EXPERIENCE WITH Ponseti Protocol and Achilles Tenotomy in THE MANAGEMENT OF Clubfoot at the Lagos STATE UNIVERSITY TEACHING HOSPITAL, lagos, Nigeria

Abstract

Background

Achilles tenotomy is very frequently performed to correct persistent equinus deformity in Ponseti clubfoot management worldwide.

Aim

To review the frequency of Achilles tenotomy and outcome of treatment of idiopathic clubfoot using the Ponseti method.

Setting

Lagos State University Teaching Hospital, Lagos, Nigeria.

Design of the study

Prospective observational study

Methodology

All the patients with idiopathic clubfoot treated using the Ponseti protocol in the clubfoot clinic between June 2013 and October 2015 were recruited. The data obtained included biographic data, Pirani score at presentation, number of casts until initial correction, number of feet that had Achilles tenotomy and complications. They were recorded in the International Clubfoot Registry (ICR) hosted by the Centre for Bioinformatics and Computational Biology at the University of Iowa, USA and were analysed using the ICR software.

Results

Of the 124 patients in this study, 77 (62.1%) had bilateral foot deformities (154 feet) and 47 patients (37.9%) had unilateral clubfoot making a total of 201 clubfeet. Their ages at presentation ranged from 1 week to 6 years. Forty (32.3%) patients were aged less than 1 month, 58(46.8%) aged between 1 and 6 months, 12 (9.7%) aged between 6 and 12 months and while 14 (11.3%) aged 12 months and above. There were 77 males and 47 females with a male/female ratio of 1.6:1. The initial Pirani score was 4 and above in 140 feet with a mean of 4.3. Correction was achieved after a mean of 5.2 casts and tenotomy was performed in 45 (23.1%) feet before foot abduction brace application.

Conclusion

This study has shown that congenital idiopathic clubfeet can be managed with good outcome using the Ponseti protocol with a reduced frequency of Achilles tenotomy.

Introduction

The Ponseti method of non-operative management of congenital clubfoot is widely acknowledged as the gold standard worldwide, reducing the need for extensive surgery1. Studies have yielded good results on long-term follow-up and even non-medically qualified personnel have been trained to practice this method in resource-challenged communities1,2. In Nigeria, the method has become quite popular and early results have been comparable with others3.

The Ponseti method entails weekly serial manipulation and casting according to a specific protocol followed by heel cord tenotomy when necessary. Thereafter, the lower limb is placed in a long leg cast in 90 degrees flexion and 70 degrees abduction for three weeks. As soon as correction is achieved, a foot abduction brace is worn 23 hours a day for 3 months and at nap and night time for 3-4 years4.

Achilles tenotomy is usually performed if there is a persistent equinus after the lateral head of the talus is reduced onto the navicular. Some authors found that the degree of equinus and the rigidity of the foot are predictors of the need for tenotomy. They also found out that the feet that corrected after tenotomy were equally well corrected as those who did not require tenotomy5. A significantly higher Pirani score has been reported in feet requiring tenotomy, the hind foot score being a better predictor of tenotomy than the midfoot score6. In the study quoted, 92% of the feet with Pirani score of 4 or more required at least 4 casts before correction. Anaesthetic protocols for tenotomy differ, some are performed under local anaesthesia, others under general anaesthesia or sedation5,7,8. Most practitioners use surgical blades for percutaneous tenotomy but a modification using a large gauge hypodermic needle has been described9.

Complications of Achilles tenotomy reported in the literature include bleeding from damage to the peroneal artery and lesser saphenous vein and a pseudoaneurysm 7,10. One author reported injury of the posterior tibial artery and nerve which required exploration, ligation of the posterior tibial artery and primary repair of the posterior tibial nerve11. The observations regarding the vascular anomalies in the lower limbs of patients with idiopathic clubfoot12,13,14 has led some authors to routinely perform doppler ultrasound studies before performing percutaneous tenotomy7. A mini-open technique has also been described to reduce the complication rate as compared with the percutaneous technique. Ankle dorsiflexion following the percutaneous procedure usually improves by 10-15 degrees only but the mini-open technique improves it up to 30 degrees15. Sometimes, tenotomies need to be performed more than once on account of recurrence but ultrasonographic studies have shown that tendon healing is not complete after tenotomy until about 12 weeks and as such, there is a need to wait for a minimum of 12 weeks before a repeat tenotomy is performed16.

