1. At the present stage of our experience, when 150 patients have been analysed over a period of five years, the conclusion has been reached that anterior interbody fusion in the lower lumbar spine is a procedure which should be added to our surgical armamentarium for use in selected cases. 2. Patients suffering from chronic intervertebral disc degeneration whose main symptoms are recurrent incapacitating backache derive the most benefit from this procedure. 3. When used as a salvage operation in patients who have had previous unsuccessful laminectomy or posterior fusion, good results can be expected. 4. In patients with spondylolisthesis anterior interbody fusion should be confined to cases in which the vertebral bodies have not slipped forward more than one-third

Twenty-two cases of paraplegia complicating injury of the cervical column have been reviewed. The vertebral injury may be due to flexion or hyperextension violence. Flexion injury—There are three types of flexion injury: 1) dislocation; 2) compression fracture of a vertebral body; 3) acute retropulsion of an intervertebral disc. Evidence is presented in support of the view that disc protrusion is the cause of the cord lesion when there is no radiographic evidence of bone injury, and in some cases at least when there is a compression fracture. Treatment is discussed and the indications for caliper traction and laminectomy are presented. Hyperextension injurv—There are two types of hyperextension injury: 1) dislocation; 2) injury to arthritic spines. Hyperextension injury of an arthritic spine is the usual cause of paraplegia in patients over fifty years of age. The mechanism of hyperextension injury is described. The possible causes of spinal cord injury, and its treatment, are discussed

Our aim was to judge the influence of preoperative psychological disturbance on the outcome of lumbar discectomy. We evaluated 66 patients, before and after operation, using a self-administered questionnaire. Disability was assessed using the Oswestry disability index and psychological disturbance the Distress and Risk Assessment Method (DRAM) score. Patients were classified as normal, at risk or distressed, and the outcome of surgery in the three groups was compared at a follow-up of six months. The mean self-reported preoperative disability was significantly higher in those with psychological disturbance. A total of 54 patients (82%) returned completed postoperative questionnaires. Postoperative disability scores at six months were not significantly different in the three risk groups. Psychological disturbance improved after surgery. Our study suggests that the early outcome of lumbar discectomy is not affected by preoperative psychological disturbance. We conclude that a patient with a symptomatic prolapsed intervertebral disc should not be denied surgery on the basis of preoperative psychological assessment

1. Thirty-five children suffering from a mild illness with narrowing of an intervertebral disc have been studied. 2. Backache was the presenting symptom in only a small proportion of children, vague aching in the legs being almost as common at the onset. 3. Stiffness of the affected part of the spine is often present, but there may be no abnormal signs in the back. 4. Radiographs reveal a narrowed disc space with adjacent bony changes. There is usually progressive narrowing of the disc space which may go on to fusion of the affected vertebrae. Less commonly there is reconstitution of the affected disc. 5. The symptoms and signs quickly subside with immobilisation in recumbency and this treatment should be continued until the blood sedimentation rate returns to normal. 6. Adults who have suffered from discitis in childhood are probably more prone to develop backache. 7. The etiology remains uncertain

We have studied the intervertebral discs adjacent to fractured vertebral bodies using MRI in 63 patients at a minimum of 18 months after injury. There were 75 thoracolumbar fractures of which 26 were treated conservatively and 37 by posterior reduction and fusion with an AO internal fixator. We identified six different types of disc using criteria based on the morphology and the intensity of the MRI signal. The inter- and intraobserver variability of this system was good. Most of the discs showed predominantly morphological changes with no variation in signal intensity. Some disc types were associated with progressive kyphosis in patients treated conservatively. In those managed by operation, recurrent kyphosis appeared to result from creeping of the disc in the central depression of the bony endplate rather than from disc degeneration. Changes in the disc space after posterior fixation should not be seen as a form of chronic instability but as a redistribution of the disc tissue in the changed morphology of the space after fractures of the endplate

