Annals of the Royal College of Suirgeons of England
Some aspects in childhood
of
(1975) ol" 57
orthopaedic surgery
G C Lloyd-Roberts Mch FRCS Orthopaedic Surgeon, Hospital for Sick Children, Great Ormond Street, and St George's Hospital, London
Summary The aetiological role of immunodeficiency in acute septic arthritis of the hip in infancy, the management of the condition after the acute infection has subsided, and the special hazards of infection in the region of the hip joint in the older child are discussed. The principles of treatment of congenital dislocation of the hip are examined in relation to the maintenance of acetabular growth potential. The factors determining the outcome of treatment in Perthes' disease are discussed and a comparison of the resuilt in a series of cases treated by femoral osteotomy with those in untreated controls is presented. Introduction This lecture is given in tribute to the memory of a great surgeon. His contributions to the development and practice of orthopaedic surgery are well known. He had a special concern for the care of children afflicted by deformity and disease of the musculoskeletal system and I propose, therefore, in his honour, to discuss certain aspects of three conditions involving the hip joints of children-namely, acute septic arthritis, acetabular development in congenital dislocation, and the treatment of Legg-Perthes' disease.
Acute septic arthritis Influence of immunodeficiency First let us consider the infantile pattern. We are all familiar with the way in which an apparently severe generalized infection in an infant may be deceiving because of the lack of consitutional response. Indeed, we may not suspect that the hip is involved until some oedema of the thigh prompts a radiograph, which may disclose damage and dislocation of the femoral head. We should of course have recognized this sooner, decompressed the joint, and immobilized it in abduction to prevent dislocation. In practice, however, this situation is far from uncommon and when it occurs we console ourselves by commenting once again on the treacherous nature of this condition and the subdued signs of infection, both local and constitutional, which characterize it. We have been interested in this phenomenon at The Hospital for Sick Children for some years-an interest which has recently gained some impetus from the rapidly developing field of immunology. In association with Kuo, Soothill, and Orme' I have investigated the immunological status of these children, some during the initial infection and others in later childhood and adolescence. The first patients to be studied were 3 infants who were investigated during the
Robert Jones Lecture delivered on igth September 1974
26
G C Lloyd-Roberts
course of their acute illness. Two were shown to be suffering from hypogammaglobulinaemia and subsequently developed chronic granulomatous disease from which they died. The third displayed consistently low plasma IgA readings. This was an encouraging start, but we wondered whether the immunodeficiency might be a transitory phenomenon associated with a delay in maturation of immune mechanisms, particularly if the babies were premature. We therefore decided to study the immunological status of I 2 children who had suffered from septic arthritis in infancy. Six (Table I) had unquestionably low IgA readings and in 2 others these were at the lowest limit of normal. It is significant that 2 of the 6 were aged i 5 years or over. Certain implications arise from these observations. First it seems that some children, because of deficiency of their immune mechanism, are particularly at risk to neonatal infection and when so affected respond abnormally to infection. This deficiency may be transitory or persistent and accounts for the subdued clinical response. Furthermore, the extent to which bone destruction proceeds may well be related to the degree of immunodeficiency. Thus of Io children with affected hips, 6 suffered complete destruction of the femoral head, of whom 5 had evidence TABLE I Six children with septic arthritis in infancy and low plasma IgA levels on review Age
Age at onset
Premature
Culture
(years)
(days) 27 35 21
I8o II
I4
at
revziew
Yes
Yes Yes
Staphylococcus Staphylococcus
Staphylococcus Staphylococcus Staphylococcus Staphylococcus
Ifi
15 9 3 I2 II
of immunodeficiency. Of the remaining 4 with partial destruction, only i was immunodeficient. Lastly, persisting immunodeficiency may have an adverse effect when, at a subsequent operation, an attempt is made to repair the damage more than a year after the initial infection has been brought under control. Of I8 such elective operations, 6 were complicated by postoperative wound infection due, in all probability, to persisting immunodeficiency. This may even occur spontaneously without further operation in such patients.
Management after acute infection has It is essential to recognize subsided that the radiograph may be misleading in that apparent bone destruction may be no more than a reflection of decalcification caused by the infection. We may assume too readily that the femoral component is destroyed when in fact it is still present though translucent. This concept is best illustrated by studying knee joints similarly affected. One femoral condyle may at first appear to be absent, but subsequently it becomes apparent that, although damaged, it has remained substantially intact2. Clinical examination of such a knee will resolve the dilemma, though arthrography will be confirmatory. The condyle is palpable and the knee retains a degree of movement and stability which would be improbable if the condyle was indeed destroyed. The same principles may be applied to the hip, though less readily. Stability may be tested clinically, and arthrography may be helpful in spite of intra-articular adhesions. In practice, however, only exploration will establish the degree to which the joint is damaged and indicate the measures needed to repair or alleviate the situation. One of three alternatives is likely to be present. First and most favourable is a pseudarthrosis within the femoral neck. Fixation, grafting,
Some aspects of orthopaedic surgery in childhood and osteotomy will restore virtual normality provided that operation is undertaken before weight-bearing causes displacement at the weakened area. Secondly, we may find that the femoral head, while maintaining continuity with the neck, has dislocated. Reduction is indicated. Lastly, a segment of the neclk may be absent and the femoral head either destroyed or ankylosed within the acetabulum. Repair is not possible, but in the young child the trochanter may be placed within the acetabulum, the glutei advanced, and a subtrochanteric osteotomy performed. In the older child a two-stage compression arthrodesis between the trochanter and the pelvis seems the most appropriate course of action.
