Osteoporosis in Women with Spinal Cord Injuries

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.

Association of Bisphosphonate Therapy With Incident of Lower Extremity Fractures in Persons With Spinal Cord Injuries or Disorders

OBJECTIVE

To investigate the association between prescriptions for bisphosphonates; calcium and vitamin D supplements; and receipt of dual-energy x-ray absorptiometry (DXA) screening, and incident fracture risk in men and women with a spinal cord injury (SCI) or disorder (SCID).

DESIGN

Propensity-matched case-control analyses.

SETTING

United States Veterans Affairs (VA) facilities.

PARTICIPANTS

A total of 7989 men and 849 women with an SCID included in VA administrative databases between October 1, 2005 and October 1, 2015 were identified (N=8838). Cases included 267 men and 59 women with a bisphosphonate prescription propensity matched with up to 4 controls.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Incident lower extremity fractures.

RESULTS

There was no significant association between prescriptions for bisphosphonates and incident lower extremity fractures in men (odds ratio [OR], 1.04; 95% confidence interval [CI], 0.62-1.77) or women (OR, 1.02; 95% CI, 0.28-3.75). In men, similar null associations were seen among those who were adherent to bisphosphonate therapy (OR, 1.25; 95% CI, 0.73-2.16), were concomitant users of vitamin D and calcium and a bisphosphonate (OR, 1.05; 95% CI, 0.57-1.96), had more than 1 fracture on different dates during the study period (OR, 0.13; 95% CI, 0.02-1.16) and in those who had undergone DXA testing prior to the date of the bisphosphonate prescription and incident fracture (OR, 1.26; 95% CI, 0.69-2.32).

CONCLUSIONS

In men with a traumatic SCI and women with a traumatic SCID, bisphosphonate therapies for osteoporosis do not appear to significantly affect fracture risk. Adequately powered randomized controlled trials are needed to definitively demonstrate efficacy of bisphosphonates for fracture prevention in this population. There is a compelling need to identify new medications to prevent fractures in this high-risk population.

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.

Perceived exercise self-efficacy as a predictor of exercise behavior in individuals aging with spinal cord injury

OBJECTIVE

The purpose of this study was to test the hypothesized association between exercise self-efficacy and exercise behavior, controlling for demographic variables and clinical characteristics, in a sample of individuals with spinal cord injuries.

DESIGN

A cross-sectional national survey of 612 community-dwelling adults with spinal cord injury in the United States ranging from 18 to 89 yrs of age was conducted. Sample consisted of 63.1% men with a mean (SD) duration of 15.8 (12.79) yrs postinjury; 86.3% reported using a wheelchair.

RESULTS

Self-efficacy was the only independent variable that consistently predicted all four exercise outcomes. Self-efficacy beliefs were significantly related to frequency and intensity of resistance training (R(2) change = 0.08 and 0.03, respectively; P < 0.01 for all) and aerobic training (R(2) change = 0.07 and 0.05, respectively; P < 0.01 for all), thus explaining between 3% and 8% of the variance. Hierarchical linear regression analysis revealed that controlling for other demographic and physical capability variables, the age-related variables made statistically significant contributions and explained between 1% and 3% of the variance in aerobic exercise frequency and intensity (R(2) change = 0.01 and 0.03, respectively; P < 0.01 for all). Clinical functional characteristics but not demographic variables explained participation in resistance exercise.

CONCLUSIONS

Self-efficacy beliefs play an important role as predictors of exercise. Variations in exercise intensity along the age continuum have implications for exercise prescription and composition. Future research should replicate findings with objective activity measures.

Utility of quantitative ultrasound of the calcaneus in diagnosing osteoporosis in spinal cord injury patients

OBJECTIVE

: The aim of this study was to assess the utility of quantitative ultrasound of the calcaneus in diagnosing osteoporosis in spinal cord injury patients in a Brazilian Teaching Hospital.

DESIGN

: This is a diagnostic test criterion standard comparison study. Between January 2008 and October 2009, the bone density of 15 spinal cord injury patients was assessed for analysis before beginning rehabilitation using muscle stimulation. The bone density was assessed using bone densitometry examination (DEXA) and ultrasound examination of the calcaneus (QUS). The measurements acquired using QUS and DEXA were compared between patients with spinal cord injury and a control group of ten healthy individuals.

RESULTS

: The T-score values for femoral neck using DEXA (P < 0.0022) and those using QUS of the calcaneus (P < 0.0005) differed significantly between the groups, and the means in the normal subjects were higher than those in spinal cord injury patients who would receive electrical stimulation. In spinal cord injury patients, the significant differences were found between the QUS T-score for calcaneus and the DEXA scores for the lumbar spine and femoral neck.

