Arthrogryposis multiplex congenita

Between 1994 and 1997 we used the Ilizarov apparatus to treat 12 recurrent arthrogrypotic club feet in nine patients with a mean age of 5.3 years (3.2 to 7). After a mean of three weeks (two to seven) for correction of the deformity and 1.5 weeks (one to four) for stabilisation in the apparatus, immobilisation in a cast was carried out for a mean of 14 weeks (7 to 24). The mean follow-up period was 35 months (27 to 57).

Before operation there were one grade-II (moderate), eight grade-III (severe) and three grade-IV (very severe) club feet, according to the rating system of Dimeglio et al. After operation, all the club feet except one were grade I (benign) with a painless, plantigrade platform. Radiological assessment and functional evaluation confirmed significant improvement. Two complications occurred in one patient, namely, epiphysiolysis of the distal tibia and recurrence of the foot deformity. These results suggest that our proposed modification of the Ilizarov technique is effective in the management of recurrent arthrogrypotic club foot in young children.

J Bone Joint Surg [Br] 2001;83-B:731-7.

Received 9 February 2000; Accepted after revision 17 July 2000

The arthrogrypotic club foot is rigid and difficult to treat, and the deformity tends to recur after treatment. Relapse occurs in growing children after primary posteromedial release (PMR)1 or posteromediolateral release.2 Repeated soft-tissue procedures are unreliable due to postoperative scarring. Some authors recommend talectomy as a salvage procedure for recurrent or severe primary deformity.3,4 Gross5 described the Verebelyi-Ogston procedure, consisting of subchondral removal of cancellous bone from the cuboid and talus. These procedures should, however, be a last resort for correction of a stiff, multiply-operated foot since both operations leave residual incongruity at the ankle.

The Ilizarov technique has been suggested as an alternative to major surgery for the treatment of neglected or recurrent deformities in club foot.6-10 We report our experience of a modified Ilizarov method for the correction of recurrent arthrogrypotic club foot, in patients who had previously undergone one or more soft-tissue procedures.

Patients and Methods

Between 1994 and 1997, we treated nine consecutive children (six boys and three girls) with 12 recurrent arthrogrypotic club feet by the Ilizarov method (Table I). All were able to walk. Their mean age at the time of surgery was 5.3 years (3.2 to 7). They had had a mean of 1.8 (one to three) previous operations, including lengthening of tendo Achillis, PMR,1 and posteromediolateral release.2 Two referred patients (cases 3 and 5) were known to have had lengthening of tendo Achillis during infancy to give better control of the hindfoot equinus during management by a plaster cast.

The results were assessed by comparing the appearance, radiographs, and function before and after the operation. The classification developed by Dimeglio et al11 was used which included equinus deviation in the sagittal plane, varus deviation in the frontal plane, denotation of the calcaneopedal block in the horizontal plane, and adduction of the forefoot relative to the hindfoot in the horizontal plane. Radiological measurements included the talocalcaneal (TC), the calcaneal-second metatarsal (Cal-2nd MT), and the talo-first-metatarsal (Talo-Ist MT) angles obtained on the standing anteroposterior radiograph. They also included the calcaneal-first-metatarsal (Cal-1st MT), the TC and the tibiocalcaneal (Tibio-cal) angles on the lateral radiograph in maximum dorsiflexion.12 Function was measured using the ankle-hindfoot clinical rating system of the American Orthopaedic Foot and Ankle Society (AOFAS).13

Statistical significance was analysed by the Wilcoxon signed-rank test of the SPSS system 10.0 (SPSS Inc, Chicago, Illinois, USA). A p value of

Operative technique. Before application of the preconstructed Ilizarov frame (Fig. 1a), a small longitudinal skin incision, approximately 2 to 3 cm in length, was made on the medial aspect of the talonavicular (TN) joint. Through this incision, we divided the posterior tibial tendon, if it remained. We then resected, in part, the dense mass of fibrous tissue around the medial aspect of the TN capsule and the plantar aspect of the foot (Fig. 1b). The dissection was deepened until the medial aspect of the head of the talus was seen. If necessary, additional soft-tissue release was combined with the dissection (Table I).