Septic arthritis in the older child I wish to emphasize the dangerous relationship which exists between osteomyelitis of the trochanteric region and ischaemic necrosis of the femoral head. This ischaemia is apparently due to occlusion of nutrient vessels by a sympathetic effusion within the hip joint. If the infection should then spread to the joint its effect on the ischaemic femoral epiphysis is likely to be devastating. In a recent review of such patients Kemp and P3 have emphasized this hazard and advocated urgent decompression of the bone and joint cavity as soon as the diagnosis is made. Whatever the virtue of an expectant attitude to osteomyelitis elsewhere, immediate operation seems indicated in this situation. Acetabular development in congenital dislocation It is difficult to select a topic for discussion in a condition about which there remains so much uncertainty and so much contention. Nevertheless, I have decided to discuss acetabtular growth potential under different circumstances. The successful outcome of
27
treatment in congenital dislocation of the hip
depends upon congruous reduction and satisfactory development of the acetabulum as growth proceeds. No one will disagree with the need for congruous reduction, but considerable uncertainty persists about acetabular potential at different ages and in relation to unilateral and bilateral displacement. In this discussion I will deal with complete dislocation only, for in persistent primary subluxation pressure of the head upon the growing lip of the acetabulum so prejudices acetabular development that some type of acetabular reconstruction is usually necessary. In dislocation, however, acetabular growth potential is preserved for a surprisingly long time provided that those conditions which are present in the normal child are restored and maintained. The essentials are that congruous reduction should be obtained in the position of weight-bearing as soon as possible and that the period of immobilization should be reduced to the minimum. This implies that we should aim to shorten the period between diagnosis and weight-bearing in the normal erect position so far as we can. It is important to emnphasize congruity in the weight-bearing position because it is only then that we expose the acetabulum to the normal growth stimulus. Harris, Gallien, and I4 have recently reviewed acetabular development in 85 dislocated hips in 72 children first admitted over the age of i year (average 2). All were over Io (average I2.4) at the time of assessment. Our purpose was to test the validity of the hvpothesis that the application of these principles will, in general, result in satisfactory acetabular development and so obviate the need for reconstructive operations upon it. Four methods of treatment were used: i) Manipulation under anaesthetic; hyperabduction plaster; Dennis Browne splint (I2 hips).
28
G C Lloyd-Roberts
2) Traction; abduction plaster; Dennis Age and quality of congruity in the weightBrowne splint (i 6 hips). bearing position Provided such congruity was obtained before the age of 42 delay did 3) As in Group 2 + femoral osteotomy not seem to prejudice the result. However, I (2 hips). failure to obtain congruity or, having ob4) Traction; open reduction; femoral ostained it, failure to maintain it during furteotomy (36 hips). There is no need to detail the techniques ther growth were important adverse factors. We were surprised employed, but it is necessary in relation to Bilateral dislocations to in contradiction of find, the general view, the hypothesis to mention some aspects of that the outcome in bilateral dislocations treatment in Groups 2 and 3. In these cases when hips were assessed individually was no Dennis Browne's controlled movement splint worse than in unilateral dislocations. This is was used following reduction by traction and possibly because all but of 3 the I3 6 weeks in an abduction plaster. The aim children with bilateral dislocations had open was to encourage mobility and reduce immobilization. The splint serves this purpose reductions. This can be more ceradmirably for it permits free rotation, ad- Ischaemic necrosis duction within a limited range, crawling, tainly recognized when the subsequent proand sometimes walking. This is likely to gress of the hip is followed, for in the early stimulate acetabular growth. An additional stages it may be difficult to distinguish isadvantage is that a hip which is not ade- chaemia from irregular ossification. The quately contained promptly redislocates, thus effects were less serious than we expected, clearly indicating the need for open reduction. for an ischaemic femoral head congruous In about half of the patients so treated (Group with the acetabulum seems to encourage 2) congruity was maintained when the legs acetabular growth, possibly by stimulating descended into the weight-bearing position. In the development of collateral vascular chanthe remainder (Group 3) congruity was lost nels. Even when the head is incongruous a in this position and an adduction-extemal normal acetabulum may develop. rotation osteotomy was consequently necessary to restore it before walking was If we now exclude obvious errors of manpermitted. agement-that is, manipulation and failure In assessing the results we divided acetab- to obtain or subsequent loss of congruity-we ular development into 4 grades-normal obtain a figure for acetabular growth poten(Hilgrenreiner angle 2I 0 or less), good (22 - tial within the age group that we are con2), fair (25°-27°), and poor (more than sidering. Only 3 of 6o hips treated without 270). In 68 hips (8o%) the result was satis- error failed to develop well. A close study factory, being normal (53) or good (I5). In of these 3 hips has failed to identify the cause the remaining I7 (20%) the result was un- of maldevelopment. satisfactory, being fair in 8 and poor in 9. What conclusions can we now reach about We then attempted to analyse the reasons the indications for acetabular reconstruction for these failures, which I will now present. and osteotomies of the pelvis or femur? One Age on admission This did not appear to point emerges clearly-that is, that congruity influence the outcome up to the age of about in abduction is an essential preliminary to all 4. The results in the older children did not methods. Acetabular reconstruction, which differ significantly from the overall results. implies that the surgeon doubts the ability
