Osteoporosis in the lower extremities in chronic spinal cord injury

Risk of fracture among patients with spinal cord injury: A nationwide cohort study in South Korea

BACKGROUND

Clinical concerns about preventing and managing fractures after spinal cord injury (SCI) have been growing.

OBJECTIVE

This study investigates the risk of fractures among SCI patients according to the presence of disability, disease severity, and level of injury.

METHODS

We performed a retrospective cohort study using the Korean National Health Insurance Service (KNHIS 2010-2018) database. We included 5190 SCI patients and 1:3 age- and sex-matched control participants. The primary outcome was fracture, and the cohort was followed until December 31, 2019.

RESULTS

SCI patients had a higher fracture risk than the matched controls (adjusted hazard ratio [aHR] 1.33, 95 % CI 1.16-1.54). The risk of fracture was higher in the presence of disability (aHR 1.57, 95 % CI 1.19-2.07), especially among patients with severe disability (aHR 1.65, 95 % CI 1.05-2.60). Higher fracture risks were observed among SCI patients regardless of injury level, but statistical significance was found only with cervical-level injury. When we considered site-specific fractures, vertebral (aHR 1.31, 95 % CI 1.04-1.64) and hip fracture risks (aHR 2.04, 95 % CI 1.39-2.98) were both higher among SCI patients than the controls. SCI patients with disability and cervical-level injury showed the highest hip fracture risk (aHR 3.67, 95 % CI 1.90-7.07).

CONCLUSIONS

Compared with the controls, SCI patients were at higher risk of any fracture, particularly hip fracture, especially those with disability and cervical-level injury. Clinicians should be aware of the fracture risk among SCI patients to provide proper management.

Malunions following lower extremity fractures in veterans with a spinal cord injury/disorder

BACKGROUND

Nearly 50% of all persons with a spinal cord injury/disorder (SCI/D) will sustain an osteoporotic fracture sometime in their life, with lower extremity fractures being the most common. There are a number of complications that can occur post fracture, including fracture malunion. To date, there have been no dedicated investigations of malunions among persons with SCI/D.

OBJECTIVES

The primary objective of this study was to identify risk factors associated with fracture malunion among fracture-related (type of fracture, fracture location, initial fracture treatment) and SCI/D-related factors. Secondary objectives were to describe treatment of fracture malunions and complications following these malunions.

METHODS

Veterans with SCI/D with an incident lower extremity fracture and subsequent malunion from Fiscal Year (FY) 2005-2015 were selected from the Veteran Health Administration (VHA) databases using International Classification of Diseases, 9th edition (ICD-9) codes for lower extremity fractures and malunion. These fracture malunion cases underwent electronic health record (EHR) review to abstract information on potential risk factors, treatments and complications for malunion. Twenty-nine cases were identified with a fracture malunion with 28 of them successfully matched with Veterans with a lower extremity fracture during FY2005-FY2014 without a malunion (matched 1:4) based on having an outpatient utilization date of care within 30 days of the fracture case. There was trend towards more nonsurgical treatment in the malunion group (n = 27, 96.43%) compared to the control group (n = 101, 90.18%) (P = 0.05), though fracture treatment proved not to be not associated with developing a malunion in univariate logistic regression analyses (OR = 0.30; 95% CI: 0.08-1.09). In multivariate analyses, Veterans with tetraplegia were significantly less likely (approximately 3-fold) to have a fracture malunion (OR = 0.38; 95% CI: 0.14-0.93) compared to those with paraplegia. Fracture malunion was significantly less likely to occur for fractures of the ankle (OR = 0.02; 95% CI: 0-0.13) or the hip (OR = 0.15; 95% CI: 0.03-0.56) compared to femur fractures. Fracture malunions were rarely treated. The most common complications following malunions were pressure injuries (56.3%) followed by osteomyelitis (25.0%).

CONCLUSIONS

Persons with tetraplegia as well as fractures of the ankle and hip (compared to the femur) were less likely to develop a fracture malunion. Attention to prevention of avoidable pressure injuries following a fracture malunion is important.

Comparison of the prevalence of osteoporosis in people with spinal cord injury according to bone mineral density reference values for the diagnosis of osteoporosis: a retrospective, cross-sectional study

BACKGROUND

Spinal cord injury (SCI) is a complex cause of rapid low bone mass that easily predisposes the affected individuals to osteoporosis-induced fractures. Several studies have investigated osteoporosis pathophysiology in SCI; however, those associated with its diagnosis in SCI are limited. Additionally, errors in osteoporosis diagnosis and its prevalence vary based on the bone mineral density (BMD) reference values (BMDRV), and no studies have reported BMDRV application for osteoporosis diagnosis in individuals with SCI. Therefore, this study aimed to compare the prevalence of osteoporosis among Korean adults aged ≥ 50 years with SCI according to BMDRV for diagnosing osteoporosis.

