More and more older adults are starting to develop scoliosis without a clear reason. Scoliosis is a curvature of the spine. De-novo scoliosis is a term used to describe the start of a new condition that was not there before. This is applied to scoliosis in older adults because most cases of scoliosis occur during childhood and adolescence. Another term used to describe this condition is adult degenerative scoliosis.
This report offers a review of adult degenerative scoliosis. From the studies that have been done so far, it looks like this type of scoliosis may be caused by unilateral (one-sided) disc degeneration. This can occur in the thoracic (mid-back) or lumbar (low back) spine. With a loss of disc height on one side, pressure is increased on the facet (spinal) joint on the same side. Muscle imbalance occurs and bone spurs form.
The patient is over the age of 50 (usually 65 or older) and often has other spinal problems such as spinal stenosis. Spinal stenosis is a narrowing of the spinal canal. De-novo degenerative scoliosis combined with spinal stenosis can lead to severe back and/or leg pain. The pain is worse when walking. This symptom is called intermittent claudication.
The best treatment for this type of scoliosis remains unknown at the present time. Each patient must be assessed individually. Treatment must be matched to each person based on clinical presentation and patient expectations. A complete assessment will include personal and family history, psychologic status, and a structural evaluation of the body and spine.
Because of the muscle imbalance that can occur, muscles must be tested carefully and thoroughly. Joint function, motion, and flexibility should also be evaluated. Nerve and muscles are tested and bowel and bladder function are reviewed. Many older adults who have difficulty walking may also have loss of blood supply to the legs causing similar symptoms of leg pain and intermittent claudication. Therefore, the physician must also assess vascular status.
Treatment is guided, in part, by imaging studies. Standard X-rays are still relied upon when making decisions about surgery to correct the deformity. Information about curve flexibility and segmental stability can be gained from X-rays.
MRIs and CTs have some useful purpose in this diagnostic process. MRIs show the full extent of the stenosis. Pre-operative bone mineral density studies are necessary because of the risk of fractures in patients who have osteoporosis.
Before surgery is considered, each patient is advised to try a conservative approach. Nonoperative treatments such as physical therapy, bracing, and injection therapies may be helpful. But there hasn’t been enough studies of high quality to show what treatment protocol works best. Treatment guidelines for conservative care are fairly limited at this time.
Surgery is done to reduce pain, stabilize the spine, and improve function. Pressure is taken off the spinal cord and spinal nerves by removing bone from around these tissues. This procedure is called surgical decompression. Patients must be selected carefully for this operation. The presence of any spinal instability may prevent the patient from having surgery that could make the instability worse.
Spinal fusion is often the best answer. Using instrumentation such as metal rods can help decompress and support the spine at the same time. Any spinal deformity is also corrected with this approach.
There are many factors to consider and many decisions to make with fusion surgery. The patient’s mental and physical health, bone density, and number of segments involved must be evaluated. Where to start and stop the fusion is important. Each of these decisions has its own factors to consider. For example, the longer the fusion, the greater the risk of blood loss, increased cost, and risk of developing motion at that level called a pseudoarthrosis. The presence of a pseudoarthrosis is a sign of fusion failure and spinal instability.
Types of surgeries to achieve the goals can include anterior fusion, posterior fusion, or both at the same time. The authors prefer an all-posterior approach. Their patients receive nutritional support and intensive rehab after surgery.
Special transforaminal lumbar interbody fusion (TLIF) grafts are used. TLIF fuses the front and back section of the spinal column through a single posterior approach. Usually a fair number of spinal segments are involved (five or more). Fusion corrects spinal deformity and restores mechanical stiffness of the spine.
The authors provide specific ways in which they use iliac screws. A diagram is provided of the placement of iliac wing screws. Putting the screws deep into the iliac bone helps reduce problems with the hardware. Attention to the details of any procedure can help reduce complications. Paying close attention can reduce the risk of revision surgery, too. That’s important in this group of patients who are often quite fragile and can’t tolerate much surgery.
Keeping in mind the goals of increased function and decreased pain doesn’t always ensure 100 per cent success. But it’s a good place to start when rebalancing the spine in older adults who have painful degenerative scoliosis.