Some aspects of orthopaedic surgery in childhood of the acetabulum to grow when the head is congruous in the weight-bearing position should not be necessary under the age of 42. This applies to both bilateral and unilateral dislocations. In this connection it is significant to say that Harris in a separate study has shown that between 3 and 4 the acetabular growth potential spans a further 6 years. Over 4 this capacity is greatly reduced. What then is the role of pelvic (innominate) osteotomy'? It is not an acetabular reconstruction in the accepted sense but a means of stabilizing congruity in abduction when the leg is brought down to neutral. Its purpose is the same as femoral osteotomy and the results are probably comparable. The choice is for the individual surgeon I prefer femoral osteotomy for its simplicity and the ease with which any initial error and any subsequent loss of congruity during further growth may be corrected. The disadvantage is that a second operation is required when open reduction is necessary for we have found that combining the two in one operation is unsatisfactory. Innominate osteotomy is certainly the more difficult for the surgeon who performs it only occasionally, and if technique is faulty and redislocation occurs salvage may be a formidable undertaking. Possibly we should favour innominate osteotomy when open reduction is necessary to obtain congruity and the femoral operation when congruity in abduction has been obtained but is lost in the weight-bearing position.
Treatment of Perthes' disease Contemporary interest in the treatment of this condition centres around deep containment of the head of the femur within the acetabulum so that lateral bulging is prevented when the head is likely to deform during the healing phase. The essence of this concept is well illustrated by a patient in
29
whom the acetabular lip has actually caused the extruded part of the head to fracture. The principle is not new, for I remember W R Bristowe treating Perthes' disease in I940 on a frame with the legs widely abducted with this objective in mind. The emphasis has now changed somewhat in that we aim to combine containment with as little interference as possible with the child's natural development. This implies that he does not spend long in hospital and is allowed to walk, provided that abduction is maintained. This may be achieved by splinting, as with Petrie's plasters or Harrison's splint, or by operation. Surgical containment may be obtained by either innominate osteotomy or an adduction-external rotation osteotomy of the femur. Both have the advantage of giving protection to the anterior part of the head, which is so often the worst affected, and reducing restriction in walking to the time required for the osteotomies to unite. I prefer femoral osteotomy not only because of its technical simplicity but also because it decompresses the femoral head, whereas innominate osteotomy may cause undesirable compression. In considering the outcome of any measure designed to obtain and maintain containment we must always remember that a simple assessment of results in terms of final head shape may well be fallacious. This is because the outcome is governed by factors over which treatment has no influencewhether or not this includes containment. If, on the contrary, we can show that a hip which would have a poor prognosis if untreated can be so influenced by the method under review that the ultimate head shape is acceptable, then we can justifiably claim that the treatment was useful. The implication is that results of treatment must be presented with controls selected for each hip individually on the basis of the
30
G C Lloyd-Roberts
parameters which we recognize as influencing the natural history of the disease. Ideally the controls would be untreated patients, which is seldom possible. Alternatively, two methods of treatment may be compared. Both methods may, however, be misleading if the parameters used are incomplete. I will give two examples. In 1958 Evans and IP compared two methods of treatment-one by Snyder sling and crutches as outpatients and the other axial traction for a year followed by a caliper. Hips were individually matched using the parameters of age and stage only; girls were excluded. When the overall results were compared these were similar and we concluded that inpatient treatment had no advantage over the outpatient method. Later Murley and F compared treated and untreated patients. Again the results were comparable. We were wrong, however, to concltude that treatment did not influence the outcome. We should have concluded rather that the methods of treatment employed-axial traction, caliper, and Snyder sling-did not influence the natural history and therefore the outcome. One feature, however, emerged with clarity. We recognized that the age of onset and the stage of the disease at the time of diagnosis were not necessarily closely related to the outcome. Indeed, apparently similar hips in respect of age and stage at the outset frequently evolved quite differently, regardless of either the mode of treatment or no treatment at all. Catteralls took uip the challenge of this paradox and explained it by evolving his classification, in which Perthes' disease is divided into four groups related to the extent to which the epiphysis has undergone ischaemic change. The types progress from Group I, in which only half the head is involved, through Groups II and III, until in Group IV the whole head is affected. The prognosis is related to the extent of capital