CONCLUSIONS

: Because of the low level of mechanical stress on the calcaneus, the results of the QUS could not be correlated with the DEXA results for diagnosing osteoporosis. Therefore, QUS seems to be not a good choice for diagnosis and follow-up.

Effects of spinal cord injury and hindlimb immobilization on sublesional and supralesional bones in young growing rats

Both spinal cord injury (SCI) and hindlimb cast immobilization (HCI) cause reduction in maturation-related bone gain in young rats, but the effects of the two interventions on bone pathophysiology may be different. The objective of this study was to compare the effects of SCI and HCI on the sublesional/supralesional bones and bone turnover indicators in young rats. Forty male Sprague-Dawley rats (six-week-old) were randomized into four groups, with ten rats in each group. The groups were classified as follows: base-line control, age-matched intact control, HCI, and SCI groups. Bone tissues, blood, and urine samples were studied at 4 weeks after treatments. The tibial dry weights and ash weights in SCI were remarkably reduced by 7.5% (dry weights) and 8.2% (ash weights) compared with HCI. SCI rats showed lower areal bone mineral density in the proximal tibiae compared with HCI rats (- 14%). Cortical thickness and cortical area of the tibial midshaft in SCI were lower than HCI (- 23%, - 33% respectively). The bone surface/bone volume, trabecular separation, trabecular number, connectivity of the trabecular network, and structure model index of the proximal tibiae were remarkably different between SCI and HCI groups. In SCI tibiae, the mineralizing surface, mineral apposition rate, and surface-based bone formation rate were significantly higher than HCI groups (12%, 47%, and 29% respectively). In the compression test, the ultimate load, the energy of ultimate load, and Young's modulus of the proximal tibiae in SCI rats were significantly lower than HCI rats. The serum levels of osteocalcin and the urinary levels of deoxypyridinoline in SCI were higher than those in HCI. There were no significant changes in supralesional bones between SCI and HCI rats. SCI results in a rapid bone loss with more deterioration of trabecular microstructure and cortical bone geometric structure in sublesional bones. High bone turnover rate and low biomechanics strength were found in tibiae in SCI rats. This might be the result of the imbalance of bone resorption and bone formation induced by the impaired neuronal function.

Treatment of immobilization hypercalciuria using weekly alendronate in two quadriplegic patients

Metabolic and urinary problems encountered in spinal cord injury patients are multifaced. We report two patients with high-level spinal cord injuries who have developed hypercalciuria after admission to the rehabilitation unit. To establish a clean intermittent self-catheterization programme, the hypercalciuria was treated successfully with alendronate. Twenty-four-hour urinary calcium excretion decreased significantly after medical treatment for hypercalciuria. Since high-level quadriplegic patients may not be mobilized in the acute phase of the rehabilitation, use of alendronate for preventing hypercalciuria and maintaining a successful clean intermittent self-catheterization programme can be considered as a supportive/complementary measure.

Neuromuscular electrical stimulation in neurorehabilitation

This review provides a comprehensive overview of the clinical uses of neuromuscular electrical stimulation (NMES) for functional and therapeutic applications in subjects with spinal cord injury or stroke. Functional applications refer to the use of NMES to activate paralyzed muscles in precise sequence and magnitude to directly accomplish functional tasks. In therapeutic applications, NMES may lead to a specific effect that enhances function, but does not directly provide function. The specific neuroprosthetic or "functional" applications reviewed in this article include upper- and lower-limb motor movement for self-care tasks and mobility, respectively, bladder function, and respiratory control. Specific therapeutic applications include motor relearning, reduction of hemiplegic shoulder pain, muscle strengthening, prevention of muscle atrophy, prophylaxis of deep venous thrombosis, improvement of tissue oxygenation and peripheral hemodynamic functioning, and cardiopulmonary conditioning. Perspectives on future developments and clinical applications of NMES are presented.

Epidemiology of Osteoporosis in Women With Cognitive Impairment

Osteoporosis is increasing due to the aging of the population. Women with cognitive impairment from childhood are at disproportionally high risk for osteoporosis and fractures. Suggested explanations for this increased risk include high use of anticonvulsant medications, lower peak bone densities, and higher rates of nonambulation. Down syndrome seems to be an independent risk factor for low bone density and fractures, presumably due to lower muscle tone. Here, the limited information available on the epidemiology of osteoporosis in the general population and in women with cognitive disabilities is briefly reviewed. Health care professionals should consider women with cognitive disabilities at high risk for osteoporosis and fractures. Studies are needed to determine screening regimens and prevention strategies appropriate for women in this population.