The afferent pathways of discogenic low-back pain have not been fully investigated. We hypothesised that this pain was transmitted mainly by sympathetic afferent fibres in the L2 nerve root, and in 33 patients we used selective local anaesthesia of this nerve. Low-back pain disappeared or significantly decreased in all patients after the injection. Needle insertion provoked pain which radiated to the low back in 23 patients and the area of skin hypoalgesia produced included the area of pre-existing pain in all but one. None of the nine patients with related sciatica had relief of that component of their symptoms. Our findings show that the main afferent pathways of pain from the lower intervertebral discs are through the L2 spinal nerve root, presumably via sympathetic afferents from the sinuvertebral nerves. Discogenic low-back pain should be regarded as a visceral pain in respect of its neural pathways. Infiltration of the L2 nerve is a useful diagnostic test and also has some therapeutic value

Thirteen patients, aged 7 to 45 years, have been treated for atypical forms of spinal tuberculosis at the Neurological Centres at Benghazi and Lahore. All presented with signs and symptoms of compression of the spinal cord or cauda equina, ranging from paraesthesiae and increasing weakness to paraplegia and loss of sphincter control. None of them showed visible or palpable spinal deformity nor the typical radiographic appearance of destruction of the intervertebral disc and the two adjoining vertebral bodies. These atypical cases fell into two well-defined groups: those with involvement of the neural arch only, with associated intraspinal cold abscesses, and those with involvement of a single vertebral body, resulting in its collapse and a radiographic appearance similar to that in secondary carcinoma of the vertebral body. The correct treatment in these two groups was diametrically opposed. Tuberculous disease of the neural arch was best traced by laminectomy; concertina collapse of a single vertebral body required cost-transversectomy and resection of the transverse process, the pedicle, and the portion of the vertebral body that was encroaching on the spinal canal

Aims

The aims of this study were to measure sagittal standing and sitting lumbar-pelvic-femoral alignment in patients before and following total hip arthroplasty (THA), and to consider what preoperative factors may influence a change in postoperative pelvic position.

1. One hundred and twenty cervical spines removed at routine necropsy from elderly patients dying in a general hospital have been examined. 2. There was some degree of degeneration of intervertebral discs in 110 cases–in forty-six this was severe. 3. Degenerative disc disease was found at an earlier age in men; mild damage preceded severe degeneration and collapse by about a decade. 4. Discs of the lower spine were most frequently and most severely affected. 5. Alterations of the normal cervical lordosis were produced by disc disease in thirty-two cases. 6. Osteoarthritis of the apophysial joints was found in seventy-eight, and by contrast to disc degeneration was commonest in the mid-cervical and upper cervical regions. In eighteen it was severe. 7. Degeneration and scarring of nerve roots was frequently associated with diseased discs; apophysial joint arthritis was found to be an important additional factor when it occurred in the lower cervical region. 8. No nerve root changes could be attributed to ischaemia resulting from narrowing or distortion of the vertebral arteries. 9. Cystic arachnoidal diverticula which excavate the posterior root ganglia were found in thirty-six cases

1. In this investigation one was impressed by the close relationship that exists between the constituent parts of the intervertebral discs and the surrounding supporting structures. The part that is responsible for the maintenance of a co-ordinated balance between these structures, and hence for the effective mechanism of the spine, is the nucleus pulposus. 2. The cruciate arrangement of the annulus fibrosus is related to spinal function, and the angle of intersection of consecutive laminae of the annulus fibrosus is more or less constant. 3. In the Bantu it was found that the interspinous and supraspinous ligaments differ from the classical descriptions given in anatomical text-books. 4. The movements taking place between two vertebrae are comparable to those of a rocking-horse. 5. Narrowing of a disc is a progressive process which is the result of the disturbances in the balance between the components of the force to which a disc is subjected. The process is initiated by the loss of nucleus pulposus content. 6. With the approximation of two adjacent vertebrae a disturbance of the relations of the structures in the intervertebral foramen was noted. On anatomical grounds, when a disc is narrowed it appears that the most likely structures to cause pressure on the nerve root are not the disc itself, but the superior articular processes with their overlying ligamentum flavum