METHODS

Overall, 855 patients with SCI who underwent BMD tests of the lumbar spine, femoral neck, and total hip at the National Rehabilitation Center (NRC) in Korea between 2010 and 2020 were included in this retrospective cross-sectional study. Osteoporosis was diagnosed in patients with SCI by comparing the differences in prevalence, diagnostic consistency, and risk factors according to the region-based BMDRV of the dual-energy x-ray absorptiometry (DXA) manufacturer and international BMDRV based on the Third National Health and Nutrition Examination Survey (NHANES III) data of females aged 20-29 years.

RESULTS

The prevalence of osteoporosis according to the T-score provided by a single reference population of the NHANES III (TNHA) (PONHA) (males: 26.69%; females: 69.35%) was significantly higher in females and males than that according to the T-scores provided by the DXA manufacturer (TDXA) (PODXA) (males: 15.32%; females: 43.15%). The lumbar spine and femoral neck were major osteoporosis diagnosis sites for the PODXA and PONHA, respectively. Risk factors for osteoporosis differed based on the probability of osteoporosis (also known as the OZ ratio) according to the BMD criteria; however, the risk factors were similar according to old age, female sex, low body mass index (BMI), and long SCI period. No significant relationship was noted between the different SCI-related clinical factors (p > 0.05).

CONCLUSIONS

The osteoporosis diagnostic site and prevalence in SCI differed according to the regional-based TDXA and international standards of the TNHA. Therefore, further studies on BMDRV are warranted to establish accurate diagnostic criteria for osteoporosis prevention in patients with SCI.

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.

Bone Mineral Loss at the Distal Femur and Proximal Tibia Following Spinal Cord Injury in Men and Women

PURPOSE

Spinal cord injury (SCI) causes rapid bone loss and increases risk of fragility fractures in the lower extremities. The majority of individuals with SCI are men, and few studies have investigated sex as a biological variable in SCI-induced osteoporosis. This cross-sectional study aimed to quantify sex-specific differences in bone mineral following SCI.

METHODS

Quantitative computed tomography (QCT) scans of the distal femur and proximal tibia were obtained at baseline of one of four clinical trials enrolling people who sustained SCI 1 month to 50 years prior to recruitment. Bone volume (BV), bone mineral content (BMC), bone mineral density (BMD), and bending strength index (BSI) were quantified in the integral, trabecular, and cortical bone in the epiphysis, metaphysis and diaphysis. Scans from 106 men and 31 women were analyzed to measure sex-specific effects on bone loss over time post-SCI.

RESULTS

BMC and BSI declined exponentially as a function of time post-SCI and were best described by separate decay curves for men and women. Women had BV, BMC, and BSI at 58-77% that of men in the acute and plateau phases, with both sexes showing similar rates of loss as a function of time post-SCI. Trabecular BMD was best described as an exponential decay versus time post-SCI, with no sex-specific differences.

CONCLUSIONS

Due to consistently lower BV, BMC, and BSI, women may be more susceptible to fractures after SCI than men.

Total Knee Arthroplasty in Patients with Spinal Cord Injury: Impact on Medical Complications, Hospital Costs and Length of Stay

INTRODUCTION

Patients with spinal cord injury (SCI) with degenerative joint disease of the knee may require total knee arthroplasty (TKA). This study examines the demographic and immediate postoperative outcomes of patients with SCI who undergo TKA.

METHODS

Admissions data for TKA and SCI were analyzed from the National Inpatient Sample database using International Classification of Diseases, 10th Revision, Clinical Modification diagnosis codes. An extensive array of preoperative and postoperative variables was compared among SCI TKA patients and non-SCI TKA patients. An unmatched and matched analysis using a 1:1 propensity match algorithm was conducted to compare the two groups.

RESULTS

Patients with SCI tend to be younger and have a 7.518 times greater risk of acute renal failure, 2.3 times greater risk of blood loss, and higher risk of local complications, including periprosthetic fracture and prosthetic infection. The average length of stay in the SCI cohort was 2.12 times greater, with a 1.58 times higher mean total incurred charge than the non-SCI group.

