Introduction

Scoliosis — defined as a curvature of the spine in the coronal plane measuring over 10 degrees — can be found in the adult population and can be a significant source of disability, especially in the elderly.^1,2 There are three principal forms of scoliotic spinal deformity that can be described: idiopathic, i.e., that whose development can be found during the juvenile or adolescent growing years of life and which persists into adulthood; de novo, which involves the development of a new scoliosis later in life as a result of degenerative changes in the lumbar spine; and osteoporotic scoliosis, a less common form of spine curvature secondary to osteopenic collapse of vertebral bodies.

In the adolescent with scoliosis, the primary focus of treatment is the deformity and concerns of curve progression. In the older patient, it is much more common that pain is the primary complaint.^3,4 In the later decades of life, curve progression becomes less and less of a concern, primarily because of the restraint provided by the degenerating and ossifying disc spaces and the arthritic facet joints. Being out of balance, especially in the sagittal plane, adds an element of posturally related fatiguing pain that limits patients’ ability to perform upright activities.⁵ Older adults are most commonly symptomatic in the lower thoracolumbar or lumbar region, due to the age-related disc degeneration and osteoarthritis associated with the deformity.

Patient Evaluation

Clinically, the evaluation of the elderly patient with scoliosis begins with an appreciation of the overall coronal and sagittal balance. There are many reasons other than spinal deformity for the patient to have difficulty standing upright: hip and knee degeneration, spinal stenosis, lumbosacral or thoracolumbar kyphosis, trunk muscle weakness, or flatback pathology. The last entity — flatback syndrome — typically due to some form of loss of the normal lumbar lordosis, can result in a loss of trunk strength and difficulty fully extending the hips. All patients should thus have a careful examination of the hip range of motion, including assessment of their ability to extend completely when in the supine examining position. Hips that have become locked into contracture may well require some form of release before considering any corrective surgery on the spine. On occasion, degenerative arthritis of the hips can be treated with arthroplasty first before proceeding with spinal surgery.

Routine radiographs are obtained in the upright position and should include standing, full-length, anterior-posterior, and lateral films to assess not only the dimensions of the curve, but the overall alignment in both the coronal and sagittal planes. It is important to obtain the images with the patient’s hips and knees as extended as possible in order to appreciate the true sagittal profile. In addition, side-bending or hyperextension lateral films are quite helpful in determining the flexibility of the curve, and, if considering surgery, whether some form of anterior release or posterior osteotomy is necessary.

Because the majority of patients present with pain, magnetic resonance imaging is often obtained. MRI can assess the quality of the distal intervertebral discs, and as many patients will complain of varying degrees of leg pain from stenosis, axial MRI imaging is useful to study the spinal canal and foramen and determine levels of decompression if necessary. MRI can also be used to study the most caudal intervertebral discs of the spine, as a fusion may on occasion stop short of the sacrum if distal painful pathology does not appear to exist, although this is somewhat less common in the elderly compared with younger patients. MRI is also very helpful in ruling out malignancies or infections.

Computerized tomography is helpful during the planning stages for studying the bony anatomy; in the setting of previous fusions, the quality and extent of the previous arthrodesis can be best obtained with CT imaging. CT is also quite helpful in analyzing the size of the pedicles, the width of the ilium, and the morphology of the vertebrae themselves.

Treatment

Elderly patients with painful scoliosis can be considered candidates for nonoperative treatment modalities, just as their younger counterparts are. As the majority of the patients present with symptomatic curves in the lumbar or thoracolumbar region, simple education and an understanding that the curvature does not present an immediate threat to their cardiac or pulmonary systems (as did primary thoracic curves left untreated) may be reassuring enough to many. Combinations of the judicious use of nonsteroidal antiinflammatory medications, activity modifications, and physical therapy are often helpful. Physical therapy will tend to be more successful when it is low-impact and focused on aerobic conditioning rather than vigorous activity. Water-based conditioning is also quite helpful in many. Use of orthotics is not typically well tolerated by the elderly, but an occasional patient may find the use of a brace supportive and helpful in his or her daily activities.

Surgery

Patients are considered candidates for surgical intervention if their symptoms have remained significant despite attempts at nonoperative care or, less commonly, if there is problematic curve progression.

Elderly patients undergoing surgery for scoliosis face the prospect of increased morbidity and mortality compared with their younger counterparts, primarily because they enter into the surgery much more disabled and with worse health status.^6–8 In the preoperative assessment, careful attention should be paid to their cardiac and pulmonary systems, as many patients have become quite sedentary and the stress of surgery may thus become problematic. If patients smoke, they should be encouraged to quit at least a number of weeks before the operation, not only to improve the chances of bone healing but to lessen the likelihood of pulmonary and wound complications, which are already elevated in the elderly population. If there is a suspicion of respiratory compromise, a history of smoking, or planned procedures about the diaphragm, preoperative pulmonary function should be assessed.

Similarly, if elderly patients have a history of cardiac or ischemic disease, they should undergo preoperative stress testing and formal cardiac evaluation. It is recommended that the elderly who have concomitant diagnoses of either hypertension, hypercholesterolemia, or diabetes be considered for perioperative beta-blockers.⁹

Elderly patients may have become relatively malnourished and the associated risks of sepsis, wound breakdown, etc., are well established.⁹ Total parenteral nutrition should be considered in staged surgical treatments, as it has been shown to diminish the rate of nutritional depletion and postoperative infections.

Surgical Techniques

A multitude of issues need to be assessed in each elderly surgical patient, including sagittal balance, coronal alignment, any complicating spinal or nerve root stenosis, disc degeneration, listhesis either anterior or lateral, osteoporosis, and any complicating medical comorbidities.

Unlike in the adolescent, where maximal safe correction of the coronal plane curvature is sought, in the elderly, aside from obtaining a solid arthrodesis, much more critical than Cobb angle correction is the obtaining and maintenance of appropriate balance in both the coronal and sagittal planes. A stable and balanced spine is the principal goal of deformity surgery in the elderly, and this often involves accepting less curvature correction. Numerous studies have emphasized that the component of postoperative radiography most closely tied to overall clinical success is the achievement of adequate balance, especially in the sagittal plane. Glassman and other members of the Spine Deformity Study Group, in a review of nearly 300 patients, have suggested that restoration of the normal sagittal balance is the most critical goal for any reconstructive spine surgery.⁵