Reports vary regarding the number of feet that undergo tenotomy before correction, but most studies report between 70% and 90%1,4,17. In a previous publication 3, the procedure was performed on only 26.6% of the feet, and this was attributed to the fear of complications since general anaesthesia was not readily available and the children often had to be physically restrained even after administering local anaesthesia. In spite of the relatively low tenotomy rate in this series, correction was achieved within the average time reported by other authors.

This study is a review of our experience with tenotomy in Ponseti management of idiopathic club feet. We reviewed our technique, complications and the number of casts applied until correction was achieved.

PATIENTS & METHODS

All the patients who visited the clubfoot clinic with idiopathic clubfoot from June 2013 to October 2015 were recruited in the study. Patients who defaulted before initial correction was achieved and those with syndromic and neurological clubfoot were excluded. All the patients were treated according to the Ponseti protocol after obtaining informed consent and permission was obtained from the parents to take photographs. Approval was given by the hospital research and ethics committee to carry out this study. No x-rays were performed on any of the patients.

After correction of the cavus and heel varus, ensuring that the head of talus was covered, heel cord tenotomy was performed for patients who had persistent equinus (Pirani rigid equinus score of 1 or 0.5) by the authors under local anaesthesia. Local infiltration of 0.2-0.3 mls of 1% lignocaine was given using a 1-ml syringe around the Achilles tendon about 1cm proximal to its insertion into the calcaneus. All the tenotomies were performed using a size 18 G hypodermic needle, introduced from the medial side of the tendon. The procedures were performed in the clubfoot clinic with sterile materials. A long leg cast with the knee flexed to 90 degrees was applied with the feet in 70 degrees of abduction for three weeks, and a Steenbeck foot abduction brace was applied immediately after cast removal. The patients were followed up at 3-month intervals specifically to check for signs of relapse for a minimum of one year.

The patients’ visits were recorded in the international clubfoot registry (ICR) hosted by The Center for Bioinformatics and Computational Biology at the University of Iowa, USA. Biographic data, Pirani score at presentation, number of casts until initial correction, number of tenotomies, complications and relapse were recorded and analysed using the ICR software.

Results

A total number of 124 patients with idiopathic clubfeet were recruited into this study, 77 (62.1%) of them had bilateral foot deformities making a total of 201clubfeet. Their ages at presentation ranged from 1 week to 6 years. Forty (32.3) patients were aged less than 1 month, 58(46.8%) aged between 1 and 6 months, 12 (9.7%) aged between 6 and 12 months while 14 (11.3%) aged 12 months and above as shown in Fig.1. There were 77 males and 47 females with a male/female ratio of 1.6:1 (Fig.2). The initial Pirani score was 4 and above in 140 feet and the mean Pirani score was 4.3. (Fig.3).

Fig. 1: Grouped Age.

Fig. 2: Sex Distribution.

Fig. 3: Pirani Score at Presentation.

Initial correction was achieved after a mean of 5.2 casts before abduction brace application. Of the total number of idiopathic clubfeet, 45 (23.1%) had tenotomy before the final three-week cast (Fig.4). No patient had a repeat tenotomy.

Fig. 4: Tenotomy Distribution.

The feet that had tenotomy had a mean of 5.9 casts. The mean cast per foot for patients who did not have tenotomy was 4.9. One patient had bleeding after tenotomy due to a suspected peroneal artery injury. Relapse was observed in 11 (5.6%) feet after at least one year of follow-up.

Discussion

The main findings of this study were the severe deformities the patients presented with and the low tenotomy rate. Treatment outcome was good and the mean number of casts applied before correction was within usual limits. The age and sex range of the patients with clubfoot seen in our series is similar to our previous series, but some of our patients still present at walking age (14.9%). The mean Pirani score of 4.3 indicates that our patients generally have rather severe deformities. These findings are similar to our previous findings3,18.

It is known that tenotomies when performed, reduce the number of casts applied before correction. However, the average number of casts in this study was 5.2 which fell well into the range of the findings of other authors 11,19. With a tenotomy rate of 23.1%, lower than the rate of other series,1,4,17 further studies would be needed to determine the place of tonotomy in the management of clubfoot. However, amongst the cases that eventually had tenotomy, more casts were applied with the average being 5.9. This indicated that tenotomies should be done when absolutely indicated. Furthermore, the clubfeet seen in this study did not appear to be less severe than in other series10, 19.

The limitations of this study included the small sample size and the short follow-up period following treatment.

Conclusions

This study has shown that congenital idiopathic clubfeet can be managed with good outcome using the Ponseti protocol with a reduced frequency of Achilles tenotomy.