Does 12 weeks of regular standing prevent loss of ankle mobility and bone mineral density in people with recent spinal cord injuries?

The purpose of this study was to determine the effects of a 12-week standing program on ankle mobility and femur bone mineral density in patients with lower limb paralysis following recent spinal cord injury. An assessor-blinded within-subject randomised controlled trial was undertaken. Twenty patients with lower limb paralysis following a recent spinal cord injury were recruited. Subjects stood weight-bearing through one leg on a tilt-table for 30 minutes, three times each week for 12 weeks. By standing on one leg a large dorsiflexion stretch was applied to the ankle and an axial load was applied to the bones of the weight-bearing leg. Ankle mobility and femur bone mineral density of both legs were measured at the beginning and end of the study. Ankle mobility (range of motion) was measured with the application of a 17 Nm dorsiflexion torque. Femur bone mineral density was measured using dual energy X-ray absorptiometry (DEXA). The effect of standing was estimated from the difference between legs in mean change of ankle mobility and femur bone mineral density. The results indicated a mean treatment effect on ankle mobility of 4 degrees (95% CI 2 to 6 degrees) and on femur bone mineral density of 0.005 g/cm(2) (95% CI -0.015 to 0.025 g/cm(2)). Tilt-table standing for 30 minutes, three times per week for 12 weeks has a small effect on ankle mobility, and little or no effect on femur bone mineral density. It is unclear whether clinicians and patients would consider such effects to be clinically worthwhile.

The relationship between bone mineral density and immobilization duration in hemiplegic limbs

OBJECTIVE

Prolonged immobilization in stroke is known to result in hypercalciuria, hypercalcemia, accelerated bone resorption, and osteoporosis. Furthermore, bone mineral loss accelerated with increasing duration of hemiplegia. Although stroke is a common disease that causes sudden immobilization, relatively few investigations of bone metabolism in stroke have been reported. The aim of this study was to investigate the changes in bone mineral density of the forearms and legs related to duration of hemiplegia-induced immobilization after stroke.

METHODS

Forty-one hemiplegic patients with stroke were evaluated. The patients' age, gender and duration of hemiplegia-induced immobilization were recorded. The measurements of bone mineral density (BMD) in all patients were evaluated with DEXA using the Norland apparatus. The BMD values (g/cm2) were determined by measurements made in the lumbar vertebrae, both forearm and legs (femoral neck and trochanter).

RESULTS

We found that bone mineral density was decreased in the affected extremities relative to the intact contralateral side on measurements by dual energy x-ray absorptiometry in bones such as forearm, femoral neck and trochanter. There was a significant difference between bone mineral density of paretic and nonparetic forearms and legs. Bone mineral density of the upper limbs was lower than that of the lower limbs. There was a negative correlation between duration of hemiplegia and BMD values.

CONCLUSIONS

Bone mineral loss may be related to the duration of hemiplegia-induced immobilization. Bone mineral loss is accelerated when the duration of hemiplegia is prolonged.

Recurrent vesical calculi, hypercalciuria and biochemical evidence of increased bone resorption in an adult male with paraplegia due to spinal cord injury: is there a role for intermittent oral disodium etidronate therapy for prevention of calcium phosphate bladder stones?

STUDY DESIGN

Clinical case report with comments by colleagues from Sweden, Poland, Spain, Brazil, Japan, Belgium and Switzerland.

OBJECTIVES

To discuss the role of disodium etidronate therapy for prevention of calcium phosphate vesical calculi in persons with spinal cord injury, who have hypercalciuria and biochemical evidence of increased bone resorption.

SETTING

Regional Spinal Injuries Centre, Southport, UK.

METHODS

A 21-year-old male sustained paraplegia (T-10; ASIA scale: A) in a road traffic accident in June 2001. He had an indwelling urethral catheter until the end of August 2001, when he started self-catheterisation. He developed bladder stones and electrohydraulic lithotripsy (EHL) was performed in May 2002. All stone fragments were removed. Recurrence of vesical calculi was noted in October 2002. These stones were fragmented by lithoclast lithotripsy in two sessions, in December 2002 and February 2003; all stone fragments were removed at the end of the second session. This patient reverted to indwelling catheter drainage when vesical calculi recurred. In September 2003, X-ray of the abdomen showed recurrence of vesical calculi. By February 2004, the stones had increased in size and number. EHL of vesical calculi was again performed in April 2004. Complete clearance was achieved.

