A Case Series Comparison of Treatment Techniques for Blount’s Disease

Abstract

Background: Blount’s disease is disordered growth at the proximal tibial physis of pediatric patients causing leg bowing known as genu vara. Diminished growth of the medial physis causes leg bowing without natural correction. The high prevalence of comorbid obesity in patients is thought to contribute to destruction of growth cells at the physis. There are two common treatments: hemiepiphysiodesis involves arresting the lateral proximal tibial physis to allow increased growth at the medial proximal tibia. Osteotomy includes realigning the tibia and fibula such that the lower extremity mechanical axis becomes increasingly linear. This case series analyzes the optimal treatment choice based on patient age. Case Descriptions: Case 1 A 10-year-old male presented with bilateral leg bowing, bilateral knee pain, and obesity (BMI = 53.8). Treatment was bilateral hemiepiphysiodesis at the lateral tibial physis using eight-plates. This correction was insufficient. Bilateral tibia-fibula osteotomies with external fixation (ex-fix) were then performed with successful correction. Case 2 An 8-year-old female presented with bilateral leg bowing, limp, knee pain, and obesity (BMI = 44.7). Treatment was bilateral hemiepiphysiodesis at the lateral tibial physis. The left hemiepiphysiodesis proved sufficient for correction, but the right hemiepiphysiodesis did not. A subsequent tibia-fibula osteotomy with ex-fix was performed and proved successful. Case 3 A 12-year-old male presented with leg bowing, knee pain, and obesity (BMI = 38.6). Treatment was bilateral hemiepiphysiodesis at the lateral tibial physis. This proved insufficient, and treatment proceeded to a left tibia-fibula osteotomy with ex-fix and a right tibial osteotomy with internal fixation. These osteotomies were sufficient for correction. Conclusion: This case series shows an indication for osteotomy as first-line treatment for Blount’s disease in patients at a relative advanced age. The study also identified further potential research targets. A retrospective look at success rates of treatments in various age groups may help determine the age at which each treatment is preferred. A retrospective analysis may be performed to determine the infection rates in both types of treatment. Finally, additional research may be performed to determine the obesity threshold required to increase risk for Blount’s disease. This data is potentially useful to pediatricians for patient education and prevention.