This diagnostic code includes the conditions kyphoscoliosis, pectus excavatum and pectus carinatum which represent abnormalities related to a curvature of the spine and inward and outward conditions of the sternum. Kyphoscoliosis is defined as a curvature of the spine away from the midline (lateral) of the body accompanied by a hump that is situated in the back. Pectus Excavatum is defined as an inward curvature of the lower sternum. Pectus carinatum is defined as an outward projection of the upper, middle, or lower sternum.

Idiopathic kyphoscoliosis accounts for 80% of cases. It usually begins in late childhood or early adolescence, and can progress as the skeleton grows. The remaining 20% of cases stem from disorders of the nerves and muscles, e.g., neurofibromatosis. Pectus excavatum is present in fewer than 0.5% of the population. The sternum deformities, pectus excavatum and pectus carinatum, appear to be more common in patients who have other structural or connective tissue disease, such as scoliosis.

In kyphoscoliosis, there are minimal restrictions to inhalation with mild to moderate deformities. However, as the scoliotic curvature intensifies, vital capacity and total lung capacity decrease considerably, and dyspnea on mild or moderate exertion becomes a common complaint.

Severe deformities, e.g., scoliotic angle greater than 100, are usually associated with significantly restricted lung volumes resulting in hypercapnia; classically, a reduction of 50% or less of predicted lung volume value. Such restriction may lead to reduced rate and depth at the alveoli, hypoxemia, pulmonary hypertension, and, ultimately, cor pulmonale.

Because breathing is chronically restricted, increased physical work and neural function are required to maintain ventilation. Minor disturbances, e.g., bacterial or viral bronchitis or pneumonia, may cause respiratory failure due to the increased workload.

In most cases of pectus excavatum and pectus carinatum, there are little to no limitations to functional abilities. Lung volumes are not affected, and cardiovascular function is normal.

Diagnosis of kyphoscoliosis is most often made by physical examination, accompanied by x-ray; computed tomography (CT) scan; magnetic resonance imaging (MRI); myelography; pulmonary function tests (PFT) which show distinct patterns of restriction; and arterial blood gases (ABG) that may be abnormal in cases of severe disease.

Diagnosis of pectus excavatum and pectus carinatum, is made most often by physical examination accompanied by x-ray; CT; MRI; and myelography.

Treatment in kyphoscoliosis involves the prevention of respiratory infections and central nervous system depression; the administration of immunizations, and pneumococcal vaccines; early treatment of respiratory tract infections; and strict avoidance of central nervous system depressants. When episodes of hypercapnia ensue, respiratory failure brought on by reversible conditions respond well to short-term supportive measures, e.g., drainage of the bronchopulmonary area, mechanical breathing support, and supplemental oxygen. Although an option, surgical procedures to straighten and stabilize the vertebral column usually fail to reinstate a relatively normal breathing capacity. These types of procedures are more apt to be helpful early in the course of kyphoscoliosis; when the procedures may prevent advancement of the deformity before the development of respiratory problems. It is possible to sustain a relatively meaningful life in these patients for many years with the use of supportive measures; even for those with chronic respiratory failure. Finally, devices used for mechanical ventilation in such patients includes: the iron lung; negative pressure ventilators; and positive pressure ventilators applied via tracheostomy or nasal mask.

In cases of severe deformity associated with pectus excavatum and pectus carinatum which are accompanied by lung restriction or cardiovascular dysfunction, surgery is an option.

Chronic respiratory insufficiency may develop after several years in patients with kyphoscoliosis. The angle of the curvature typically worsens with age, making older patients with kyphoscoliosis at risk for the development of respiratory failure. Data obtained in long-term follow-up of kyphoscoliosis patients suggests that those with a vital lung capacity of less than 45% of the predicted value and a curvature angle greater than 110° are at the greatest risk for respiratory failure.

Modest improvements in lung volumes may be seen after surgery in patients with severe deformities associated with pectus excavatum and pectus carinatum.

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See  38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• A 100% rating shall be assigned for pleurisy with empyema, with or without pleurocutaneous fistula, until resolved.

• Following episodes of total spontaneous pneumothorax, a rating of 100% shall be assigned as of the date of hospital admission and shall continue for three months from the first day of the month after hospital discharge.

• Gunshot wounds of the pleural cavity with bullet or missile retained in lung, pain or discomfort on exertion, or with scattered rales or some limitation of excursion of diaphragm or of lower chest expansion shall be rated at least 20% disabling. Disabling injuries of shoulder girdle muscles (Groups I to IV) shall be separately rated and combined with ratings for respiratory involvement. Involvement of Muscle Group XXI (Diagnostic Code 5321), however, will not be separately rated.  

• Review special provisions regarding the evaluation of specific respiratory conditions under 38 CFR 4.96(a)- Rating co-existing respiratory conditions and 38 CFR 4.96(d) - Special provisions for the application of evaluation criteria for diagnostic codes 6600, 6603, 6604, 6825–6833, and 6840–6845.