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SPONDYLOLISTHESIS
791 SPONDYLOLISTHESIS PROFESSOR
HARRIS’S
HUNTERIAN LECTURE
ON April 29, at the Royal College of Surgeons, Prof. R. I. HARRIS, of Toronto, received the honorary fellowship of the college and before a large audience delivered a Hunterian lecture on Spondylolisthesis. Professor Harris remarked that among the numerous causes of low-back pain spondylolisthesis is of special interest because of its problems of setiology, diagnosis, Patients with symptoms are only a and treatment. fraction of those who possess the essential vertebral defect. Apart from Friberg’s monograph and Meyerding’s paper, most articles deal with small numbers of cases. The essential defect in the neural arch between the superior and inferior articular facets is well known and occurs most often in the 5th lumbar vertebra. The defect produces an unstable spinal column and allows the body of the deficient vertebra to slip forward, carrying with it the superimposed spinal column. The small posterior fragment maintains its normal relationship to the subjacent vertebra. The defect may be found without any anterior displacement of the body (spondylolysis). In such cases the defect may be unilateral or bilateral, and is difficult to detect without oblique radiographs of the spine. Rarely anterior displacement of the 5th lumbar vertebra on the sacrum may take place as a result of injury to, or a deficiency of, the superior articular facet of the sacrum. In such cases the whole of the 5th lumbar vertebra is displaced forward. _ETIOLOG Y
Despite much work, little is known of the aetiology of the neural-arch defect. It has commonly been supposed to result from deficient fusion of the centres of ossification in the neural arch. The work of Willis and of Grant has shown that the incidence of these neural-arch defects in adult cadavers is 5%. If the defect is a developmental anomaly, one would expect a similar incidence in foetuses. Batts, however, examined 200 fcetuses without finding any defect in the 5th neural arch. It has been suggestedthat the lesion might result from a hyperextension injury The pars interarticularis is then sustained at birth. bony, and if the lesion were produced by fracture at this site callus formation would be expected ; this has never been reported. The same criticism applies to the theory that trauma sustained in adult life is the aetiological factor. Notwithstanding lack of positive evidence, the lesion probably arises as a result of deficient ossification, the nature of which is still unknown. Trauma, though it may not cause - the neural-arch defect, probably precipitates the anterior dislocation that later occurs gradually. Most patients relate the onset of their symptoms to some specific injury. Of 100 patients, 16 described a sudden hyperextension strain and 39 some other kind of injury, generally a fall on to the buttocks ; in the remaining 45 there was no history of injury. SYMPTOMS
AND
SIGNS
The clinical picture has two main features-pain and deformity. Both arise from the instability of the spine. The pain is of two types. The first type, due to instability alone, is felt in the low lumbar region ; it is aggravated by weight-bearing and activity, and is relieved by rest. The second type of pain, due to root-pressure, may arise from a prolapse of the lumbosacral disc, causing pain in the lst sacral area, or from compression of the 5th lumbar roots by narrowing of the intervertebral foramina. The former root symptoms are usually unilateral and the latter bilateral. The deformity in spondylolisthesis is produced by the anterior displacement of the vertebra and superimposed spinal column and by compensatory changes that follow. In the case of the 5th lumbar vertebra the spinous process
remains in situ, producing a step. between the 4th and 5th spinous processes which can be detected clinically. In order to maintain the erect posture in the presence of marked anterior displacement, there is an increase in the lumbar lordosis, and at the same time a backward rotation of the pelvis which brings the sacrum more vertical. Normally the anterior superior spines lie at a lower level than the posterior superior spines ; in some cases of spondylolisthesis this relationship is reversed. As a secondary effect of backward pelvic rotation, there may be limitation of extension of the hip-joint. The patient then adopts a peculiar stance, either with slight flexion of the hips and the trunk leaning forward, or with the trunk erect and the hips and knees slightly flexed. Rarely there is an asymmetrical degree of slipping ; and then lumbar scoliosis is added to the other deformities. TREATMENT