A two-ring Ilizarov frame was applied to the proximal and distal tibia using small transfixion wires (1.5 or 1.8 mm in diameter) and half-pins (5 mm in diameter). The fibula was not fixed by pins. The foot assembly was constructed using a half-ring for the hindfoot and another half-ring for the forefoot in the usual manner. Hinges and threaded rods were then assembled to allow concomitant correction of the forefoot adduction, midfoot cavus, and hindfoot equinus and varus deformities. Under fluoroscopic guidance, an olive wire, coupled to a small washer, was inserted in the mid-portion of the neck of the talus from the lateral side, perpendicular to its longitudinal axis. This wire was gradually pulled towards the medial side, which facilitated derotation of the talus and resulted in an increase in the TC angle. As the orientation of the frame was changed during correction of the deformity, the direction in which the talar pin was pulled was adjusted at the sites of the attachment of the conical washer to the post and its base on the calcaneal half-ring, so that the talus moved in an arc. In three of the later cases (cases 7 to 9) a transfixing pin was inserted in the distal tibial epiphysis to prevent epiphysiolysis. In addition, a Steinmann pin, 2 mm in diameter, was fixed medially into the cuneiforms to prevent epiphysiolysis of the first metatarsal bone (Fig. 1).

Correction was begun on the second or third day after operation. The distraction ranged from 1 to 2 mm in four increments. The rate of distraction was adjusted depending upon the stiffness, the severity of the deformity, and the pain or discomfort. The hindfoot equinus and varus were corrected by distraction of the threaded rods connected between the tibial and calcaneal rings. The ankle was overdistracted for 3 to 5 mm during the procedure for correction of the equinus deformity. The forefoot adduction and the midfoot cavus were managed by differential distraction of the medial and lateral rods connected between the calcaneal and metatarsal rings. Two anterior rods, connected between the tibial and metatarsal rings, were used to correct the hindfoot equinus and forefoot supination by differentially shortening the length of the medial and lateral rods.

When all the components of the deformity were satisfactorily corrected after a mean of three weeks (two to seven), a period of stabilisation followed for a mean of 1.5 weeks (one to four), and then the fixator was removed under general anaesthesia. After inserting two pins longitudinally in the realigned TN and calcaneocuboid joints, all the feet were immobilised in a below-knee cast for a mean of 14 weeks (7 to 24). These two pins were removed between six and 12 weeks after removal of the fixator. All feet were thereafter braced by day and splinted at night. The mean follow-up period was for 35 months (27 to 57).

Results

Before operation there were one grade-II (moderate), eight grade-III (severe) and three grade-IV (very severe) deformities, according to the rating system devised by Dimeglio et al11 (Table II); the mean ankle movement was 22.5 deg (15 to 30). After operation, all of the club feet except one became grade I (benign) with a painless, plantigrade platform (Figs 2 and 3). The range of movement of the ankle was marginally better than before surgery (Table III). In one patient (case 6), who neglected to use bracing and splinting after operation, the foot deteriorated from grade I at follow-up at six months to grade II at 31 months. He has recently had further Ilizarov treatment. This patient had had knee stiffness and a moderate limp because of avascular necrosis of the left hip after a closed reduction for dislocation.

Radiographs showed that all measurements except calcaneal-first-metatarsal angles were significantly improved. The mean AOFAS foot score13 was 57.4 (44 to 69) before and 87.8 (70 to 97) after operation (Table III). This difference was statistically significant.

There was one major complication, epiphysiolysis of the distal tibia during distraction between the tibial and calcaneal rings. This occurred in one patient (case 6) in whom the distal tibial epiphysis had not been transfixed with a wire despite a very stiff ankle. In this patient, the distracted tibial physis was reduced soon after the epiphysiolysis was detected. There was no obvious formation of a physeal bar at the latest radiological follow-up. No patient had radiological signs of avascular necrosis of the talus related to the transfixing pin in the neck of the talus.

Discussion

The purpose of treating an arthrogrypotic club foot is to convert a deformed, rigid structure into a plantigrade platform.14 Soft-tissue release has been the procedure of choice, but remains controversial because of the high reported rate of failure. Although Guidera and Drennan15 performed PMR 28 times in 15 patients with arthrogryposis multiplex congenita, they reported that only seven were considered to be successful. Sodergard and Ryoppy16 have described the largest series of soft-tissue procedures, including PMR, for treatment in patients with arthrogrypotic club feet. In their series, 41 of 72 (57%) equinovarus deformities recurred. As a result of these high rates of failure some authors have advocated more radical operative methods.4,17 The potential disadvantages of talectomy, however, are the difficulty in salvage, and joint incongruity between the tibia and the calcaneus. Triple arthrodesis is not indicated in children.

