It is a constant theme throughout this book that, when contemplating back surgery, one should look at the whole patient. To ignore obvious emotional and situation pressures deflecting the patient toward a larger or longer period of disability will result in failure of the surgical exercise. The reader is reminded that the first question to be asked in the differential diagnosis of any low back disability is:

All too often this question is only answered in the affirmative after failed surgery.

It is not infrequent that a surgeon is faced with a patient who has a protracted disability. The patient has been in and out of work, in and out of hospital, in and out of physical therapy departments, and in and out of the offices of drugless practitioners. It is understandably tempting to regard this long period of disability as indicating severe pain. However, if this group of patients, suffering from low back pain only, cannot be retrained to undertake lighter jobs, then a desperation fusion will be unlikely to succeed.

In this regard, it must be emphasized that a patient cannot describe the pain; he or she can only describe the disability. Pain and disability are not synonymous, and the disability complained of is not necessarily indicative of the degree of pain experienced.

In the simplest superficial analysis, disability has three components: the pain, the patient’s reaction to the pain, and the situation prevailing at the time of the pain. A certain degree of what might be termed a functional reaction can be regarded as normal. When the functional response is gross, it becomes a major part of the disease process. This concept is best exemplified by describing three hypothetical workmen, three bricklayers who presented with the same degree of disability. They had pain in their backs; although they could walk around, they could not do their work. They could not climb ladders, carry bricks, or stoop to lay the bricks. They were not able to describe the amount of pain they had; they could only describe their disability. They all had degenerative disc disease. The radiographs could not describe how much pain they were experiencing. All that was known was that the disability claimed by all three was the same: They could not work. In one patient (patient A), the disability was largely due to the anatomic basis of his pain. In another patient (patient C), there was little anatomic source of pain, but he was overcome by the functional reaction or the emotional response to his discomforts (Fig. 17-1).

Surgery meticulously performed might overcome 90% of the anatomic basis of the disability. The first patient (A) would be cured and would be able to return to work, but even with 90% of the organic basis of his disability removed, the third patient (C) would still be incapacitated (Fig. 17-2). In such instances, because of failure of treatment, the functional reaction will get worse, and the story of patient C is best exemplified by the letters that were written to the workmen’s compensation board about him:

Patients A, B, and C all presented with the same disability. They were bricklayers who could not work. They had the same radiographic changes, but the constitution of their disability varied enormously, and, predictably, the results of operative treatment varied also (Fig. 17-4).

In patient C, the degenerative disc disease was not causing too much pain, and in better emotional health, the discomfort he experienced would not have taken him to a doctor. However, because of factors outside his spine, in fact, outside his soma, he was totally disabled by his discomfort; and this disability was later compounded, perpetuated, and exaggerated by the failure of surgical treatment.

Patients A and C do not really constitute much of a problem because the gross functional overlay of patient C is usually recognizable. These two groups of patients have been discussed in detail throughout this book to emphasize the fact that pain and disability are not synonymous. The middle group, patient B, typifies the most difficult problem. The surgeon who regards a functional overlay as a solid contraindication to operation will not help patient B even though he does have an organic basis of discomfort.

There are two important aspects in the management of patient B that must always be kept in mind: first, the recognition of the organic basis of pain, despite the clouding of the clinical picture by the functional elements; and second, an analysis of the constitution of the functional component of the disability.

The functional overlay is derived from a combination of many factors. A large part of the emotional overlay is due to the patient’s personality; the patient may have no drive, no motivation, and may even be a psychopath. Whatever it is, it probably cannot be altered. It is important to recognize a gross personality defect because these patients will not do well with treatment directed solely at their spines.

Other factors must be considered, such as the patient’s affect or mood, the significance of pain to the patient, and the patient’s ability to adjust to his or her environment. The importance of financial security and work demands are obvious. Finally, the reaction of the patient to pain must be considered: the individual’s pain tolerance and pain threshold. If the patient, because of inheritance or constitution, for example, tends to have an exaggerated reaction to any painful stimulus, it makes it very difficult to recognize the fact that the patient is suffering from an organic lesion.

For example, a patient may react violently at the limit of one phase of clinical examination: straight leg raising (SLR). On experiencing discomfort, the patient may writhe, groan, shout, bang his or her hands, and finally collapse, sobbing and weeping. Such patients react excessively to pain produced by an organic disability. However, when this excessive reaction is of a hysterical nature, it becomes extremely difficult to determine whether the problem is one of a hysterical patient with pain or a patient with hysterical pain. Suffice it to say, if these considerations are made preoperatively, it is less likely that the patient will fail to respond to surgical intervention because of nonorganic factors.

