**3. Clinical presentation**

Patients are generally over 50 years of age. Clinical presentation is variable. Onset is generally gradual, though it can be sudden, after a day's work, repetitive bending of the low back, poor sitting posture, or prolonged standing.

Most of the patients complain of low back pain, radiculopathy, and claudication [28]. Liu et al. [28], in a study of the clinical features of 112 patients with DLS treated surgically, found that 77% of them complained of low back pain, 90% complained of radiculopathy, and 48% complained of neurogenic intermittent claudication. Only 3% of them had neurological symptoms [28]. The symptoms can present singly or in combination [28].

### **3.1 Low back pain**

Low back pain is generally diffuse. It is often located in the apex and concavity of the curve and at the junction between two curves [28]. The severity of the pain varies with different curve types, with thoracolumbar, lumbar, and lumbosacral curves being more painful than thoracic curves. A compensatory hemicurve is the least painful, except for the left compensatory lumbosacral hemicurve [29–31]. Pain is also localized on the iliac crest and the coccyx, where the tendons of the lumbar paraspinal muscles insert [1]. Rarely, the lowest ribs impinge on the iliac crest and cause pain [1]. In the presence of a reduced lumbar lordosis or a complete loss of the natural lumbar curve, the muscle pain is generally greater. This is not unexpected as the lumbar paraspinal muscles have to contract continuously to maintain coronal and sagittal spinal balance.

Whether the extent of the pain is related to the magnitude of the curve and coronal balance has not been clearly elucidated as yet [29, 32]. A number of studies have shown that Cobb angles in excess of 45° are associated with more pain [33].

Other studies, however, have shown that the magnitude of the curve was not related to the pain [29, 34].

The impact of coronal balance on low back pain is likewise controversial. Some studies showed that a coronal imbalance in excess of 4–5 cm. is associated with more pain and reduction in function in un-operated scoliosis patients [32, 35]. Further trunk shift is a predictor of surgery in patients with DLS [35]. Other studies, however, did not show such an association [36].

### **3.2 Radiculopathy**

Radiculopathy is common in patients with DLS. Many studies have attempted to investigate the relationship between the scoliosis curve, VRO, and the nerve roots involved [28, 37, 38]. In a study evaluating 47 male and 65 female DLS patients with a mean age of 54.7 years, Liu et al. [28] showed that L3 and L4 nerve roots are generally compressed on the concave side of the scoliosis [28]. Conversely, L5 and S1 nerve roots are more commonly afflicted on the convex side of the scoliosis [28].

Liu et al. [37] evaluated the site of nerve root irritation in 22 DLS patients [37]. They identified three zones (**Figure 4**) where the nerve root could be compressed or irritated. These included the lateral recess zone, the foraminal zone, and the extraforaminal zone [37]. The lateral recess zone refers to the zone where the nerve root passes from the thecal sac to the entrance of the foramen; the foraminal zone refers to the interval canal beneath the pedicle, and the extra-foraminal zone refers to the zone outside the lateral border of the pedicle [37]. They found that the L3 and L4 nerve roots are more commonly compressed in the foraminal and extra-foraminal zones in the concavity of the scoliosis curve. Conversely, L5 and S1 nerve roots are more commonly affected by a lateral recess stenosis on the convex side [37].

Gardner et al. [38] evaluated different patterns of lumbar spinal stenosis with lateral subluxation in patients with DLS and had similar findings [38]. They showed that the pattern of nerve root compression varies with the types of lateral subluxation, viz., the open subluxation and closed dislocation. Open subluxation refers to subluxation where the disc is open on the side where the vertebra above is slipping. The wedge is open on the convexity of the curve (**Figure 5**). Conversely, closed dislocation is present when the disc is closed on the side where the vertebra above is slipping [23]. Gardner et al. [38] showed that open subluxation commonly affects L3 and L4 levels. When present, it causes contralateral lateral recess and foraminal

### **Figure 4.**

*The magnified view of the spinal canal and the intervertebral foramina. Nerve root irritation can occur in (a) the lateral recess zone, (b) the foraminal zone, and (c) the extra-foraminal zone; (d) is the sagittal diameter of the spinal canal. Spinal stenosis can result from narrowing of the sagittal diameter of the spinal canal or that of the lateral recess, when they are known as lumbar spinal stenosis and lateral lumbar spinal stenosis, respectively.*

*Conservative Treatment of Degenerative Lumbar Scoliosis DOI: http://dx.doi.org/10.5772/intechopen.90052*

### **Figure 5.**

*VRO was evident at Ll, L2, and L3 levels. L1 translated tangentially to the right, with no disc wedging. L2 similarly translated to the right though to a smaller extent, with disc closing on the right, which was the concavity of the lumbar curve. This is defined as closed dislocation. L3, on the other hand, slipped to the left. The disc wedged open on the side of curve convexity. This is termed open subluxation.*

stenosis. Closed dislocation, on the other hand, is generally seen on the concavity of the curve, causing an ipsilateral pattern of stenosis [38, 39]. L1 and L2 are the most frequently involved [38].

In a study of a cohort of 78 patients with DLS and spinal canal stenosis, Ferrero et al. [39] demonstrated that foraminal and lateral stenosis were most frequently observed on the concavity of the distal lumbosacral curve. L5 radicular pain was significantly more frequent in the presence of compensatory lumbosacral hemicurve [39].

In view of the different patterns of vertebral instability and compensatory curve patterns, it is understandable that the clinical presentation of DLS varies. Nerve root irritation may be single or multilevels, causing pain in different dermatomes [40, 41].

It is interesting to note that the side of radicular pain frequently corresponded to the side of coronal shift. Patients with right truncal coronal shift more frequently present with right radicular pain; similarly, patients with left coronal shift more commonly present with left radicular pain [39]. The mechanism involved was not clear, though it was found that in 69% of the cases, the truncal coronal shift was associated with the side of the lumbosacral counter-curve (i.e., C7 is shifted to the convex side of the main lumbar curve) [39].
