Exploring the determinants of fracture risk among individuals with spinal cord injury

Potential Effects of an Exoskeleton-Assisted Overground Walking Program for Individuals With Spinal Cord Injury Who Uses a Wheelchair on Imaging and Serum Markers of Bone Strength: Pre-Post Study

BACKGROUND

As many as 60% of individuals use a wheelchair long term after a spinal cord injury (SCI). This mode of locomotion leads to chronic decline in lower-extremity weight-bearing activities and contributes to the development of severe sublesional osteoporosis and high rates of fragility fracture. Overground exoskeleton-assisted walking programs provide a novel opportunity to increase lower-extremity weight bearing, with the potential to improve bone health.

OBJECTIVE

The aim of the study is to measure the potential effects of an exoskeleton-assisted walking program on lower-extremity bone strength and bone remodeling biomarkers in individuals with chronic (≥18 months) SCI who use a wheelchair.

METHODS

In total, 10 participants completed a 16-week exoskeleton-assisted walking program (34 individualized 1-hour sessions, progressing from 1 to 3 per week). Bone mineral density and bone strength markers (dual-energy x-ray absorptiometry: total body, left arm, leg, total hip, and femoral neck and peripheral quantitative computed tomography: 25% of left femur and 66% of left tibia) as well as bone remodeling biomarkers (formation=osteocalcin and resorption=C-telopeptide) were measured before and after intervention and compared using nonparametric tests. Changes were considered significant and meaningful if the following criteria were met: P<0.1, effect size ≥0.5, and relative variation >5%.

RESULTS

Significant and meaningful increases were observed at the femur (femoral neck bone mineral content, bone strength index, and stress-strain index) and tibia (cortical cross-sectional area and polar moment of inertia) after the intervention (all P<.10). We also noted a decrease in estimated femoral cortical thickness. However, no changes in bone remodeling biomarkers were found.

CONCLUSIONS

These initial results suggest promising improvements in bone strength markers after a 16-week exoskeleton-assisted walking program in individuals with chronic SCI. Additional research with larger sample sizes, longer interventions (possibly of greater loading intensity), and combined modalities (eg, pharmacotherapy or functional electrical stimulation) are warranted to strengthen current evidence.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03989752; https://clinicaltrials.gov/ct2/show/NCT03989752.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/19251.

Exercise prescription for persons with spinal cord injury: a review of physiological considerations and evidence-based guidelines

Persons with spinal cord injury (SCI) experience gains in fitness, physical and mental health from regular participation in exercise and physical activity. Due to changes in physiological function of the cardiovascular, nervous, and muscular systems, general population physical activity guidelines and traditional exercise prescription methods are not appropriate for the SCI population. Exercise guidelines specific to persons with SCI recommend progressive training beginning at 20 min of moderate to vigorous intensity aerobic exercise twice per week transitioning to 30 min three times per week, with strength training of the major muscle groups two times per week. These population-specific guidelines were designed considering the substantial barriers to physical activity for persons with SCI and can be used to frame an individual exercise prescription. Rating of perceived exertion (i.e., perceptually regulated exercise) is a practical way to indicate moderate to vigorous intensity exercise in community settings. Adapted exercise modes include arm cycle ergometry, hybrid arm-leg cycling, and recumbent elliptical equipment. Body weight-supported treadmill training and other rehabilitation modalities may improve some aspects of health and fitness for people with SCI if completed at sufficient intensity. Disability-specific community programs offer beneficial opportunities for persons with SCI to experience quality exercise opportunities but are not universally available.

Using Risk Scores to Estimate Lower Extremity Fragility Fracture Risk among Individuals with Chronic Spinal Cord Injury: A Preliminary Model

Objectives

To develop SCI-FX, a risk score to estimate 5-year lower extremity fragility fracture risk among patients living with chronic spinal cord injury (cSCI).

Methods

Adults with traumatic cSCI (n = 90) participated in a 2-year prospective longitudinal cohort study describing bone mineral density (BMD) change and fracture incidence conducted at the Lyndhurst Centre (University Health Network), University of Waterloo, and Physical Disability Rehabilitation Institute of Québec City. Prior publication and clinical intuition were used to identify fragility fracture risk factors including prior fragility fracture, years post-injury, motor complete injury (AIS A/B), benzodiazepine use, opioid use, and parental osteoporosis. We conducted bivariate analyses to identify variables associated with fracture. Multiple logistic regressions were performed using fragility fracture incidence as the dependent variable and all variables from the univariate analyses with a highly liberal p value at 0.2. Using the odds ratios (ORs) from the multiple logistic regression model, a point system for fragility fracture risk score was developed, and the odds of fracture for each point was estimated.

Results

All initial variables, with the exception of benzodiazepine exposure, were included in the final model.

Conclusion

We identified a simple preliminary model for clinicians to estimate 5-year fracture risk among patients with cSCI based on their total score.

Alteration of Volumetric Bone Mineral Density Parameters in Men with Spinal Cord Injury

Spinal cord injury (SCI) induces severe losses of trabecular and cortical volumetric bone mineral density (vBMD), which cannot be discriminated with conventional dual-energy X-ray absorptiometry (DXA) analysis. The objectives were to: (i) determine the effects of SCI on areal BMD (aBMD) and vBMD determined by advanced 3D-DXA-based methods at various femoral regions and (ii) model the profiles of 3D-DXA-derived parameters with the time since injury. Eighty adult males with SCI and 25 age-matched able-bodied (AB) controls were enrolled in this study. Trabecular and cortical vBMD, cortical thickness and derived strength parameters were assessed by 3D-SHAPER® software at various femoral subregions. Individuals with SCI had significantly lower integral vBMD, trabecular vBMD, cortical vBMD, cortical thickness and derived bone strength parameters (p < 0.001 for all) in total proximal femur compared with AB controls. These alterations were approximately to the same degree for all three femoral subregions, and the difference between the two groups tended to be greater for cortical vBMD than trabecular vBMD. There were minor differences according to the lesion level (paraplegics vs tetraplegics) for all 3D-DXA-derived parameters. For total proximal femur, the decreasing bone parameters tended to reach a new steady state after 5.1 years for integral vBMD, 7.4 years for trabecular vBMD and 9.2 years for cortical vBMD following SCI. At proximal femur, lower vBMD (integral, cortical and trabecular) and cortical thickness resulted in low estimated bone strength in individuals with SCI. It remains to be demonstrated whether these new parameters are more closely associated with fragility fracture than aBMD.

Zoledronic acid after spinal cord injury mitigates losses in proximal femoral strength independent of ambulation ability

Rapid bone loss can occur after spinal cord injury (SCI) and a standard of care to prevent or treat this phenomenon is an active area of research. Using advanced analysis techniques, this study demonstrates that zoledronic acid, a possible treatment, prevented loss of bone strength at the hip following SCI.

INTRODUCTION

Bone loss below the level of neurological lesion is a well-known complication of spinal cord injury (SCI), and effective preventive treatment for this phenomenon is an active area of research. Zoledronic acid has demonstrated efficacy to attenuate bone loss at the hip after SCI, but previous studies relied on measurements from dual-energy X-ray absorptiometry. The purpose of this investigation was to more thoroughly characterize changes to bone mineral and strength at the proximal femur in individuals receiving zoledronic acid in the acute SCI stage; we also examined the influence of ambulatory ability on bone outcomes.

METHODS

Participants randomized to either zoledronic acid (n = 29) or placebo (n = 30) received computed tomography (CT) scans and ambulatory assessments at baseline and 6 and 12 months following drug infusion. CT-based finite element (FE) modeling was used to predict changes in proximal femoral strength associated with treatment.

RESULTS

After 12 months, FE-predicted bone strength was reduced by a mean (SD) of 9.6 (17.9)% in the zoledronic acid group versus 24.6 (24.5)% in the placebo group (p = 0.007). These differences in strength were explained by reductions in CT measurements of both trabecular (p < 0.001) and cortical (p ≤ 0.021) bone at the femoral neck and trochanteric region. Ambulation ability influenced select trabecular and cortical parameters, but we were unable to detect an impact on FE-predicted bone strength.

CONCLUSION

These findings demonstrate that treatment with zoledronic acid in acute SCI attenuates losses in proximal femoral strength, which may reduce the risk of hip fractures across patients with varying degrees of ambulatory abilities.

The Pathophysiology, Identification and Management of Fracture Risk, Sublesional Osteoporosis and Fracture among Adults with Spinal Cord Injury

BACKGROUND

The prevention of lower extremity fractures and fracture-related morbidity and mortality is a critical component of health services for adults living with chronic spinal cord injury (SCI).

METHODS

Established best practices and guideline recommendations are articulated in recent international consensus documents from the International Society of Clinical Densitometry, the Paralyzed Veterans of America Consortium for Spinal Cord Medicine and the Orthopedic Trauma Association.

RESULTS

This review is a synthesis of the aforementioned consensus documents, which highlight the pathophysiology of lower extremity bone mineral density (BMD) decline after acute SCI. The role and actions treating clinicians should take to screen, diagnose and initiate the appropriate treatment of established low bone mass/osteoporosis of the hip, distal femur or proximal tibia regions associated with moderate or high fracture risk or diagnose and manage a lower extremity fracture among adults with chronic SCI are articulated. Guidance regarding the prescription of dietary calcium, vitamin D supplements, rehabilitation interventions (passive standing, functional electrical stimulation (FES) or neuromuscular electrical stimulation (NMES)) to modify bone mass and/or anti-resorptive drug therapy (Alendronate, Denosumab, or Zoledronic Acid) is provided. In the event of lower extremity fracture, the need for timely orthopedic consultation for fracture diagnosis and interprofessional care following definitive fracture management to prevent health complications (venous thromboembolism, pressure injury, and autonomic dysreflexia) and rehabilitation interventions to return the individual to his/her pre-fracture functional abilities is emphasized.

