Spinal cord injury (SCI) results in rapid and severe osteoporosis that increases the risk of low-impact fractures (i.e., spontaneous or with little trauma). In contrast to persons without SCI, where the hip and lumbar spine are sites of greatest fracture risk, in SCI, the sites most commonly fractured are the metaphyses of the distal femur and proximal tibia, sites of greatest bone loss.
However, these sites are not included in standardized dual x-ray absorptiometry (DXA) protocols designed for screening for osteoporosis in the able-bodied. The rate of fracture in SCI is estimated to be 2% per year, double that in the general population, but is probably underestimated because adequate population-based data has not been collected. Data are also lacking on the full health consequences of low-impact fractures in SCI. Fractures reduce independence and mobility and put people with SCI at risk for severe complications associated with immobility during healing. Despite the health implications of low impact fractures, there is currently no specific set of guidelines for prevention or treatment of SCI-induced osteoporosis. Osteoporosis appears to be under-diagnosed and there are no consensus-based screening recommendations or preventative measures.
We will address uncertainties regarding the identification and treatment of osteoporosis in chronic SCI. The objectives are to (1) identify risk factors for hospitalization in VA medical centers 1996 through 2003 for low-impact fractures in veterans participating in a prospective health study at VA Boston; (2) use an internet-based survey to assess current practice patterns regarding the diagnosis and treatment of osteoporosis by physiatrists, SCI specialists, and other SCI-service personnel in the VHA nationally, and compared this to best practices suggested by the literature; (3) since DXA scanners are designed for use in the able-bodied, assess physical barriers to providing DXA scan services, and (4) assess the precision of bone mineral density (BMD) data obtained by scanning the distal femur and proximal tibia in chronic SCI.
(1) Fracture-related hospitalization: Since 1994, we have conducted a prospective health study at VA Boston and have collected personal health and clinical information on SCI patients. Through 12/2002, 315 veterans were recruited to complete a standardized health questionnaire. Each person also had an exam that included an assessment of weight, stature, and level and completeness of SCI. We have abstracted acute hospitalization data from the VA National Patient Care Dataset located in Austin, Texas 10/1/1996 through 12/31/2003 to allow at least one year of follow-up after study enrollment. We assessed risk factors for hospital admission for fracture of lower limbs (ICD=820-829) and upper limbs (810-819) listed as primary and secondary diagnosis. Cox Proportional hazards methods for repeated outcomes (TPHREG procedure in SAS software version 9.1 [SAS Inc, Cary, NC] will be used to assess predictors of fracture related admissions.
(2) Internet-based survey: We designed an internet based survey that was sent to VA SCI specialists, nurses, and nurse practitioners to describe practice patterns and attitudes regarding osteoporosis in SCI. VHA National SCI Staff Physicians and VHA National SCI Nurses (total n=450) were sent an email with an invitation to participate in this survey
(3) Physical Barriers: Since DXA scanners were designed for use in the able-bodied, will reviewedthe configuration of DXA scanners available for clinical use and described physical barriers to providing these scan services to persons with SCI
(4) Reproducibility of BMD data at the distal femur and proximal tibia: We used a standardized protocol to scan areas three times in 20 SCI patients
(1) Fracture-related hospitalizations: There were 1,487 admissions among 315 participants, and of these hospitalizations 39 were for treatment of low impact osteoporotic fractures. In a multivariate model, persons with complete motor SCI compared to others were more likely to have a fracture related admission (hazard ratio [HR] =3.73, 95%CI=1.46-10.50), and the risk significantly increased with greater alcohol consumption after injury. Medical record review indicated that no individual with a fracture-related admission underwent an evaluation for osteoporosis.
(2) Internet-based survey: The response rate was 28%. 92 prescribing practitioners (MD, DO, NP, PA) were included in the analysis. Of these respondents, 50 (54%) prescribe medications for SCI-induced bone loss; 39 (42%) prescribe bisphosphonates and 46 (50%) prescribe vitamin D. There were 54 (59%) respondents who routinely order diagnostic tests, including DXA scans in 50 (54%). Variations in practice were not explained by age, gender, or years practicing SCI medicine. Many respondents (23%) reported barriers to osteoporosis testing including lack of scanning protocols, cost, wheelchair inaccessibility of scanning facilities, and lack of effective treatment guidelines once osteoporosis is diagnosed.
(3) Physical Barriers: We identified several barriers including scanner design and configuration in the scanning room that limit accessibility, increase typical scanning time, and make additional staff necessary.
(4) Reproducibility of BMD data at the distal femur and proximal tibia: Precision as determined by root mean square coefficient of variation (RMS-CV) and root mean standard deviation (RMS-SD). At the distal femur the root RMS-CV was 3.01% and RMS-SD was 0.025 g/cm2 and at the proximal tibia the RMS-CV was 5.91% and RMS-SD 0.030 gm/cm2.
(1) Fracture-related hospitalizations: Our results confirm that persons with neurologically complete SCI are at increased risk for being hospitalized for osteoporotic fractures, and that alcohol consuption increases this risk.
(2) Internet-based survey: Despite an absence of screening and treatment guidelines, more than half of all respondents are actively diagnosing and treating osteoporosis with bisphosphonates within the VA healthcare setting. These data suggest that evidence-based practice guidelines are necessary to reduce practice variations and improve clinical care for this population.
(3) Physical Barriers: In order for dual energy x-ray absorptiometry to become a routine component of ongoing care in spinal cord injury medicine, we recommend the following changes: fitting the scanning room with ceiling-mounted hydraulic lifts and grab bars to facilitate transfers, increased staffing during scans, increased time allotment for scans, installation of the scanner in an adequately-sized room, and partnering with administrators and staff to raise awareness of access issues faced by individuals with spinal cord injury.
(4) Reproducibility of BMD data at the distal femur and proximal tibia: The distal femur was more reliably repositioned and reimaged than the proximal tibia.
- Morse LR, Lazzari AA, Battaglino R, Stolzmann KL, Matthess KR, Gagnon DR, Davis SA, Garshick E. Dual energy x-ray absorptiometry of the distal femur may be more reliable than the proximal tibia in spinal cord injury. Archives of physical medicine and rehabilitation. 2009 May 1; 90(5):827-31.
- Morse LR, Battaglino RA, Stolzmann KL, Hallett LD, Waddimba A, Gagnon D, Lazzari AA, Garshick E. Osteoporotic fractures and hospitalization risk in chronic spinal cord injury. Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA. 2009 Mar 1; 20(3):385-92.
- Morse LR, Giangregorio L, Battaglino RA, Holland R, Craven BC, Stolzmann KL, Lazzari AA, Sabharwal S, Garshick E. VA-based survey of osteoporosis management in spinal cord injury. PM & R : the journal of injury, function, and rehabilitation. 2009 Mar 1; 1(3):240-4.
- Morse LR, Geller A, Battaglino RA, Stolzmann KL, Matthess K, Lazzari AA, Garshick E. Barriers to providing dual energy x-ray absorptiometry services to individuals with spinal cord injury. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists. 2009 Jan 1; 88(1):57-60.