Tibia vara (TV) or Blount’s disease is a growth abnormality of the medial part of the physis and proximal tibial epiphysis, resulting in a three-dimensional deformity of the lower limb, the main axial abnormality being progressive genu varum [1]. It occurs mainly in children during growth and presents in two main clinical forms: the infantile form, which appears before the age of 4, and the juvenile/adolescent form, which begins after the age of 10 [2]. Several techniques have been described in the literature, but none have been unanimously accepted, particularly for advanced cases in which residual deformities and recurrences are common. Some authors recommend a multi-stage approach to address these complications and achieve complete anatomical correction and joint stability. We report a case of very advanced Blount’s disease in a 13-year-old adolescent girl who underwent sequential, long-term treatment. The aim is to demonstrate the role of this therapeutic approach in the management of advanced and complex cases of Blount’s disease.

Surgical management was indicated for the patient. It was performed in three stages.

The post-operative course was marked at 3 months by suppuration of the wound, requiring debridement in the operating theatre.

At the last follow-up at A1 + M2 post-op, she presented (Figure 11):

Independent walking with slight limpingA normally aligned limb A 2 cm difference in leg length Complete healing of the wounds No pain

The external fixator was removed 8 months post-operatively (Figure 12).

Figure 11. Complete correction of varus and recurvatum at the last follow-up.

Figure 12. X-ray after removal of the external fixator.

Blount’s disease, or tibia vara, is a rare and progressive osteochondrodysplasia of the proximal tibial metaphysis, characterized by inhibition of growth of the medial tibial cartilage, resulting in varus deformity of the knee [3]. The case of our patient, aged 13 at the time of her first consultation, is consistent with the adolescent form of Blount’s disease, with deformity developing since childhood, reflecting a disease that was not diagnosed early, as can be observed in contexts of limited resources or delayed access to specialist expertise [4].

In our patient, examination of the contralateral knee was normal, suggesting unilateral involvement, which is common in the adolescent form [5].

Imaging revealed Langenskiöld stage VI Blount’s disease, with collapse of the medial tibial plateau and irregularity of the growth plate, reflecting advanced and irreversible damage to the medial physis.

Stage VI is rare and occurs mainly in cases diagnosed late or not previously treated. According to Lamont et al., less than 5% of patients with juvenile or adolescent Blount’s disease have such an advanced form. At this stage, angular and rotational deformities are usually fixed and associated with limb shortening [6].

In our patient, treatment required three successive corrective osteotomies, which illustrates the therapeutic complexity of severe and rigid forms in adolescents. Several surgical techniques have been described in the literature for the treatment of stage VI Blount disease:

Proximal tibial corrective osteotomy (classic or double-level): proximal tibial osteotomy is often valgus. In stage VI, this option is generally insufficient on its own. Janoyer et al. showed that correction was often incomplete [7]. Sabharwal et al. recommend a double-level osteotomy [3].External fixator (Ilizarov or Taylor spatial frame type): Indicated for severe forms, it allows for three-dimensional correction. Ghoneem et al. reported good alignment in 80% of cases [8]. Burghardt and Herzenberg prefer the Taylor spatial frame (TSF) for fine corrections [9]. Correction in several stages (2- or 3-stage approach): Ferland et al. reported a series of 4 cases of stage VI Blount’s disease treated in 2 to 3 stages. Dogan et al. recommend personalized management. This technique is similar to ours.

In our patient, the first stage consisted of an external valgus tibial osteotomy combined with an internal tibial plateau lift. This technique, which has been well described in adolescents, allows for direct angular correction [10][11]. However, in our patient, persistent residual varus (40˚) and recurvatum were noted, probably due to an insufficient initial assessment of the sagittal component [12].

A new external tibial osteotomy was performed to correct residual abnormalities. The failure of this second attempt, marked by recurrence of varus and recurvatum 7 years and 5 months post-operatively, is consistent with data in the literature on the high frequency of recurrence in advanced stages, especially in the absence of treatment of the aetiopathogenic basis [10][13]. In addition, initial management without external epiphysiodesis could also explain this recurrence, but this allowed us to minimize the limb length discrepancy.

An internal addition osteotomy with a cortico-cancellous graft stabilized by an Orthofix-type external fixator was performed during the third stage of surgery. This technique, well described by Paley and others [14][15], allows for more stable correction with medial support.

In order to better situate our case in the international therapeutic context, we have produced a comparative table of the main surgical treatments described for Langenskiöld stage VI Blount disease (Table 1). This table compares the different approaches used in different countries, their clinical results, associated complications, and specific comments on each strategy.

Analysis of these data clearly shows that combined or multi-stage treatments (osteotomy + external fixator + ligament stabilisation) give the best results in stage VI cases, particularly in terms of complete anatomical correction, joint stability, and reduced risk of recurrence. These approaches also allow for gradual adaptation to the patient’s biomechanical response.

Our three-stage therapeutic strategy is in line with this modern trend. Unlike isolated osteotomies, which are often insufficient in stage VI [7], or single treatments with fixators, our progressive approach has achieved almost complete correction. These results are consistent with those reported by Ferland et al. in their series of patients treated in several stages [16].

Thus, our case study supports current recommendations in the literature that personalised, multimodal, and progressive management is most appropriate for advanced forms of Blount’s disease.

Table 1. Comparative table of surgical treatments for stage VI Blount’s disease.

Blount’s disease is a rare but potentially severe growth disorder that can lead to significant deformities of the lower limb if not treated early and appropriately. In this paper, we present a clinical case that is particularly indicative of an advanced and complex form of the disease in a 13-year-old adolescent.

These advanced cases represent a major surgical challenge. A multimodal and personalised approach offers the best results. Our three-step strategy, although unplanned, is part of this personalised approach and long-term follow-up for a satisfactory outcome.