The diagnosis of low back pain of orthopedic origin

Abstract A clinical study of sixty-two patients with low back pain of orthopedic origin resulted in the following observations: 1. 1. Acute trauma played a minor role in the etiology of these cases. 2. 2. Foci of infection were considered of little importance as causative factors. 3. 3. The character of the pain, its mode of onset and methods of exaggeration and relief were of no assistance in determining the exact area or type of the causative lesion. Change of weather was an exaggerating feature in equal proportions in cases due to arthritis and those due to strain. Practically all were relieved by rest. The same number were relieved by lying on the painful side as on the opposite side. The majority of females found no increase in pain at the time of the menses. 4. 4. Complaints of numbness and stiffness were of no assistance in arriving at the diagnosis. Stiffness was noted in similar proportions in cases due to both arthritis and strain. Stiffness occurred somewhat more frequently in lumbosacral lesions. 5. 5. Regarding the area of the patients' complaints, all lumbosacral cases complained of pain in the lower back or center of the lower back. Of the sacroiliac cases, many more complained of pain in the center of the lower back than of pain in the buttock. All patients complaining of pain in the middle of the back had lesions which were lumbar or dorsolumbar. Pain in the middle of the back was noted almost exclusively in cases due to hypertrophie arthritis. 6. 6. The greatest number of patients constituting sacroiliac cases complained of unilateral pain. The greatest number of patients in the lumbosacral cases complained of midline or bilateral pain. There was no relationship between laterality of complaints and the type of causative lesion. 7. 7. Sciatic radiation of pain was noted in 22 per cent of the lumbar cases, 27 per cent of the lumbosacral cases and 75 per cent of the sacroiliac cases. Radiation to the outer thigh, front of the thigh, groin and abdomen was noted in lumbar cases only. The three dorsolumbar cases presented no radiation of pain. 8. 8. The direction of limitation of spinal motion did not indicate the area of the lesion, but cases of strain were more likely to produce limitation in either the anterior or posterior direction, while arthritic cases were more apt to produce universal limitation of motion. Improvement in range and comfort on anterior bending in the sitting position did not definitely indicate but suggested a sacroiliac cause of the complaints. The area of the pain produced on spinal bending did not consistently represent the area of the causative lesion. Pain on forced thigh flexion was noted in cases due to lumbar, sacroiliac or lumbosacral lesions, but was more frequently seen in the latter group. These cases almost invariably had a strain as the type of causative lesion rather than arthritic changes. 9. 9. Most patients presented multiple points of tenderness. Tenderness was found most frequently at the lumbosacral joint, the posterior, superior iliac spines and in the paraspinal muscle areas. The areas of tenderness bore no definite relationship to the area or type of the lesion. Three cases with lumbar spinal tenderness alone were all diagnosed lumbar hypertrophic arthritis. Five cases with tenderness chiefly in the sciatic notch with lesser points of tenderness elsewhere were diagnosed as sacroiliac strain. 10. 10. There was no relationship between areas of referred tenderness and the area and type of the lesion. Referred tenderness was apparently not related to the areas of referred pain. 11. 11. There was no definite relationship between the clinical diagnoses and the areas on the roentgenograms showing the greatest abnormality. Great caution must be used in interpreting a given roentgenologic abnormality as the cause of the low back or sciatic pain. 12. 12. Altered Achilles reflexes were noted chiefly in lumbosacral cases. All were found in cases of strain and the one case of protruded intervertebral disc. 13. 13. Limited painful straight leg raising was of no assistance in determining the area of the lesion, but in the great majority of cases in which it was positive, the condition was thought to be due to strain. In cases of bilateral limited straight leg raising, the production of pain on the side of the complaints by raising the opposite leg suggested a sacroiliac lesion. The added test of dorsiflexion of the foot in the straight leg raising procedure was of no further aid in diagnosis. 14. 14. There was no relationship between muscular atrophy and the diagnosis, alteration in reflexes, laterality ot complaints, areas of referred tenderness or inequality of leg length. 15. 15. The finding of faulty posture, while suggestive as a factor in the low back pain, was of no assistance in determining the area or type of the causative lesion. Inequality of leg length, however, was noted entirely in cases thought to be due to strain. 16. 16. The Nachlas and Yergason tests were negative in all patients in this series. The Ober test, rectal examination, fabere test, and painful, limited internal rotation of the hip were of no assistance in determining the diagnosis. 17. 17. The Gaenslen sign was positive in similar proportion in all of the groups of the area classification, but it was found almost invariably in cases due to strain. It was of no value in reproducing the area of the patients' complaints or in suggesting the anatomic area at fault. The hyperextension test was similarly of no assistance in diagnosis of the area or type of the lesion. 18. 18. There is apparently no clinical sign, symptom, or special test, and no combination of them, which can be reliably considered as diagnostic of either the area or type of the causative lesion. Certain observations may be considered suggestive of a diagnosis. 19. 19. The differentiation is probably almost entirely of academic interest. If intraspinal, osseous, neoplastic and remote causes are eliminated, the remaining 90 per cent of cases of low back and sciatic pain will be found to be muscular, intermuscular, articular or ligamentous in origin. Of these, regardless of the exact type or area of the causative lesion, 90 per cent will be relieved by identical, conservative, therapeutic procedures. The importance of exact diagnosis as to the area and type of the causative lesion in these strictly orthopedic cases is, therefore, limited to the 10 per cent or less which require operative procedures, such as fasciotomy, myotomy or arthrodesis to obtain relief.