Surgery of the Knee in Children with Spina Bifida R. BIRCH Introduction Deformities of the knee joint create problems for the child with spina bifida and hamper the achievement of useful independent mobility. Dedicated physiotherapy fails to overcome these deformities in a number of cases and surgical correction becomes necessary. Patients This paper is a review of 34 children with knee deformities requiring surgery at Queen Mary’s Hospital for Children, Carshalton, between 1968 and 1975. The total number of knees operated on was 58 and the age range was from two to 13 years. These 34 children represent 10 per cent of all new cases of spina bifida (approximately 350) presenting at Queen Mary’s Hospital over the period. There were three groups of deformity: stiff bent knees with flexion deformity (19 children, 31 knees); stiff, straight and hyperextended knees which did not bend (13 children, 24 knees); and severe genu valgum (two children, three knees). The majority of the knees with flexion deformity had markedly greater power in the hamstrings than in the quadriceps, but in one-third of cases there was no significant muscle power in either group. I n two-thirds of the knees that were stiff. straight and could not bend there was no useful power in the lower limbs. I n one-third of cases there was significantly greater power in extension than in flexion. Indications for Surgery Knees that do not bend may aid walking initially. but as the child grows in height it becomes increasingly difficult for him to sit, use a wheelchair and get into and out of a car. Knee-bending calipers cannot be used if the knee is not straight; it will not fit into calipers if the flexion deformity is greater than 30 , and is unstable without calipers. In the paralysed leg, even 5” off full extension will prevent the knee being stabilised in hyperextension. Pressure sores are also a constant problem in knees with flexion or valgus deformities. Physiotherapy is of prime importance in the treatment of knee deformities, and parents are taught how to stretch the child’$ knee gently several times a day. Only if this fails is surgery undertaken. Treatment Flexion Deformity In knees with no useful activity in quadriceps or hamstrings, posterior soft-tissue release is indicated. Through a vertical posterior incision, tight structures are divided as necessary. In this procedure only blood-vessels are safeguarded. The greater the flexion deformity the more extensive is the release necessary, including division of the capsule. collateral ligaments and cruciate ligaments. Post-operatively, well-padded plaster back-slabs are applied with Queen Mary’s Hospital for Children, Carshalton, Surrey.
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the knee flexed, and over the next 10 days the knee is gradually extended, using serial plasters, with a careful watch being kept on the circulation. N o vascular complications have occurred. Tendon transfers can help overcome fixed flexion when there is useful muscle power, and we have used modifications of the Eggers procedure.
Knees That Cannot Bend Treatment of these stiff, straight knees is not usually required under the age of seven years, and in fact may help the child to walk. When the deformity becomes a nuisance, and regular parental stretching has failed to help, adequate anterior release can be performed by subcutaneous tenotomy. The more extensive open operation is unnecessary. Postoperatively, a cotton-wool and crCpe dressing is applied and physiotherapy is started early. Children whose knees do not bend but who have useful power in the quadriceps present a dilemma-how to gain flexion without destroying the ability to stabilise the knee in extension. A small number of quadriceps plasties have been performed, with good results. Valgus Knees Many knees with flexion deformity have some degree of valgus, which disappears when the flexion deformity is released. The more severe valgus deformities require supracondylar osteotomy, preferably by osteoclasis. Results Complete posterior tissue release. In this group were seven children (12 knees) with an average age of 5& years. The average range of movement at operation was 65" to loo", six months post-operatively it was 10" to 90" and 24 months post-operatively it was 10" to 80". At review, six of the 12 knees had no flexion deformity. Partial posterior soft-tissue release. There were seven children (nine knees) in this group, with an average age of 49 years. The average range of movement at operation was 40" to 1lo", six months post-operatively it was 10" to 90" and 24 months post-operatively it was 10" to 100". At review, four of the nine knees had no flexion deformity. Eggers Procedure. The three children (six knees) in this group had an average age of six years. The average fixed flexion deformity at operation was 30", and six months postoperatively it was 5". At review, four of the six knees had no fixed flexion, but two others had come to further surgery (posterior release) since the operation. S t i f , straight knees. There were 13 children (24 knees) in this group, with an average age of eight years. The average range of movement at operation was 5" to 40°, six months post-operatively it was 5" to 70" and 24 months post-operatively it was 5" to 90". At review, passive extension was retained in 14 of the 23 knees. Osteotomies. These four children (seven knees) had an average age of 99 years. In three knees the aim was correction of valgus deformity, and in four of flexion deformity. At review, correction of deformity was maintained, although one child required two osteotomies in the same knee. Twelve knees were released by subcutaneous tenotomy. The range of movement obtained by this simple procedure was similar to those following open release.
