The clinical evaluation starts with ambulation to check the overall balance when the patient walks. Patients are frequently asked to walk in the hallway of the clinic. This is a good opportunity to observe them walking posteriorly as they are walking away from the clinician and anteriorly when they are walking toward the clinician. The overall gait speed of the patient is an important assessment of the current physical condition. The gait speed depends on the cardiovascular condition, pulmonary status, neurodegenerative disorder, and arthritis in the weightbearing joints. Gait speed has been correlated to perioperative complication rates in cardiovascular surgery.² Several observations can be made during ambulation. The overall spinal balance in both coronal and sagittal plane can be visualized as the patient walks.

As the patient walks, several simultaneous observations can be made on nerve, arthritic, and muscle conditions. For example, a Trendelenburg gait can diagnose hip abductor or specifically gluteus medius weakness. Patients with hip osteoarthritis usually walk with an antalgic gait on the side of the arthritic hip. It is not unusual for them to also have a concomitant hip flexion contracture; therefore this patient would usually walk slightly bent forward toward the side of the arthritic hip and have a limping gait on that side. Patients with spinal stenosis can also bend forward as they walk far to relieve the symptoms of neurogenic claudication. These patients appear to have a positive sagittal balance, but in reality they are opening the spinal canal to a wider diameter by bending forward. The spinal canal gets wider as the ligamentum flavum is stretched between the laminae as the patient bends forward. Patients sometimes start out standing straight, but as they walk they start bending forward in a positive sagittal balance because their extensor muscles are weak owing to neuromuscular disease, muscle disease, or an unknown etiology. There is a lot to be learned about the extensor muscles that cause the positive sagittal balance in the elderly. In general, loss of muscle is a normal process as we age.

The clinical evaluation also entails having the patient walk on his or her toes and on the heels. They are usually asked to squat down and get up. These simple tests can determine if the patient has a weakness in the muscle groups innervated by the lumbar nerve roots such as inability to stand on heels because of weakness of the anterior tibialis, or a gastrocsoleus weakness results in the inability to stand on toes. Proximal weakness results in inability to

climb stairs or get up from a squatting position from quadriceps weakness. The patients are then asked to perform some balance testing such as a Romberg test, which points to dysfunction in proprioception or a cerebellar dysfunction. Patients with peripheral neuropathy may not be able to tell where their feet are. They usually have trouble in low light and are asked to invest in multiple night lights. Single leg stance is also a good test to see the patient’s balance. This tests proprioception, any neuro degenerative disorder, and muscle strength at the same time. The functional testing is as important as the manual muscle testing when grading each muscle group. There are times when the patient is tested to be grade 5 out of 5 in the manual muscle testing but actually cannot get up on heels or toes as the case may be. Sequential toe raises one leg at a time can also bring out asymmetric weakness between the legs. Another hidden weakness that can be seen is if you ask the patient to get up on a step or chair, which will bring out functional quadriceps weakness not apparent on manual muscle testing.

The neurologic exam should include motor, sensory, and reflex testing for upper and lower extremities. This is because there are several conditions that affect the cervical and lumbar spine such as degenerative conditions creating spinal stenosis. Often, patients with lumbar spinal stenosis have concomitant cervical stenosis, although unrecognized, which needs to be diagnosed and treated first if more severe than lumbar stenosis. The comparison of reflexes of upper and lower extremities also provides insight to conditions that might be causing hyperreflexia or upper motor neuron signs in the lower extremities. The thoracic spine can have spinal stenosis from ossified posterior longitudinal ligament, ligamentum flavum hypertrophy, or large disk herniations, which maybe painless and can otherwise go undetected. The only symptom could be unsteadiness in ambulation. In spinal deformity patients, Arnold-Chiari malformations, syringomyelia, tethered cord, and diastematomyelia can all be present that might need to be addressed before a surgical procedure is considered.

Examination of the spine includes observation for manifestations of a hairy patch or sacral dimples suggesting spinal dysraphism. First, an overall coronal and sagittal examination is performed. The patient is then asked to perform an Adam forward bend test. The rotational deformity is then measured off the ribs and lumbar spine with either a scoliometer or a ruler to understand cosmetic concerns of the patients. Large rotational deformities may benefit from a thoracoplasty if the patient is very concerned about it. The amount of kyphosis and lordosis can also be visualized. These sagittal curves have to be tested for their flexibility by lying prone, supine, or on a hyperextension bolster. Similarly, the coronal curves can be tested to see how flexible they are by placing the patient supine or prone and pushing on the deformity. The pelvis has to be checked to rule out any pelvic obliquity and leg asymmetry. Leg length asymmetry and pelvic obliquity can give rise to coronal imbalance if not taken into account when correcting the spinal deformity. The side of the apex of the lumbar spine and the coronal malalignment should be checked. If the apex of the lumbar spine is on the same side as the coronal malalignment, the fractional lumbosacral curve needs surgical correction, otherwise worse coronal balance will be felt postoperatively.