CONCLUSIONS

Interprofessional care teams should use recent consensus publications to drive sustained practice change to mitigate fracture incidence and fracture-related morbidity and mortality among adults with chronic SCI.

Regional and temporal variation in bone loss during the first year following spinal cord injury

Osteoporosis is a consequence of spinal cord injury (SCI) that leads to fragility fractures. Visual assessment of bone scans suggests regional variation in bone loss, but this has not been objectively characterised. In addition, substantial inter-individual variation in bone loss following SCI has been reported but it is unclear how to identify fast bone losers. Therefore, to examine regional bone loss, tibial bone parameters were assessed in 13 individuals with SCI (aged 16-76 years). Peripheral quantitative computed tomography scans at 4 % and 66 % tibia length were acquired within 5 weeks, 4 months and 12 months postinjury. Changes in total bone mineral content (BMC), and bone mineral density (BMD) were assessed in ten concentric sectors at the 4 % site. Regional changes in BMC and cortical BMD were analysed in thirty-six polar sectors at the 66 % site using linear mixed effects models. Relationships between regional and total loss at 4 months and 12 months timepoints were assessed using Pearson correlation. At the 4 % site, total BMC (P = 0.001) decreased with time. Relative losses were equal across the sectors (all P > 0.1). At the 66 % site, BMC and cortical BMD absolute losses were similar (all P > 0.3 and P > 0.05, respectively) across polar sectors, but relative loss was greatest in the posterior region (all P < 0.01). At both sites, total BMC loss at 4 months was strongly positively associated with the total loss at 12 months (r = 0.84 and r = 0.82 respectively, both P < 0.001). This correlation was stronger than those observed with 4-month BMD loss in several radial and polar sectors (r = 0.56-0.77, P < 0.05). These results confirm that SCI-induced bone loss varies regionally in the tibial diaphysis. Moreover, bone loss at 4 months is a strong predictor of total loss 12 months postinjury. More studies on larger populations are required to confirm these findings.

Loss of lower extremity bone mineral density 1 year after denosumab is discontinued in persons with subacute spinal cord injury

Twelve months following discontinuation of denosumab, the percent decrease in mean bone mineral density (BMD) values at the hip and knee regions were similar between both the denosumab and placebo groups. These findings emphasize the need for additional trials to understand the effect of continued administration of denosumab after subacute spinal cord injury (SCI) to avoid this demineralization.

OBJECTIVE

To determine changes in BMD 1 year after denosumab was discontinued in participants with subacute SCI who had drug treatment initiated within 90 days post SCI and continued for 1 year.

METHODS

Fourteen participants who completed a randomized, double-blinded, placebo-controlled drug trial (parent study: denosumab 60 mg (Prolia, Amgen Inc., n = 8) or placebo (n = 6); administered at baseline, 6, and 12 months) were followed 12 months after the 18 months from baseline primary end point was completed. The BMD of skeletal regions below the SCI at higher risk of fracture was measured [total hip, distal femur epiphysis (DFE), distal femur metaphysis (DFM), and proximal tibia epiphysis (PTE)] by dual energy X-ray absorptiometry.

RESULTS

The percent decreases in mean BMD values at all regions of the hip and knee from 18 to 30 months were similar in both the denosumab and placebo groups. However, at 30 months, the absolute values for mean BMD remained significantly higher in the drug treatment than that of the placebo group at the DFM (p = 0.03), DFE (p = 0.04), and PTE (p = 0.05).

CONCLUSIONS

In persons with SCI who initiated denosumab treatment during the subacute injury phase and maintained treatment for 1 year, the discontinuation of drug resulted in percent loss of mean BMD similar to that of the placebo group, with absolute mean BMD values at the knee regions at the 12-month follow-up visit significantly higher in the drug treatment than those in the placebo group. These data underscore the need to study continued administration of denosumab after subacute SCI to avoid marked demineralization in the sublesional skeleton upon discontinuation of this agent.

Generation of a Reference Dataset to Permit the Calculation of T-scores at the Distal Femur and Proximal Tibia in Persons with Spinal Cord Injury

Persons with traumatic spinal cord injury (SCI) have severe bone loss below the level of lesion with the distal femur (DF) and proximal tibia (PT) being the skeletal regions having the highest risk of fracture. While a reference areal bone mineral density (aBMD) database is available at the total hip (TH) using the combined National Health and Nutrition Examination Survey (NHANES) III study and General Electric (GE) combined (GE/NHANES) to calculate T-score (T-score_GE/NHANES), no such reference database exists for aBMD of the DF, and PT. The primary objectives of this study were (1) to create a reference dataset of young-healthy able-bodied (YHAB) persons to calculate T-score (T-score_YHAB) values at the DF and PT, (2) to explore the impact of time since injury (TSI) on relative bone loss in the DF and PT regions using the two computation models to determine T-score values, and (3) to determine agreement between T-score values for a cohort of persons with SCI using the (T-score_YHAB) and (T-score_GE/NHANES) reference datasets. A cross-sectional prospective data collection study. A Department of Veterans Affairs Medical Center and a Private Rehabilitation Hospital. A normative reference aBMD database at the DF and PT was collected in 32 male and 32 female Caucasian YHAB participants (n=64) and then applied to calculate T-score values at the DF and PT in 105 SCI participants from a historical cohort. The SCI participants were then grouped based on TSI epochs (E-I: TSI < 1y, E-II: TSI 1-5y, E-III: TSI 6-10y, E-IV: TSI 11-20y, E-V: TSI > 20y). N/A. The knee and hip aBMD values were obtained by dual energy X-ray absorptiometry (GE Lunar iDXA) using standard clinical software for proximal femur orthopedic knee software applications. There were no significant differences in mean aBMD values across the four YHAB age subgroups (21-25, 26-30, 31-35, and 36-40 yr of age) at the TH, DF, and PT; mean aBMD values were higher in men compared to the women at all skeletal regions of interest. Using the mean YHAB aBMD values to calculate T-score values at each TSI epoch for persons with SCI, T-score values decreased as a function of TSI, and they continued to decline for 11-20 yr. Moderate kappa agreement was noted between the YHAB and the GE/NHANES reference datasets for the T-score cutoff criteria accepted to diagnose osteoporosis (i.e., SD <-2.5). A homogeneous reference dataset of YHAB aBMD values at the DF and PT was applied to calculate T-score values in persons with chronic SCI. There was a moderate level of agreement at the TH between the YHAB and GE/NHANES reference datasets when applying the conventional T-score cutoff value for the diagnosis of osteoporosis.

Prevalence and influencing factors of spinal cord injury-related osteoporosis and fragility fractures in Thai people with chronic spinal cord injury: A cross-sectional, observational study

OBJECTIVE

To investigate the prevalence and influencing factors of spinal cord injury (SCI)-related osteoporosis and fragility fractures in Thai people with chronic spinal cord injury.

DESIGN

A cross-sectional, observational study.

SETTING

Outpatient clinic, Department of Rehabilitation Medicine, Maharaj Nakorn Chiang Mai Hospital.

PARTICIPANTS

Thais with chronic spinal cord injury (SCI) (duration of injury at least one year).

INTERVENTION

Not applicable.

OUTCOME MEASURES

Dual-energy X-ray absorptiometry (DXA) was performed to measure bone mineral density (BMD) at the hip. Analyses were performed to identify risk factors for SCI-related osteoporosis or fragility fracture development. Thai FRAX® score was calculated with and without BMD and compared for each participant.

RESULTS

Among 64 Thais with chronic SCI, the prevalence of SCI-related osteoporosis was 43.8%. Female sex, non-ambulatory status, and at least 10 years duration of spinal cord injury increased the risk of having SCI-related osteoporosis. The prevalence of fragility fracture was 9.4%. Female sex, duration of SCI, and being diagnosed with SCI-related osteoporosis increased the risk of having a fragility fracture. Thai FRAX® score without BMD value underestimated the risk of prevalent fracture in 7.8% of participants.

CONCLUSIONS

SCI-related osteoporosis and fragility fractures are common in Thais with chronic SCI. Our findings emphasize the importance of SCI-related osteoporosis and fragility fracture surveillance in people with chronic SCI regardless of their ethnicity. FRAX® without BMD calculations could underestimate the risk of fragility fracture in people with chronic SCI. Therefore, further studies are needed to develop an SCI-specific fracture-risk assessment tool using risk factors proposed in previous studies and in this study.

Prediction of Distal Femur and Proximal Tibia Bone Mineral Density From Total Body Dual Energy X-Ray Absorptiometry Scans in Persons with Spinal Cord Injury

Bone density decreases rapidly after spinal cord injury (SCI), increasing fracture risk. The most common fracture sites are at the knee (i.e., distal femur or proximal tibia). Despite this high fracture incidence, knee-specific scans for bone density using dual x-ray absorptiometry (DXA) were not available until 2014 and are still not routinely used in clinical practice today. This has made it difficult to determine the rehabilitation efficacy and hindered understanding of the long-term changes in knee areal bone density. The purpose of this investigation was to compare areal bone mineral density values for the knee from both total-body and knee-specific DXA scans in persons with SCI. A total of 20 participants (16 males) >1 yr-post spinal cord injury received two DXA scans; a total-body scan and a knee-specific scan. Standardized methods were used to create regions of interest to determine bone density of four regions - the epiphysis and metaphysis of the distal femur and proximal tibia - from the total-body scan. Linear regressions and Bland-Altman analyses were conducted to determine the correlation (r²) and agreement (mean bias ± 95% level of agreement) respectively between the two scan types for each region. Linear regression analyses showed strong significant (p < 0.001) relationships between the two scan types for the distal femur epiphysis (r² = 0.88) and metaphysis (r² = 0.98) and the proximal tibia epiphysis (r² = 0.88) and metaphysis (r² = 0.99). The mean bias ± 95% level of agreement were distal femur epiphysis (0.05 ± 0.1 g/cm²) and metaphysis (0.02 ± 0.04 g/cm²); proximal tibia epiphysis (-0.02 ± 0.1 g/cm²) and metaphysis (0.02 ± 0.03 g/cm²). Results suggest knee-specific bone density can be assessed using a total-body DXA scan. This may allow for more comprehensive use of DXA scans which would reduce the burden of multiple site-specific scans for persons with SCI and enable more widespread adoption of knee bone density assessment in this population.