involvement. He found that age still had a relevance within the groups and that the stage was important when late diagnosis was associated with established deformity which could not then be corrected. The earlier distinction between the prognosis for boys and girls was shown to be due to the tendency for girls to suffer from the more severe types of disease. He also emphasized that heads at special risk of deformity could be identified by early lateral extrusion or translucency and specks of calcification in this area. We therefore have additional parameters to consider in assessing the results of treatment namely, age, type, stage, and whether the head was at risk at the time of diagnosis. Failure to appreciate types of disease was responsible for the misleading conclusions that we drew from our earlier surveys. The concept of the 'head at risk' is of importance, as will be seen later. Catterall, Salamon, and IP have recently reviewed a series of hips treated by femoral osteotomy assessed on these parameters. We excluded Group I disease because treatment is unnecessary. Some cases were excluded because the head was already so severely deformed at diagnosis that congruous containment could not be obtained in abduction and internal rotation. It is possibly harmful to attempt containment in these, for secondary changes frequently result in adaptation of the acetabulum to the deformned head, resulting in a state of incongruous congruity. This probably explains the relatively good long-term prognosis in these unpromising hip
joints. There were 48 hips treated by femoral osteotomy which did not fall into either of the categories mentioned above and which were followed up for at least 4 years. The controls were represented by 75 untreated hips in the same categories (Table II). The outcome in each hip was categorized as
Some aspects of orthopaedic surgery in childhood
31
TABILE II Distribution of cases in osteotomy not 'at risk' shows no difference in outcome and control series (Table V). This observation correlates well with the (;roup Osteotomy Control apparent advantages of operation in patients with III Group or IV disease, for most of II '9 33 III 20 25 these had evidence of a head 'at risk', whereas IV 9 17 its incidence was low in those with Group II disease. Total 48 75 We may conclude, therefore, that the concept of containment in Perthes' disease is TABLE III Results of femoral osteotomy com- justified in some patients. The results of obtaining and maintaining containment by pared with untreated controls-all cases femoral osteotomy suggest that the containSeries Good Fair Poor ment method should be used for all patients with signs of 'head at risk', regardless of age O)stcotomy (48) 28 (58 ) I I (23 %) 9 (19 %) Control (75) 32 (43 %) 21 (28 %) 22 (29 %) or type of disease. Such treatment is unnecessary if the head is not 'at risk' and undesirable if deformity is such that containment can no longer be achieved. good, fair, or poor on the criteria previously used by Catteralls and the results are shown in Table III. TABLE iv Results of femoral osteotomy comA detailed analysis will be published later, pared with untreated controls-heads 'at but I will record our main conclusions here. risk' The overall results were not spectacular, for Series Good Fair Poor those operated upon showed no more than a I5% advantage in respect of final head Ostcotomy (34) I8 (53 %) 8 8 shape categorized as good. This was largely CoIntrol (54) 17 (31%) 22 I5 due to the high proportion of patients with Group II disease between 4 and 6 years old without 'at risk' signs. Benefit was apparent, TABLE V Results of femoral osteotomy comhowever, in Groups III and IV. For example, pared with untreated controls-heads not 'at of 17 untreated controls in Group IV, only risk' I obtained a good result, whereas 5 of 9 Series Good Fair Pooi operated upon were so classified. An apparent advantage was also demonstrable in Osteotomy (I4) I0 (71 %) 3 I patients over the age of 6, the ratio between Conltrol (21) 6 o I i (71 %) operative results and controls in respect of good results being 50% :28%. The significant observation, however, is References based upon analysis of heads 'at risk'. Here I Kuo, K, Lloyd-Roberts, G C, Soothill, J, and there is a 20% advantage in favour of operaOrme, I M (1975) Archives of Disease in Childhood, 50 5 I. tion in respect of the good and poor results (Table IV). In contrast a comparison between 2 Lloyd-Roberts, G C (I960) Journal of Bone and the operative and control groups for heads Joint Surgery, 42B, 706.
32
G C Lloyd-Roberts
3 Kemp, H, and Lloyd-Roberts, G C (X974) Journal of Bone and Joint Surgery, 56B, 688. 4 Harris, N H, Lloyd-Roberts, G C, and Gallien, R (I 975) Journal of Bone and Joint Surgery,
57B, 46. 5 Salter, R B (1969) Recent Advances in Orthopaedics. London, Churchill. 6 Evans, D, and Lloyd-Roberts, G C (1958) Journal of Bone and Joint Surgery, 4oB, 182.
7 Murley, A H G, and Lloyd-Roberts, G C (I962) Journal of Bone and Joint Surgery, 44A, I 705.
8 Catterall, A (1970) Journal of Bone and Joint Surgery, 52B, i86. 9 Lloyd-Roberts, G C, Catterall, A, and Salomon, P Journal of Bone and Joint Surgery. In press.
