Adult and Adolescent Scoliosis

Abigail K. Allen, MD

Elizabeth Zhu, MD

Samuel K. Cho, MD

Dr. Cho or an immediate family member serves as a paid consultant to DePuy, A Johnson & Johnson Company, Medtronic, Stryker, and Zimmer; has received research or institutional support from Zimmer; and serves as a board member, owner, officer, or committee member of the AOSpine North America, the Cervical Spine Research Society, the North American Spine Society, and the Scoliosis Research Society. Neither of the following authors nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article: Dr. Allen and Dr. Zhu.

Introduction

Adolescent Scoliosis

Adolescent scoliosis is a spinal deformity in the coronal and sagittal planes that is broadly categorized into neuromuscular, congenital, and idiopathic etiologies. Of these, adolescent idiopathic scoliosis (AIS) accounts for 80% to 85% of cases and is most common. Congenital scoliosis results from the failure of formation or segmentation of vertebral precursors that allow asymmetric vertebral growth and curvature. Neuromuscular scoliosis has many etiologies, such as cerebral palsy, muscular dystrophy, spinal muscular atrophy, and myelomeningocele. AIS will be the focus of discussion in this chapter.

Scoliosis is radiographically defined by the curvature of the spine in the coronal plane greater than 10° using the Cobb method (Figure 64.1). Anatomically, scoliosis is a 3-dimensional deformity that includes vertebral rotation as well. Although present in 2% to 4% of children between ages 10 and 16 years, only about 10% of patients with AIS progress and require medical intervention. Without treatment, severe curves may cause chronic back pain, respiratory dysfunction, and degenerative arthritis. Risk factors for progression include large curve magnitude, skeletal immaturity, and female gender. In general, surgery is performed for curves greater than 45° to 50°. Spinal fusion is the current gold standard; its aim is to correct the deformity and prevent further progression.

Adult Scoliosis

When scoliosis occurs in a skeletally mature patient, it is called adult scoliosis. Reported rates of scoliosis in adults vary widely. As in adolescents, curvature greater than 10° as measured by the Cobb method is defined as scoliosis. However, most adults that seek treatment have curves that exceed 30°. Adult scoliosis may simply be progression of untreated adolescent scoliosis, or it may be caused by other spinal conditions such as degeneration, osteoporosis, or osteomalacia. In addition, adult scoliosis occurs frequently with spinal stenosis, rotatory subluxation, and nerve compression. Adults with scoliosis may also have loss of height, shortness of breath, and early satiety. Unlike in AIS, patients usually present with axial back and radicular leg pain, sometimes along with progressive truncal imbalance. The pain may be related to the curve or to the compression of the spinal nerves. There is considerable variability in management of adult scoliosis, including nonoperative care, decompression, limited stabilization, and long fusions. Surgical intervention is indicated for patients with pain and functional limitations unresponsive to nonoperative care, progression of deformity, neural impairment, and lung function impairment.

Surgery

The goal of surgery is to achieve a solid, well-balanced spinal fusion to prevent long-term dysfunction and disability. Posterior spinal fusion is the mainstay of treatment in scoliosis. Other surgical approaches include anterior and combined anterior–posterior spinal fusions. The surgical approach used depends on a number of factors, including curve magnitude, flexibility, location, as well as surgeon preference and experience. Currently, segmental pedicle screws, hooks, and wires provide better correction and less frequent implant failures. The pedicle, the hardest part of the vertebral body, serves as an excellent anchor point for fixation devices.

The posterior spinal musculature consists of deep and superficial layers (Figure 64.2). The superficial erector spinae includes the iliocostalis, longissimis, and sacrospinal muscles. The deep layer includes the short rotators (multifidus and rotators), intertransversarii, and interspinous muscles. The spinal musculature is innervated segmentally by the dorsal rami of the thoracolumbar nerve roots. The blood supply is
segmentally distributed from the dorsal branches of the posterior intercostal arteries.

Figure 64.1 Cobb method. (Reproduced with permission from Flynn JM, ed: Operative Techniques in Pediatric Orthopaedics. Philadelphia, PA, Wolters Kluwer Health, 2010.)

Typically, a straight midline back incision is used for the posterior surgical approach. The skin and subcutaneous fat are transected until the thoracolumbar fascia is reached. The thoracolumbar fascia is dissected between the tips of the spinous processes and dissection is carried out to the transverse processes. Surgery exposes and traumatizes paravertebral muscles, which serve as important stabilizers, especially in the lumbar spine. Posterior dissection of the spine also carries risk of denervation of the paraspinal musculature and decrease in trunk strength. Prolonged retraction during surgery can cause ischemic damage to the paraspinal muscles as well. Postoperative complications are rarer in adolescents than adults, and may include neural injury, neural compression, infection, nonunion, instability, and medical complications such as myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism. Last, spinal fusion leads to loss of range of motion (ROM) to varying degrees dependent on the site and length of the fusion (Figures 64.3–64.6).

Postoperative Rehabilitation

The main goal of postoperative rehabilitation for scoliosis patients is to optimize function following surgery. Primarily, rehabilitation interventions aim to decrease pain and restore function in activities of daily living (ADLs). Rehabilitation protocols following spinal fusion have not been well established, and differ from surgeon to surgeon. There are not any comprehensive guidelines that are agreed upon. Therefore, the rehabilitation protocols described are the authors’ based on our clinical experience.

Postoperative care as currently practiced can be divided into three phases: immediate postoperative care and mobilization, back-specific rehabilitation, and return to functional activity level. In the immediate postoperative care phase, the therapist evaluates the patient’s physical capacity and addresses any special needs. Therapy centers on transfer, gait, and basic back care after surgery. In the back-specific rehabilitation phase, the patient gradually increases muscular coordination, strength, and endurance through a home or subacute rehabilitation exercise program under the guidance of the physician. Therapy centers on maximizing functional status. When patients enter the final phase to help them return to their baseline functional activity level, the patients progress further in exercise tolerance and aerobic conditioning, while continuing to focus on back stretching and strengthening.

The health care team—consisting of the orthopaedic surgeon, pain service, physical therapist, and ancillary staff—should encourage patients to mobilize soon after surgery. Pain is a poor indicator of determining exercise program duration and intensity. Kool et al. found that patients who were trained to stop exercising because of pain fared worse in all measures, including strength, ROM, disability, limping, guarding, pain killer dosage, and health care seeking. In contrast, patients who were trained to continue with therapy despite pain had decreased disability overall. Therefore, psychological support to overcome fear about pain, injury, and function should be given in addition to active physical treatment.

Immediate Postoperative Care and Mobilization

The goal of rehabilitation between surgery and discharge from the hospital is independent ambulation and regaining some of ADLs. ADLs refers to the basic tasks of life, such as eating, bathing, dressing, toileting, and transferring. In addition to postoperative wound and medical care, patients require physical, and occasionally occupational, therapy. Prior to initiating physical therapy, a comprehensive medical evaluation—including pain control, postoperative hemoglobin levels, and cardiovascular and neurologic status—should be performed. For pain, we use patient-controlled anesthesia (PCA) immediately after surgery (given to the patient in the recovery room) with transition to oral medications as soon as the patient can tolerate oral intake. Adequate pain control is essential to the rehabilitation process.

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