The Ilizarov technique has recently been suggested as an option for recurrent club-foot deformity.6-10 It is less invasive and allows for simultaneous correction of all components of the deformity without resection of bone or shortening of the foot. Soft-tissue viability and function can be assessed directly, and the rate of correction can be adjusted accordingly. Grill and Franke9 reported the use of the Ilizarov method to treat nine severely deformed feet, with a satisfactory outcome in terms of function and appearance. In their report, a plantigrade foot was achieved in all patients and was confirmed by the radiological appearances. There was, however, stiffness of the subtalar and midtarsal joints in all feet, and the mean range of ankle movement was only 20 deg. Henrik et al10 reviewed the outcome in seven patients with ten idiopathic club feet treated by the Ilizarov external fixator for persistent foot deformities after previous surgery. They reported that six patients and their parents were satisfied with the correction. There was improvement in walking in all patients, except one. None of these series, however, included objective radiological data. We agree with other authors 1,18-20 that anatomical realignment of the mid- and hindfoot is essential to prevent recurrence and achieve a satisfactory outcome, and that this should be confirmed by radiography.

Our modification of the Ilizarov technique is different from those reported previously. We have found that a medial pulling system using an olive pin transfixed into the neck of the talus derotates the talus and restores the TC angle. This is based on the concept proposed by Carroll et al18,21 and others2,12,19 that with medial rotation of the talus and reduction of the head of the talus to the navicular, the foot assumes a normal appearance. This occurs because there is slight external rotation of the body of the talus around a vertical axis in the ankle mortise despite the decreased declining angle of the talus. An attempt to restore the TC angle with the aid of a force pulling medially is only effective when the subtalar and midtarsal joints can be mobilised during correction of the deformity. We believe that a medial pulling system may not be useful in cases in which bony fusion has occurred in the mid- and/or hindfoot or where there is a markedly deformed talus after multiple previous operations. In these cases additional bony surgery may be necessary.

We combined several limited soft-tissue procedures, such as posterior tibial tenotomy and partial capsulotomy of TN and ankle joints, through a small skin incision to localise precisely the distraction stress at the targeted joints in order to facilitate realignment of the mid- and hindfoot. We also limited the time of treatment with the external fixator for correction of deformity and stabilisation to a mean of 4.5 weeks. Most patients could not bear weight properly because of discomfort, and non-compliance results in osteopenia. When the fixator was removed, however, we were surprised to find that most of the feet, which had been scarred and rigid before, had become sufficiently mobile for the mid- and hindfoot to be realigned by manipulation. The corrected position could then be maintained by pins and a cast. Special care was nevertheless taken to maintain the plantigrade position by continuing with the cast, splinting and bracing, and intensive physiotherapy. In one patient, who neglected to use either a night-splint or a brace during the day, the foot deformity recurred and function deteriorated. This illustrates the importance of prolonged bracing and physiotherapy after correction of the deformities of the foot by the Ilizarov method.

Several complications have been reported from the use of the Ilizarov external fixator to correct foot deformities: pin-track infection, dysaesthesia, pain during treatment, subluxation of a tarsal bone, transient nerve palsies, joint contractures and others.9,17,22 Henrik et al10 reported two serious complications; namely anterior subluxation of the talus and partial separation of the distal tibial physis.

We noted transient epiphysiolysis of the distal tibial epiphysis in one of the earlier cases in this series. It is therefore recommended that the distal tibial epiphysis be transfixed to avoid this when the hindfoot is rigidly deformed. An attempt to prevent epiphysiolysis of the first metatarsal by inserting a pin into the cuneiforms may also be justified if the medial column is very short and fibrotic.

The preliminary results in our series clearly showed that our modification of the Ilizarov technique was effective in the management of the relapsed arthrogrypotic foot in young children. After the operation, all feet except one had a painless, plantigrade platform, and were classified as grade I (benign) according to the rating system developed by Dimeglio et al,11 which is a strict system that applies to the arthrogrypotic club foot. Cosmetic and functional improvements were also validated by radiological assessment. The long-term results have yet to be determined. On the basis of this preliminary experience, continued use of distraction by the Ilizarov technique is warranted before resorting to more radical salvage procedures.