Objectives

Degenerative disc disease (DDD) and osteoarthritis (OA) are relatively frequent causes of disability amongst the elderly; they constitute serious socioeconomic costs and significantly impair quality of life. Previous studies to date have found that aggrecan variable number of tandem repeats (VNTR) contributes both to DDD and OA. However, current data are not consistent across studies. The purpose of this study was to evaluate systematically the relationship between aggrecan VNTR, and DDD and/or OA.

We have used an experimental model employing the bent tail of rats to investigate the effects of mechanical forces on bones and joints. Mechanical strain could be applied to the bones and joints of the tail without direct surgical exposure or the application of pins and wires. The intervertebral disc showed stretched annular lamellae on the convex side, while the annulus fibrosus on the concave side was pinched between the inner corners of the vertebral epiphysis. In young rats with an active growth plate, a transverse fissure appeared at the level of the hypertrophic cell layer or the primary metaphyseal trabecular zone. Metaphyseal and epiphyseal trabeculae on the compressed side were thicker and more dense than those of the distracted part of the vertebra. In growing animals, morphometric analysis of hemiepiphyseal and hemimetaphyseal areas, and the corresponding trabecular bone density, showed significant differences between the compressed and distracted sides. No differences were observed in adult rats. We found no significant differences in osteoclast number between compressed and distracted sides in either age group. Our results provide quantitative evidence of the working of ‘Wolff’s law’. The differences in trabecular density are examples of remodelling by osteoclasts and osteoblasts; our finding of no significant difference in osteoclast numbers between the hemiepiphyses in the experimental and control groups suggests that the response of living bone to altered strain is mediated by osteoblasts

We investigated the distribution of compressive ‘stress’ within cadaver intervertebral discs, using a pressure transducer mounted in a 1.3 mm diameter needle. The needle was pulled along the midsagittal diameter of a lumbar disc with the face of the transducer either vertical or horizontal while the disc was subjected to a constant compressive force. The resulting ‘stress profiles’ were analysed in order to characterise the distribution of vertical and horizontal compressive stress within each disc. A total of 87 discs from subjects aged between 16 and 87 years was examined. Our results showed that age-related degenerative changes reduced the diameter of the central hydrostatic region of each disc (the ‘functional nucleus’) by approximately 50%, and the pressure within this region fell by 30%. The width of the functional annulus increased by 80% and the height of compressive ‘stress peaks’ within it by 160%. The effects of age and degeneration were greater at L4/L5 than at L2/L3, and the posterior annulus was affected more than the anterior. Age and degeneration were themselves closely related, but the stage of degeneration had the greater effect on stress distributions. We suggest that structural changes within the annulus and endplate lead to a transfer of load from the nucleus to the posterior annulus. High ‘stress’ concentrations within the annulus may cause pain, and lead to further disruption

1. In this series of posterior onlay grafting with fresh autogenous bone and without internal fixation, in the treatment of non-infective structural lesions in the lumbo-sacral area, 71 per cent of the patients were relieved of their symptoms, but bony fusion was obtained in only 60 per cent. 2. It is probable that with this technique twelve weeks' immobilisation in a plaster bed is required. 3. Some failures are ascribed to the use of an insufficient quantity of bone or to poor apposition of the graft to its bed. 4. It is evident that the more vertebrae one attempts to fuse the more difficult it is to succeed. When the diseased area is successfully fused but an unnecessarily long graft has been used, a pseudarthrosis above the level of the pre-operative pathology may be the cause of persisting backache. For these reasons we believe that one should not attempt to graft more vertebrae than is necessary to stabilise the local lesion. 5. The complication rate, particularly from deep vein thrombosis, was high. This major complication could perhaps be overcome by using banked bone. 6. The indications for the operation are assessed as follows. It should be done for low back pain only when there is a definite diagnosis and a limited extent of structural pathology; one can then expect excellent results when successful fusion is achieved and also an appreciably high proportion of satisfied patients even when bony fusion has not been obtained, presumably because there is a fibrous union strong enough to stabilise the affected spine. It is inadvisable to undertake lumbar-lumbo-sacral fusion for intervertebral disc degeneration when there are more than three adjacent vertebrae involved, and in any case operation should be confined to the indicated extent