Conzplicat ions There have been few serious complications in this series. The children were immobilised for the minimum amount of time compatible with sound healing of their wounds, which 112
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reduced complications from osteoporosis and stiffness. Careful observation of circulation following release of the more severe flexion deformities prevented vascular problems. The complications encountered were: haematoma (six, following anterior release); delayed wound-healing (two, following anterior release); one case each of significant infection and fracture, both following supracondylar osteotomy; and there were two failures with the modified Eggers procedure which later needed posterior release.
Discussion Children with spina bifida spend much of their lives in hospital and undergo many surgical procedures, but the handicap imposed by the more severe knee deformities justifies surgical treatment in a proportion of cases. In this series, surgery for fixed flexion has allowed the use of knee-bending calipers and the substitution of short for long calipzrs. In the more severe flexion deformities, posterior release has allowed the use of calipers, which had not been possible previously. Anterior release for straight knees that cannot bend has overcome difficulties in sitting and in the use of wheelchairs. Arknowkdgrtnmfs: 1 thank Mr. Geoffrey Walker for his encouragement and advice and Miss Susan Wadd for typing this manuscript.
SUMMARY
The achievement of independent mobility by children with spina bifida is often hampered by deformities of the knee joints. This report reviews the results of surgical treatment in 34 spina-bifida children with knee deformities. The surgical procedures are described and it is concluded that surgery is justified in a proportion of cases with fixed-knee deformities.
RESUME
Chirurgie pour [a dtforniation des genous chez les enfants porteurs de spina bifida L’obtention d’une mobilite independante chez les enfants porteurs de spina bifida est souvent emp&chte par les deformations des genoux. Cet article rapporte les resultats du traitement chirurgical de 34 enfants atteints de spina bifida avec deformation du genou. Les techniques chirurgicales sont decrites et I’auteur conclut que la chirurgie est justifiee dans une certaine proportion de cas avec deformations fixies des genoux.
ZUSAMMENFASSUNG
Chirirrgische Behandlung von Kniefehlstellungen bei Kindern niit Spina bijida Die Moglichkeit, sich eigenstandig zu bewegen, ist bei Kindern mit Spina bifida haufig durch Kniegelenksfehlstellungen eingeschrankt. Die vorliegende Arbeit gibt einen Bericht uber die Ergebnisse chirurgischer Behandlungen bei 34 Kindern mit Spina bifida und Kniefehlstellungen. Die chirurgischen Methoden werden beschrieben. Man 1st der Meinung, daR bei einem Teil der Faille mit fixierten Kniefehlstellungen chirurgische Eingriffe gerechtfertigt sind. 113
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DEVELOPMENTAL MEDICINE A N D CHILD NEUROLOGY.
1976, 18. Supp. 37
the knee flexed, and over the next 10 days the knee is gradually extended, using serial plasters, with a careful watch being kept on the circulation. N o vascular complications have occurred. Tendon transfers can help overcome fixed flexion when there is useful muscle power, and we have used modifications of the Eggers procedure.