Exercise and physical activity in individuals at risk of fracture

This is a review of evidence and practical tips on exercise for individuals with osteoporosis, including individuals with hip and vertebral fractures. Balance and functional training, with or without strength training, can prevent falls. Several types of exercise can improve outcomes that are important to patients, such as physical functioning or quality of life. Individuals with osteoporosis should prioritize balance, functional and resistance training ≥ twice weekly, where exercises, volume, intensity, and progression are aligned with the patient's goals and abilities. Patients who want to participate in other activities (e.g., walking, impact exercise, yoga, Pilates) can do them in addition to, but not instead of, balance and functional or strength training, if they can be done safely or modified. Avoid generic advice like "Don't bend or twist", which is difficult or impossible to operationalize, and may create fear and activity avoidance. Instead, be specific about the types of activities to avoid or modify, and provide tips on how to make daily activities safer, or signpost to resources from national osteoporosis societies. For example, not all bending or twisting is bad; it is activities that involve rapid, repetitive, sustained, weighted, or end range of motion twisting or flexion of the spine that may need to be modified, especially in individuals at high risk of fracture.

Forearm bone mineral density in adult men after spinal cord injuries: impact of physical activity level, smoking status, body composition, and muscle strength

Background

In the present cross-sectional study, we analyzed the relationships of physical activity level, muscle strength, body composition, injury parameters, and smoking status with bone health in the non-paralyzed upper limb in adult men after spinal cord injuries (SCI).

Methods

The study covered 50 men after spinal cord injuries aged 35.6 ± 4.9 years (25 wheelchair rugby players and 25 non-athletes). Forearm bone mineral density (BMD), bone mineral content (BMC) in distal (dis) and proximal (prox) part was measured by densitometry. Body mass index (BMI) and body fat percentage (BF) were calculated. Fat mass (FM) and fat-free mass (FFM) were estimated from somatic data. An interview was conducted based on the Global Adult Tobacco Survey questionnaire. Muscle strength (maximal hand grip strength) was measured using a Jamar dynamometer.

Results

Active male smokers after SCI had significantly lower BMD dis, BMC dis and prox, T-score dis, and prox (large effect > 0.8) than male non-smokers after SCI. Physical activity was a significant predictor (positive direction) for BMC prox (adjusted R2 = 0.56; p < 0.001). The predictor of interactions of physical activity and fat mass was significant for BMC dis (positive direction, adjusted R2 = 0.58; p < 0.001). It was also found that the predictor of interactions of four variables: physical activity, fat mass, hand grip strength (positive direction), and years of active smoking (negative direction) was significant for BMD dis (adjusted R2 = 0.58; p < 0.001). The predictor of interactions of age at injury (additive direction) and the number of cigarettes smoked per day (negative direction) was significant for T-score prox (adjusted R2 = 0.43; p < 0.001). Non-smoking physically active men after SCI had the most advantageous values of mean forearm BMD.

Conclusion

Rugby can be considered a sport that has a beneficial effect on forearm BMD. The physically active men after SCI had significantly higher bone parameters. Physical activity itself and in interactions with fat mass, hand grip strength (positive direction), and years of active smoking (negative direction) had a significant effect on bone health in non-paralyzed upper limbs. Active smoking may reduce the protective role of physical activity for bone health.

Exploring changes in bone mass in individuals with a chronic spinal cord injury

People experience rapid bone loss shortly after a spinal cord injury (SCI), but the long-term bone changes are yet to be confirmed. This study showed that trabecular bone may have reached a steady state, whereas cortical bone continued to decline in people with a chronic SCI (mean time post injury: 15.5 ± 10 years).

INTRODUCTION

(1) To explore changes in bone [primary measure: trabecular volumetric bone mineral density (vBMD); secondary measures: cortical vBMD, cortical thickness, cortical cross-sectional area (CSA), and polar moment of inertia] over 2 years in individuals with a chronic spinal cord injury (SCI). (2) To explore whether muscle density changes were potential correlates of the observed bone changes.

METHODS

This study is a secondary data analysis of a prospective, observational study involving 70 people with a chronic SCI (≥ 2 years post injury). The study included 4 strata of participants with diverse impairments: (1) Paraplegia (T1-T12) motor complete American Spinal Injury Association Impairment Scale (AIS) A/B (n = 23), (2) Paraplegia motor incomplete AIS C/D (n = 11), (3) Tetraplegia (C2-C8) AIS A/B (n = 22), and (4) Tetraplegia AIS C/D (n = 14). Peripheral quantitative computed tomography scans were taken at the 4% (distal tibia), 38% (diaphyseal tibia), and 66% (muscle cross-sectional area) tibia sites by measuring from the distal to proximal tibia starting at the inferior border of the medial malleolus. The tibia sites were assessed annually over a span of 2 years. Comparisons were made using a paired-samples t test and simple linear regression was used to adjust for sex, time post injury, and bisphosphonate use.

RESULTS

We observed no changes in trabecular vBMD at the 4% tibia site, but there was a statistically significant decline in cortical vBMD, cortical thickness, and CSA at the 38% tibia site. Changes in muscle density were not associated with the decreases observed in cortical bone.

CONCLUSION

Our findings suggest that individuals with chronic SCI (mean duration of injury: 15.5 ± 10 years) may have reached a plateau in bone loss with respect to trabecular bone, but cortical bone loss can continue well into the chronic stages.

Neurogenic Obesity and Skeletal Pathology in Spinal Cord Injury

Spinal cord injury (SCI) results in dramatic changes in body composition, with lean mass decreasing and fat mass increasing in specific regions that have important cardiometabolic implications. Accordingly, the recent Consortium for Spinal Cord Medicine (CSCM) released clinical practice guidelines for cardiometabolic disease (CMD) in SCI recommending the use of compartmental modeling of body composition to determine obesity in adults with SCI. This recommendation is guided by the fact that fat depots impact metabolic health differently, and in SCI adiposity increases around the viscera, skeletal muscle, and bone marrow. The contribution of skeletal muscle atrophy to decreased lean mass is self-evident, but the profound loss of bone is often less appreciated due to methodological considerations. General-population protocols for dual-energy x-ray absorptiometry (DXA) disregard assessment of the sites of greatest bone loss in SCI, but the International Society for Clinical Densitometry (ISCD) recently released an official position on the use of DXA to diagnose skeletal pathology in SCI. In this review, we discuss the recent guidelines regarding the evaluation and monitoring of obesity and bone loss in SCI. Then we consider the possible interactions of obesity and bone, including emerging evidence suggesting the possible influence of metabolic, autonomic, and endocrine function on bone health in SCI.

Osteoporosis after spinal cord injury: aetiology, effects and therapeutic approaches

Osteoporosis is a long-term consequence of spinal cord injury (SCI) that leads to a high risk of fragility fractures. The fracture rate in people with SCI is twice that of the general population. At least 50% of these fractures are associated with clinical complications such as infections. This review article presents key features of osteoporosis after SCI, starting with its aetiology, a description of temporal and spatial changes in the long bones and the subsequent fragility fractures. It then describes the physical and pharmacological approaches that have been used to attenuate the bone loss. Bone loss after SCI has been found to be highly site-specific and characterised by large inter-variability and site-specific changes. The assessment of the available interventions is limited by the quality of the studies and the lack of information on their effect on fractures, but this evaluation suggests that current approaches do not appear to be effective. More studies are required to identify factors influencing rate and magnitude of bone loss following SCI. In addition, it is important to test these interventions at the sites that are most prone to fracture, using detailed imaging techniques, and to associate bone changes with fracture risk. In summary, bone loss following SCI presents a substantial clinical problem. Identification of at-risk individuals and development of more effective interventions are urgently required to reduce this burden.

Factors influencing providers' decisions on management of bone health in people with spinal cord injury

STUDY DESIGN

Survey.

OBJECTIVES

Managing osteoporosis in persons with chronic spinal cord injury (SCI) is difficult as little evidence exists regarding effective strategies. We examined the effect of key factors on providers' bone health management decisions in persons with SCI.

SETTING

USA.

METHODS

Providers reviewed blocks of 9 hypothetical cases that varied on four factors: osteoporosis, osteopenia, or normal bone mineral density using dual-energy X-ray absorptiometry (DXA); DXA region of interest (lumbar spine, hip, knee), prior lower extremity fracture; and no or limited ambulation. They indicated how likely they would recommend pharmacological management, what treatment(s) they would recommend, and whether they would request another DXA before treatment.

RESULTS

Eighty-two healthcare providers completed the survey. Treatment recommendations for bisphosphonates and Vitamin D/calcium supplements, respectively, were more likely if there was a prior fracture (OR: 2.65, 95%CI: 1.76-3.99, p < 0.0001; OR: 2.96, 95%CI: 1.40-6.26, p = 0.004) and if a DXA scan found osteopenia (OR: 2.23, 95%CI: 1.41-3.54, p = 0.001; OR: 6.56, 95%CI: 2.71-15.85, p < 0.0001) or osteoporosis (OR: 12.08, 95%CI: 7.09-20.57, p < 0.0001; OR: 4.54, 95%CI: 2.08-9.90, p < 0.0001). Another DXA scan was more likely to be requested if there was a prior fracture (OR: 1.75, 95%CI: 1.10-2.78, p = 0.02) but less likely if the person was nonambulatory (OR: 0.41, 95%: 0.19-0.90, p = 0.03).