The condition may be treated conservatively by means of a spinal support, or surgically by spinal fusion. It requires nice judgment to select cases for operation, but in the main it may be said that fusion is recommended for the young and for patients with severe symptoms. Correction of severe displacement may be attempted before fusion, by skeletal traction applied to the lower femora and counter-traction by means of a " vest " fastened to the chest with ’Mastisol’ and to the head of the bed by shoulder-straps. Replacement of the sacrum under the lumbar spine is effected by forward skeletal traction through each anterior superior spine. Satisfactory correction was obtained in the 4 cases treated in this way. Professor Harris roundly condemned anterior fusion by the abdominal route. Such a graft contravenes the general principles of bone-grafting in that it has to cross the relatively avascular area of the intervertebral disc. Moreover the approach does not allow for exploration of possible causes of root-pressure. The only patient so treated subsequently developed intestinal obstruction and- a ventral hernia, while the graft fractured. Satisfactory posterior spinal fusion can be obtained in a high proportion of cases only if the graft is massive, the anchorage to the sacrum is large and secure, the graft does not extend beyond the vertebra. above the lesion, and adequate postoperative recumbency is maintained for at least four months. Professor Harris uses twin tibial grafts supplemented with cancellous chips. The lower end of the cortical grafts are slotted into windows cut into the posterior aspect of the sacrum, and above this level are secured to each other and to the spinous processes by stainless-steel wire. Extension of the grafts to the 2nd vertebra above the lesion has led to fracture of the graft and is now avoided. Plaster-beds for recumbency have been abandoned in favour of Stryker frames, which can be turned with great ease. A brace is worn for the first six months of ambulation. Of the 100 patients reviewed, 67 were treated by operation, and in 56 of these the results were satisfactory. ’
HONOURS FOR THE KING’S DOCTORS
HONOURS for the following doctors who attended the King during his recent illness are announced: G.C.V.O.
Sir MAURICE CASSIDY, K.C.V.O., C.B., M.D. Camb., F.R.C.P. Sir THOMAS DUNHILL, K.C.V.O., C.M.G., M.D. Melb., hon. F.R.C.S.,
F.R.A.C.S.
-
Sir MORTON SMART, K.C.V.O., D.S.O.,
M.D.
Edin.
K.C.V.O.
HORACE EVANS, M.D. Lond., F.R.C.P. JAMES PATERSON Ross, M.S. Lond., F.R.C.S. M.V.O.
CEDRIC JAMES LONGLAND, M.B. Lond., F.R.C.S. ALEXANDER JOHNSTON SLESSOR, M.B. Aberd., F.R.C.S. The appointment of Professor Learmonth as n.c.v.o. and of Dr. John Gillies as c.v.o. was announced in March.
HARRIS’S
HUNTERIAN LECTURE
ON April 29, at the Royal College of Surgeons, Prof. R. I. HARRIS, of Toronto, received the honorary fellowship of the college and before a large audience delivered a Hunterian lecture on Spondylolisthesis. Professor Harris remarked that among the numerous causes of low-back pain spondylolisthesis is of special interest because of its problems of setiology, diagnosis, Patients with symptoms are only a and treatment. fraction of those who possess the essential vertebral defect. Apart from Friberg’s monograph and Meyerding’s paper, most articles deal with small numbers of cases. The essential defect in the neural arch between the superior and inferior articular facets is well known and occurs most often in the 5th lumbar vertebra. The defect produces an unstable spinal column and allows the body of the deficient vertebra to slip forward, carrying with it the superimposed spinal column. The small posterior fragment maintains its normal relationship to the subjacent vertebra. The defect may be found without any anterior displacement of the body (spondylolysis). In such cases the defect may be unilateral or bilateral, and is difficult to detect without oblique radiographs of the spine. Rarely anterior displacement of the 5th lumbar vertebra on the sacrum may take place as a result of injury to, or a deficiency of, the superior articular facet of the sacrum. In such cases the whole of the 5th lumbar vertebra is displaced forward. _ETIOLOG Y
Despite much work, little is known of the aetiology of the neural-arch defect. It has commonly been supposed to result from deficient fusion of the centres of ossification in the neural arch. The work of Willis and of Grant has shown that the incidence of these neural-arch defects in adult cadavers is 5%. If the defect is a developmental anomaly, one would expect a similar incidence in foetuses. Batts, however, examined 200 fcetuses without finding any defect in the 5th neural arch. It has been suggestedthat the lesion might result from a hyperextension injury The pars interarticularis is then sustained at birth. bony, and if the lesion were produced by fracture at this site callus formation would be expected ; this has never been reported. The same criticism applies to the theory that trauma sustained in adult life is the aetiological factor. Notwithstanding lack of positive evidence, the lesion probably arises as a result of deficient ossification, the nature of which is still unknown. Trauma, though it may not cause - the neural-arch defect, probably precipitates the anterior dislocation that later occurs gradually. Most patients relate the onset of their symptoms to some specific injury. Of 100 patients, 16 described a sudden hyperextension strain and 39 some other kind of injury, generally a fall on to the buttocks ; in the remaining 45 there was no history of injury. SYMPTOMS
