Treatment of Late-Onset Blount's Disease using Linear Rail System and Double Corrective Osteotomies at the Intra-Articular and Metaphyseal Regions

Background: Blount's disease is a developmental anomaly that affects the posteromedial aspect of the proximal tibia physis with changes seen in the epiphysis, metaphysis, and sometimes, in severe cases, the distal femur as well. It results in a posteromedial deformity, internal tibial torsion, and shortening of the affected leg. Aim: The purpose of this study is to document the results of the treatment of the late form of this deformity using intra-articular and metaphyseal osteotomies of the proximal tibia and a linear rail system (LRS) device. Patients and Methods: Six patients were treated for late-onset unilateral Blount's disease. The procedure consisted of intra-articular osteotomy below the physis to elevate the depressed medial tibia plateau and a metaphyseal osteotomy below the tibia tubercle to address any residual varus deformity, tibial torsion, and leg shortening using a LRS device. Results: The mechanical axis deviation was corrected from a mean of 6.0 cm (range of 3.1–9.6 cm) to 1.4 cm (0–2.9 cm). The tibiofemoral angle was corrected from a mean of 23.2° varus (range of 16°–30°) to a mean of 1.8° varus (range of 5° valgus–7° varus). The limb length discrepancy was corrected. Operation time was 90 min on average. The device use time was three months on average. Schoenecker outcome criteria were good for all the patients. Conclusion: The use of double corrective osteotomies at the proximal tibia and the LRS device were found to be cheap, easy to use, and very effective in the treatment of Blount's disease deformity.