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

References

1. Turco VJ. Resistant congenital clubfoot: one-stage posteromedial release with internal fixation: a follow-up report of a fifteen-year experience. J Bone Joint Surg [Am] 1979;61-A:805-14.

2. Simons GW. Complete subtalar release in club feet. Part 1. A preliminary report. J Bone Joint Surg [Am] 1985;67-A:1044-55.

3. Drummond DS, Cruess RL. The management of the foot and ankle in arthrogryposis multiplex congenita. J Bone Joint Surg [BrI 1978;60-B:96-9.

4. Green ADL, Fixsen JA, Lloyd-Roberts GC. Talectomy for arthrogryposis multiplex congenita. J Bone Joint Surg [Br] 1984;66-B:697-- 9.

5. Gross RH. The role of the Verebelyi-Ogston procedure in the management of the arthrogrypotic foot. Clin Orthop 1985;194:99-103.

6. Desgrippes Y, Souchet P, Bensahel H. Use of the Ilizarov external fixator in multioperated, recurrent clubfoot. J Pediatr Orthop 1992;1:181.

7. De la Huerta F. Correction of the neglected clubfoot by the Ilizarov method. Clin Orthop 1994;301:89-93.

8. Grant AD, Lehman WB. Clubfoot correction using the Ilizarov technique. Bull Hosp Jr Dis Orthop Inst 1991;51:84-7.

9. Grill F, Franke J. The Ilizarov distractor for the correction of relapsed or neglected clubfoot. J Bone Joint Surg [Br] 1987;69-B:593-7.

10. Henrik W, Goran H, Bjorn T. Correction of persistent clubfoot deformities with the Ilizarov external fixator. Acta Orthop Scand 1996;67:283-7.

11. Dimeglio A, Bensahel H, Souchet P, Mazeau P, Bonnet F. Classification of clubfoot. J Pediatr Orthop B 1995;4:129-36.

12. Simons GW. Complete subtalar release in club feet. Part II. Comparison with less extensive procedures. J Bone Joint Surg [Am] 1985;67-A:1056-65.

13. Kitaoka HB, Alexander IJ, Adelaar RS, et al. Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes. Foot Ankle Int 1994;15:349-53.

14. Lloyd-Roberts GC, Lettin AWE Arthrogryposis multiplex congenita. J Bone Joint Surg [Br] 1970;52-B:494-508.

15. Guidera KJ, Drennan JC. Foot and ankle deformities in arthrogryposis multiplex congenita. Clin Orthop 1985;194:93-8.

16. Sodergard J, Ryoppy S. Foot deformities in arthrogryposis multiplex congenita. J Pediatr Orthop 1994;14:768-72.

17. Segal LS, Mann DC, Feiwell E, Hoffer MM. Equinovarus deformity in arthrogryposis and myelomeningocele: evaluation of primary talectomy. Foot Ankle 1989;10:12-6.

18. Carroll NC, McMurtry R, Leete SE The pathoanatomy of congenital clubfoot. Orthop Clin North Am 1978;9:225-32.

19. Howard P, Dias L. Medial rotation of the talus and complete calcaneocuboid release: its effect on the surgical results in idiopathic clubfoot. In: Simons GW, ed. The clubfoot: the present and a view of the future. New York, NY: Springer-Verlag, 1994:209-15.

20. McKay DW. New concept of and approach to club foot treatment. Section II: correction of the club foot. J Paediatr Orthop 1983;3:10-21.

21. Carroll NC. Controversies in the surgical management of clubfoot. International Course Lecture 1996;37:331-7.

22. Atar D, Lehman WB, Grant AD. Complications in clubfoot surgery. Orthop Rev 1991;20:233-9.

I. H. Choi, M. S. Yang, C. Y. Chung, T. J. Cho, Y. J. Sohn

From Seoul National University Children's Hospital and Clinical Research Institute, Seoul National University Hospital, Korea

I. H. Choi, MD, Professor

M. S. Yang, MD, Chief Resident

C. Y. Chung, MD, Associate Professor

T. J. Cho, MD, Assistant Professor

Y. J. Sohn, MD, Clinical Fellow

Department of Orthopaedic Surgery, Seoul National University Children's Hospital, 28 Yongon-dong, Chongno-ku, Seoul 110-744, Korea.

Correspondence should be sent to Professor I. H. Choi.

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