CONCLUSION

SCI is associated with an increased risk of acute renal failure, blood loss anemia, periprosthetic fractures and infections, a longer length of stay, and greater incurred charges in TKA patients.

STUDY DESIGN

Retrospective study.

Impact of vitamin D on the prognosis after spinal cord injury: A systematic review

Vitamin D (VitD) insufficiency is a worldwide health problem and affects billions of people. Spinal cord injury (SCI) patients seem more susceptible to developing suboptimal levels of VitD. However, the literature regarding its impact on the prognosis of SCI is limited. Thus, in this review, we systematically investigated the published studies via a combination of keywords associated with SCI and VitD in four medical databases (Medline, Embase, Scopus, and Web of Science). All included studies were analyzed, and selected clinical data on the prevalence of VitD insufficiency (serum 25-hydroxyvitamin D < 30 ng/ml) and deficiency (serum 25-hydroxyvitamin D < 20 ng/ml) were collected for further meta-analysis via random effects. Through literature review, a total of 35 studies were eligible and included. The meta-analysis of VitD status (13 studies, 1,962 patients) indicated high prevalence of insufficiency (81.6% [75.7, 87.5]) and deficiency (52.5% [38.1, 66.9]) after SCI. Besides, low levels of VitD were reported to be associated with a higher risk of skeletal diseases, venous thromboembolism, psychoneurological syndromes, and chest illness after injury. Existing literature suggested that supplemental therapy might act as an adjuvant treatment to facilitate post-injury rehabilitation. Non-human experimental studies highlighted the neuroprotective effect of VitD, which was associated with enhancing axonal and neuronal survival, suppressing neuroinflammation, and modulating autophagy. Therefore, the current evidence suggests that the prevalence of VitD insufficiency is high in the SCI population, and low-level VitD may impair functional restoration after SCI. VitD supplemental treatment may have potential benefits to accelerate rehabilitation in mechanistically related processes after SCI. However, due to the limitation of the available evidence, more well-designed randomized controlled trials and mechanism experimental research are still needed to validate its therapeutic effect, elucidate its neuroprotective mechanism, and develop novel treatments.

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.

Comparison of DXA-based versus CT-based indices to predict prevalent fracture history in men with spinal cord injury

Fracture risk prediction remains challenging in adults with spinal cord injury. Here, we compare the ability of CT- and DXA-derived indices to discriminate between those with and without prevalent osteoporotic fracture. Novel CT-derived indices may offer improved assessment of fragility fracture risk as well as improved monitoring of response to therapies.

INTRODUCTION

Individuals with spinal cord injury are particularly susceptible to osteoporosis. As advanced imaging techniques become more readily available clinically, there is limited information on the relative strength of various outcomes for fracture risk prediction. The purpose of this study was to compare the ability of DXA-based versus CT-based indices to predict prevalent fracture history in adults with spinal cord injury.

METHODS

Thirty-six men with known SCI underwent dual energy X-ray absorptiometry and computed tomography assessments of the lower extremities. We used age-adjusted area under the curve models to compare the predictive value for each bone parameter to identify prevalent fracture history.

RESULTS

CT-based indices outperformed DXA-based indices at all sites. The site with the highest AUC was the trabecular BMD at the proximal tibial epiphysis.

CONCLUSIONS

CT imaging may have clinical utility to improve fracture risk prediction in adults with SCI. More work is needed to confirm these findings and to assess the value of CT-based indices to predict incident fracture, monitor longitudinal bone loss, and monitor response to various therapies, both pharmacological and rehabilitation.

Guidelines for management of pediatric acute hyperextension spinal cord injury

Pediatric acute hyperextension spinal cord injury (SCI) named as PAHSCI by us, is a special type of thoracolumbar SCI without radiographic abnormality and highly related to back-bend in dance training, which has been increasingly reported. At present, it has become the leading cause of SCI in children, and brings a heavy social and economic burden. Both domestic and foreign academic institutions and dance education organizations lack a correct understanding of PAHSCI and relevant standards, specifications or guidelines. In order to provide standardized guidance, the expert team formulated this guideline based on the principles of science and practicability, starting from the diagnosis, differential diagnosis, etiology, admission evaluation, treatment, complications and prevention. This guideline puts forward 23 recommendations for 14 related issues.

Cross-Sectional Study of Knee Bone Mineral Density and Fragility Fractures in Patients with Neurological Injuries and Neuromuscular Disorders

BACKGROUND

Patients with neurological injury and neuromuscular disorders are at increased risk for osteoporosis and fragility fracture. This cross-sectional study investigated whether knee bone mineral density (BMD) correlates with fragility fracture in patients with neurological injury and neuromuscular injuries.

