Blount’s disease, also known as tibia vara, is a developmental disorder involving the posteromedial proximal tibial physis resulting in progressive varus, procurvatum and internal torsion of the affected tibia 1. The condition was first published by Blount in 1973 2. The aetiology of this disease is unkown. However, associations exist between blount’s disease and the Afro-Caribbean race, early age of walking and obesity 34. Furthermore, genetic predisposition has been postulated as well as mechanical loading of the physis. 456 Affected children are usually overweight and start walking early. The role of weight bearing in the pathogenesis of tibia vara was demonstrated in a study by Cook and others 5 who concluded that weight bearing was necessary for the disease to occur, since it is almost never diagnosed before 2 years of age. The disease often manifests after at least 1 year of walking and is never encountered in non-ambulatory children. Blount’s disease is a progressive disorder which if left untreated leads to premature physeal arrest at the proximal posteromedial tibia with a resultant varus deformity of the proximal tibia.

16. It is bilateral in 80% of cases 7 and a cause of significant knee pain and activity limitation among affected children and adolescents.

A 13-year old boy presented to our hospital with a 10-year history of progressive severe lateral bowing of both legs which was noticed by the mother when the child was 3 years of age. Lateral bowing of the legs had become so severe that his walking had become limited to a few meters, beyond which he developed knee pain. He was borne to a 38-year old multiparous petty trader.

Physical examination revealed a boy who looked well with bilateral tibia vara, procurvatum and internal tibial torsion, Figure 3. There was a palpable posteromedial metaphyseal beak. There were no abnormalities detected in other systems.  

There was a varus angle of 70 degrees as measured by a goniometer when weight-bearing. The range of motion in both knees was 0-100 degrees. X-ray confirmed a Langenskiold stage VI tibia vara on either side, Figure 4.

He was then prepared for operative correction of the deformity and surgery was performed.

The diagnosis of infantile blount’s disease is made clinically and confirmed with plain radiographs of the affected limbs.

The efficacy of bracing as a method of treatment is yet to be proven 4. There are limited reports in the last decade on the use of proximal tibial osteotomy in the correction of this deformity. Acute or gradual correction are both appropriate treatment options 4.

Early surgical intervention at the early stages of the disease results in a low incidence of recurrence of the deformity and reduced knee symptoms at skeletal maturity 15. Patients with blount’s disease should be managed operatively as soon as the disease is diagnosed since the deformities worsen if left untreated 15.

When neglected, blount’s disease is characterized by multiple deformities and a detailed patient-specific treatment plan is mandatory 16. Tibial valgus osteotomy does not offer adequate correction of the deformity and additional elevation of the depressed tibial plateau is essential 16 i. e. ‘double corrective osteotomy’ of the tibia, with medial plateau elevation. It is a demanding and a relatively high-risk procedure. However, in spite of the technical difficulties, it offers favourable results in Langenskiold and Riska stage V or greater 16.

The use of the Taylor Spatial Frame or the Ilizarov Frame are modern treatment mothods that allow gradual correction as well as weight-bearing throughout the treatment period 16. Their main demerits are their relatively high cost and the complexity of their application.

Operative treatment of blount’s disease requires corrective osteotomy, proximal tibila physeal distraction, physeal bar resection and elevation of the medial tibial plateau; lateral hemiepiphyseodesis is recommended particularly in young patiennts 17.

Osteotomy and gradual deformity correction of either infantile or adolescent blount’s disease with the use of a circular external fixation offers satisfactory correction without significant complications 18.

The risk of recurrence of the deformity is related to the poor growth potential of the posteromedial proximal tibial physis 19. Young age of patient and disease severity are the important determinants of deformity recurrence, being 50% for Langenskiold stage III and 69.6% for Langenskiold stage IV respectively. Age 5 seems to be a critical transition in the risk of recurrence of deformity after osteotomy of the tibia.

After high tibial osteotomy or in combination with epiphysiodesis, severe vertical sloping of the metaphyseal defect carries a poor prognosis for success 14. The complications reported in the literature after high tibial osteotomies are: common peroneal nerve palsy, compartment syndrome, haematoma, deep vein thrombosis, osteomyelitis, delayed union, malunion, non-union and infarction of the proximal tibia 2021

In 1964, Langenskiold and Riska described elevating the medial plateau in late cases of infantile Blount’s disease 2. Gradual correction using the Ilizarov method for Langenskiold types IV, V and VI has also been described 1. There are various treatment methods of this condition with varying degrees of efficacy and ease of application. Studying the various methods for the correction of neglected blount’s disease will enhance the development of treatment algorithms 22232425.

In this report we present our correction procedure for Langenskiold Type VI with a single-stage double tibial osteotomy and maintenance of correction of deformity with a Taylor Spatial Frame. Figure 5, Figure 6.

We have presented our management of a boy with a late-presenting infantile tibia vara langenskiold type VI using a single-stage double osteotomy of the tibia and fibular-shortening osteotomy. The child had knee pain, abnormal gait and a cosmetic stigma which limited his social integration and activities of daily living prior to surgery. Our surgical intervention has restored him to the company of his peers by successfully correcting his limb deformities. He now ambulates without knee pain, has a remarkable improvement in his gait, no lateral knee thrust, no limb length discrepancy and is able to participate in activities at a higher level and is cosmetically optimised.

The single-stage double osteotomy surgical technique for correcting neglected tibia vara and Taylor Spatial Frame stabilization of the osteotomy are a feasible method in a low-resource setting. It is a safe and effective method of correction of the disease and has a favourable 2-year outcome. The child would be followed until skeletal maturity for recurrence due to unpredictable proximal tibial physeal growth.

Nil