Knees That Cannot Bend Treatment of these stiff, straight knees is not usually required under the age of seven years, and in fact may help the child to walk. When the deformity becomes a nuisance, and regular parental stretching has failed to help, adequate anterior release can be performed by subcutaneous tenotomy. The more extensive open operation is unnecessary. Postoperatively, a cotton-wool and crCpe dressing is applied and physiotherapy is started early. Children whose knees do not bend but who have useful power in the quadriceps present a dilemma-how to gain flexion without destroying the ability to stabilise the knee in extension. A small number of quadriceps plasties have been performed, with good results. Valgus Knees Many knees with flexion deformity have some degree of valgus, which disappears when the flexion deformity is released. The more severe valgus deformities require supracondylar osteotomy, preferably by osteoclasis. Results Complete posterior tissue release. In this group were seven children (12 knees) with an average age of 5& years. The average range of movement at operation was 65" to loo", six months post-operatively it was 10" to 90" and 24 months post-operatively it was 10" to 80". At review, six of the 12 knees had no flexion deformity. Partial posterior soft-tissue release. There were seven children (nine knees) in this group, with an average age of 49 years. The average range of movement at operation was 40" to 1lo", six months post-operatively it was 10" to 90" and 24 months post-operatively it was 10" to 100". At review, four of the nine knees had no flexion deformity. Eggers Procedure. The three children (six knees) in this group had an average age of six years. The average fixed flexion deformity at operation was 30", and six months postoperatively it was 5". At review, four of the six knees had no fixed flexion, but two others had come to further surgery (posterior release) since the operation. S t i f , straight knees. There were 13 children (24 knees) in this group, with an average age of eight years. The average range of movement at operation was 5" to 40°, six months post-operatively it was 5" to 70" and 24 months post-operatively it was 5" to 90". At review, passive extension was retained in 14 of the 23 knees. Osteotomies. These four children (seven knees) had an average age of 99 years. In three knees the aim was correction of valgus deformity, and in four of flexion deformity. At review, correction of deformity was maintained, although one child required two osteotomies in the same knee. Twelve knees were released by subcutaneous tenotomy. The range of movement obtained by this simple procedure was similar to those following open release.
Conzplicat ions There have been few serious complications in this series. The children were immobilised for the minimum amount of time compatible with sound healing of their wounds, which 112
K. BIRCH
reduced complications from osteoporosis and stiffness. Careful observation of circulation following release of the more severe flexion deformities prevented vascular problems. The complications encountered were: haematoma (six, following anterior release); delayed wound-healing (two, following anterior release); one case each of significant infection and fracture, both following supracondylar osteotomy; and there were two failures with the modified Eggers procedure which later needed posterior release.
Discussion Children with spina bifida spend much of their lives in hospital and undergo many surgical procedures, but the handicap imposed by the more severe knee deformities justifies surgical treatment in a proportion of cases. In this series, surgery for fixed flexion has allowed the use of knee-bending calipers and the substitution of short for long calipzrs. In the more severe flexion deformities, posterior release has allowed the use of calipers, which had not been possible previously. Anterior release for straight knees that cannot bend has overcome difficulties in sitting and in the use of wheelchairs. Arknowkdgrtnmfs: 1 thank Mr. Geoffrey Walker for his encouragement and advice and Miss Susan Wadd for typing this manuscript.
SUMMARY
The achievement of independent mobility by children with spina bifida is often hampered by deformities of the knee joints. This report reviews the results of surgical treatment in 34 spina-bifida children with knee deformities. The surgical procedures are described and it is concluded that surgery is justified in a proportion of cases with fixed-knee deformities.
RESUME
Chirurgie pour [a dtforniation des genous chez les enfants porteurs de spina bifida L’obtention d’une mobilite independante chez les enfants porteurs de spina bifida est souvent emp&chte par les deformations des genoux. Cet article rapporte les resultats du traitement chirurgical de 34 enfants atteints de spina bifida avec deformation du genou. Les techniques chirurgicales sont decrites et I’auteur conclut que la chirurgie est justifiee dans une certaine proportion de cas avec deformations fixies des genoux.
ZUSAMMENFASSUNG
Chirirrgische Behandlung von Kniefehlstellungen bei Kindern niit Spina bijida Die Moglichkeit, sich eigenstandig zu bewegen, ist bei Kindern mit Spina bifida haufig durch Kniegelenksfehlstellungen eingeschrankt. Die vorliegende Arbeit gibt einen Bericht uber die Ergebnisse chirurgischer Behandlungen bei 34 Kindern mit Spina bifida und Kniefehlstellungen. Die chirurgischen Methoden werden beschrieben. Man 1st der Meinung, daR bei einem Teil der Faille mit fixierten Kniefehlstellungen chirurgische Eingriffe gerechtfertigt sind. 113
