A SURVEY OF SURGICAL MANAGEMENT OF LUMBAR DISC PROLAPSE IN THE UNITED KINGDOM AND EIRE

1211

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TABLE II-ANNUAL TOTALS OF OPERATIONS FOR LUMBAR-DISC PROLAPSE

A SURVEY OF SURGICAL MANAGEMENT OF LUMBAR DISC PROLAPSE IN THE UNITED KINGDOM AND EIRE DAVID LE VAY M.S. Lond., F.R.C.S. CONSULTANT ORTHOPÆDIC SURGEON, WOOLWICH

A

of the

TABLE 111--OPERATIONS IN RELATION TO ANNUAL TOTAL

MEMORIAL HOSPITAL

of

survey operative Summary lumbar disc prolapse showed that almost treatment

all neurosurgeons but little more than half the orthopædic surgeons perform this operation. Most non-operating orthopædic surgeons refer their cases to neurosurgeons. Operation-rates and annual numbers of operations Over a fifth of are notably higher for neurosurgeons. 5 fewer occasions on or orthopædic surgeons operate is used more often a year. Myelography by neurosurgeons; 25% of orthopædic surgeons use it rarely, if ever. There are no striking differences in operative technique but orthopædic surgeons use hypotension and blood-transfusion far more often. Neurosurgical patients are up and about earlier but times of return to work are the same for both groups. Approximate totals are given for the numbers of patients operated on annually. It is suggested that patients may benefit if the occasional (mainly orthopædic) operators refer their cases to busier units.

less per annum. Only 1-5% did more than 40 operations and none more than 90. The average annual number was 12. The neurosurgical picture is verydifferent : only 17% did 10 operations a year or less, and the average was 30. The annual totals are shown in table 11, with extrapolation to cover those surgeons not responding to the questionary. The average total is over twice as high for neurosurgeons ; and so, though only a fifth of the relevant surgical cases or

TABLE IV-OPERATION-RATE IN DIAGNOSED CASES

INTRODUCTION

LUMBAR disc prolapse is a major personal and economic problem, but opinion on operative indications and technique has never been precisely investigated partly

because this is divided between neurosurgeons and

orthopaedic

surgeons.

I

sent

a

questionary

to

four

hundred and fifty-two fellows and members of the British Orthopaedic Association and a hundred members and some associates of the Society of British Neurological in the United Kingdom and the Republic of Ireland. Three hundred and seventy-four orthopaedic surgeons (82-3%) and sixty-eight neurosurgeons (68%)

Surgeons

replied. Sixty-seven (98-5%) of the neurosurgeons but only two hundred and seventeen (58-0%) of the orthopaedic surgeons performed the operation for lumbar-disc prolapse ; but of the two hundred and seventy-four operators, orthopaedic surgeons outnumber neurosurgeons by 3/1. Of the one hundred and fifty-seven orthopaedic surgeons who do not operate the majority (92%) refer their cases to a neurosurgeon,

while the remainder refer

another

surgeon.

orthopaedic

cases to

CLINICAL ASPECTS

Table I shows the annual number of times this operation is done by the two groups of surgeons (excluding those who do not operate). From here on, " orthopaedic surgeons " refers only to those known to do the operation. Over half (55%) of orthopaedic surgeons operate on 10 TABLE I-ANNUAL NUMBER OF OPERATIONS

population, these perform two-fifths of the operations. Looking at these figures another way, 17% of operations are done by those dealing with 10 cases or less in a year, and nearly 1 operation in 6 is done by an orthopaedic surgeon operating less than once a month. A third are done by surgeons operating 11-20 times a year; and at the top of the scale, 1 patient in 10 goes to a neurosurgeon operating 2-3 times a week (table ill). The operation-rate in diagnosed cases is shown in table iv. In deciding to operate, over 90% of orthopaedic surgeons intervene mainly on clinical grounds whereas a substantial minority (22%) of neurosurgeons prefer

1212 The indications for The totals exceed 100% operation of and because overlapping categories plural indications. Failed conservative treatment is the commonest indication; while other answers indicated that around two-thirds of all surgeons prefer not to intervene in acute episodes unless their hands are forced by severe pain or florid neurological

additional

(myelographic) evidence.

are

shown in table

TABLE VIII-TIME BEFORE MOBILISATION AND WALKING AFTER

INTERLAMINAR.SURGERY OR LAMINECTOMY

v.