CONCLUSIONS

Prior fracture and DXA findings influenced treatment recommendations for bone health management in SCI. Reliance on lumbar spine scans to determine bone loss and treatment identifies a knowledge gap for which future education is required.

Stiffness and Strength Predictions From Finite Element Models of the Knee are Associated with Lower-Limb Fractures After Spinal Cord Injury

Spinal cord injury (SCI) is associated with bone fragility and fractures around the knee. The purpose of this investigation was to validate a computed tomography (CT) based finite element (FE) model of the proximal tibia and distal femur under biaxial loading, and to retrospectively quantify the relationship between model predictions and fracture incidence. Twenty-six cadaveric tibiae and femora (n = 13 each) were loaded to 300 N of compression, then internally rotated until failure. FE predictions of torsional stiffness (K) and strength (T_ult) explained 74% (n = 26) and 93% (n = 7) of the variation in experimental measurements, respectively. Univariate analysis and logistic regression were subsequently used to determine if FE predictions and radiographic measurements from CT and dual energy X-ray absorptiometry (DXA) were associated with prevalent lower-limb fracture in 50 individuals with SCI (n = 14 fractures). FE and CT measures, but not DXA, were lower in individuals with fracture. FE predictions of T_ult at the tibia demonstrated the highest odds ratio (4.98; p = 0.006) and receiver operating characteristic (0.84; p = 0.008) but did not significantly outperform other metrics. In conclusion, CT-based FE model predictions were associated with prevalent fracture risk after SCI; this technique could be a powerful tool in future clinical research.

Relationships between T-scores at the hip and bone mineral density at the distal femur and proximal tibia in persons with spinal cord injury

Objective: To identify T-score values at the total hip (TH) and femoral neck (FN) that correspond to the cutoff value of <0.60 g/cm² for heightened risk of fracture at the distal femur (DF) and proximal tibia (PT).Design: Retrospective analysis of data in a research center's database. Setting: Community-based individuals with spinal cord injury (SCI). Participants: 105 unique individuals with SCI. Outcome Measurements: DXA derived areal BMD (aBMD) and T-score of the DF, PT, TH, and FN. Results: The aBMD at the DF and PT regions were predictors of T-scores at the TH (R² = 0.63, P < 0.001 and R² = 0.65, P < 0.001) and FN (R² = 0.55, P < 0.001 and R² = 0.58, P < 0.001). Using the DF and PT aBMD of 0.60 g/cm² as a value below which fractures were more likely to occur, the predicted T-score was -3.1 and -3.5 at the TH and -2.6 and -2.9 at the FN, respectively. However, when the predicted and observed T-score values disagree outside the 95% limit of agreement, the predicted T-score values are lower than the measured T-score values, overestimating the measured values between -2.0 and -4.0 SD. Conclusion: The DF and PT cutoff value for aBMD of 0.60 g/cm² was a moderate predictor of T-score values at the TH and FN, with considerable inaccuracies outside the clinically acceptable limits of agreement. As such, the direct measurement of knee aBMD in persons with SCI should be performed, whenever possible, prior to prescribing weight bearing upright activities, such as robotic exoskeletal-assisted walking.

Factors Associated With In-Hospital Outcomes of Traumatic Spinal Cord Injury: 10-year Analysis of the US National Inpatient Sample

INTRODUCTION

Traumatic spinal cord injury (SCI) is a life-altering event. Motor vehicle accidents and falls are common causes of traumatic SCI, and SCI outcomes may be affected by patients' ages and injury sites. This study aimed to investigate the factors associated with unfavorable in-hospital outcomes, focusing on the impact of patients' ages and SCI lesion sites.

METHODS

Data of 25,988 patients hospitalized with traumatic SCI in the US National Inpatient Sample (NIS) database from 2005 to 2014 were extracted and analyzed. Univariate and multivariate logistic regression analyses were performed to determine the factors associated with SCI outcomes, including in-hospital deaths, adverse discharge, and prolonged hospital stays.

RESULTS

Multivariate analysis revealed that the oldest ages (>65 years) were significantly associated with increased in-hospital mortality compared with the youngest ages at all lesion sites (cervical, odds ratio [OR]: 5.474, 95% confidence interval [CI]: 4.465 to 6.709; thoracic, OR: 5.940, 95% CI: 3.881 to 9.091; and lumbosacral, OR: 6.254, 95% CI: 2.920 to 13.394). Older ages were also significantly associated with increased adverse outcomes at all sites (cervical, OR: 2.460, 95% CI: 2.180 to 2.777; thoracic, OR: 2.347, 95% CI: 1.900 to 2.900; and lumbosacral, OR: 2.743, 95% CI: 2.133 to 3.527). Intermediate ages (35 to 64) were also significantly associated with increased in-hospital death and adverse discharge at cervical and thoracic SCIs, but not at lumbosacral sites.

DISCUSSION

For hospitalized patients with traumatic SCI, older age independently predicts worse in-hospital outcomes, with greatest effects seen in patients aged 65 years and older. Study findings suggest that extra vigilance and targeted management strategies are warranted in managing SCI patients aged 65 years and older during hospitalization.

The design of a randomized control trial of exoskeletal-assisted walking in the home and community on quality of life in persons with chronic spinal cord injury

There are more than 300,000 estimated cases of spinal cord injury (SCI) in the United States, and approximately 27,000 of these are Veterans. Immobilization from SCI results in adverse secondary medical conditions and reduced quality of life. Veterans with SCI who have completed rehabilitation after injury and are unable to ambulate receive a wheelchair as standard of care. Powered exoskeletons are a technology that offers an alternative form of limited mobility by enabling over-ground walking through an external framework for support and computer-controlled motorized hip and knee joints. Few studies have reported the safety and efficacy for use of these devices in the home and community environments, and none evaluated their impact on patient-centered outcomes through a randomized clinical trial (RCT). Absence of reported RCTs for powered exoskeletons may be due to a range of challenges, including designing, statistically powering, and conducting such a trial within an appropriate experimental framework. An RCT for the study of exoskeletal-assisted walking in the home and community environments also requires the need to address key factors such as: avoiding selection bias, participant recruitment and retention, training, and safety concerns, particularly in the home environment. These points are described here in the context of a national, multisite Department of Veterans Affairs Cooperative Studies Program-sponsored trial. The rationale and methods for the study design were focused on providing a template for future studies that use powered exoskeletons or other strategies for walking and mobility in people with immobilization due to SCI.

Bone Muscle Crosstalk in Spinal Cord Injuries: Pathophysiology and Implications for Patients' Quality of Life

PURPOSE OF REVIEW

The goal of this review is to provide a comprehensive overview of (i) bone and muscle tissue modifications pathophysiology in spinal cord injury (SCI), (ii) experimental data on the physiopathological mechanisms underpinning these modifications and their similarities with the aging process, and (iii) potential clinical implications in the management of the disabling sequelae of SCI.

RECENT FINDINGS

Several studies attempted to describe the biology underpinning the links between bone and muscle tissues in the setting of highly disabling conditions, such as osteoporosis, sarcopenia, and neurodegenerative disorders, although these bidirectional connections remain still unclear. SCI could be considered an in vivo paradigmatic model of the bone muscle interactions in unloading conditions that might be expanded in the field of neurodegenerative disorders or cancer studies. Future studies should take into consideration the newer insights into bone muscle crosstalk in order to develop multitargeted and therapeutic interventions.

Spinal cord injury providers' perspectives on managing sublesional osteoporosis

Objective: Persons with spinal cord injuries (SCI) experience rapid sublesional bone loss following injury (1, 3). Evidence on preventing/managing osteoporosis in SCI is lacking. This project examined how providers manage bone loss in SCI. Design: Telephone interviews with SCI providers. Setting: VA SCI centers and clinics. Participants: Veterans Administration SCI centers and clinics were categorized on their average number of dual-energy X-ray absorptiometry (DXA) scans (FY2014-2016). Twelve SCI providers from high and low DXA-ordering sites were interviewed. Questions included osteoporosis screening/diagnosis, prevention/treatment strategies, secondary causes of osteoporosis, and osteoporotic fracture complications. Interviews were audio-recorded, transcribed, and analyzed. Results: Providers described a lack of standardized guidelines for managing osteoporosis in SCI. They most often screened for osteoporosis using DXA when: (1) considering use of a new device or activity, (2) for patients with a history of fracture. Some providers assumed that non-ambulatory SCI patients already have osteoporosis so infrequently ordered DXAs. Assessment of secondary causes of osteoporosis was uncommon. Fracture prevention strategies identified included weight-bearing and engaging in activities like adaptive sports. Vitamin D and calcium were frequently prescribed as a result of deficiencies identified during lab testing. Providers seldom prescribed FDA-approved medications for osteoporosis. Post-fracture complications encountered included nonunion/malunion and compartment syndrome. Providers indicated that patients often experienced psychological stress, anxiety and depression following fractures. Conclusion: Providers described a lack of evidence for screening and management of patients with SCI and osteoporosis. Future efforts should include developing evidence-informed guidelines to aid providers in osteoporosis management.