Some aspects in childhood
of
(1975) ol" 57
orthopaedic surgery
G C Lloyd-Roberts Mch FRCS Orthopaedic Surgeon, Hospital for Sick Children, Great Ormond Street, and St George's Hospital, London
Summary The aetiological role of immunodeficiency in acute septic arthritis of the hip in infancy, the management of the condition after the acute infection has subsided, and the special hazards of infection in the region of the hip joint in the older child are discussed. The principles of treatment of congenital dislocation of the hip are examined in relation to the maintenance of acetabular growth potential. The factors determining the outcome of treatment in Perthes' disease are discussed and a comparison of the resuilt in a series of cases treated by femoral osteotomy with those in untreated controls is presented. Introduction This lecture is given in tribute to the memory of a great surgeon. His contributions to the development and practice of orthopaedic surgery are well known. He had a special concern for the care of children afflicted by deformity and disease of the musculoskeletal system and I propose, therefore, in his honour, to discuss certain aspects of three conditions involving the hip joints of children-namely, acute septic arthritis, acetabular development in congenital dislocation, and the treatment of Legg-Perthes' disease.
Acute septic arthritis Influence of immunodeficiency First let us consider the infantile pattern. We are all familiar with the way in which an apparently severe generalized infection in an infant may be deceiving because of the lack of consitutional response. Indeed, we may not suspect that the hip is involved until some oedema of the thigh prompts a radiograph, which may disclose damage and dislocation of the femoral head. We should of course have recognized this sooner, decompressed the joint, and immobilized it in abduction to prevent dislocation. In practice, however, this situation is far from uncommon and when it occurs we console ourselves by commenting once again on the treacherous nature of this condition and the subdued signs of infection, both local and constitutional, which characterize it. We have been interested in this phenomenon at The Hospital for Sick Children for some years-an interest which has recently gained some impetus from the rapidly developing field of immunology. In association with Kuo, Soothill, and Orme' I have investigated the immunological status of these children, some during the initial infection and others in later childhood and adolescence. The first patients to be studied were 3 infants who were investigated during the
Robert Jones Lecture delivered on igth September 1974
26
G C Lloyd-Roberts
course of their acute illness. Two were shown to be suffering from hypogammaglobulinaemia and subsequently developed chronic granulomatous disease from which they died. The third displayed consistently low plasma IgA readings. This was an encouraging start, but we wondered whether the immunodeficiency might be a transitory phenomenon associated with a delay in maturation of immune mechanisms, particularly if the babies were premature. We therefore decided to study the immunological status of I 2 children who had suffered from septic arthritis in infancy. Six (Table I) had unquestionably low IgA readings and in 2 others these were at the lowest limit of normal. It is significant that 2 of the 6 were aged i 5 years or over. Certain implications arise from these observations. First it seems that some children, because of deficiency of their immune mechanism, are particularly at risk to neonatal infection and when so affected respond abnormally to infection. This deficiency may be transitory or persistent and accounts for the subdued clinical response. Furthermore, the extent to which bone destruction proceeds may well be related to the degree of immunodeficiency. Thus of Io children with affected hips, 6 suffered complete destruction of the femoral head, of whom 5 had evidence TABLE I Six children with septic arthritis in infancy and low plasma IgA levels on review Age
Age at onset
Premature
Culture
(years)
(days) 27 35 21
I8o II
I4
at
revziew
Yes
Yes Yes
Staphylococcus Staphylococcus
Staphylococcus Staphylococcus Staphylococcus Staphylococcus
Ifi
15 9 3 I2 II
of immunodeficiency. Of the remaining 4 with partial destruction, only i was immunodeficient. Lastly, persisting immunodeficiency may have an adverse effect when, at a subsequent operation, an attempt is made to repair the damage more than a year after the initial infection has been brought under control. Of I8 such elective operations, 6 were complicated by postoperative wound infection due, in all probability, to persisting immunodeficiency. This may even occur spontaneously without further operation in such patients.
Management after acute infection has It is essential to recognize subsided that the radiograph may be misleading in that apparent bone destruction may be no more than a reflection of decalcification caused by the infection. We may assume too readily that the femoral component is destroyed when in fact it is still present though translucent. This concept is best illustrated by studying knee joints similarly affected. One femoral condyle may at first appear to be absent, but subsequently it becomes apparent that, although damaged, it has remained substantially intact2. Clinical examination of such a knee will resolve the dilemma, though arthrography will be confirmatory. The condyle is palpable and the knee retains a degree of movement and stability which would be improbable if the condyle was indeed destroyed. The same principles may be applied to the hip, though less readily. Stability may be tested clinically, and arthrography may be helpful in spite of intra-articular adhesions. In practice, however, only exploration will establish the degree to which the joint is damaged and indicate the measures needed to repair or alleviate the situation. One of three alternatives is likely to be present. First and most favourable is a pseudarthrosis within the femoral neck. Fixation, grafting,
Some aspects of orthopaedic surgery in childhood and osteotomy will restore virtual normality provided that operation is undertaken before weight-bearing causes displacement at the weakened area. Secondly, we may find that the femoral head, while maintaining continuity with the neck, has dislocated. Reduction is indicated. Lastly, a segment of the neclk may be absent and the femoral head either destroyed or ankylosed within the acetabulum. Repair is not possible, but in the young child the trochanter may be placed within the acetabulum, the glutei advanced, and a subtrochanteric osteotomy performed. In the older child a two-stage compression arthrodesis between the trochanter and the pelvis seems the most appropriate course of action.
