but age-related loss of muscle mass occurs even in healthy individuals. However, the mild metabolic acidosis associated with an acidogenic dietary acid-base load could influence loss of muscle mass. METHODS: We investigated the association between fat-free mass (FFM), percentage FFM (FFM%) and fat-free mass index (FFMI, weight/height²), measured using dual-energy X-ray absorptiometry in 2,689 women aged 18-79 years from the TwinsUK Study, and dietary acid-base load. Body composition was calculated according to quartile of potential renal acid load and adjusted for age, physical activity, misreporting and smoking habit (FFM, FFMI also for fat mass) and additionally with percentage protein. RESULTS: Fat-free mass was positively associated with a more alkalinogenic dietary load (comparing quartile 1 vs 4: FFM 0.79 kg P < 0.001, FFM% 1.06 % <0.001, FFMI 0.24 kg/m² P = 0.002), and with the ratio of fruits and vegetables to potential acidogenic foods. CONCLUSIONS: We observed a small but significant positive association between a more alkaline diet and muscle mass indexes in healthy women that was independent of age, physical activity and protein intake equating to a scale of effect between a fifth and one half of the observed relationship with 10 years of age. Although protein is important for maintenance of muscle mass, eating fruits and vegetables that supply adequate amounts of potassium and magnesium are also relevant. The results suggest a potential role for diet in the prevention of muscle loss.

Twin studies and the heritability of MS: a conclusion.

OBJECTIVE: The classical twin study has the potential to evaluate the relative contribution of genes and environment and guide further research strategies, provided the sampling and methods of analysis are correct. We wish to review all the more informative twin studies on multiple sclerosis (MS). METHODS: We examined six large population-based twin studies in MS and calculated indices of heritability (h(2)), which is the traditional method of assessing genetic contribution to disease and to allow comparison between studies. RESULTS: This index was found to vary widely from 0.25 to 0.76 with large confidence intervals that reflect small sample size and prevent robust interpretation. CONCLUSION: Overall the studies support a genetic contribution to disease; however, the imprecision of the heritability estimates and potential biases that they contain mean that very little inference can be drawn its exact size. Given that the magnitude of genetic effect cannot be measured because of the relative infrequency of MS; the consequent difficulty in collecting an informative sample; and in many countries, the lack of a comprehensive twin register, we suggest that further twin prevalence surveys should not be undertaken. Twin studies could be used more effectively in other ways, such as the co-twin case-control approach.

The genetic influence on radiographic osteoarthritis is site specific at the hand, hip and knee.

OBJECTIVE: To identify whether a shared genetic influence accounts for the occurrence of OA at different skeletal sites. METHODS: Multivariate modelling of data on prevalent radiographic OA at the hand (DIP, PIP and CMC joints), hip and knee joints assessed in 992 monozygotic and dizygotic female twin participants from the TwinsUK Registry. RESULTS: OA at all the five joint sites was heritable. Genetic influences were strongly correlated among joints in the hand; however, there was little evidence of common genetic pathways to account for the co-occurrence of OA at the hand, hip and knee. CONCLUSIONS: While genetic influences are important in explaining the variation in occurrence of OA at the hand, hip and knee, there is no evidence that common or shared genetic factors determine the occurrence of disease across all these skeletal sites. The findings suggest that there are important aetiological differences in the disease that are site-specific in women. These results have implications for the design of studies examining the genetic basis of OA as well as for strategies aimed at preventing and treating the disease.

Migraine and antiphospholipid antibodies: no association found in migraine-discordant monozygotic twins.

Migraine headache (with and without aura) is common in the general population and is known to be influenced by genetic factors with heritability estimates between 34-57%. Antiphospholipid syndrome (APS) is a hypercoagulable state characterized by clinical features including venous and arterial thromboses, pregnancy loss and migraine, and by association with antiphospholipid antibodies (aPL). Numerous small studies have investigated whether aPL are associated with migraine in the general population--with contradictory results. In this study, the question was addressed by studying the prevalence of aPL in members of monozygotic (MZ) twin pairs differing in their migraine status. Such twins provide a unique natural experiment, matched as they are for age, sex and genetic factors, and allow the role of environmental factors, such as aPL, to be determined. Despite 95% power to detect a difference of 0.59 IgG units per litre in anticardiolipin antibody IgG titres, no difference in prevalence of aPL could be detected in migraine-discordant MZ twins.