Proceedings of the 2019 Santa Fe Bone Symposium: New Concepts in the Care of Osteoporosis and Rare Bone Diseases

The 20th annual Santa Fe Bone Symposium was held August 9-10, 2019, in Santa Fe, New Mexico, USA. This is an annual meeting devoted to clinical applications of recent advances in skeletal research that impact the care of patients with osteoporosis, metabolic bone diseases, and inherited bone diseases. Participants included practicing and academic physicians, fellows, advanced practice providers, fracture liaison service (FLS) coordinators, clinical researchers, and bone density technologists. The symposium consisted of lectures, case presentations, and panel discussions, with an emphasis on learning through interaction of all attendees. Topics included new approaches in the use of anabolic agents for the treatment osteoporosis, a review of important events in skeletal health over the past year, new and emerging treatments for rare bone diseases, the use of genetic testing for bone diseases in clinical practice, medication-associated causes of osteoporosis, new concepts in the use of estrogen therapy for osteoporosis, new Official Positions of the International Society for Clinical Densitometry, skeletal consequences of bariatric surgery, and update on the progress and potential of Bone Health TeleECHO, a virtual community of practice using videoconferencing technology to link healthcare professionals for advancing the care of osteoporosis worldwide. Sessions on rare bone diseases were developed in collaboration with the Rare Bone Disease Alliance. Symposium premeetings included an FLS workshop by the National Osteoporosis Foundation and others devoted to the use of new therapeutic agents for the care of osteoporosis and related disorders.

Prevention and management of osteoporosis and osteoporotic fractures in persons with a spinal cord injury or disorder: A systematic scoping review

Objectives: The primary objective was to review the literature regarding methodologies to assess fracture risk, to prevent and treat osteoporosis and to manage osteoporotic fractures in SCI/D.Study Design: Scoping review.Settings/Participants: Human adult subjects with a SCI/D.Outcome measures: Strategies to identify persons with SCI/D at risk for osteoporotic fractures, nonpharmacological and pharmacological therapies for osteoporosis and management of appendicular fractures.Results: 226 articles were included in the scoping review. Risk of osteoporotic fractures in SCI is predicted by a combination of DXA-defined low BMD plus clinical and demographic characteristics. Screening for secondary causes of osteoporosis, in particular hyperparathyroidism, hyperthyroidism, vitamin D insufficiency and hypogonadism, should be considered. Current antiresorptive therapies for treatment of osteoporosis have limited efficacy. Use of surgery to treat fractures has increased and outcomes are good and comparable to conservative treatment in most cases. A common adverse event following fracture was delayed healing.Conclusions: Most of the research in this area is limited by small sample sizes, weak study designs, and significant variation in populations studied. Future research needs to address cohort definition and study design issues.

Bone Mineral Density Testing in Spinal Cord Injury: 2019 ISCD Official Position

Spinal cord injury (SCI) causes rapid osteoporosis that is most severe below the level of injury. More than half of those with motor complete SCI will experience an osteoporotic fracture at some point following their injury, with most fractures occurring at the distal femur and proximal tibia. These fractures have devastating consequences, including delayed union or nonunion, cellulitis, skin breakdown, lower extremity amputation, and premature death. Maintaining skeletal integrity and preventing fractures is imperative following SCI to fully benefit from future advances in paralysis cure research and robotic-exoskeletons, brain computer interfaces and other evolving technologies. Clinical care has been previously limited by the lack of consensus derived guidelines or standards regarding dual-energy X-ray absorptiometry-based diagnosis of osteoporosis, fracture risk prediction, or monitoring response to therapies. The International Society of Clinical Densitometry convened a task force to establish Official Positions for bone density assessment by dual-energy X-ray absorptiometry in individuals with SCI of traumatic or nontraumatic etiology. This task force conducted a series of systematic reviews to guide the development of evidence-based position statements that were reviewed by an expert panel at the 2019 Position Development Conference in Kuala Lumpur, Malaysia. The resulting the International Society of Clinical Densitometry Official Positions are intended to inform clinical care and guide the diagnosis of osteoporosis as well as fracture risk management of osteoporosis following SCI.

Trabecular Bone Score at the Distal Femur and Proximal Tibia in Individuals With Spinal Cord Injury

Rapid declines in bone mineral density (BMD) at the knee after spinal cord injury (SCI) are associated with an increased risk of fracture. Evaluation of bone quality using the trabecular bone score (TBS) may provide a complimentary measure to BMD assessment to examine bone health and fracture risk after SCI. The purpose of this study was to assess bone mineral density (BMD) and trabecular bone score (TBS) at the knee in individuals with and without SCI. Nine individuals with complete SCI (mean time since SCI 2.9 ± 3.8 yr) and 9 non-SCI controls received dual-energy X-ray absorptiometry scans of the right knee using the lumbar spine protocol. BMD and TBS were quantified at epiphyseal, metaphyseal, diaphyseal, and total bone regions of the distal femur and proximal tibia. Individuals with SCI illustrated significantly lower total BMD at the distal femur (23%; p = 0.029) and proximal tibia (19%; p = 0.02) when compared with non-SCI controls. Despite these marked differences in BMD from both locations, significant differences in total TBS were observed at the distal femur only (6%; p = 0.023). The observed differences in total BMD and TBS could be attributed to reductions in epiphyseal rather than metaphyseal or diaphysis measurements. The relationship between TBS and duration of SCI was well explained by a logarithmic trend at the distal femoral epiphysis (r² = 0.54, p = 0.025). The logarithmic trend would predict that after 3 yr of SCI, TBS would be approximately 6% lower than the non-SCI controls. Further evaluation is needed to determine if TBS measures at the knee provide important information about bone quality that is not captured by traditional BMD.

Progressive Sublesional Bone Loss Extends into the Second Decade After Spinal Cord Injury

OBJECTIVE

The rate of areal bone mineral density (aBMD) loss at the knee (distal femur (DF) and proximal tibia ) and hip (femoral neck (FN) and total hip (TH)) was determined in persons with traumatic spinal cord injury (SCI) who were stratified into subgroups based on time since injury (TSI).

DESIGN

Cross-sectional retrospective review.

SETTING

Department of Veterans Affairs Medical Center and Private Rehabilitation Hospital.

PARTICIPANTS

Data on 105 individuals with SCI (TSI ≤12 months, n = 19; TSI 1-5 years, n = 35; 6-10 years, n = 19; TSI 11-20 years, n = 16; TSI >20 years, n = 15) and 17 able-bodied reference (AB_ref) controls.

INTERVENTIONS

NA Main Outcome Measures: The knee and hip aBMD values were obtained by dual energy X-ray absorptiometry (GE Lunar iDXA) using standard clinical software for the proximal femur employed in conjunction with proprietary research orthopedic knee software applications. Young-normal (T-score) and age-matched (Z-scores) standardized scores for the FN and TH were obtained using the combined GE Lunar/National Health and Nutrition Examination Survey (NHANES III) combined reference database.

RESULTS

When groups were stratified and compared as epochs of TSI, significantly lower mean aBMD and reference scores were observed as TSI increased, despite similar mean ages of participants among the majority of TSI epoch subgroups. Loss in aBMD occurred at the distal femur (DF), proximal tibia (PT), FN, and TH with 46%, 49%, 32%, and 43% of the variance in loss, respectively, described by the exponential decay curves with a time to steady state (t_ss) occurring at 14.6, 11.3, 14, and 6.2 years, respectively, after SCI.

CONCLUSIONS

Sublesional bone loss after SCI was marked and occurred as an inverse function of TSI. For aBMD at the hip and knee, t_ss extended into the second decade after SCI.

Peripheral Quantitative Computed Tomography: Review of Evidence and Recommendations for Image Acquisition, Analysis, and Reporting, Among Individuals With Neurological Impairment

In 2015, the International Society for Clinical Densitometry (ISCD) position statement regarding peripheral quantitative computed tomography (pQCT) did not recommend routine use of pQCT, in clinical settings until consistency in image acquisition and analysis protocols are reached, normative studies conducted, and treatment thresholds identified. To date, the lack of consensus-derived recommendations regarding pQCT implementation remains a barrier to implementation of pQCT technology. Thus, based on description of available evidence and literature synthesis, this review recommends the most appropriate pQCT acquisition and analysis protocols for clinical care and research purposes, and recommends specific measures for diagnosis of osteoporosis, assigning fracture risk, and monitoring osteoporosis treatment effectiveness, among patients with neurological impairment. A systematic literature search of MEDLINE, EMBASE^©, CINAHL, and PubMed for available pQCT studies assessing bone health was carried out from inception to August 8th, 2017. The search was limited to individuals with neurological impairment (spinal cord injury, stroke, and multiple sclerosis) as these groups have rapid and severe regional declines in bone mass. Of 923 references, we identified 69 that met review inclusion criteria. The majority of studies (n = 60) used the Stratec XCT 2000/3000 pQCT scanners as reflected in our evaluation of acquisition and analysis protocols. Overall congruence with the ISCD Official Positions was poor. Only 11% (n = 6) studies met quality reporting criteria for image acquisition and 32% (n = 19) reported their data analysis in a format suitable for reproduction. Therefore, based on current literature synthesis, ISCD position statement standards and the authors' expertise, we propose acquisition and analysis protocols at the radius, tibia, and femur sites using Stratec XCT 2000/3000 pQCT scanners among patients with neurological impairment for clinical and research purposes in order to drive practice change, develop normative datasets and complete future meta-analysis to inform fracture risk and treatment efficacy evaluation.

