Bone Health After Spinal Cord Injury
Following a spinal cord injury (SCI), people can experience bone loss and muscle atrophy. Bone density decreases from the point of injury, increasing the risk of osteoporosis and fractures. While the loss of bone density is one of the most common conditions following SCI, there are several ways to manage bone health and reduce risk.
What is Osteoporosis?
Osteoporosis is a condition where bone loss is more rapid than bone growth, causing a gradual thinning of the bone, making it more porous and susceptible to fractures and other injuries. We all build bone density until around our mid-30s, and then as we age we lose bone density over time. With SCI, however, this process is much different than what is experienced by the process of aging. Bone loss generally begins at the point of injury and below. It can start to occur as soon as 6-weeks post-injury and plateaus two to three years post-injury. Osteopenia is an intermediate condition where the bone is losing density and strength but has yet to reach the more fragile state of osteoporosis. Individuals with complete injury experience more bone loss than those with incomplete injury. With SCI, osteoporosis occurs for many reasons, including disuse, sluggish blood flow, hormonal change, metabolic disturbances, and autonomic nervous system dysregulation.Bone Fracture and Spinal Cord Injury
Osteopenia and osteoporosis also increase the risk of bone fracture. Each year, about 2-4% of the SCI population fractures a bone, and most fractures are at the bottom of the femur or the top of the tibia. The annual occurrence of bone fractures is approximately 1% for injuries sustained less than 10 years ago, and 4.6% annually for injuries that occurred more than 10 years ago. Frequent causes of fractures include:- Falling from a wheelchair or shower chair
- Bumping into objects or walls
- Turning in bed
- Other low impact range of motion activities.