Osteoporosis After a Spinal Cord Injury

Birgitte HansenClinic of Spinal Cord Injury

Hornbæk - Denmark

Osteoporosis results from reduced bone mass

disruption of the micro-architecture of bone,

decreased bone strength

increased risk of fracture.

A Spinal Cord Injury Has

Increase in bone resorption Hormonal alternations Modification of body composition

Wide-ranging physiological and pathological effects

1% - 46% incidence of lower extremity fractures in people who sustain an SCI

Risk Factors For Osteoporosis in SCI Individuals Completeness Low BMI (< 25 kg/m2) Age

Gender (female) Age at injury ( < 18 years) Duration of injury

Bone Evaluation - DXA

•Non pharmacological treatment

•Pharmacologic Therapy

Non pharmacological treatment

MES (muscular electrical stimulation) FES cycle ergometry (functional electrical

stimulation) Standing Walking Teach safe transferring skills

Passive standing do not maintain or improve BMD in the hip or knee regionKunkel et al (Arch Phys Med Rehabil) 1993

Needham-Shropshire et al. (Arch Phys Med Rehabil) 1997

FES cycle ergometry

Conflicting results for bone parameters for six studies

MES –FES assisted training Belanger et al (Arch Phys Med Rehabil

2000) 14 men and women with SCI and 14 controls 5 days/week, 24 weeks

Results BMD regained almost 30 % of lost bone mass

compared to controls

Pharmacologic Therapy Calcium – just supplement Vitamin D – just supplement Calcitonin – optimal dosage and long-term

effectiveness unclear

Vitamin D analog (Etalpha®) – Increase in lower-limb BMD

Bisphosphonates - reduction in bone loss

Vitamin D Analog Treatment

19 subjects had 1-α-D2 4 μg/day for 24 months (21 placebo)

Leg BMD increased significantly from baseline in the treatment group at 12, 18 and 24 months.

Smoking prevents bone effect with 1-α-D2 - reason unclear

Both groups received calcium (1.3 g/d) and vitamin D (800 IU/d)

Conclusion – Vitamin D Analog

Treatment of 1-α-D2 increased lower-limb BMD Current smokers had not this effect Long-term effect of continued 1-α-D2 therapy in

persons with chronic SCI requires further investigation

Bisphosphonates + 1-α-D2 or 1-α-D2 followed by bisphosphonates should be investigated

1-α-D2 + physical intervention may be considered

Bisphosphonates treatment

• First-generation

• Etidronate, clodronate

• Second-generation

• Pamidronate

• Third-generation

• Alendronate, ibandronate, risedronate, tiludronate and zolendronic acid

Treatment With Bisphosphonates

Oral bisphosphonates must be Ingested on an empty stomach With 150-200 ml water Followed by sitting up for 1 hour prior to

taking any other food or medication Side effects

Joint pain Stomach upset/gastric ulcer

Treatment With Bisphosphonates II Intravenous bisphosphonates

Available in daily, monthly, quarterly and yearly preparations

Assured compliance Reduced relative risk of gastric ulcer

Side effects Fever and muscle pain (flu-like symptoms) Low serum calcium

Clodronate P. Minaire et al. (J. Clin. Invest. 1981)

14 had clodronate (2 different doses), 7 placebo (17 males, 4 females)

Started 17.6 days after injury. 3.5 months of treatment – total 6 months study

Results No decrease in hip and knee region on bone

mineral content in the treated groups

Etidronate and Tiludronate have positive results for treatment within the 1 year of injury

Alendronate Y. Zehnder et al. (JBMR, 2004)

33 men had Aln + Ca, 32 men had Ca in 2 years

9.8 years since SCI Results

BMD in distal and proximal tibia, and total hip remained stable in the Aln – Ca group and decreased in the Ca group

Future Prospects Large prospective longitudinal studies DXA methods to target areas Reducing the risk of falls Osteoprotegerin/RANKL system

Questions to be answered Who When How – and how long to treat?

• Osteoporosis Research Centre, Hvidovre Hospital

Ulla PedersenAnne-Mette RasmussenSolveig PetersenJenni TeilmannOle Helmer SørensenJens-Erik Bech Jensen

• Clinic For Spinal Cord Injury, Rigshospitalet

Lisbeth NielsenFin Biering-Sørensen

Thank you for your attention