Abstract
Background:
Tibia Vara (Blount's disease) is characterized by a growth disturbance of the posteromedial proximal tibial physis. This results in the typically complex tibial deformity of varus, procurvatum and internal tibial torsion. Knee instability is due to medial tibial joint depression and lateral ligament complex attenuation. Femoral angular and rotational deformity are associated features. Obesity often complicates management. Langenskiöld observed six stages of the disorder on X-ray (stage 6 not occurring before 9 years) and obtained good results with proximal tibial realignment osteotomy if performed before the age of 8 years. Our experience is very different.
Purpose:
To evaluate our experience with treatment of a consecutive cohort of patients with early onset Blount's disease in terms of clinical findings, recurrence rate and factors associated with recurrence and treatment methods and indications.
Methods:
A retrospective chart and imaging review was completed of 100 extremities (58 patients) treated surgically for early onset Blount's disease. Follow-up ranged between 1 and 7 years.
Results:
These children all presented with a history of onset of deformity between the ages of 1 and 3 years. Their age at first treatment varied between 2 and 10 years. Langenskiöld stage V and VI occurred in younger patients than originally described.
The recurrence rate of extremities treated with simple osteotomy was 42% (25/58). Factors associated with recurrence include age >4 (p<0.001), obesity (p=0.007), instability (p=0.003), severity of deformity (femoro-tibial angle) (p<0.001), medial physeal slope (p<0.001) and advanced Langenskiöld stage (p<0.001).
Surgical treatment included the use of growth retardation alone, dome realignment osteotomy with and without growth retardation, oblique proximal tibial (Rab) osteotomy, 3-in-1 procedure (medial elevation, tibial osteotomy and lateral epiphyseodesis) and gradual correction with hexapod fixators was used in some recurrent cases. In addition we describe a new surgical technique which obtains acute deformity correction at the level of the growth plate.
Conclusion:
We propose that the disease follows a more aggressive course in the black population of Kwa-Zulu Natal, South Africa. The management is often complex and recurrence is not uncommon.
