People diagnosed with osteoporosis are likely to lose so much bone tissue that they end up with a vertebral compression fracture. Most vertebral compression fractures heal in months. However, osteoporosis patients in convalescence are predisposed to back pain and compression neuropathy and are to the detriment of physical ability; as a result, they become bedridden and even suffer from complications, such as bedsores, pneumonia, and urinary tract infections. Sometimes osteoporosis-induced vertebral compression fractures do not heal, and the unhealed fractures are accompanied by persistent pain, leading to spinal instability and even lordosis, kyphosis, scoliosis, and deformation of vertebrae; eventually, adjacent vertebrae undergo vertebral compression fractures multiplied by a domino effect.
Both open posterior vertebral fixation and spine fusion surgery entail driving screws into a vertebrae to lend support thereto. However, screws driven into osteoporosis patients' vertebrae are likely to loosen. To solve this problem, more screws are driven into more vertebrae of an osteoporosis patient than a non-osteoporosis patient; as a result, prolonged surgery and massive bleeding lead to more complications, such as cardiopulmonary failure and infections.
Minimally invasive percutaneous vertebroplasty involves introducing bone cement into a fractured vertebra. The bone cement is introduced into the fractured vertebra by using a bone puncture needle guided by x-ray imaging while being admitted into a small wound and then passed through the pedicle before it reaches the fractured vertebra. The purpose of introducing bone cement into a fractured vertebra is to support an otherwise collapsed vertebra and achieve analgesia. Nonetheless, minimally invasive percutaneous vertebroplasty cannot correct a deformed vertebra. By contrast, minimally invasive percutaneous kyphoplasty, which restores the height of a fractured vertebra with an inflatable balloon, entails putting the inflatable balloon in the fractured vertebra, removing the balloon from the fractured vertebra, and introducing polymethylmethacrylate into the cavity created as a result of distension of the balloon, thereby correcting the collapsed, deformed vertebra in part.
A recently developed technique for the sped-up healing of a vertebra that suffers from compression fracture involves implanting a filler into the vertebra through the pedicle. However, when the required filler is too large, it is likely to injure peripheral nerves while passing through the pedicle. But if the implanted filler is too small, it cannot support the vertebra.