Septic arthritis in the older child I wish to emphasize the dangerous relationship which exists between osteomyelitis of the trochanteric region and ischaemic necrosis of the femoral head. This ischaemia is apparently due to occlusion of nutrient vessels by a sympathetic effusion within the hip joint. If the infection should then spread to the joint its effect on the ischaemic femoral epiphysis is likely to be devastating. In a recent review of such patients Kemp and P3 have emphasized this hazard and advocated urgent decompression of the bone and joint cavity as soon as the diagnosis is made. Whatever the virtue of an expectant attitude to osteomyelitis elsewhere, immediate operation seems indicated in this situation. Acetabular development in congenital dislocation It is difficult to select a topic for discussion in a condition about which there remains so much uncertainty and so much contention. Nevertheless, I have decided to discuss acetabtular growth potential under different circumstances. The successful outcome of
27
treatment in congenital dislocation of the hip
depends upon congruous reduction and satisfactory development of the acetabulum as growth proceeds. No one will disagree with the need for congruous reduction, but considerable uncertainty persists about acetabular potential at different ages and in relation to unilateral and bilateral displacement. In this discussion I will deal with complete dislocation only, for in persistent primary subluxation pressure of the head upon the growing lip of the acetabulum so prejudices acetabular development that some type of acetabular reconstruction is usually necessary. In dislocation, however, acetabular growth potential is preserved for a surprisingly long time provided that those conditions which are present in the normal child are restored and maintained. The essentials are that congruous reduction should be obtained in the position of weight-bearing as soon as possible and that the period of immobilization should be reduced to the minimum. This implies that we should aim to shorten the period between diagnosis and weight-bearing in the normal erect position so far as we can. It is important to emnphasize congruity in the weight-bearing position because it is only then that we expose the acetabulum to the normal growth stimulus. Harris, Gallien, and I4 have recently reviewed acetabular development in 85 dislocated hips in 72 children first admitted over the age of i year (average 2). All were over Io (average I2.4) at the time of assessment. Our purpose was to test the validity of the hvpothesis that the application of these principles will, in general, result in satisfactory acetabular development and so obviate the need for reconstructive operations upon it. Four methods of treatment were used: i) Manipulation under anaesthetic; hyperabduction plaster; Dennis Browne splint (I2 hips).
28
G C Lloyd-Roberts
2) Traction; abduction plaster; Dennis Age and quality of congruity in the weightBrowne splint (i 6 hips). bearing position Provided such congruity was obtained before the age of 42 delay did 3) As in Group 2 + femoral osteotomy not seem to prejudice the result. However, I (2 hips). failure to obtain congruity or, having ob4) Traction; open reduction; femoral ostained it, failure to maintain it during furteotomy (36 hips). There is no need to detail the techniques ther growth were important adverse factors. We were surprised employed, but it is necessary in relation to Bilateral dislocations to in contradiction of find, the general view, the hypothesis to mention some aspects of that the outcome in bilateral dislocations treatment in Groups 2 and 3. In these cases when hips were assessed individually was no Dennis Browne's controlled movement splint worse than in unilateral dislocations. This is was used following reduction by traction and possibly because all but of 3 the I3 6 weeks in an abduction plaster. The aim children with bilateral dislocations had open was to encourage mobility and reduce immobilization. The splint serves this purpose reductions. This can be more ceradmirably for it permits free rotation, ad- Ischaemic necrosis duction within a limited range, crawling, tainly recognized when the subsequent proand sometimes walking. This is likely to gress of the hip is followed, for in the early stimulate acetabular growth. An additional stages it may be difficult to distinguish isadvantage is that a hip which is not ade- chaemia from irregular ossification. The quately contained promptly redislocates, thus effects were less serious than we expected, clearly indicating the need for open reduction. for an ischaemic femoral head congruous In about half of the patients so treated (Group with the acetabulum seems to encourage 2) congruity was maintained when the legs acetabular growth, possibly by stimulating descended into the weight-bearing position. In the development of collateral vascular chanthe remainder (Group 3) congruity was lost nels. Even when the head is incongruous a in this position and an adduction-extemal normal acetabulum may develop. rotation osteotomy was consequently necessary to restore it before walking was If we now exclude obvious errors of manpermitted. agement-that is, manipulation and failure In assessing the results we divided acetab- to obtain or subsequent loss of congruity-we ular development into 4 grades-normal obtain a figure for acetabular growth poten(Hilgrenreiner angle 2I 0 or less), good (22 - tial within the age group that we are con2), fair (25°-27°), and poor (more than sidering. Only 3 of 6o hips treated without 270). In 68 hips (8o%) the result was satis- error failed to develop well. A close study factory, being normal (53) or good (I5). In of these 3 hips has failed to identify the cause the remaining I7 (20%) the result was un- of maldevelopment. satisfactory, being fair in 8 and poor in 9. What conclusions can we now reach about We then attempted to analyse the reasons the indications for acetabular reconstruction for these failures, which I will now present. and osteotomies of the pelvis or femur? One Age on admission This did not appear to point emerges clearly-that is, that congruity influence the outcome up to the age of about in abduction is an essential preliminary to all 4. The results in the older children did not methods. Acetabular reconstruction, which differ significantly from the overall results. implies that the surgeon doubts the ability