METHODOLOGY

In this retrospective chart review, 435 participants underwent dual-energy X-ray absorptiometry (DXA) for BMD analysis. Distal femur and proximal tibial BMD measurements were performed as per the Toronto protocol. Spine, hip, and forearm DXA was performed following the standards of the International Society of Clinical Densitometry, 2019. Blinded and independent clinical evaluations and laboratory exams were performed. Participants were divided into groups with and without fracture confirmed by clinical history and radiography.

RESULTS

Distal femur and proximal tibial BMD were measured in 288/435 (66.2%) participants. Osteoporosis was noted in 138/288 (47.9%) patients. Fractures occurred in 95/435 participants (21.8%), including one fracture in 64/435 participants (14.7%), two fractures in 24/435 participants (5.5%), and greater than two fractures in 7/435 patients (1.6%). Fractures were noted in 23/54 (42.6%) participants with post-polio syndrome, 21/66 with brain injury (31.8%), 3/10 (30%) with brain injury and spinal cord injury, 24/98 (24.5%) with neuromuscular disorders, 9/52 (17.3%) with nontraumatic spinal cord injury, and 15/155 (9.7%) with traumatic spinal cord injury. The median BMD of the knee and hip was lower in participants with fractures. Distal femur and proximal tibial BMD (odds ratio [OR] = 0.02, 95% confidence interval [CI]: 0.01-0.45) remained independently associated with fragility fracture in multivariable analysis.

CONCLUSION

Proximal tibial and distal femur BMD measurements offered additional information on neurological injury and neuromuscular disorders.

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.

Musculoskeletal morbidity following spinal cord injury: A longitudinal cohort study of privately-insured beneficiaries

BACKGROUND

People living with spinal cord injuries (SCIs) experience motor, sensory and autonomic impairments that cause musculoskeletal disorders following the injury and that progress throughout lifetime. The range and severity of issues are largely dependent on level and completeness of the injury and preserved function.

OBJECTIVE

High risk of developing musculoskeletal morbidities among individuals after sustaining a traumatic SCI is well known in the clinical setting, however, there is a severe lack of evidence in literature. The objective of this study was to compare the incidence of and adjusted hazards for musculoskeletal morbidities among adults with and without SCIs.

METHODS

Privately-insured beneficiaries were included if they had an ICD-9-CM diagnostic code for SCI (n = 9081). Adults without SCI were also included (n = 1,474,232). Incidence estimates of common musculoskeletal morbidities (e.g., osteoporosis, sarcopenia, osteoarthritis, fractures, etc.) were compared at 5-years of enrollment. Survival models were used to quantify unadjusted and adjusted hazard ratios for incident musculoskeletal morbidities.

RESULTS

Adults living with traumatic SCIs had a higher incidence of any musculoskeletal morbidities (82.4% vs. 47.5%) as compared to adults without SCI, and differences were to a clinically meaningful extent. Survival models demonstrated that adults with SCI had a greater fully-adjusted hazard for any musculoskeletal morbidity (Hazard Ratio [HR]: 2.41; 95%CI: 2.30, 2.52), and all musculoskeletal disorders, and ranged from HR: 1.26 (1.14, 1.39) for rheumatoid arthritis to HR: 7.02 (6.58, 7.49) for pathologic fracture.

CONCLUSIONS

Adults with SCIs have a significantly higher incidence of and risk for common musculoskeletal morbidities, as compared to adults without SCIs. Efforts are needed to facilitate the development of improved clinical screening algorithms and early interventions to reduce risk of musculoskeletal disease onset/progression in this higher risk population.

Clinical guidelines for neurorestorative therapies in spinal cord injury (2021 China version)

Treatment of spinal cord injury (SCI) remains challenging. Considering the rapid developments in neurorestorative therapies for SCI, we have revised and updated the Clinical Therapeutic Guidelines for Neurorestoration in Spinal Cord Injury (2016 Chinese version) of the Chinese Association of Neurorestoratology (Preparatory) and China Committee of International Association of Neurorestoratology. Treatment of SCI is a systematic multimodal process that aims to improve survival and restore neurological function. These guidelines cover real-world comprehensive neurorestorative management of acute, subacute, and chronic SCI and include assessment and diagnosis, pre-hospital first aid, treatment, rehabilitation, and complication management.