presentation. RADIOLOGY

The

in both groups found

majority plain X-rays not in or localisation, though the very helpful diagnosis vote minority neurosurgical (41% and 33%) was considerable. MYELOGRAPHY

myelography (usually with 5-6 ml.‘ Myodil ’, iophendylate) is used by only a small similar percentage of both groups; frequent and routine use together account for half the neurosurgeons and a third of orthopaedic surgeons; a quarter of the orthopaedic surgeons disdain myelography altogether but the corresponding neurosurgical minority is very small. Routine

TABLE VI-SAFETY AND RELIABILITY OF MYELOGRAPHY

Myelography

is

performed

more

often where the

technique is

available; some orthopaedic surgeons dispense with a service not readily to hand. 85% of neurosurgeons had the services of

neuroradiologist, unavailable to most orthopaedic surgeons. Ordinary screening was used most often by both; but 39% of neurosurgeons--over double the proportion of orthopaedistsused television with an image intensifier. One in four of all surgeons attempted to remove the medium at the time of lumbar puncture or operation. The orthopaedist tends to rate both the safety and reliability of myelography lower than does the neurosurgeon (table vi). Removal of the dye is correlated with doubt as to its safety and reliability: for both groups, one a

i

muscles on one or both sides; two-thirds of neurosurgeons favour bilateral reflection. The groups differ only slightly in their surgical approach (table vn), a large proportion have no hard-and-fast rule. 90% of both groups remove as much disc as possible; only one in ten takes the loose fragments alone. POSTOPERATIVE MANAGEMENT

Speed of mobilisation and time before walking is permitted seems to depend on type of surgeon and degtee of surgical exposure (table vm). There is a notable difference in practice. Twice as many (53-7%) neurosurgeons as orthopxdic surgeons allow patients up within a week of interlaminar operation. 7-12 days account for a third of each group, but longer periods account for only 11-1% neurosurgeons as against 41-6% orthopaedists. 21-5% of orthopaedists but only 3-7% of neurosurgeons, delay mobilisation more than 15 days. Over 60% of neurosurgeons but only 29% of orthopaedic surgeons allow walking within 9 days of interlaminar operation; 51% of neurosurgeons but only 17-5% of orthopaedists allow walking within 9 days of laminectomy. For both operations, only orthopaedic surgeons delay more than 3 weeks. But this difference is not reflected in speed of return to work where both groups run parallel (table ix). Orthopaedists divide evenly on use of a postoperative belt, nine out of ten neurosurgeons are against. In each TABLE IX-RETURN TO WORK AFTER OPERATION

the medium for three who do not, but, of those who too risky for routine use, five remove it for every four who do not. The commonest error is considered by most surgeons to be a false-negative, from failure to demonstrate a lumbosacral prolapse because of thecal narrowing at that level. Very few surgeons favour discography. removes

think

myelography

OPERATIVE

TECHNIQUE routine hypotensive anaesthesia Orthopaedic surgeons and blood-transfusion far more often than do neurosurgeons use

(table VII). Neurosurgeons (60-6%) favour the prone position with unsupported abdomen; orthopxdists divide evenly between this and the lateral position. The small minority who prefer the crouching posture is mainly orthopaedic. Orthopaedic surgeons also divide evenly as to reflecting the paravertebral TABLE

VII-HYPOTENSION, BLOOD-TRANSFUSION, SURGICAL APPROACH

AND

group

and

half

a

extension exercises the remainder none.

use

extension,

only,

a

third flexion

SPINAL FUSION

of neurosurgeons and 60% of orthopaedic consider fusion rarely or never indicated. Neurosurgeons are most conservative and the minute group that fuses often is entirely orthopaedic. Spinal fusion in lumbar-disc surgery is one of the most disputed fields in orthopxdics; some urge routine fusion to improve functional results, others argue that trials in alternate cases show it is never required. So it is interesting that, of two hundred and twelve orthopsedic surgeons prepared to remove a prolapse if necessary and qualified to perform fusion, ninety-six find fusion rarely necessary and thirtyeight never necessary. To some extent, this lack of Over

80%

surgeons

1213

enthusiasm may be due to shortage of beds and time, economic factors, or disinclination to fuse cases complicated by neurosis or compensation. Of the indications for fusion (table x) backache is outstanding in both lists. Two-thirds of the surgeons in both groups prefer spinal fusion to be done as a separate procedure. Many orthopxdic surgeons vary their technique; conventional posterior fusion is most popular by far, followed by the Bosworth H-graft, other methods being little used.