Recognition of inflammatory back pain and ankylosing spondylitis in primary care.

OBJECTIVE: The diagnosis of AS is often delayed in primary care. This may partly be due to inability to differentiate inflammatory back pain (IBP) from mechanical. The aim of this study was to assess current practice of general practitioners (GPs) in using clinical, radiological and laboratory investigations to assess patients with IBP. METHODS: A postal questionnaire was sent to all GPs in Norfolk. It was designed to test GPs ability to identify symptoms suggestive of IBP in patients with back pain. It also enquired whether GPs considered other features of SpA. Their perceptions of usefulness of various investigations when considering a diagnosis of AS, management and their unmet needs were recorded. RESULTS: A total of 62% of completed questionnaires were returned. Only 5% of GPs could identify all eight features known to be indicative of IBP, 78% between four and eight and 17% identified less than four features. GPs had a range of views regarding the utility of a positive family history, HLA-B27, use of X-ray and physiotherapy in patients with suspected IBP. GPs awareness of the associated features of SpA was low. There were inconsistencies in the use of diagnostic tests and management of AS. Improving musculoskeletal education in primary care was identified as one of the unmet needs by the majority of GPs. CONCLUSIONS: In a survey of GPs, we identified inconsistencies in their perceptions and approach to the diagnosis and management of AS. Education in primary care and the wider use of diagnostic algorithms may improve early detection and hence outcome of AS.

Genetic associations in peripheral joint osteoarthritis and spinal degenerative disease: a systematic review.

UNLABELLED: We conducted a systematic review of genetic association studies for osteoarthritis of the peripheral joints (OA) and spinal degenerative disease (SDD). Electronic searches were carried out for any English language article reporting on a gene association study for either OA or SDD published up until the end of 2006. A team of seven reviewers used a standardised template to extract data in duplicate. In all, 90 studies fulfilled our inclusion criteria, reporting a total of 94 significant associations from 83 different genes. We found relatively few instances in which a specific gene-disease association had been analysed by more than one study, and there were 14 cases in which significant associations were replicated in independent studies (at joints associated with the AGC1, ASPN, COL9A2, COL9A3, COL11A2, ESR1, FZRB, HFE, IL1A, IL1RN, PTGS2 and VDR genes). METHOD: logical and reporting problems were widespread, including failure to report full results, missing population details, multiple testing, and over-reliance on subgroup analysis. In summary, the complex phenotypes of OA and SDD may have made it difficult for researchers to focus their efforts. The field is dominated by isolated analyses of disparate potential associations, a problem that is amplified by the frequent analysis of different polymorphisms within individual genes. Flaws in study methodology and interpretation undoubtedly increase the risk of publication bias. Closer adherence to published recommendations (in particular those produced by HuGENet) will help to ensure that future studies are well-designed and build on current understanding, rather than simply adding to the growing bank of potential associations.

Lumbar disc disease shows linkage to chromosome 19 overlapping with a QTL for hand OA.

OBJECTIVE: Cervical and lumbar degenerative disc disease (CDD and LDD, respectively) form part of the spine osteoarthritis (OA) phenotype and are known to be influenced by genetic factors. A genome-wide linkage analysis was performed to identify new chromosomal regions of interest. METHODS: Dizygotic healthy female twin volunteers (n = 348) from the TwinsUK register who had magnetic resonance imaging scans 10 years ago coded for degenerative disease, were identified. Multipoint genome-wide linkage analysis was conducted using 737 highly polymorphic markers of approximate spacing 10 cM. RESULTS: The mean age of the twins was 52 years. Significant linkage peaks (log of the odds (LOD) >3) were identified for LDD at three chromosomal regions. These included chromosome 1 (position 285 cM), chromosome 5 (position 175 cM) and chromosome 19 (position 80 cM). The peak on chromosome 19 had LOD = 4.06, and the empirical p = 6.7x10(-4) confirmed reliability of the linkage signal. It lies close to a linkage peak previously obtained by our group for hand OA. CONCLUSIONS: This genome-wide linkage study of CDD and LDD shows evidence of linkage for LDD on chromosome 19. The region of interest is likely to harbour genes that are common to LDD and hand OA.