Assessment of Bone Mineral Density at the Distal Femur and the Proximal Tibia by Dual-Energy X-ray Absorptiometry in Individuals With Spinal Cord Injury: Precision of Protocol and Relation to Injury Duration

Spinal cord injury (SCI) is characterized by marked bone loss at the knee, and there is a need for established dual-energy X-ray absorptiometry (DXA) protocols to examine bone mineral density (BMD) at this location to track therapeutic progress and to monitor fracture risk. The purpose of this study was to quantify the precision and reliability of a DXA protocol for BMD assessment at the distal femur and the proximal tibia in individuals with SCI. The protocol was subsequently used to investigate the relationship between BMD and duration of SCI. Nine individuals with complete SCI and 9 able-bodied controls underwent 3 repeat DXA scans in accordance with the short-term precision methodology recommended by the International Society of Clinical Densitometry. The DXA protocol demonstrated a high degree of precision with the root-mean-square standard deviation ranging from 0.004 to 0.052 g/cm² and the root-mean-square coefficient of variation ranging from 0.6% to 4.4%, depending on the bone, the region of interest, and the rater. All measurements of intra- and inter-rater reliability were excellent with an intraclass correlation of ≥0.950. The relationship between the BMD and the duration of SCI was well described by a logarithmic trend (r² = 0.68-0.92). Depending on the region of interest, the logarithmic trends would predict that, after 3 yr of SCI, BMD at the knee would be 43%-19% lower than that in the able-bodied reference group. We believe the DXA protocol has the level of precision and reliability required for short-term assessments of BMD at the distal femur and the proximal tibia in people with SCI. However, further work is required to determine the degree to which this protocol may be used to assess longitudinal changes in BMD after SCI to examine clinical interventions and to monitor fracture risk.

Does Muscle Atrophy and Fatty Infiltration Plateau or Persist in Chronic Spinal Cord Injury?

Atrophy and fatty infiltration of lower extremity muscle after spinal cord injury (SCI) predisposes individuals to metabolic syndrome and related diabetes and cardiovascular disease. The objective of this study was to prospectively measure changes in muscle atrophy and fat content of distal lower extremity muscles and explore related factors in a cohort of adults with chronic SCI and diverse impairments. Muscle cross-sectional area and density were calculated from peripheral quantitative computed tomography scans of the 66% site of the calf from 70 participants with chronic SCI (50 male, mean age 49 years, C2-T12, American Spinal Injury Association Impairment Scale A-D) at study enrollment and annually for 2 years. Mixed-model repeated measures analysis of variance (rANOVA) examined longitudinal changes in muscle area and density, and regression analyses explored factors related to muscle changes using 16 potential correlates selected a priori. A high degree of individual variation in muscle area and density change was observed over 2 years (range: 8.5 to  -22.6 cm²; 6.4 to -8.6 mg/cm³). Repeated measures analysis of variance revealed significant reductions in muscle area (estimated mean difference [95% confidence intervals] -1.76 [-3.29 to -0.23]) cm², p = 0.025) and density (-1.04 [-1.94 to -0.14] mg/cm³, p < 0.024); however, changes in area were not significant with outliers removed. Regression analyses explained a small proportion of the variability in muscle density change; however, none of the preselected variables were significantly related to changes in muscle density after post hoc sensitivity analyses. Lower extremity muscle size and fat content may not reach a "steady-state" after chronic SCI. Progressive atrophy and fatty infiltration of lower extremity muscle may have adverse implications for metabolic syndrome and cardiovascular disease risk and related mortality after chronic SCI.

Participation in moderate-to-vigorous leisure time physical activity is related to decreased visceral adipose tissue in adults with spinal cord injury

Increased visceral adiposity places individuals with chronic spinal cord injury (SCI) at increased risk of cardiometabolic disease. The purpose of this study was to identify if people with chronic SCI who participate in any moderate- to vigorous-intensity leisure time physical activity (LTPA) have lower visceral adipose tissue (VAT) area compared with those who report none. Participants included 136 adult men (n = 100) and women (n = 36) with chronic (mean (±SD) 15.6 ± 11.3 years post-injury) tetraplegia (n = 66) or paraplegia (n = 70) recruited from a tertiary rehabilitation hospital. VAT area was assessed via whole-body dual-energy X-ray absorptiometry using a Hologic densitometer and the manufacturer's body composition software. Moderate-to-vigorous LTPA was assessed using the Leisure Time Physical Activity Questionnaire for People with SCI (LTPAQ-SCI) or the Physical Activity Recall Assessment for People with SCI (PARA-SCI). Summary scores were dichotomized into any or no participation in moderate-to-vigorous LTPA to best represent the intensity described in current population-specific physical-activity guidelines. Data were analyzed using univariate and multiple regression analyses to identify the determinants of VAT. Overall, the model explained 67% of the variance in VAT area and included time post-injury, age-at-injury, android/gynoid ratio, waist circumference, and moderate-to-vigorous LTPA. Participation in any moderate-to-vigorous LTPA was significantly (95% confidence interval: -34.71 to -2.61, p = 0.02) associated with VAT after controlling for injury-related and body-composition correlates. Moderate-to-vigorous LTPA appears to be related to lower VAT area, suggesting potential for LTPA to reduce cardiometabolic disease risk among individuals with chronic SCI.

Investigating comparability of quantitative computed tomography with dual energy x-ray absorptiometry in assessing bone mineral density of patients with chronic spinal cord injury

STUDY DESIGN

Psychometric study using retrospectively collected data.

OBJECTIVES

We investigated the comparability of quantitative computed tomography (qCT) in assessing bone mineral density (BMD) with dual energy X-ray absorptiometry (DXA). We evaluated how well previously suggested normal values for spinal Hounsfield units (HU) correlated with routine DXA results in patients with chronic spinal cord injury (SCI). Furthermore, we investigated inter/intra-observer reliability of measuring HU in the spine.

SETTING

Academic medical center in Tehran, Iran.

METHODS

Spinal CT scans of 44 male participants with chronic SCI who had undergone DXA studies on the same day were selected. The main outcome measures were sensitivity, specificity, and area under curve (AUC) of HU at each spinal region against DXA results of areal BMD. The secondary outcome was inter/intra-observer reliability of measuring HU in the spinal column.

RESULTS

We found no significant difference between qCT and DXA results (p-value = 0.237, R = 0.188). However, the two methods showed overall unfavorable comparability, with a sensitivity of 0%, 0%, and 80%, specificity of 50%, 90%, and 85%, and area under curve (AUC) of 0.27, 0.53, and 0.83 for cervical, thoracic, and lumbar spine, respectively. The best comparability was achieved at the lumbar region although not statistically significant (p-value = 0.072). Measuring HU was reliable (inter/intra-observer reliability >98%).

CONCLUSIONS

This study demonstrates that currently proposed normal values result in unfavorable comparability in the cervical and thoracic regions; however, as the agreement improved at the lumbar spine, it is possible that qCT could become an indicator of bone strength with further research.

Rehabilitation Interventions to modify endocrine-metabolic disease risk in Individuals with chronic Spinal cord injury living in the Community (RIISC): A systematic review and scoping perspective

CONTEXT

Endocrine-metabolic disease (EMD) risk following spinal cord injury (SCI) is associated with significant multi-morbidity (i.e. fracture, diabetes, heart disease), mortality, and economic burden. It is unclear to what extent rehabilitation interventions can modify EMD risk and improve health status in community-dwelling adults with chronic SCI.

OBJECTIVES

To characterize rehabilitation interventions and summarize evidence on their efficacy/effectiveness to modify precursors to EMD risk in community-dwelling adults with chronic SCI.

METHODS

Systematic searches of MEDLINE PubMed, EMBASE Ovid, CINAHL, CDSR, and PsychInfo were completed. All randomized, quasi-experimental, and prospective controlled trials comparing rehabilitation/therapeutic interventions with control/placebo interventions in adults with chronic SCI were eligible. Two authors independently selected studies and abstracted data. Mean differences of change from baseline were reported for EMD risk outcomes. The GRADE approach was used to rate the quality of evidence.

RESULTS

Of 489 articles identified, 16 articles (11 studies; n=396) were eligible for inclusion. No studies assessed the effects of rehabilitation interventions on incident fragility fractures, heart disease, and/or diabetes. Individual studies reported that exercise and/or nutrition interventions could improve anthropometric indices, body composition/adiposity, and biomarkers. However, there were also reports of non-statistically significant between-group differences.

CONCLUSIONS

There was very low-quality evidence that rehabilitation interventions can improve precursors to EMD risk in community-dwelling adults with chronic SCI. The small number of studies, imprecise estimates, and inconsistency across studies limited our ability to make conclusions. A high-quality longitudinal intervention trial is needed to inform community-based rehabilitation strategies for EMD risk after chronic SCI.

Agreement between fragility fracture risk assessment algorithms as applied to adults with chronic spinal cord injury

STUDY DESIGN

Cross-sectional.

OBJECTIVES

The objective of the study was to determine and report agreement in fracture risk stratification of adults with spinal cord injury (SCI) using (1) Canadian Association of Radiologists and Osteoporosis Canada (CAROC) and Canadian Fracture Risk Assessment (FRAX) tools with and without areal bone mineral density (aBMD) and (2) SCI-specific fracture thresholds.

SETTING

Tertiary rehabilitation center, Ontario, Canada.

METHODS

Community-dwelling adults with chronic SCI (n=90, C2-T12, AIS A-D) consented to participation. Femoral neck aBMD values determined 10-year fracture risk (CAROC and FRAX). Knee-region aBMD and distal tibia volumetric BMD values were compared to SCI-specific fracture thresholds. Agreements between CAROC and FRAX risk stratifications, and between fracture threshold risk stratification, were assessed using prevalence- and bias-adjusted Kappa statistics (PABAK).

