Results of the Ponseti Method in Patients with Clubfoot Associated with Arthrogryposis

Abstract

Clubfoot associated with arthrogryposis has been traditionally considered very resistant to manipulation and casting, and therefore has required surgical correction. The purpose of this study was to evaluate the results of the Ponseti method of clubfoot casting in this patient population. We reviewed the records of patients with clubfoot associated with arthrogryposis consecutively treated at our respective institutions from January 1992 to December 2004. All patients were treated by serial manipulations and casting following the principles of the Ponseti method. Main outcome measures included initial correction of the deformity, relapses and the need for surgical releases or any other surgeries. Average age at last follow up was 4.6 years. There were 16 patients, all with bilateral deformities (32 clubfeet). there were 11 males and 5 females. Nine patients had both upper and lower extremity involvement. Seven patients had previous treatment elsewhere and one patient had an Achilles tenotomy. Initial correction was obtained in all but 1 patient. Average number of casts required for correction was 7 (range: 5 to 12). Average post-tenotomy dorsiflexion was 5 degrees. One patient required a posterior-medial release (PMR) for insufficient initial correction. Four cases required subsequent surgery for relapses (1 bilateral PMR with a repeat left PMR; 2 posterior releases (PR), 1 PR and anterior tibialis transfer (ATT), and 1 ATT). No talectomies were required. This study demonstrates that the Ponseti method is very effective for the correction of patients with clubfoot associated to arthrogryposis. Although this deformity is more rigid than in idiopathic clubfoot, many cases can be corrected when started in the first few weeks after birth.

INTRODUCTION

Arthrogryposis includes a heterogeneous group of disorders characterized by multiple, generally non-progressive joint contractures. More than 100 disorders are included in that classification, but most of these disorders share common deformities including clubfeet, flexed or extended knees, hip dislocations, and upper extremity deformities.

Clubfoot in arthrogryposis is very rigid, difficult to correct, and tends to recur. As in other cases of club foot, the goal in treating this deformity “is to convert a deformed, rigid foot into a plantigrade platform,” as stated by Lloyd-Roberts and Lettin.¹ However, because of the clinical features, the method of correction is controversial. Traditional manipulation and serial casting usually required months of treatment and frequently resulted in incomplete or defective corrections. As a result, the alternative of extensive corrective surgery had been indicated in the majority of the cases; unfortunately, surgery still often resulted in a high failure rate and number of complications.^2–6 These disturbing results led some authors to recommend primary correction by talectomy.^7–15

The excellent results obtained using the Ponseti method in patients with very rigid idiopathic clubfoot led to the expansion of our traditional indications to include arthrogryposis rather than defaulting to extensive corrective surgery or talectomy. The purpose of this study was to evaluate the results of the Ponseti method in this patient population.

METHODS

We reviewed the records of 16 patients diagnosed with clubfoot (32 clubfeet) associated with arthrogryposis treated with the Ponseti method.¹⁶ Studies were performed with the approval or our Institutional Review Board (IRB). We evaluated the following variables: age of the patient at first visit to our institution, previous treatment and type of treatment before referral, number of casts, previous Achilles tenotomy, number of casts required for correction at our institutions, need for percutaneous Achilles tenotomy, and degree of ankle dorsiflexion after tenotomy. Main outcome measures included successful initial correction of the deformity, relapses and the need for surgical releases or any other surgeries. The average age at last follow up was 4.6 years (range, 10 months to 12 years).

RESULTS

There were 11 males and 5 females. Average age at first visit was 3 months (range: newborn to 12 months). Nine patients had both upper and lower extremity involvement. Eight patients had an ultrasound during pregnancy, five of which were diagnosed with clubfoot at an average of 16 weeks (range: 10 to 20 weeks). Seven patients had previous casting treatment elsewhere with an average of 6 casts (range: 1 to 18 casts) and one patient had an Achilles tenotomy. No patient had surgical releases prior treatment at our institutions.

Initial correction by manipulation and casting was obtained in all but one patient. Thirteen patients required less than 7 casts for correction, with one patient requiring 12 casts (Figure 1). Fifteen patients required an Achilles tenotomy with an average post-tenotomy dorsiflexion of 5 degrees (range: 0 to 15 degrees). One patient had skin breakdown secondary to cast problems and one patient had overcorrection at the midfoot that resolved spontaneously over time (Figure 2). No infections, profuse bleeding or skin slough were observed after tenotomy. The post casting brace was worn for an average of 3.6 years (range: 3 months to 4.5 years).

Figure 1.

Newborn patient with distal arthrogryposis affecting both upper and lower extremities. A) Hand deformities. b) bilateral club-feet with mild knee flexion contracture. c) Note the severe hindfoot deformity. D) results after manipulation and casting (12 casts) at the age of 8 months. Note the increased flexibility of the ankle and maintenance of the full correction of the deformity. E and F) clinical results of the upper and lower extremity deformities at 4 years of age. Note full correction of the clubfeet.

Figure 2.

Two-month-old baby with midfoot overcorrection during manipulation and casting. This deformity resolved spontaneously with time.

One patient required a primary posterior-medial release for insufficient initial correction. Four patients had a relapse (25%) and required subsequent surgery: one case of bilateral postero-medial releases with repeat left postero-medial release; two cases of posterior releases; one case of posterior release and anterior tibialis transfer, and one case of bilateral anterior tibialis transfers. No surgical complications were noted in these cases. No talectomies were required (Table 1).

