1 Introduction

Osteogenesis imperfecta (OI), is characterized by bone fragility, multiple bone fractures, resultant bony deformities, and short stature.¹ It is a connective tissue disorder, most cases caused by mutations in COL1A1 and COL1A2 genes, encoding type I collagen. The abnormal collagen production leads to its rapid degeneration (in severe OI) and its clinical features. Mutations in several other genes have also been described that can cause OI, some of which affect post-translational modification of collagen and others that affect bone formation. Many patients may have no family history. The severity of this disease is classically graded by Sillence classification.^2,3 The spectrum can be as severe as lethal presentation (type II), with multiple repeated fractures during infancy and whole childhood (type III & IV) (see Fig. 1)

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Fig. 1 Clinical and radiological images.

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Based on the presentation of multiple low-energy trauma fractures during infancy, the diagnosis of OI is usually obvious clinically. OI is a rare disease with reported population frequencies of type I OI in the range between 2.35 and 4.7 in 100,000 worldwide.⁴ The exact incidence of types III and IV OI is not known, although the incidence is much less common than in types I.^2,3

Congenital talipes equinovarus (CTEV), or clubfoot, is a structural malformation that develops early in gestation. The reported incidence of clubfoot in India is 1.19 of every 1000 children born.⁵ The combination of these two diseases in children makes it a very rare one.

2 Case report

We report the case of a male child with idiopathic clubfeet with OI type III. Eight months old child was bought to us for deformity over both feet since birth. There was forefoot adduction, cavus of the midfoot and hindfoot was in equinus and varus deformity. On examination, Spine, hips, and other limbs were normal. The child was diagnosed with bilateral idiopathic congenital talipes equinovarus deformity.

The patient had a history of left side shaft humerus fracture 5 days after birth. In the next month, the other side's humerus fractured followed by shaft femur fracture of the left side, after 3 months. All fractures were treated conservatively with splints. Presently, all fractures are in healed status. With the background of multiple fractures, the child was diagnosed with OI type III by whole genome sequencing. Intravenous (IV) bisphosphonate (Zoledronic acid) therapy was started. Before the start of casting, two cycles of zoledronic acid infusion were given to the child.

Owing to the multiple fractures, serial manipulation and casting for clubfeet was deferred by previous treating doctor. Therefore, Casting for clubfeet was started at the age of eight months. The Pirani scores⁶ of the child at the time of presentation were 5 & 5.5 on the left and right foot respectively (Table 1). We started casting following the Ponseti method. While Ponseti casting, besides the usual method, we took extra precautions to avoid fractures in this child with OI. The child was gently put on a soft mattress (small size), calming the child from a head end. We did extremely gentle manipulation for at least 5 ​min before Ponseti casting. We used regular plaster of Paris (POP) bandages for casting. We did not use fibre or woodcast as POP provides better molding of foot without applying undue pressure. Casting was done toe to high groin. Parents were advised to avoid dangling the child with cast, to prevent any pathological fracture at proximal end. The patient was called weekly, for cast change and manipulation. At every visit, Pirani scoring was done. By the end of the application of the 7th cast, we achieved full talar head coverage with 50° of abduction. The Midfoot score was 0 and the hindfoot score was 1.5. Percutaneous tendoachillis tenotomy (PCTA) was planned. The child was taken under general anesthesia. This was done, to avoid undue resistance from the child while doing manipulation of foot. PCTA was done with a 15-number surgical blade and hemostasis was achieved. After thin cotton padding below knee pop was applied which was extended into above knee pop cast with the knee in 90–100° of flexion. No undue forces were applied and we applied cast gently at 10° of dorsiflexion, this was done to avoid iatrogenic distal tibia fracture as it can happen while forced dorsiflexion. The cast was given for 3 weeks. After the removal of the final cast, the maintenance phase was started. The child was given a foot abduction brace (23 hours a day). We used a Steinbeck foot abduction brace for this purpose. The patient was called after 4 weeks for periodic evaluation. At six months follow up, full correction is maintained.

3 Discussion

Long bone fractures can occur during difficult labor. If we Exclude trauma and child abuse, long bone fractures or multiple fractures during the neonatal period may signify underlying bone pathology. Hence timely diagnosis has an important role in further management. The two most important causes of multiple bone fractures in neonates are the metabolic bone disease of prematurity and Osteogenesis imperfecta (OI).⁷ Diagnosing OI requires a high degree of clinical suspicion along with radiological investigations. Although Genetic testing remains the gold standard for diagnosis of OI, the vast majority of children can be diagnosed with OI (72%) based solely on clinical grounds.⁸ In our case, we have diagnosed OI, by whole genome sequencing. The presence of another orthopedic pathology along with OI makes it a difficult entity to address considering the associated bone fragility. There is a greater risk of iatrogenic fracture, in cases of clubfoot associated with OI. Treatment of clubfoot requires serial manipulation and casting for several weeks. There are reported cases of metaphyseal bony injury that can happen during forced dorsiflexion With Ponseti casting.^9,10

To our knowledge, there are only two case reports of the association of with OI available globally.^11,12 To the best of our knowledge, this is the first case report in the Indian subcontinent. The combination of clubfoot with osteogenesis imperfecta makes it a very rare entity. Munns et al.¹² reported in his case about the mother's exposure to pamidronate which may have been the causative factor for the clubfoot. In our case, there was no significant history of such exposure during the antenatal and postnatal periods. The child's parents are not having a consanguineous marriage. In recent years growth hormone (GH) and bisphosphonate have been used in OI therapy. Bisphosphonate therapy has a beneficial role in children with OI.¹³

Our case child is taking medical treatment as intravenous zoledronate therapy. The zoledronate therapy was started as soon as child was diagnosed with OI type III. All old fractures are now in healed status. With the start zolendronate therapy there are no new fractures and the child is achieving all his age-related milestones. Association of clubfoot with OI made it difficult to deal with. All serial manipulations were done with extra precautions. With Ponseti casting, it was possible to correct the deformity, without causing pathological fractures. We recommend, bisphosphonate therapy can be started prior to initiation of casting and extra care while handling such a combination case.

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Informed consent

Informed consent was taken from parents of child for this publication.

Declaration of patient consent form -

Patient's parents declare no conflict of interest in publishing the case.

Report for academic purposes.

Author contribution

1^st author contributed as corresponding author and manuscript writing. 2^nd author conceptualized the manuscript and manuscript proof reading. 3^rd author contributed as manuscript writing and proof reading.

Ethical approval

This study has been duly approved with our institutional ethical committee.