Some aspects of orthopaedic surgery in childhood of the acetabulum to grow when the head is congruous in the weight-bearing position should not be necessary under the age of 42. This applies to both bilateral and unilateral dislocations. In this connection it is significant to say that Harris in a separate study has shown that between 3 and 4 the acetabular growth potential spans a further 6 years. Over 4 this capacity is greatly reduced. What then is the role of pelvic (innominate) osteotomy'? It is not an acetabular reconstruction in the accepted sense but a means of stabilizing congruity in abduction when the leg is brought down to neutral. Its purpose is the same as femoral osteotomy and the results are probably comparable. The choice is for the individual surgeon I prefer femoral osteotomy for its simplicity and the ease with which any initial error and any subsequent loss of congruity during further growth may be corrected. The disadvantage is that a second operation is required when open reduction is necessary for we have found that combining the two in one operation is unsatisfactory. Innominate osteotomy is certainly the more difficult for the surgeon who performs it only occasionally, and if technique is faulty and redislocation occurs salvage may be a formidable undertaking. Possibly we should favour innominate osteotomy when open reduction is necessary to obtain congruity and the femoral operation when congruity in abduction has been obtained but is lost in the weight-bearing position.
Treatment of Perthes' disease Contemporary interest in the treatment of this condition centres around deep containment of the head of the femur within the acetabulum so that lateral bulging is prevented when the head is likely to deform during the healing phase. The essence of this concept is well illustrated by a patient in
29
whom the acetabular lip has actually caused the extruded part of the head to fracture. The principle is not new, for I remember W R Bristowe treating Perthes' disease in I940 on a frame with the legs widely abducted with this objective in mind. The emphasis has now changed somewhat in that we aim to combine containment with as little interference as possible with the child's natural development. This implies that he does not spend long in hospital and is allowed to walk, provided that abduction is maintained. This may be achieved by splinting, as with Petrie's plasters or Harrison's splint, or by operation. Surgical containment may be obtained by either innominate osteotomy or an adduction-external rotation osteotomy of the femur. Both have the advantage of giving protection to the anterior part of the head, which is so often the worst affected, and reducing restriction in walking to the time required for the osteotomies to unite. I prefer femoral osteotomy not only because of its technical simplicity but also because it decompresses the femoral head, whereas innominate osteotomy may cause undesirable compression. In considering the outcome of any measure designed to obtain and maintain containment we must always remember that a simple assessment of results in terms of final head shape may well be fallacious. This is because the outcome is governed by factors over which treatment has no influencewhether or not this includes containment. If, on the contrary, we can show that a hip which would have a poor prognosis if untreated can be so influenced by the method under review that the ultimate head shape is acceptable, then we can justifiably claim that the treatment was useful. The implication is that results of treatment must be presented with controls selected for each hip individually on the basis of the
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parameters which we recognize as influencing the natural history of the disease. Ideally the controls would be untreated patients, which is seldom possible. Alternatively, two methods of treatment may be compared. Both methods may, however, be misleading if the parameters used are incomplete. I will give two examples. In 1958 Evans and IP compared two methods of treatment-one by Snyder sling and crutches as outpatients and the other axial traction for a year followed by a caliper. Hips were individually matched using the parameters of age and stage only; girls were excluded. When the overall results were compared these were similar and we concluded that inpatient treatment had no advantage over the outpatient method. Later Murley and F compared treated and untreated patients. Again the results were comparable. We were wrong, however, to concltude that treatment did not influence the outcome. We should have concluded rather that the methods of treatment employed-axial traction, caliper, and Snyder sling-did not influence the natural history and therefore the outcome. One feature, however, emerged with clarity. We recognized that the age of onset and the stage of the disease at the time of diagnosis were not necessarily closely related to the outcome. Indeed, apparently similar hips in respect of age and stage at the outset frequently evolved quite differently, regardless of either the mode of treatment or no treatment at all. Catteralls took uip the challenge of this paradox and explained it by evolving his classification, in which Perthes' disease is divided into four groups related to the extent to which the epiphysis has undergone ischaemic change. The types progress from Group I, in which only half the head is involved, through Groups II and III, until in Group IV the whole head is affected. The prognosis is related to the extent of capital
