Orthopaedics Springer-Verlag 1987

Transcription

1 International Orthopaedics (SICOT) (1987) 11:83-87 International Orthopaedics Springer-Verlag 1987 The correlation of arthrography with the results of treatment in late diagnosed congenital dislocation of the hip H. Saraste and T. Aparisi Department of Orthopaedic Surgery, Karolinska Hospital, S-141 Stockholm, Sweden Summary. The aim of this study was to assess the value of arthrography of the hip in the investigation of late diagnosed congenital dislocation. The results of the treatment of 19 hips were related to the findings at arthrography. The hip radiographs at follow-up were normal in all cases where the arthrogram had demonstrated a congruent reduction (86). When the arthrogram had indicated a block in reduction the results were less favourable, and dysplasia or subluxation was present at follow-up in 19 cases, despite repeated conservative or operative treatment. Four hips appeared normal after operation. Arthrography gave valuable information and showed good correlation with the results of treatment. R~sum/~. Le but de ee travail est d'bvaluer l'intbr~t de l'arthrographie dans le bilan des luxations congbnitales de la hanche dkpistkes tardivement. Les rbsultats du traitement de 19 hanches ont btb comparbs aux donnbes de l'arthrographie. Au cours de la surveillance les radiographies de contr61e ktaient normales dans tous les cas (86) oft l'arthrographie avait montrk une rbduction parfaite. Quand l'arthrographie avait dbcelk un obstacle ~ la r~duction les rbsultats btaient moins bons et il persistait une dysplasie ou une subluxation dans 19 cas, malgrb la reprise d'un traitement orthopodique ou chirurgical. Quatre hanches paraissaient normales apr~s intervention. L'arthrographie fournit donc des renseignements valables qui coneordent bien avec les rbsultats du traitement. Offprint requests to: Helena Saraste Key words: Arthrography, Congenital dislocation of the hip, Late diagnosis Introduction In Sweden, the frequency of late diagnosed cases of congenital dislocation of the hip (CDH) has increased during the past twenty years despite well developed programmes for the examination of new born children [9]. Arthrography of the hip in those patients who fail to respond to early conservative therapy, or who are diagnosed late, has been advocated by Severin (1939) [1], Laurent (1953) [5], Mitchell (1963) [7], Astley (1967) [2], Nakamura (1968) [8], Almby et al. (1979) [1], LSnnerholm et al. (198) [6] and Goldman (1981) [4]. There are large variations in the results of treatment in late diagnosed CDH, and analyses of prognostic factors other than age are lacking. Surgical reduction has been recommended as a method of choice in the treatment of infants diagnosed late [3]. Most children aged less than one year can be treated conservatively. Few studies have investigated the possible common features of those dislocated or subluxated hips in which treatment was unsuccessful. The aim of this study was to analyse the prognostic value of hip arthrography in the examination of late diagnosed CDH. Materials and methods During the period , 98 children with suspected or established CDH were examined by hip arthrography at the Department of Orthopaedic Surgery, Karolinska Hospital. Most children had both hips examined, the normal serving as a control. Some had bilateral dislocation or dysplasia. Thus,

2 84 H. Saraste and T. Aprisi: Arthrography in congenital hip dislocation Fig. 1. The sites for adductor tenotomy and contrast medium injection Fig. 2. The location of the injection needle; potential contrast medium leakage takes place caudal to the hip image 19 pathological hips were included in the study. The mean age at examination was 1 months, with a range from 3 months to 3 years and 9 months. Fifty eight of the children were between 3 and 12 months old. The follow-up study was made in 1982 to 1983, one to seven years following hip arthrography. Examination of all radiographs was made by the same person to avoid bias. The arthrographic examination was performed by an Orthopaedic Surgeon with experience in paediatric orthopaedics. An image intensifier was used in the examination which was carried out under general anasthesia and sterile conditions. Hip traction, with or without percutaneous adductor tenotomy, preceded arthrography in those cases where contracture was expected to hinder reduction. Injection of contrast medium was made with a lumbar puncture needle placed 1 mm lateral to the ischial tuberosity, with the child's hips in abduction and flexion. The needle was first directed perpendicularly to the femoral neck. After bone contact it was retracted slightly and then directed medially to puncture the joint capsule cau- dally (Fig. 1). Isotonic saline solution was injected into the joint space to confirm the location of the needle. If the location was correct a piston effect would be seen in the syringe. Then, 1-2 mls of contrast medium (Urografin, 45% for intravenous use) was injected under image intensifier control. The position of the syringe piston was allowed to stabilise before the needle was withdrawn. This allowed the return of superfl u - ous medium into the syringe, thus minimizing leakage. When this did occur the leaked medium was located distal to the hip image and so did not interfere with definition (Fig. 2), The projections used for the radiographs included the anteroposterior, forced adduction, 9 of abduction, and 6 of abduction combined with internal rotation. Additional projections were also used according to the Surgeon's choice. Results In the late diagnosed cases of CDH, the arthrograms were compared with radiographs at follow- Table 1. Hip arthrography at diagnosis and radiography at follow-up Findings at arthrography Number of Conservative Surgical casbs treatment treatment Normal radiography at follow-up Subluxation and/or dysplasia at follow-up Dysplasia with stable hip, congruence at arthrography Subluxation no postreduction impediment a impediment after reduction not seen in plain radiographs 11 5 Complete hip dislocation no postreduction impediment I 4 impediment after reduction not seen in plain radiographs b 55 4 b a Impediment = increased distance between femoral head and acetabulum b All cases osteotomized

