Zip Line To Fracture Line: An Unusual Cause Of Pediatric Fracture

Abstract

HISTORY: An 8-year-old male presented to the orthopedic clinic for follow up of a nondisplaced pathologic fracture. He was initially seen at an urgent care center with his mother, presenting with left lower leg pain after falling off a zip line at school. He was diagnosed with a pathologic fracture through an undifferentiated tibial diaphyseal lesion. He was placed in a splint followed by a long leg cast. He was sent for MRI and referred to orthopedic oncology for further diagnostic workup of his bone lesion. PHYSICAL EXAMINATION: Left lower leg: Positive for ecchymosis, swelling, and tenderness to palpation over the middle third of the tibia shaft. There are no gross deformities, skin breakdown, or tense compartments. DIFFERENTIAL DIAGNOSIS: 1.Nonossifying fibroma 2. Bone cyst 3.Osteofibrous dysplasia4. Adamantinoma TESTS AND RESULTS: X-Ray Left tibia/fibula: -“pathologic nondisplaced fracture of the tibia shaft. There is a discrete lesion of the tibia shaft with expansion of the cortex. No obvious periosteal reaction.”MRI Left tibia/fibula-“Distal tibial diaphysis expansile T2 hyperintense/T1 hypointense intramedullary lesion with associated cortical thinning”Follow up X-Ray Left tib/fib (16 weeks after fracture): -“Redemonstrated asymmetrically located lucency in the mid shaft tibia with scalloping.”FINAL/WORKING DIAGNOSIS:Osteofibrous dysplasia TREATMENT AND OUTCOMES:1.Treated with immobilization of the fracture 2.Returned to normal activities without pain at 11 weeks3.MRI showed findings concerning for osteofibrous dysplasia versus adamantinoma4. He had follow-up with the orthopedic oncologist and serial x-rays following the completion of his MRI5. After discussion at tumor board and little change on sequential x-rays, he was treated for presumed osteofibrous dysplasia6.He has since sustained a second pathologic fracture which is currently being treated with immobilization7.The surgery team discussed deferring surgical intervention due to his age