title: Bone loss at the distal femur and proximal tibia in persons with spinal cord injury: imaging approaches, risk of fracture, and potential treatment options.
abstract: 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.
authors.affiliation: Department of Veterans Affairs Rehabilitation Research & Development Service National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Cirnigliaro
authors.affiliation: Department of Physical Therapy, School of Health Related Professions, Rutgers New Jersey Medical School, Newark, NJ, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Myslinski
authors.affiliation: Department of Veterans Affairs Rehabilitation Research & Development Service National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA.|Department of Physical Therapy, School of Health and Medical Sciences, Seton Hall University, South Orange, NJ, USA.|The Institute for Advanced Study of Rehabilitation and Sports Science, School of Health and Medical Sciences, Seton Hall University, South Orange, NJ, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: La Fountaine
authors.affiliation: Kessler Institute for Rehabilitation, West Orange, NJ, USA.|Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, NJ, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Kirshblum
authors.affiliation: Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, NJ, USA.|Kessler Foundation, West Orange, NJ, USA.
authors.forename: G F
authors.initials: GF
authors.lastname: Forrest
authors.affiliation: Department of Veterans Affairs Rehabilitation Research & Development Service National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA. william.bauman@va.gov.|Departments of Medicine and Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA. william.bauman@va.gov.
authors.forename: W A
authors.initials: WA
authors.lastname: Bauman
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D015519:Bone Density / Q000502:physiology; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D018570:Risk Assessment / Q000379:methods; D013119:Spinal Cord Injuries / Q000150:complications* / Q000503:physiopathology; D013977:Tibia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Distal femur; Dual energy x-ray absorptiometry; Peripheral quantitative computed tomography; Proximal tibia; Quantitative computed tomography; Spinal cord injury