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herniated disc, pseudoarthrosis, internal disc derangement and degenerative scoliosis.
Jonsson and Stromqvist in a perspective consecutive study of 50 patients over 70 years of ago, who underwent a lumbar nerve root compression, can be managed without complications related to anesthesia and with outcomes at two years that are on par with those of decompressive surgery in younger patients.
Conley, et al., reported good results in a group of 25 patients with a mean age of 66 years who underwent decompression and stabilization of lumbar spinal stenosis with Knodt rods.
In a comprehensive study of claims records of more than 200,000 cases, Stoll, et al., found that for patients 60 to 85 years old, advancing age had no effect on the mortality rates associated with excision or decompression. Clearly, as our patient population ages, and as Iowa has the second largest elderly state in the union, if patients present that are medically cleared by their internist and have a disability and can safely be assisted, it would be unethical to withhold surgery just because of an advancing age.
Disk changes with Aging and Degeneration
The earliest MRI finding in disc degeneration is loss of disc signal on T2 weighted images. A disc undergoes further dehydration, fissure development in the annulus. When the fissure is coalesced, the result is an annular tear. Annular tears are either concentric or radial in orientation. The outer annular fibers and posterior longitudinal ligament are richly innovated by branches of the sinuvertebral nerve. Irritation of these nerve endings by inflammatory polypeptides associated with annular tears and disc herniation may result in back or leg pain. It is important to recognize that annular tears may result in frank radiculopathies in the absence of mechanical compression. Disc degeneration may be associated with changes within the adjacent mural spaces. Modic has described these changes as type I or type II depending on signal characteristics. These have been previously described.
A way of diagnosing degenerative disc disease is discography. In the early 1940's a Swedish radiologist, Lindblom, performed the first discography. In his paper in 1948, he stated diagnostic disc puncture with injection of opaque medium demonstrates disc ruptures and protrusions and tells if the patient's symptoms originate from the punctured disc. In 1950, Wise and Weiford performed the first discography in the United States. In 1952, Erlacher showed anatomic correlation with discographic findings in 200 cadaveric discs. Discograms give important preoperative (Continued on page 64)
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