RESULTS

A 24-h urinalysis detected hypercalciuria--18.7 mmol/day (reference range: 2.5-7.5). Biochemical analysis of vesical calculus revealed calcium phosphate (85%) and magnesium ammonium phosphate (15%). Plasma C-terminal telopeptide (CTX) was increased - 1.06 ng/ml (reference range: 0.1-0.5 ng/ml). Free deoxypyridinoline/creatinine ratio (fDPD/Cr) in urine was also increased - 20.2 (reference range: 2.3-5.4). In April 2004, this patient was prescribed disodium etidronate 400 mg day. Nearly 3 months after commencing therapy with etidronate, plasma CTX decreased to 0.87 ng/ml. fDPD/Cr in urine also decreased to 12.4. After 4 months of etidronate therapy, 24-h urinary calcium excretion had decreased to 6.1 mmol/day.

CONCLUSION

Etidronate (400 mg daily) is a very effective inhibitor of calcium phosphate crystallisation. Etidronate decreased urinary excretion of calcium, an important factor in prevention of calcium phosphate bladder stones. Etidronate therapy is not a substitute for other well-established methods for prevention of vesical calculi in spinal cord injury patients, for example, large fluid intake, avoiding long-term catheter drainage. Intermittent therapy with etidronate may be considered in selected patients, in whom hypercalciuria persists after instituting nonpharmacological therapy for an adequate period, for example, early mobilisation, weight-bearing exercises, and functional electrical stimulation. However, possible side effects of etidronate, and the fact that etidronate is not licensed in United Kingdom for prevention of urolithiasis, should be borne in mind.

Hormone replacement therapy in women with spinal cord injury – a survey with literature review

STUDY DESIGN

Postal questionnaire survey.

OBJECTIVE

To examine the current use of hormone replacement therapy (HRT) in a sample of menopausal women with spinal cord injury (SCI).

SETTING

National Spinal Injuries Centre (NSIC), Stoke Mandeville Hospital, Aylesbury, UK.

METHOD

A postal questionnaire was sent to 94 women from the NSIC patient database who met the study inclusion criteria (wheelchair dependent, aged 49 years and above, last seen or heard from within the last 3 years).

RESULTS

A total of 59 valid questionnaires were analysed. At the time of the survey, 50 women were menopausal and 11 of them were using HRT, six for menopausal symptoms and five for osteoporosis prevention. Another 11 had used HRT, eight for menopausal symptoms and three for osteoporosis prevention, but had discontinued it. The main reasons for stopping HRT were side effects. Of the 28 women who had never been on HRT, 20 had either enquired about it, or had been offered HRT, but decided against it. Of the nine women who were still premenopausal at the time of the survey, four would consider using HRT.

CONCLUSIONS

Results show that 44% of the menopausal women in our sample have used HRT at some point and 22% still do, mostly for treatment of menopausal symptoms and for osteoporosis prevention. In view of the latest literature findings in able-bodied women, use of HRT for osteoporosis prevention in women with SCI may have to be reconsidered.

Osteoporosis in women with disabilities

Women with physical and cognitive disabilities are at high risk for osteoporosis and osteoporosis-related fractures. Women with physical disabilities frequently are nonambulatory and have bone loss due to immobility. Women with cognitive disabilities have high rates of osteopenia and osteoporosis, likely partially due to high rates of anticonvulsant medication use. Women with Down syndrome are at especially high risk of osteopenia and osteoporosis, possibly because of lower peak bone density levels. Prevention of osteoporosis and related fractures in this population includes population-based measures, such as calcium and vitamin D supplementation and risk-based screening procedures. Primary care providers and specialists need to prioritize osteoporosis prevention strategies when taking care of women with disabilities. Future research is needed to determine optimal screening and prevention strategies in this very high risk population.

The decision to take hormone replacement therapy among women with disabilities

Whereas making decisions during menopause can be challenging for all women, those with physical impairments face special issues with respect to menopause in general and hormone replacement therapy (HRT) in particular. In this correlational study the authors explored the factors such women consider when making decisions about HRT One hundred sixty-seven women with physical impairments throughout the United States completed surveys concerning their attitudes and knowledge about HRT Approximately half the menopausal women were currently taking HRT The strongest predictor of HRT use was women's perceptions of their health care providers opinions about their taking HRT, combined with their motivation to comply with the provider's recommendation. Thisfinding points to the significant role that nurses and other health care providers play in assisting women to make informed health care choices during menopause.