3 H. Saraste and T. Aprisi: Arthrography in congenital hip dislocation 85 Fig. 3a-d. Dislocation of the right hip a, b. In flexion and abduction of the hip there is no increase in distance between femoral head and acetabulum e. The result of conservative treatment was good d up. The results are presented in Table 1. Figures 3 and 4 are examples of good results following conservative therapy in cases in which the arthrogram revealed no interposition. Figures 5, 6 and 7 demonstrated poor results in cases where the arthrogram showed interposition. Dysplasia with a stable hip In all the 21 cases in which the arthrogram showed dysplasia without subluxation or dislocation, with congruence on all projections, the hip radiographs were normal at follow-up. These Fig. 4a-d. Subluxation of the right hip a, b. In the reduced position the distance is not increased between the femoral head and acetabulum c. The hip is normal at follow-up d after conservative treatment

4 86 H. Saraste and T. Aprisi: Arthrography in congenital hip dislocation Fig. 5a-e. Subluxation of the right hip a. In the position of reduction there is an increased distance between the femoral head and acetabulum b, c. The result is not satisfactory after conservative treatment d, and acetabular osteotomy was performed e cases were all treated conservatively in a plaster cast. Dysplasia with hip subluxation Dysplasia with hip subluxation was noted in 66 cases. In 55 no obstruction to reduction was seen at arthrography. These hips returned to normal with conservative treatment in plaster casts. The remaining 11 cases in this category demonstrated an impediment to congruous reduction on the arthrograms with increased distance between the acetabulum and the femoral head. In these patients the radiotogical results were less favourable, and in 7 out of the 11 hips subluxation or d~splasia was seen at follow-up. Complete hip dislocation In the 1 cases of complete dislocation of the hip, where congruous reduction was set~n arthrographically, conservative or surgical treatment resulted in normal appearances. However, in those 12 cases in which the arthrogram demonstrated a block to congruous reduction, the results were poor with resistant subluxation. Complications No anaesthetic, neurological, circulatory or other complications followed arthrography. Avascular necrosis of the femoral head, as a complication of the disease or treatment, was seen in 11 hips (1%). In all these cases there had been complete dislocation of the hip with signs of obstructed reduction on all the arthrograms performed. In only one of the poor results was a congruent reduction demonstrated arthrographically. In this case, however, distortion of the femoral head was apparent on the arthrogram, and avascular necrosis followed. In none of the cases could an inverted limbus be demonstrated as an impediment to reduction. Discussion Hip arthrography is demanding of resources and is invasive, but has considerable adventages in demonstrating structures not seen on plain radiographs. It is also a dynamic examination, allowing modifications to be performed during the procedure. In this study arthrographic findings before treatment have been related to results at followup. Our findings do not support the idea of a correlation between the presence of a limbus on

5 H. Saraste and T. Aprisi: Arthrography in congenital hip dislocation 87 the arthrogram and the results of reduction and subsequent treatment. They emphasise the importance of achieving a complete reduction at the first attempt. An increased distance between the femoral head and the acetabulum, indicating a block to congruous reduction, was unive)sally related to poor results. The arthrographic findings gave valuable information and showed a good correlation with the results of treatment. Fig. 6a-c. Subluxation of the right hip a. The arthrogram showes an increased distance between the femoral head and acetabulum in the position of the reduction b. The result of conservative treatment was poor c References 1. Almby B, Hjelmstedt A, L6nnerholm T (1979) Neonatal Hip Instability. Reason for failure of early abduction treatment. Acta Orthop Scand 5: Astley R (1967) Arthrography in congenital dislocation of the hip. Clin Radiol 18: Diepstraten AFM (1985) Open reduction of congenital hip dislocation. Acta Orthop Scand 56: Goldman AB (1981) Hip arthrography. Evaluation of disorders of children, adolescents and adults without prothesis. Radiol Clin North Am 19: Laurent LE (1953) Congenital dislocation of the hip. Acta chit scand [Suppl] L6nnerholm T (198) Arthrography of the hip in children. Technique, normal anatomy and findings in unstable hip joints. Acta Radiol Diagn 21 : Mitchell GP (1963) Arthrography in congenital dislocation of the hip. J Bone Joint Surg 45B: Nakamura K (1968) Arthrography study of congenital dislocation of the hip joint. J Japan Orthop Ass 42: Palm6n K (1984) Prevention of congenital dislocation of the hip. Acta Orthop Scand [Suppl] Severin E (1939) Arthrography in congenital dislocation of the hip. J Bone Joint Surg 21:34 Fig. 7a-d. Dislocation of the hips a. The arthrogram shows a dislocation of the right and a subluxation of the left hip with increased distance between the femoral head and acetabulum in all positions b, c. The result of the conservative treatment was poor d