We obtained intervertebral discs with cartilage endplates and underlying cancellous bone at operation from patients with degenerative disc disease and then used immunohistochemical techniques to localise the nerves and nerve endings in the specimens. We used antibodies for the ubiquitous neuronal protein gene product 9.5 (PGP 9.5). Immunoreactivity to neuropeptide Y was used to identify autonomic nerves and calcitonin gene-related peptide (CGRP) and substance P to identify sensory nerves. Blood vessels were identified by immunoreactivity with platelet-endothelial cell-adhesion molecule (CD31; PECAM). In a control group with no known history of chronic back pain, nerve fibres immunoreactive to PGP 9.5 and neuropeptide Y were most closely related to blood vessels, with occasional substance P and CGRP immunoreactivity. In patients with severe back pain and markedly reduced disc height, proliferation of blood vessels and accompanying nerve fibres was observed in the endplate region and underlying vertebral bodies. Many of these nerves were immunoreactive to substance P or CGRP, and in addition, substance P- and CGRP-immunoreactive nociceptors were seen unrelated to blood vessels. Quantification by image analysis showed a marked increase in CGRP-containing sensory nerve fibres compared with normal control subjects. We speculate that a chemotactic response to products of disc breakdown is responsible for the proliferation of vascularity and CGRP-containing sensory nerves found in the endplate region and vertebral body adjacent to degenerate discs. The neuropeptides substance P and CGRP have potent vasodilatory as well as pain-transmitting effects. The increase in sensory nerve endings suggests increase in blood flow, perhaps as an attempt to augment the nutrition of the degenerate disc. The increase in the density of sensory nerves, and the presence of endplate cartilage defects, strongly suggest that the endplates and vertebral bodies are sources of pain; this may explain the severe pain on movement experienced by some patients with degenerative disc disease

Aims

The aim of this study was to determine the influence of developmental spinal stenosis (DSS) on the risk of re-operation at an adjacent level.

Infection after intradiscal injections has been recognised as a distinct entity, but discitis after discography has often been attributed to an aseptic process or a chemical reaction to the contrast material. We examined the hypothesis that discitis after discography is always due to infection, and report a clinical review and an experimental study. Part I. We reviewed the case records and radiographs of 432 patients who had undergone lumbar discography. When an 18-gauge needle without a stilette had been used, discitis was diagnosed in 2.7% of 222 patients but stiletted needles and a two-needle technique at each level reduced the incidence to 0.7%. Seven patients with discitis after discography had undergone anterior discectomy and fusion; in them the histopathological findings were of a chronic inflammatory response. Bacteria were isolated from the discs of three of the four patients who had open biopsy less than six weeks from the time of discography. These findings suggest that bacteria were initiators rather than promoters of the response. Part II. Multiple level lumbar discography was carried out in mature sheep, injecting contrast material with or without various concentrations of bacteria. Radiographs were taken and the discs and end-plates were examined histologically and cultured for bacteria at intervals after injection. None of the controls showed any evidence of discitis but all sheep injected with bacteria had typical radiological and histopathological changes by six weeks, though cultures were almost all negative. However, at one and two weeks after injection, but usually not after three weeks, bacteria could be isolated. We suggest that all cases of discitis after discography are initiated by infection, and that a very strict aseptic technique should be used for all injections into intervertebral discs