involvement. He found that age still had a relevance within the groups and that the stage was important when late diagnosis was associated with established deformity which could not then be corrected. The earlier distinction between the prognosis for boys and girls was shown to be due to the tendency for girls to suffer from the more severe types of disease. He also emphasized that heads at special risk of deformity could be identified by early lateral extrusion or translucency and specks of calcification in this area. We therefore have additional parameters to consider in assessing the results of treatment namely, age, type, stage, and whether the head was at risk at the time of diagnosis. Failure to appreciate types of disease was responsible for the misleading conclusions that we drew from our earlier surveys. The concept of the 'head at risk' is of importance, as will be seen later. Catterall, Salamon, and IP have recently reviewed a series of hips treated by femoral osteotomy assessed on these parameters. We excluded Group I disease because treatment is unnecessary. Some cases were excluded because the head was already so severely deformed at diagnosis that congruous containment could not be obtained in abduction and internal rotation. It is possibly harmful to attempt containment in these, for secondary changes frequently result in adaptation of the acetabulum to the deformned head, resulting in a state of incongruous congruity. This probably explains the relatively good long-term prognosis in these unpromising hip
joints. There were 48 hips treated by femoral osteotomy which did not fall into either of the categories mentioned above and which were followed up for at least 4 years. The controls were represented by 75 untreated hips in the same categories (Table II). The outcome in each hip was categorized as
Some aspects of orthopaedic surgery in childhood
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TABILE II Distribution of cases in osteotomy not 'at risk' shows no difference in outcome and control series (Table V). This observation correlates well with the (;roup Osteotomy Control apparent advantages of operation in patients with III Group or IV disease, for most of II '9 33 III 20 25 these had evidence of a head 'at risk', whereas IV 9 17 its incidence was low in those with Group II disease. Total 48 75 We may conclude, therefore, that the concept of containment in Perthes' disease is TABLE III Results of femoral osteotomy com- justified in some patients. The results of obtaining and maintaining containment by pared with untreated controls-all cases femoral osteotomy suggest that the containSeries Good Fair Poor ment method should be used for all patients with signs of 'head at risk', regardless of age O)stcotomy (48) 28 (58 ) I I (23 %) 9 (19 %) Control (75) 32 (43 %) 21 (28 %) 22 (29 %) or type of disease. Such treatment is unnecessary if the head is not 'at risk' and undesirable if deformity is such that containment can no longer be achieved. good, fair, or poor on the criteria previously used by Catteralls and the results are shown in Table III. TABLE iv Results of femoral osteotomy comA detailed analysis will be published later, pared with untreated controls-heads 'at but I will record our main conclusions here. risk' The overall results were not spectacular, for Series Good Fair Poor those operated upon showed no more than a I5% advantage in respect of final head Ostcotomy (34) I8 (53 %) 8 8 shape categorized as good. This was largely CoIntrol (54) 17 (31%) 22 I5 due to the high proportion of patients with Group II disease between 4 and 6 years old without 'at risk' signs. Benefit was apparent, TABLE V Results of femoral osteotomy comhowever, in Groups III and IV. For example, pared with untreated controls-heads not 'at of 17 untreated controls in Group IV, only risk' I obtained a good result, whereas 5 of 9 Series Good Fair Pooi operated upon were so classified. An apparent advantage was also demonstrable in Osteotomy (I4) I0 (71 %) 3 I patients over the age of 6, the ratio between Conltrol (21) 6 o I i (71 %) operative results and controls in respect of good results being 50% :28%. The significant observation, however, is References based upon analysis of heads 'at risk'. Here I Kuo, K, Lloyd-Roberts, G C, Soothill, J, and there is a 20% advantage in favour of operaOrme, I M (1975) Archives of Disease in Childhood, 50 5 I. tion in respect of the good and poor results (Table IV). In contrast a comparison between 2 Lloyd-Roberts, G C (I960) Journal of Bone and the operative and control groups for heads Joint Surgery, 42B, 706.
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3 Kemp, H, and Lloyd-Roberts, G C (X974) Journal of Bone and Joint Surgery, 56B, 688. 4 Harris, N H, Lloyd-Roberts, G C, and Gallien, R (I 975) Journal of Bone and Joint Surgery,
57B, 46. 5 Salter, R B (1969) Recent Advances in Orthopaedics. London, Churchill. 6 Evans, D, and Lloyd-Roberts, G C (1958) Journal of Bone and Joint Surgery, 4oB, 182.
7 Murley, A H G, and Lloyd-Roberts, G C (I962) Journal of Bone and Joint Surgery, 44A, I 705.
8 Catterall, A (1970) Journal of Bone and Joint Surgery, 52B, i86. 9 Lloyd-Roberts, G C, Catterall, A, and Salomon, P Journal of Bone and Joint Surgery. In press.