RESULTS

CAROC and FRAX assessment tools showed moderate agreement for post-menopausal women (PABAK=0.56, 95% confidence interval (CI): 0.27, 0.84) and men aged ⩾50 years (PABAK=0.51, 95% CI: 0.34, 0.67), with poor agreement for young men and pre-menopausal women (PABAK⩽0). Excellent agreement was evident between FRAX with and without aBMD in young adults and in those with motor incomplete injury (PABAK=0.86-0.92). In other subgroups, agreement ranged from moderate to substantial (PABAK=0.41-0.73). SCI-specific fracture thresholds (Eser versus Garland) showed poor agreement (PABAK⩽0).

CONCLUSION

Fracture risk estimates among individuals with SCI vary substantially with the risk assessment tool. Use of SCI-specific risk factors to identify patients with high fracture risk is recommended until a validated SCI-specific tool for predicting fracture risk is developed.

Dual-energy X-ray absorptiometry and fracture prediction in patients with spinal cord injuries and disorders

Low T-scores at the hip predict incident fractures in persons with a SCI.

INTRODUCTION

Persons with a spinal cord injury (SCI) have substantial morbidity and mortality following osteoporotic fractures. The objective of this study was to determine whether dual-energy X-ray absorptiometry (DXA) measurements predict osteoporotic fractures in this population.

METHODS

A retrospective historical analysis that includes patients (n = 552) with a SCI of at least 2 years duration who had a DXA performed and were in the VA Spinal Cord Disorders Registry from fiscal year (FY) 2002-2012 was performed.

RESULTS

The majority of persons (n = 455, 82%) had a diagnosis of osteoporosis or osteopenia, with almost half having osteoporosis. BMD and T-scores at the lumbar spine were not significantly associated with osteoporotic fractures (p > 0.48) for both. In multivariable analyses, osteopenia (OR = 4.75 95% CI 1.23-17.64) or osteoporosis (OR = 4.31, 95% CI 1.15-16.23) compared with normal BMD was significantly associated with fractures and higher T-scores at the hip were inversely associated with fractures (OR 0.73 (95% CI 0.57-0.92)). There was no significant association of T-scores or World Health Organization (WHO) classification with incident fractures in those with complete SCI (p > 0.15 for both).

CONCLUSION

The majority (over 80%) of individuals with a SCI have osteopenia or osteoporosis. DXA-derived measurements at the hip, but not the lumbar spine, predict fracture risk in persons with a SCI. WHO-derived bone density categories may be useful in classifying fracture risk in persons with a SCI.

Bone loss at the distal femur and proximal tibia in persons with spinal cord injury: imaging approaches, risk of fracture, and potential treatment options

Persons with spinal cord injury (SCI) undergo immediate unloading of the skeleton and, as a result, have severe bone loss below the level of lesion associated with increased risk of long-bone fractures. The pattern of bone loss in individuals with SCI differs from other forms of secondary osteoporosis because the skeleton above the level of lesion remains unaffected, while marked bone loss occurs in the regions of neurological impairment. Striking demineralization of the trabecular epiphyses of the distal femur (supracondylar) and proximal tibia occurs, with the knee region being highly vulnerable to fracture because many accidents occur while sitting in a wheelchair, making the knee region the first point of contact to any applied force. To quantify bone mineral density (BMD) at the knee, dual energy x-ray absorptiometry (DXA) and/or computed tomography (CT) bone densitometry are routinely employed in the clinical and research settings. A detailed review of imaging methods to acquire and quantify BMD at the distal femur and proximal tibia has not been performed to date but, if available, would serve as a reference for clinicians and researchers. This article will discuss the risk of fracture at the knee in persons with SCI, imaging methods to acquire and quantify BMD at the distal femur and proximal tibia, and treatment options available for prophylaxis against or reversal of osteoporosis in individuals with SCI.

Pixel-Based DXA-Derived Structural Properties Strongly Correlate with pQCT Measures at the One-Third Distal Femur Site

While bone mineral density has been traditionally used to quantify fracture risk for individuals with spinal cord injuries, recent studies are including engineering measurements such as section modulus and cross sectional moment of inertia. These are almost exclusively calculated by peripheral QCT scanners which, unlike DXA scanners, are rarely found in clinical settings. Using fifty-four fresh frozen femora, we developed and validated a pixel-by-pixel method to calculate engineering properties at the distal femur using a Hologic QDR-1000 W DXA scanner and compared them against similar parameters measured using a Stratec XCT-3000 peripheral QCT scanner. We found excellent agreement between standard DXA and pixel-by-pixel measured BMD (r ² = 0.996). Cross-sectional moment of inertia about the anteroposterior axis measured using DXA and pQCT correlated very strongly (r ² = 0.99). Cross-sectional moment of inertia about the anteroposterior axis measured using DXA also correlated strongly with pQCT measured bone strength index (r ² = 0.99). These correlations indicate that DXA scans can measure equivalent pQCT parameters, and some existing DXA scans can be reprocessed with pixel-by-pixel techniques. Ultimately, these engineering parameters may help better quantify fracture-risk in fracture-prone populations such as those with spinal cord injuries.

Measuring muscle and bone in individuals with neurologic impairment; lessons learned about participant selection and pQCT scan acquisition and analysis

Peripheral quantitative computed tomography (pQCT) can be used to examine bone strength outcomes and muscle size and fatty infiltration. Our research team and others have used it to examine bone loss after spinal cord injury (SCI). However, the high prevalence of restricted lower extremity range of motion, spasticity, edema, excessive muscle atrophy, or severe osteoporosis necessitates changes to standard protocols for screening, positioning during scan acquisition, and analysis methods. This manuscript outlines the challenges that we experienced using pQCT in individuals with SCI, and provides solutions, ones that may also be applicable when using pQCT in individuals with other chronic conditions or in older adults. Suggestions for participant screening, positioning individuals for scanning while in a wheelchair, scan site selection, need for attendant assistance, and considerations in the presence of secondary complications, such as contracture, spasticity, and paralysis, are presented. In the presence of very low bone mineral density or severe muscle atrophy, the default analysis modes provided by the manufacturer may not provide valid estimates of bone or muscle indices; we propose alternates. We have used watershed segmentation methods to determine muscle size and density based on lower precision error compared to threshold-based edge-detection segmentation, particularly for adults with SCI, where more fatty infiltration was present. By presenting our "lessons learned," we hope to reduce the learning curve for researchers using pQCT in the future.

Sarcopenic Obesity in Adults With Spinal Cord Injury: A Cross-Sectional Study

OBJECTIVES

To describe (1) the frequency and utility of clinically relevant spinal cord injury (SCI)-specific and general population thresholds for obesity and sarcopenic obesity; and (2) the fat and lean soft tissue distributions based on the neurologic level of injury and the American Spinal Injury Association Impairment Scale.

DESIGN

Cross-sectional.

SETTING

Tertiary SCI rehabilitation hospital.

PARTICIPANTS

Persons (N=136; men, n=100; women, n=36) with chronic (mean ± SD: 15.6±11.3y postinjury) tetraplegia (n=66) or paraplegia (n=70).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Body composition was assessed with anthropometrics and whole-body dual-energy x-ray absorptiometry. Muscle atrophy was quantified using a sarcopenia threshold of appendicular lean mass index (ALMI) (men, ≤7.26kg/m²; women, ≤5.5kg/m²). Obesity was defined by percentage body fat (men, ≥25%; women, ≥35%), visceral adipose tissue (≥130cm²), and SCI-specific obesity thresholds (body mass index [BMI] ≥22kg/m²; waist circumference ≥94cm). Sarcopenic obesity was defined as the presence of both sarcopenia and obesity. Groups were compared based on impairment characteristics using an analysis of covariance.

RESULTS

Sarcopenic obesity was prevalent in 41.9% of the sample. ALMI was lower among participants with motor-complete (6.2±1.3kg/m²) versus motor-incomplete (7.5±1.6kg/m²) injuries (P<.01). Whole-body fat was greater among participants with tetraplegia (28.8±11.2kg) versus paraplegia (24.1±8.7kg; P<.05). Compared with general population guidelines (20.6%), SCI-specific BMI thresholds identified all the participants with obesity (77.9%) based on percentage body fat (72.1%).

CONCLUSIONS

The observed frequency of sarcopenic obesity in this sample of individuals with chronic SCI is very high, and identification of obesity is dissimilar when using SCI-specific versus general population criteria.

Musculoskeletal Effects of 2 Functional Electrical Stimulation Cycling Paradigms Conducted at Different Cadences for People With Spinal Cord Injury: A Pilot Study

OBJECTIVE

To compare the musculoskeletal effects of low cadence cycling with functional electrical stimulation (FES) with high cadence FES cycling for people with spinal cord injury (SCI).

DESIGN

Randomized pre-post design.

SETTING

Outpatient rehabilitation clinic.

PARTICIPANTS

Participants (N=17; 14 men, 3 women; age range, 22-67y) with C4-T6 motor complete chronic SCI were randomized to low cadence cycling (n=9) or high cadence cycling (n=8).

INTERVENTIONS

Low cadence cycling at 20 revolutions per minute (RPM) and high cadence cycling at 50 RPM 3 times per week for 6 months. Cycling torque (resistance per pedal rotation) increased if targeted cycling cadence was maintained.

MAIN OUTCOME MEASURES

Dual-energy x-ray absorptiometry was used to assess distal femur areal bone mineral density, magnetic resonance imaging was used to assess to assess trabecular bone microarchitecture and cortical bone macroarchitecture and thigh muscle volume, and biochemical markers were used to assess bone turnover. It was hypothesized that subjects using low cadence cycling would cycle with greater torque and therefore show greater musculoskeletal improvements than subjects using high cadence cycling.