AND
SIGNS
The clinical picture has two main features-pain and deformity. Both arise from the instability of the spine. The pain is of two types. The first type, due to instability alone, is felt in the low lumbar region ; it is aggravated by weight-bearing and activity, and is relieved by rest. The second type of pain, due to root-pressure, may arise from a prolapse of the lumbosacral disc, causing pain in the lst sacral area, or from compression of the 5th lumbar roots by narrowing of the intervertebral foramina. The former root symptoms are usually unilateral and the latter bilateral. The deformity in spondylolisthesis is produced by the anterior displacement of the vertebra and superimposed spinal column and by compensatory changes that follow. In the case of the 5th lumbar vertebra the spinous process
remains in situ, producing a step. between the 4th and 5th spinous processes which can be detected clinically. In order to maintain the erect posture in the presence of marked anterior displacement, there is an increase in the lumbar lordosis, and at the same time a backward rotation of the pelvis which brings the sacrum more vertical. Normally the anterior superior spines lie at a lower level than the posterior superior spines ; in some cases of spondylolisthesis this relationship is reversed. As a secondary effect of backward pelvic rotation, there may be limitation of extension of the hip-joint. The patient then adopts a peculiar stance, either with slight flexion of the hips and the trunk leaning forward, or with the trunk erect and the hips and knees slightly flexed. Rarely there is an asymmetrical degree of slipping ; and then lumbar scoliosis is added to the other deformities. TREATMENT
The condition may be treated conservatively by means of a spinal support, or surgically by spinal fusion. It requires nice judgment to select cases for operation, but in the main it may be said that fusion is recommended for the young and for patients with severe symptoms. Correction of severe displacement may be attempted before fusion, by skeletal traction applied to the lower femora and counter-traction by means of a " vest " fastened to the chest with ’Mastisol’ and to the head of the bed by shoulder-straps. Replacement of the sacrum under the lumbar spine is effected by forward skeletal traction through each anterior superior spine. Satisfactory correction was obtained in the 4 cases treated in this way. Professor Harris roundly condemned anterior fusion by the abdominal route. Such a graft contravenes the general principles of bone-grafting in that it has to cross the relatively avascular area of the intervertebral disc. Moreover the approach does not allow for exploration of possible causes of root-pressure. The only patient so treated subsequently developed intestinal obstruction and- a ventral hernia, while the graft fractured. Satisfactory posterior spinal fusion can be obtained in a high proportion of cases only if the graft is massive, the anchorage to the sacrum is large and secure, the graft does not extend beyond the vertebra. above the lesion, and adequate postoperative recumbency is maintained for at least four months. Professor Harris uses twin tibial grafts supplemented with cancellous chips. The lower end of the cortical grafts are slotted into windows cut into the posterior aspect of the sacrum, and above this level are secured to each other and to the spinous processes by stainless-steel wire. Extension of the grafts to the 2nd vertebra above the lesion has led to fracture of the graft and is now avoided. Plaster-beds for recumbency have been abandoned in favour of Stryker frames, which can be turned with great ease. A brace is worn for the first six months of ambulation. Of the 100 patients reviewed, 67 were treated by operation, and in 56 of these the results were satisfactory. ’
HONOURS FOR THE KING’S DOCTORS
HONOURS for the following doctors who attended the King during his recent illness are announced: G.C.V.O.
Sir MAURICE CASSIDY, K.C.V.O., C.B., M.D. Camb., F.R.C.P. Sir THOMAS DUNHILL, K.C.V.O., C.M.G., M.D. Melb., hon. F.R.C.S.,
F.R.A.C.S.
-
Sir MORTON SMART, K.C.V.O., D.S.O.,
M.D.
Edin.
K.C.V.O.
HORACE EVANS, M.D. Lond., F.R.C.P. JAMES PATERSON Ross, M.S. Lond., F.R.C.S. M.V.O.
CEDRIC JAMES LONGLAND, M.B. Lond., F.R.C.S. ALEXANDER JOHNSTON SLESSOR, M.B. Aberd., F.R.C.S. The appointment of Professor Learmonth as n.c.v.o. and of Dr. John Gillies as c.v.o. was announced in March.