Pronounced femur malunion after pathological bone fracture due to a simple bone cyst in the shaft of the femur, treated using Ilizarov fixation: a case report

• Published in: Journal of medical case reports Vol. 12; no. 1; p. 173
• Main Authors: Nishiwaki, Toru, Uchikawa, Shinichi, Kusakabe, Hiroshi, Seki, Atsuhito, Eguchi, Yoshitaka, Takayama, Shinichiro, Oya, Akihito, Nakamura, Masaya, Matsumoto, Morio, Kanaji, Arihiko
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 21.06.2018; BioMed Central; BMC
• Subjects: Age; Bone cysts; Bone Cysts - complications; Bone Cysts - surgery; Bone marrow; Care and treatment; Case Report; Case reports; Child; Complications and side effects; Cysts; Disease Progression; Female; Femoral Fractures - etiology; Femoral Fractures - surgery; Femur - surgery; Fractures; Fractures (Injuries); Fractures, Malunited - etiology; Fractures, Malunited - surgery; Fractures, Spontaneous - etiology; Fractures, Spontaneous - surgery; Humans; Ilizarov Technique; Malunion; Orthopedic fixation devices; Pathological bone fracture; Risk factors; Simple bone cyst; Surgery; Malunion; Simple bone cyst; Pathological bone fracture
• DOI: 10.1186/s13256-018-1710-3
• ISSN: 1752-1947

Although a simple bone cyst carries the risk of pathological fractures, it rarely causes severe deformity. Here we report a case of severe femoral deformity after multiple pathological fractures due to simple bone cysts, and consider the reason for the progression of malunion despite multiple previous treatments. Finally, we propose a treatment option for malunion correction. A 9-year, 7-month-old Japanese girl was referred to our facility with obvious deformity of her right femur, caused by multiple simple bone cyst-related pathological fractures. The deformity included bowing of approximately 90° and an internal rotation of 60° in the middle third of the femoral shaft. To correct this deformity, we excised the lesion, thus shortening the femur, then corrected the alignment and applied an Ilizarov fixator to extend the bone. At present, 3 years after surgery, the deformity has not recurred and our patient is living without any limitations in daily activities or regular exercise. When a long bone is in a prolonged state of deformation, the deformity not only progresses as the bone grows, but the soft tissues remain unbalanced and treatment becomes increasingly difficult. To prevent increasing bone deformity and fragility, the deformity should be corrected as quickly as possible using intramedullary nailing or other fixation techniques. We believe that our shortening-distraction method is effective for the treatment of severe deformity with unbalanced soft tissues.