Scoliosis is not simply just a “curve” of the spine. It is way more complex and it is defined as a three dimensional deformation in which the lateral curvature of the spine is more than 10° in the coronal plane. The causes of scoliosis vary and are classified into congenital, syndromic and idiopathic. 1. Congenital scoliosis refers to spinal deformity caused by abnormally formed vertebrae.
2. Syndromic scoliosis is associated with neuromuscular conditions (eg cerebral palsy, spinal cord injury or Duchenne muscular dystrophy) or other syndromes (eg Marfan syndrome or neurofibromatosis).
3. Idiopathic scoliosis has no known cause.
While scoliosis is associated with many medical diagnoses, the vast majority of patients encountered are idiopathic in nature.
At an early stage, it is usually painless and asymptomatic. Beside of cosmetic issues, scoliosis can affect lung function in many ways. Most researchers agreed that (1) a Cobb angle greater than 90˚ greatly predisposes to cardiorespiratory failure, (2) lung function abnormalities are detectable when a Cobb angle is greater than 50˚ to 60˚, (3) lung function abnormalities are mainly of the restrictive type and (4) the duration of scoliosis correlates with the patient’s degree of disability.
Breathing pattern is significantly altered in severe scoliosis at rest, on exertion and during sleep. The reduction in lung volume is multifactorial and it is mainly due to restriction which is related to the degrees of the curve, the location of the curve, and the loss of normal thoracic kyphosis. Radiological studies have shown that the movements of the diaphragm (respiratory muscle) are greater on the convex side. The movement of rib cage has been reported to vary considerably from almost no expansion to normal thoracic movement.
In a recent study of 60 scoliotic patients with Cobb angle more than 40°, their lung function, muscle function and exercise capacity were assessed. It was found that reduced muscle strength of the respiratory muscles and also the quadriceps (thigh muscles) correlated with reduced work capacity. Exercise was stopped due to leg discomfort rather than the complaint of breathless. The results showed that generalized muscle dysfunction contributed to the reduction in their exercise capacity, even in the absence of severe ventilatory impairment. It is also possible that displacement or compression of the heart due to thoracic deformity may not allow the increase in the volume of blood pumped from the heart that is necessary during exercise. In addition, exercise is likely to increase the already elevated pulmonary artery pressure. In patients with a Cobb angle more than 100°, pulmonary arterial hypertension (PAH) may contribute to decreased exercise capacity, and commonly associated with reported symptoms of shortness of breath and fatigue.
Regular posture screening is important to catch the conditions early. The visible signs of scoliosis can typically be observed in one’s posture.
Asymmetry in shoulder level
Shoulder blade stick out
Rib hump
Uneven waist level
One or both hips are raised
Body leans to one side
Leg length discrepancy
Speak to doctor or health care professionals if you suspect of scoliosis. Scoliosis should be identified and treated as early as possible to prevent future complications including deformity progression, back pain, cosmetic problems, nerve compression, and even cardiopulmonary restriction.
References:
1. Farhaan Altaf, Alexander Gibson, Zaher Dannawi, Hilali Noordeen. 2013. Adolescent Idiopathic Scoliosis. BMJ 346: 1-7.
2. Theofanis Tsiligiannis and Theodoros Grivas. 2012. Pulmonary Function in Children with Idiopathic Scoliosis. Scoliosis 7(7): 1-6.
3. Martinez-Llorens J, Ramirez M, Colomina MJ, Bago J, Molina A, Caceres E, Gea J. 2010. Muscle Dysfunction and Exercise Limitation in Adolescent Idiopathic Scoliosis. Eur Respir J 36(2): 93-400.