Bone Mineral Density Post a Spinal Cord Injury: A Review of the Current Literature Guidelines

Spinal cord injury (SCI) causes rapid osteoporosis below the level of injury in a multi-factorial manner. This literature review focused on the early diagnosis of low bone mass (LBM) in SCI patients and aimed to summarize all the available recent data on the diagnosis and treatment of osteoporosis in this unique patient population.  Materials and Methods: Advanced literature research was conducted in the online PubMed database using the keywords 'bone mineral density, 'spinal cord injury, 'skeletal fragility', and 'osteoporotic fractures'. Out of the initial 430 articles, duplicates were removed and the remaining studies were assessed for eligibility. Two reviewers independently extracted data from each study and assessed variable reporting of outcome data. The exclusion criteria were: studies not measuring bone mineral density (BMD), studies comparing SCI to other diseases, animal studies, molecular studies, studies including children, and studies not written in English. The 83 remaining papers were divided into studies focusing on treatment and studies investigating LBM in SCI. Following this step, studies with small patient samples set at 20 patients with SCI for the treatment group and 30 patients for the diagnosis of the LBM group, were also excluded.

In the remaining 32 studies, 18 focused on the diagnosis of LBM in SCI and 14 focused on the various treatment options to address this phenomenon. Most of these studies (n=13) used the dual-energy X-ray absorptiometry (DXA) method to evaluate bone mass while five studies preferred quantitative computed tomography (QCT) measurements and one evaluated LBM using calcaneal qualitative ultrasound. In the treatment group of studies, seven papers administered medication to address LBM and four clinical protocols used physiotherapy methods to reduce bone loss post-SCI while three studies combined medical treatment with physiotherapy.

The unawareness of the unique mechanism through which bone is rapidly lost in the first months post-SCI led to initial scientific confusion. In this review, we summarize information to increase physicians' awareness of the dangers of 'silent' osteoporosis progression post-SCI. We have also provided information on the best timing to evaluate bone loss as well as treatment options that could prevent fragility fractures in this population.