With the heightening criticism directed at spine surgeons for the all too frequent poor outcome, we are looking at the many factors that lead us into failure. It is becoming more apparent that the nutritionally compromised patient does not have the physical foundation for adequate wound healing (11). The authors are becoming more convinced that the heavy smoker and/or drinker has also compromised wound healing, specifically graft incorporation, and is more likely to end up with a pseudarthrosis after attempted fusion (10).

There are many pitfalls awaiting the unwary in evaluating and treating low back and leg pain. If an incorrect diagnosis was the basis of the surgical procedure, there is virtually no hope of a successful outcome. The “step back and take a long look” approach is then indicated. The second question to be answered satisfactorily is: Did I fall into a diagnostic trap and make an error in diagnosis (Tables 17-2 and 17-3)?

It seems rhetorical to state that even though you make the right diagnosis in the right patient, operating at the wrong level will fail to cure the disease. There is more “wrong level” surgery being done than we, as surgeons, have admitted. This occurs in two situations: (a) preoperative selection of the wrong level for surgery (Figs. 17-5 and 17-6) and (b) making the technical error of selecting the wrong level intraoperatively. Systems approaches for consistently arriving at the site of pathology have been proposed. The “Sign, Mark and X-Ray (SMaX)” program from the North American Spine Society is a reasonable methodology (48).

If you are satisfied that no error was made in the differential diagnosis of low back pain or sciatica, and the operation was done at the correct level, then was an error made in the third question? Specifically, is this a mechanical low back pain condition and, if so, what is the syndrome (Table 17-4)?

Surgery for degenerative conditions in the lumbar spine consists of two basic types: (a) decompression surgery for nerve root compromise and (b) stabilization/fusion surgery for a painful motion segment.

There are many occasions when both surgeries (decompression and fusion) are indicated. However, if one type of surgery was carried out and the patient fails to improve, was the wrong operation performed on the basis of an incorrect preoperative diagnosis? Was encroachment surgery done when stabilization surgery was indicated (20)? This is a common error and is most often due to referred leg pain being confused for radicular leg pain; removal of a “sucker disc” (Fig. 17-9) with the result being even more instability and more back pain.

An example might be failure after laminectomy for spinal stenosis due to incomplete apophyseal decompression. Incomplete decompression of the involved nerve roots is seen in the following circumstances: missed fragment of ruptured disc material. A reasonable criticism of microdiscectomy is the potential, because of a limited surgical field, to leave behind fragments of ruptured disc.

This error will be avoided if the mobility of the root is assessed after the apparent source of compression is removed. It should be possible to displace a normal or completely decompressed nerve root at least 1 cm medially. The S1 root can normally be displaced to the midline.

Incomplete decompression may result when more than one root is involved in an apparently uni-segmental degenerative stenosis. This source of failure emphasizes the need for complete preoperative evaluation of the roots involved. The surgeon must know what roots to explore.

A decompression laminectomy for spinal stenosis is always started by the removal of a portion or the whole of one or more laminae. If this is technically difficult because of shingling or overgrowth of the laminae, it is understandable that the surgeon confine his/her attention to a midline decompression. Even though a very complete midline decompression is performed, the patient will not be helped if, as is commonly the case, he or she is suffering from both canal stenosis and concomitant lateral zone stenosis giving rise to root compression. This error is more likely to occur if the lateral zone stenosis is at a different segment from the canal stenosis.

Here again, an accurate preoperative assessment followed by a preoperative design of the procedure required will avoid this only too frequent source of error.

Sometimes a midline decompression is incomplete. It must be remembered that this operation is most frequently performed on older patients with the surgeon being understandably reluctant to carry out extensive surgery. The operation is frequently tedious, hemorrhagic, time consuming, and apparently destructive. Despite the temptation to short-circuit the operative procedure, when the
patient’s symptoms superficially appear to stem from laminar compression at one or two segments only, decompression must occur at the appropriate levels.

Macnab’s landmark article on “Negative Disc Exploration” (20) described the foraminal disc. If you are in the canal looking for a foraminal disc there is a good chance you will miss it, and the patient will wake with identical leg pain.

A small disc herniation compressing a conjoint root can not only produce a lot of sciatica, it can be a very difficult fragment to retrieve. This combination of events occurs most often at L5–S1 and requires a wide decompression, without sacrificing the facet joint, and removal of the fragment under the axilla of the root.