Schmorl's nodes: common, highly heritable, and related to lumbar disc disease.

OBJECTIVE: Schmorl's nodes (SN) are common, but little is known of their relationship with degenerative change and back pain or genetic and environmental factors influencing their expression. We studied healthy female twin volunteers to determine the prevalence and clinical features associated with SN. METHODS: Serial sagittal T1- and T2-weighted magnetic resonance images of the lower thoracic and lumbar spine were analyzed in 516 healthy female twins (150 monozygotic and 366 dizygotic). The images were scored for lumbar degenerative change. Presence of SN was noted at cranial and caudal vertebral levels T9 to L5. Data on physical activity and back pain were collected by questionnaire. Heritability of SN was calculated using variance components modeling. RESULTS: SN were found in 30% of subjects. Of the 374 SN, 153 (41%) were in the lumbar spine and 221 (59%) were in the thoracic spine. SN heritability was >70%. There was a positive association between SN and lumbar disc disease (LDD). SN were more frequent in subjects with back pain (for >/=2 SN: odds ratio [OR] 2.68, 95% confidence interval [95% CI] 1.11-6.47, P = 0.03), but this was largely accounted for by the association of SN with LDD (OR 1.97, 95% CI 0.78-5.0, P = 0.15 adjusted for LDD). No independent association of SN with back pain was identified. CONCLUSION: SN are common in middle-aged women and are strongly genetically determined. They are associated with lumbar degenerative change, which is a risk factor for back pain, but are not themselves an independent risk factor for back pain.

Epidemiology of back disorders: prevalence, risk factors, and prognosis.

PURPOSE OF REVIEW: This article reviews some of the advances that have taken place in understanding back disorders, with a particular emphasis on low back pain, as this area has been most represented in the literature in the preceding year (September 2003 to September 2004). RECENT FINDINGS: Epidemiological studies continue to provide insights into the prevalence of back pain and have identified many individual, psychosocial, and occupational risk factors for its onset. Psychological factors have an important role in the transition from acute to chronic pain and related disability. Recent advances show that there is a significant genetic effect on severe low back pain in the community. Data emerging from candidate gene studies show an association between lumbar disc disease and mutations of genes encoding the alpha-2 and alpha-3 subunits of collagen IX. SUMMARY: Back pain is among the most common conditions for which patients seek medical care. Interventions based on behavioral and cognitive principles and exercise programs are effective in improving disability in chronic back pain. Although progress has been made in understanding the role of genetic mutations in disorders such as lumbar disc disease, further investigation of the interaction between genetic and environmental factors such as physical stress is needed.

The effect of moderate alcohol consumption on bone mineral density: a study of female twins.

BACKGROUND: Osteoporosis is associated with morbidity and mortality, particularly in postmenopausal women. The effect of moderate alcohol intake on bone mineral density (BMD) and fracture risk remains unclear. OBJECTIVE: To carry out a twin study to investigate this effect while controlling for genetic effects and other confounding variables. METHODS: BMD was determined at the hip and lumbar spine in 46 pairs of monozygotic twins discordant for alcohol consumption. Biochemical evidence of altered bone metabolism was sought. RESULTS: A positive association between alcohol consumption and BMD was shown, in contrast to the negative effect of smoking on BMD. Markers of bone turnover were not associated with alcohol or BMD. CONCLUSIONS: Moderate alcohol consumption is not harmful to bone health in women and may even be beneficial. Beneficial effects do not appear to be mediated through an action on bone metabolism.