The patient is then placed in prone position to see which portion of the spine is the most painful. For example, in a middle-aged adult idiopathic scoliosis patient if only the lumbar curve is painful and the lumbosacral curve is not, one can avoid fusing down to the pelvis. The hip range of motion is a very important test because patients with lumbar degenerative disease can have concomitant hip osteoarthritis. On occasion, the osteoarthritis of the hip is so severe that the hip is almost ankylosed and as one ranges the hip the pelvis rotates with it. In these cases, the hip needs to be reconstructed (i.e., hip arthroplasty) before spine surgery, because rehabilitation is easier from a spine surgery once the hip is painless and the ambulation is better. Rarely, there have been some patients whose back pain markedly improved after the hip was replaced and they could be treated nonoperatively for their spine condition. The Eli test can demonstrate how much hip flexion contracture is present. The hip flexion contracture can be addressed with physical therapy and prone lying to prevent the patient from leaning forward postoperatively.

Radiographic evaluation of spinal deformity includes long cassette films that are at least 36 inches in length to analyze the coronal and sagittal planes. Usually, posteroanterior (PA) exposure and a lateral exposure are performed. The overall coronal and sagittal alignment can
also be measured. Capturing the entire spinal column on one radiograph enables us to study the relationship of the coronal curves such as the primary and secondary curves. In the past, the long films did not show if the patient was standing with bent knees. The patient’s spine will be captured on one long film by bending the knees for example in a flat back syndrome. The radiograph then gives a false impression that the sagittal deformity is not as severe as in the clinical observation of the patient. Taking the radiograph in the correct position is important in the sagittal plane. Horton et al. demonstrated that the arm position can influence the sagittal vertical axis.³ They determined that holding the arms in the clavicle position and not holding on to a pole or simply holding them out in front was not as accurate.

Flexibility radiographs are also necessary to determine the type of procedure needed. In idiopathic scoliosis, bending x-rays in the supine position can be very helpful to determine the flexibility of the primary and secondary curves. If the secondary curves are flexible and bending down to below 25 degrees, then they are determined not to be structural according to the Lenke classification, and are not included in the instrumentation and fusion. On the other hand, if the secondary curves are rigid or have an abnormal sagittal plane those curves are included in the instrumentation and fusion. Luk et al. have used bolsters to determine the flexibility of the curve.⁴ The fulcrum bending x-ray has been found to be more predictive of the final correction achieved by surgical correction and instrumentation. Push prone radiographs have also been shown to be useful to determine the lower instrumented vertebra in adolescent idiopathic scoliosis.⁵ Supine AP and lateral x-rays in adults are very useful in determining the severity of the spinal deformity. Adult patients have weak extensor muscles and other conditions that determine the standing posture. Supine radiographs remove the effect of gravity and highlight the remaining rigid spinal deformity. Thus, the surgical procedure can be tailored to the residual spinal deformity. If the decision for the surgical procedure is made from the standing x-rays only, the surgical procedure may be planned to be more extensive, such as three column osteotomies, than required. Often, the residual spinal deformity can be treated with posterior releases or Smith-Petersen type osteotomies. There are times where an intradiscal release is needed with a formal anterior approach, minimally invasive lateral approach, or a posterior transforaminal lumbar interbody fusion. This is especially true for rigid fractional lumbosacral curves.

After the radiographs are thoroughly evaluated, additional specialized studies are usually necessary for further evaluation before planning an operative procedure. Magnetic resonance imaging (MRI) is a great screening tool. The MRI can delineate any intraspinal anomalies, identify disk herniations or spinal stenosis, show the bone marrow and the endplates of the vertebral bodies, and the degree of degeneration of the lumbar disks. It is also useful in identifying any pathology of the facet joints. A large effusion in the facet joints represents a sign of instability such as spondylolisthesis. A myelogram followed by a computed tomography (CT) scan can help identify bony elements such as pedicles to plan pedicle screw placement, bridging osteophytes making the curve almost ankylosed, or osteophytes that might be impinging on nerve roots. A DEXA scan is also very useful to identify the degree of osteopenia or osteoporosis present preoperatively. If the patient has a very low bone density, preoperative treatment with Forteo, parathyroid hormone, can be useful in preventing proximal junctional kyphosis (PJK) or screw migration postoperatively. The patient is usually also placed on Forteo postoperatively for at least a year.