RESULTS

A total of 15 participants completed the study. Low cadence cycling obtained a maximal average torque of 2.9±2.8Nm, and high cadence cycling obtained a maximal average torque of 0.8±0.2Nm. Low cadence cycling showed greater decreases in bone-specific alkaline phosphatase, indicating less bone formation (15.5% decrease for low cadence cycling, 10.7% increase for high cadence cycling). N-telopeptide decreased 34% following low cadence cycling, indicating decreased resorption. Both groups increased muscle volume (low cadence cycling by 19%, high cadence cycling by 10%). Low cadence cycling resulted in a nonsignificant 7% increase in apparent trabecular number (P=.08) and 6% decrease in apparent trabecular separation (P=.08) in the distal femur, whereas high cadence cycling resulted in a nonsignificant (P>.3) 2% decrease and 3% increase, respectively.

CONCLUSIONS

This study suggests that the greater torque achieved with low cadence cycling may result in improved bone health because of decreased bone turnover and improved trabecular bone microarchitecture. Longer-term outcome studies are warranted to identify the effect on fracture risk.

Muscle Density and Bone Quality of the Distal Lower Extremity Among Individuals with Chronic Spinal Cord Injury

BACKGROUND

Understanding the related fates of muscle density and bone quality after chronic spinal cord injury (SCI) is an important initial step in determining endocrine-metabolic risk.

OBJECTIVE

To examine the associations between muscle density and indices of bone quality at the distal lower extremity of adults with chronic SCI.

METHODS

A secondary data analysis was conducted in 70 adults with chronic SCI (C2-T12; American Spinal Injury Association Impairment Scale [AIS] A-D; ≥2 years post injury). Muscle density and cross-sectional area (CSA) and bone quality indices (trabecular bone mineral density [TbBMD] at the distal tibia [4% site] and cortical thickness [CtTh], cortical area [CtAr], cortical BMD [CtBMD], and polar moment of inertia [PMI] at the tibial shaft [66% site]) were measured using peripheral quantitative computed tomography. Calf lower extremity motor score (cLEMS) was used as a clinical measure of muscle function. Multivariable linear regression analyses were performed to determine the strength of the muscle-bone associations after adjusting for confounding variables (sex, impairment severity [AIS A/B vs AIS C/D], duration of injury, and wheelchair use).

RESULTS

Muscle density was positively associated with TbBMD (b = 0.85 [0.04, 1.66]), CtTh (b = 0.02 [0.001, 0.034]), and CtBMD (b = 1.70 [0.71, 2.69]) (P < .05). Muscle CSA was most strongly associated with CtAr (b = 2.50 [0.12, 4.88]) and PMI (b = 731.8 [161.7, 1301.9]) (P < .05), whereas cLEMS was most strongly associated with TbBMD (b = 7.69 [4.63, 10.76]) (P < .001).

CONCLUSIONS

Muscle density and function were most strongly associated with TbBMD at the distal tibia in adults with chronic SCI, whereas muscle size was most strongly associated with bone size and geometry at the tibial shaft.

Bone Imaging and Fracture Risk after Spinal Cord Injury

Spinal cord injury (SCI) is characterized by marked bone loss and an increased risk of fracture with high complication rate. Recent research based on advanced imaging analysis, including quantitative computed tomography (QCT) and patient-specific finite element (FE) modeling, has provided new and important insights into the magnitude and temporal pattern of bone loss, as well as the associated changes to bone structure and strength, following SCI. This work has illustrated the importance of early therapeutic treatment to prevent bone loss after SCI and may someday serve as the basis for a clinical fracture risk assessment tool for the SCI population. This review provides an update on the epidemiology of fracture after SCI and discusses new findings and significant developments related to bone loss and fracture risk assessment in the SCI population based on QCT analysis and patient-specific FE modeling.

Lower-extremity muscle atrophy and fat infiltration after chronic spinal cord injury

BACKGROUND

Atrophy and fatty-infiltration of lower-extremity muscle after spinal cord injury (SCI) predisposes individuals to metabolic disease and related mortality.

OBJECTIVES

To determine the magnitude of atrophy and fatty-infiltration of lower-extremity muscles and related factors in a group of individuals with chronic SCI and diverse impairment.

METHODS

Muscle cross-sectional area and density were calculated from peripheral quantitative computed tomography scans of the 66% site of the calf of 70 participants with chronic SCI [50 male, mean age 49 (standard deviation 12) years, C2-T12, AIS A-D] and matched controls. Regression models for muscle area and density were formed using 16 potential correlates selected a priori.

RESULTS

Participants with motor-complete SCI had ≈ 32% lower muscle area, and ≈ 43% lower muscle density values relative to controls. Participants with motor-incomplete SCI had muscle area and density values that were both ≈ 14% lower than controls. Body mass (+), tetraplegia (+), motor function (+), spasticity (+), vigorous physical activity (+), wheelchair use (-), age (-), and waist circumference (-) were associated with muscle size and/or density in best-fit regression models.

CONCLUSIONS

There are modifiable factors related to muscle size, body composition, and activity level that may offer therapeutic targets for preserving metabolic health after chronic SCI.

Self-report of one-year fracture incidence and osteoporosis prevalence in a community cohort of canadians with spinal cord injury

BACKGROUND

Sublesional declines in hip and knee region bone mass are a well-established consequence of motor complete spinal cord injury (SCI), placing individuals with SCI at risk for fragility fracture, hospitalization, and fracture-related morbidity and mortality.

OBJECTIVES

To describe the 1-year incidence of fracture and osteoporosis prevalence in a community cohort of Canadians with chronic SCI.

METHODS

As part of the SCI Community Survey, consenting adult participants with chronic SCI completed an online or telephone survey regarding their self-reported medical comorbidities, including fracture and osteoporosis, in the 12 months prior to survey conduct. Survey elements included sociodemographic and impairment descriptors and 4 identified risk factors for lower extremity fragility fracture: injury duration ≥ 10 years, motor complete and sensory complete (AIS A or A-B) paraplegia, and female gender.

RESULTS

Consenting participants included 1,137 adults, 70.9% were male, mean (SD) age was 48.3 (13.3) years, and mean (SD) time post injury was 18.5 (13.1) years. Eighty-four participants (7.4%) reported a fracture in the previous 12 months and 244 (21.5%) reported having osteoporosis in the same time period, with corresponding treatment rates of 84.5% and 64.8%, respectively. The variables most strongly associated with fracture were osteoporosis (odds ratio [OR], 4.3; 95% CI, 2.72-6.89) and having a sensory-complete injury (OR, 2.2; 95% CI, 1.38-3.50) or a motor complete injury (OR, 1.7; 95% CI, 1.10-2.72).

CONCLUSIONS

The discordance between fracture occurrence and treatment and the strength of the association between osteoporosis diagnosis and incident fractures necessitates improved bone health screening and treatment programs, particularly among persons with complete SCI.

Tea consumption didn't modify the risk of fracture: a dose-response meta-analysis of observational studies

Background

Fractures are important causes of healthy damage and economic loss nowadays. The conclusions of observational studies on tea consumption and fracture risk are still inconsistent. The objective of this meta-analysis is to determine the effect of tea drinking on the risk of fractures.

Methods

A comprehensive literature search was conducted in PubMed, Embase and reference lists of the relevant articles. Observational studies that reported an estimate of the association between tea drinking and incidence of fractures were included. A meta-analysis was conducted by the STATA software.

Results

A total of 9 studies involving 147,950 individuals that examined the association between tea consumption and risk of fractures were included in this meta-analysis. The odds risks (ORs) with 95% confidence intervals (CIs) were pooled using a random-effects model. The pooled OR of 9 observational studies for the tea consumption on risk of fracture was 0.89 (95% CI, 0.78-1.04). In the subgroup analyses, no significant association was detected in neither cohort studies (n = 3; OR, 0.97; 95% CI, 0.89-1.06) nor case–control studies (n = 6; OR, 0.91; 95% CI, 0.70-1.19), respectively. No significant association was detected in the dose–response meta-analysis.

Conclusions

Tea consumption might not be associated with the risk of fractures. The following large-sample and well-designed studies are required to confirm the existing conclusions.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5309904231178427.

Incidence of skeletal fractures after traumatic spinal cord injury: a 10-year follow-up study

OBJECTIVE

To analyse the incidence and factors related to the development and clinical evolution of fractures in patients with traumatic spinal cord injury.

DESIGN

A retrospective 10-year follow-up study.

SETTING

Neurorehabilitation centre.

SUBJECTS

Sixty-three patients (50M/13F) with a mean age of 36 ± 20 years with recent traumatic spinal cord injury attended over a one-year period (January to December 2000).

MAIN MEASURES

Medical reports were reviewed, evaluating risk factors for osteoporosis, fracture incidence during the 10 years following spinal cord injury, severity (ASIA score) and level of spinal cord injury (paraplegia/tetraplegia), type of lesion (spastic/flaccid), weight-bearing standing activity, and the cause, location and evolution of the fracture.

RESULTS

Of the 129 patients attending during the study period, 75 had traumatic spinal cord injury (7 died and 5 had no follow-up). Finally, 63 patients were included. Fifty-four per cent had complete motor injury (ASIA A). Twenty-five per cent of these patients developed fractures, with 2.9 fractures per 100 patient-years. The femur was the most frequent location of the fractures. Fractures were observed 6.4 ± 2.4 years after spinal cord injury (range 2-10 years), all in males. Most fractures (70%) were related to low-impact injuries. Fifty per cent presented with associated clinical complications and only 20% of the patients had received anti-osteoporotic treatment. Spinal cord injury severity was the only risk factor for the development of fractures (complete spinal cord injury (ASIA A)) (RR 4.043; 95% confidence interval (CI) 1.081-23.846, P = 0.037).

CONCLUSION

The incidence of fractures after spinal cord injury is high, with severity and time since spinal cord injury being the main determinants for their development. Fractures were frequently associated with clinical complications. However, the use of anti-osteoporotic treatment was uncommon.