they receive

a

neurosurgeons

tions that the areas were not

disproportionate excess of cases. Some complained they were doing those operaorthopaedic surgeons in their catchment doing. If those orthopaedic surgeons who

do not operate had done so, and at the same average annual those who do, the additional number of operations would be almost identical with the whole of the present rate as

neurosurgical tally.

also differ widely. 63% of orthopaedic surgeons operate 5% or less diagnosed cases, 58% of neurosurgeons operate on 70-100%. True, the clinical material is not the same. The orthopaedic surgeon sees patients early, at or near their homes, and conservatively keeps operation as a last resort. The neurosurgeon is often the last court of appeal; for patients with persistent symptoms, florid neurological picture, suspected tumour or sphincter involvement, to diagnose is often to operate. The orthopaedic surgeon remains closer to his patients after operation. He sees frequent recurrence, root irritation, impaired back function, and disability. He sees, perhaps more plainly than the neurosurgeon, that relief of satisfactory removal of a spaceNeurosurgeons also favour posterior fusion but gave a pain by technically lesion is not identical with social and economic occupying high place to posterior interbody fusion. there are problems of work and comthat rehabilitation, SPONDYLOLISTHESIS AND SPINAL TUMOUR It be may speculated, therefore, that if some pensation. The majority (85 % of orthopaedic surgeons and 65 % of orthopaedic surgeons operate too seldom, some neuroneurosurgeons) think that disc removal in spondylo- surgeons operate too often. But it may be more valuable listhesis is not often needed. The number of cases where for a patient to have his disc removed by a surgeon who an unsuspected tumour was found is shown in table xi. does this 2-3 times a week rather than 2-3 times a year, This gives no clue to the actual incidence of this error. even if there is some risk of an unnecessary operation. The One in four in both groups have had the experience at expert knowledge needed to remove a prolapse with least once. There is little difference in scoring; and, as minimal damage to bone, ligaments, articulations, and nerve-roots, not to miss high or lateral lesions or not to TABLE XI-CASES OF UNSUSPECTED TUMOUR incise an immature lesion or normal disc, can only be obtained by frequent performance. Too many orthopaedic surgeons cling uncertainly to the occasional operation. If they cannot or will not do more it might be wiser (and the willingness was expressed) to refer cases to a busier orthopaedic or neurosurgical colleague. The numbers involved in segregation are not excessive. If the 940 operations done by surgeons doing 10 or less operations a year were transferred to busier surgeons, the burden neurosurgeons operate twice as often, orthopaedic could readily be taken up, especially if shared more evenly surgeons are probably more frequently mistaken. than the present load transferred from orthopaedic DISCUSSION surgeons who do not operate at all. The survey response indicated widespread interest, Communication between the two surgical groups was especially by orthopaedic surgeons, and frequent dissatisfac- poor, except at a small number of regional and university tion with results. Almost half the orthopaedic surgeons centres. The questionary revealed some mutual wariness preferred not to operate, perhaps because of timidity but in this field. An eminent orthopaedic surgeon wrote: mainly because they consider disc removal is not an "It is well known that surgeons overoperate neurological intrinsically orthopaedic procedure; surgeons opening the for discs". An equally eminent neurosurgeon commented: spine must be able to deal with any lesion encountered. " how to deal do not know Many orthopaedic surgeons For most who did operate the intervention was a major with disc lesions ... I do not think these should be the one, to be treated with respect, hence the far commoner exclusive province of neurosurgeons but most neurouse of hypotension and transfusion. Neurosurgeons are better equipped by training to deal with found it the lighter relief of their work, though numerically surgeons them ". The two views are really complementary. As the irksome. Nevertheless, three-quarters of all operators are continued: " Unless the orthopaedic orthopaedic and they do well over half of all operations. orthopaedic surgeon and competently treats discs surgically The average annual number for these is only 12.4 against surgeon regularly he will overtreat his patients conservatively; orthopaedic 30-2 for neurosurgeons. Of every ten operating orthoshould be trained to provide a complete range of paedic surgeons, five deal with 10 or fewer patients a year, surgeons treatment". whereas only a handful of neurosurgeons operate at the treatment, including surgical This survey was made possible by a research grant from the South lower rates. East Metropolitan Regional Hospital Board. I thank the many Logistics are important here. Neurosurgical units are orthopxdic and neurosurgical colleagues who took the time and regionally organised, with disc surgery routine work, and trouble to complete a lengthy questionary and Mrs. Pat Clark for cases are also referred by nonoperating orthopaedists, so secretarial assistance. TABLE X-INDICATIONS FOR FUSION

Operation-rates

on