Although it has been accepted throughout that all patients have received adequate medical screening, occasionally patients with serious pathology or mechanical disorders unsuited to mechanical treatment are encountered during routine examination. If in the examination no position or movement can be found which reduces the presenting pain, the patient is unsuited for mechanical therapy, at least at this time.
The existence of serious pathology should be considered when the history states that there has been no apparent reason for the onset of symptoms; that the symptoms have been present for many weeks or months, and have during that time increased in intensity; and that they are constant; and the patient feels that he is gradually getting worse. On examination the pain remains exactly the same, irrespective of positions assumed or movements performed. Usually there is little loss of function if any, and postural deformity is not often seen. In addition to the examination finding, the patient often looks unwell and may complain of feeling unwell. Mechanical procedures described in this book should never be applied to patients presenting with signs and symptoms of this nature.
Saddle anaesthesia and bladder weakness are indications of compression of the fourth sacral nerve root. These symptoms occur in major disc herniation and, when present, form a definite contra-indication to manipulative procedures.
Patients who exhibit signs of extreme pain — that is, who become transfixed on movement, and freeze and immobilise the spine when palpation is attempted — are considered unsuitable for mechanical therapy, at least at this stage.
Developmental or acquired anomalies of bone structures which may lead to weakness or instability of mechanical articulations are hazards to manipulative procedures. Architectural faults should be excluded from mechanical therapy. Exceptions are minor grades of spondylolisthesis where symptoms are mild and intermittent. The presence of spondylolisthesis at a certain segment is not necessarily an indication that symptoms are forthcoming from that segment. It is seen very often indeed that pain is the result of disc derangement at a different level.
A simple clinical test may determine whether spondylolisthesis is responsible for the presenting pain, as it will often reduce or abolish pain in the presence of that condition. Place one hand across the sacrum of the standing patient and the other firmly against the abdomen. By further compressing the abdominal content while at the same time increasing pressure on the sacrum, pain in standing arising from spondylolisthesis is markedly reduced or abolished. On the other hand, pain arising from derangement of any of the lumbar discs will usually be enhanced by this procedure, and postural or dysfunctional pain remains unaffected. Thus, if pain is increased with this test the patient should be treated as for the derangement syndrome, but if pain is reduced the presence of spondylolisthesis must be investigated and the necessary precautions must be taken in the treatment.
Patients with mechanical low back pain are often advised to rest as much as possible, preferably in bed. In many instances this is inappropriate if not bad advice. The nutrition of the intervertebral discs depends entirely on osmosis, and movements of the spine are essential for the flow of fluids containing nutriments. To rest the joints of patients with mechanical low back pain often only adds to the problems of restoration of function and full rehabilitation. The only patient who should be placed on bed rest is the very acute patient with severe constant low back pain with or without sciatica whose symptoms are considerably worse during weight bearing, and in whom no movement or position can be found to reduce or centralise the pain.
In order to prevent the development of dysfunction within or about the involved intervertebral joint following derangement, regular assessment of the patient on bed rest is required and treatment must be instituted as early as possible. This is particularly important in the patient who responds very well to bed rest, because without movement this patient will become painfree but may develop a significant loss of function.
If, following reduction of derangement, all efforts at prevention of immediate recurrence are unsuccessful, it may be desirable to supply the patient with a corset for short term support and stability. Long term use of a corset is undesirable as it merely hastens the development of dysfunction.
The question of surgical intervention inevitably arises in the minds of doctors, therapists and patients alike when progress is slow or non-existent. The decision as to whether one should or should not operate must always concern the orthopaedic surgeon.
It is my experience that, in New Zealand, surgery will be performed only when conservative treatment methods have failed. This does not always include adequate mechanical therapy, but usually it has allowed adequate passage of time. Fortunately, few patients in New Zealand receive surgery for low back pain only, and the procedures of laminectomy and discectomy are reserved for patients suffering significant nerve root compression.
The difficulties surrounding the diagnostic criteria for surgical intervention are enormous. One study showed a large number of positive myelograms in lumbar spines of patients who were asymptomatic and had been admitted and X-Rayed for conditions other than low back pain.5 Thus the value of the myelogram, the good old standby relied upon by many doctors, has become somewhat suspect.
The results of surgery can also be seen to vary significantly. Randomly selected patients with low back pain, referred pain to one leg, and positive myelograms coupled with clinical signs, were divided into two groups. The patients in the one group received surgery, those in the other group not. It was found that at the end of one year ninety percent of the non-operated patients were better; that the operated patients were only better in the first two months following surgery; and that at the end of one year the results in the group that had received surgery were the same as in the group that had not been operated upon.
The final result of a disc lesion is not endangered by a three months’ waiting period before surgery is undertaken. However, a longer wait may be prejudicial as it may leave the patient with residual disability.
Fielding states that Nachemson, Rothman and Hirsch have all found that there is a clear correlation between the early return of symptoms following surgery and the formation of scar tissue. Quoting Fielding:
“Early return of symptoms usually means the formation of scarring which cannot be cured by surgery and means that the results will be poor’’.
Rothman examined sixty-eight patients who had undergone two or more unsuccessful spinal surgical interventions. He reports that seventy-five percent of the patients claimed partial or total disability. Half of the failures in multiple surgery are due to scarring or nerve root adherence. Scarring and fibrosis are associated with a high failure rate and dismal results.
It is appropriate to make clear that scarring causes dysfunction, described earlier in this book. Scarring does not necessarily have to cause problems provided it is discovered early enough and dealt with adequately in the manner suggested in previous chapters. I believe that one procedure is mandatory following surgery for lumbar disc protrusion: that is, the regular performance of one full straight-leg-raising movement at two hourly intervals. This should reduce significantly the complications of fibrosis and nerve root adherence. Just as recent scars can be stretched and lengthened by dysfunction treatment procedures, so should the prevention of inextensible scar formation be feasible by the even earlier use of the same procedures.