TABLE 1.

Age first visit (months)	Gender	Extremity Involvement	Previous Treatment (# cast)	# Ponseti casts	Relapses	Age at last Follow-up (mo)	Surgery
5	M	Both	12	1	1	41	PR + TLA + ATT
2	M	Both	7	4	1	9	2nd tenotomy
9	F	Both	18	3	0	21	PMR
0	F	Both	0	10	0	69	Bilateral PMR—left repeat PMR
1	M	Lower	0	3	0	15
1	F	Both	0	7	0	10	PR
0	F	Lower	0	6	1	145
0	M	Both	0	6	0	50
0	M	Lower	10	10	1	46
1	M	Both	2	6	0	67
4	M	Lower	0	6	0	69
3	M	Both	2	6	0	76
2	M	Lower	0	5	0	72
2	M	Lower	0	6	0	73
2	M	Both	1	6	0	72
12	F	Lower	0	12	1	51	TAL + ATT

PMR: Postero-medial release; PR: Posterior release; TAL: TendoAchilles lengthening; ATT: Anterior Tibialis Transfer to third cuneiform

DISCUSSION

Arthrogryposis represents a large group of disorders, all of which include multiple joint contractures and dislocations present at birth. There are 113 entries for distinct syndromes coded under the term “arthrogryposis” on the Online Mendelian Inheritance in Man (ONIM) web-site, caused by a wide variety of etiologies.¹⁷ Although individual syndromes have different clinical courses and prognoses, orthopaedic management for many of these disorders follows similar guidelines: self care with the upper extremities and ambulation with stable, aligned lower extremities. Overall outcomes tend to be better when treatment is started at a younger age, usually before adaptive changes occur. Early motion and avoidance of prolonged immobilization may increase joint stability, thereby improving function.

A severe, resistant clubfoot is the most common foot deformity associated with arthrogryposis. Its correction has been always been very difficult and fraught with complication and relapses. Surgery for clubfoot was traditionally delayed until after the management of larger joints such as the knee, usually after 1 year of age. The orthopaedic literature suggests that primary talectomy is the procedure of choice for correction because of the high incidence of failed soft tissue surgery.^7–15 However, recent reports show better outcomes with circumferential release alone if performed before 1 year of age.

Drummond and Cruess reported clubfeet associated with arthrogryposis that underwent posterior releases relapsed in 74% of cases. And all children eventually had recurrence of their deformity, measured at an average of 12 years of age.² Other authors have found similar rates of failures.^3,4,5 Interestingly, Zimbler and Craig and Widmann et al. found that radical releases performed in younger patients (less than 1 year) had a lower relapse rate than posterior releases only.^5,6 However, these patients required circumferential tendon resections, Steinmann pinning across the tibio-talar joint for 6-8 weeks postoperatively, and full time use of orthotics after surgery until skeletal maturity.

In this study, we found that manipulation and casting resulted in the initial correction of the clubfeet deformity in 90% of the patients. This correction could be achieved with an average of 7 casts changed weekly. In only one case, 12 casts were required, and this patient was the oldest in this series (12 months old at the initiation of treatment at our institution). Only one patient failed correction and required early surgical releases. One patient had overcorrection of the midfoot, which spontaneously resolved over time. To avoid this, we believe it is better to obtain only 40-50 degrees of abduction of the foot rather than overstressing the foot to get the usual 70- degrees recommended with idiopathic clubfeet.

We found that after Achilles tenotomy, ankle dorsiflexion (average 5 degrees) is less than in cases of idiopathic clubfeet (average 20 degrees).¹⁸ However, we have observed clinically that the foot and ankle flexibility improves over time with the use of the brace. Further-more, several cases surprisingly improved dramatically by 3-4 years of age with feet looking very similar to idiopathic clubfeet.

With regard to maintenance bracing, it is important to adjust the rotation of the shoes to the degree of abduction and dorsiflexion provided by the final cast post tenotomy. In general, we have found that the 70 degrees of abduction recommended in idiopathic clubfeet is difficult to achieve and in most cases an average of 50 degrees the most that is possible. The shoes of the brace should be placed accordingly. Since ankle dorsiflexion is usually only 5 degrees in a corrected foot, bending the bar between the shoes may put extra pressure on the feet, so much so that the child may not tolerate the brace. Therefore, since the brace is of utmost importance to maintain the child’s foot correction, it is important to remove only enough bend for compliance. As flexibility of the feet progresses over time, more bend in the bar can be added.

Finally, relapses are relatively common (25%) and not always related to non-compliance using the brace, but to the underlying stiffness associated with the disorder. Relapsed feet can be treated with repeat manipulations and casting, followed by Achilles tenotomies. In older children (>3 years of age), if flexibility is restored, an anterior tibialis transfer could be added to balance the foot and prevent further relapses. In only 3 cases a posterior release was required to obtain full correction. Importantly, this was a relatively small operation without complications in our hands. To date, no patient has required a talectomy.

In conclusion, the Ponseti method of manipulation and serial casting is very effective for initial correction of patients with clubfoot associated to arthrogryposis. Although surgery may be necessary, it is less extensive than previously report and has minimal rate of complications.