A study was made of 941 consecutive cases of back injuries in industrial employees.
Sprain occurred in 498 cases, or fifty-three per cent. The most frequent site was the lumbosacral region where about two-thirds of the cases were located. In about eleven per cent. the condition seemed to be sufficiently localized about the region of the sacro-iliac joint to warrant the term sacro-iliac sprain. This was regarded simply as a neighborhood injury and not as a specific entity. The next most frequent site was the mid and upper lumbar region, where about a fourth of the cases occurred. The dorsal region is relatively fixed and is very infrequently subject to sprain, while the cervical region is protected by its position. In about half of the cases the lesion seemed to be unilateral or at least predominatingly so. In the other half the lesion was located centrally. The average period of disability in 310 cases where it was known was five weeks. This showed a steady increase from one week in dorsal lesions to eleven weeks in sacro-iliac lesions. There was also a progressive increase in the period of disability according to the age of the patient. Static abnormalities occurred in twenty-one cases and distinctly increased the period of disability.
Contusions occurred in 122 cases, or thirteen per cent. The average period of disability in the seventy-nine cases in which it was known was about seven weeks.
Fracture of the vertebral processes occurred in forty-one cases or four per cent. In thirty-six cases the fracture involved one or more of the transverse processes. In about half of these the fracture was due to abnormal muscular pull and in about half to direct violence. In about a third the fracture was single and in about two-thirds more than one process was involved. Of the individual vertebrae the processes of the third were most frequently involved; those of the others in decreasing frequency above and below. In those cases due to the indirect violence of muscular pull almost all the fragments were widely displaced. In the cases due to direct violence, few showed more than appreciable displacement. Cases without much displacement showed evidence of callous formation and union in one to three months. In sixteen cases where the period of disability was known it averaged twenty-four weeks. There were two cases each of fracture of the spinous processes and neural arches, and one case of involvement of an articular facet.
Fracture of the vertebral bodies occurred in thirty cases, or three per cent. Many of these followed what seemed to be slight accidents and were surprisingly devoid of symptoms. Two-thirds gave no history or showed no evidence of cord involvement. In eighty per cent. the force causing the fracture was applied indirectly, the majority of the men being struck on the back while in the stooped position. About a third of the cases showed a distinct posterior kyphos or knuckle. The prognosis in these cases, of course, varied with the extent of the injury. Eleven cases, or a little over a third, were known to have returned to some form of active labor in the mines. In ten of these the period of disability was known and averaged thirty-four weeks.
Chronic deforming arthritis was found in 107 cases, or eleven per cent. This is regarded primarily as a chronic infectious disease. Spines so involved are damaged structures permitting of motion only through limited arcs. Slight injuries seem capable of increasing the local activity of the process, while motion forced beyond the limited arc may result in serious consequences. Most of the cases so classified showed gross foci of infection, about half showed well marked arteriosclerosis, and about a sixth static abnormalities of the feet and legs. Two-thirds of the cases studied early in the course of their disability gave a more or less definite history of chronic lame back. This was absent in practically all of those seen after an interval of more than a few weeks, so that it occurred in only ten per cent. of the whole group. In nearly a fourth of the cases, there was a definite history of progression. In fifty-two or about half of the cases the period of disability was known and averaged fifteen weeks.
A neurosis was diagnosed in eleven cases, or one per cent. The fundamental condition here is a disorder in conduct occurring in individuals who are fearful, dissatisfied, and who seek compensation. Their condition results not so much from the accident as from the erroneous opinion they have formed of the nature and extent of that accident and of the rights to which they are entitled. They are probably all inherently neurotic. This diagnosis can only be made by exclusion. The greatest difficulty comes in differentiating a true neurosis from malingering. Unless there is sufficient evidence to definitely answer this question, it is safest to maintain a purely objective viewpoint and merely determine the extent to which the patient is dominated or disabled by his neurosis.
Malingering occurred in thirty-five cases, or four per cent. It was believed that fourteen per cent. of the entire group showed more or less marked exaggeration at some time during their observation.
In ninety-seven cases, or ten per cent., the condition of the back and the symptoms complained of seemed entirely attributable to disease.
Variations in the spine from the normal or text book anatomy occurred in four and eight-tenths per cent. of the cases in the dorsolumbar region and in twelve and three-tenths per cent. of the cases in the lumbosacral region. The most common anomalies were split spinous processes, usually of the first sacral vertebra, and sacralization of the fifth lumbar vertebra. The importance of these anomalies is their tendency to weaken the mechanical construction of the back, thus predisposing it to injury and delaying its recovery after injury.
(C) 1927 All Rights Reserved.The Journal of Bone and Joint Surgery, Inc.