Introduction: Secondary osteoporosis is rare in children/adolescents. Delays in the specific management of risk factors for bone fragility can lead to a silent loss of bone mass and an increased risk of early osteoporosis. We reported a case of a teenage girl with multifactorial bone fragility complicating a chronic neuropathy treated between 2021 and 2024. Case Report: A 15-year-old girl patient has been under observation for demyelinating sensorimotor neuropathy since the neonatal period. The condition was complicated by multiple skeletal deformities that have required surgical treatment. Bone fragility was noted intraoperatively. The etiologic diagnosis favored a multifactorial origin, including neurological, endocrine, nutritional, and mechanical factors. Treatment of the offending factors was inadequate. Osteoporosis was diagnosed in the presence of a z-score for bone densitometry below -2 standard deviation and multiple long bone fractures. The specific treatment of osteoporosis was limited by the lack of pediatric approval for most molecules. After a two-year course of symptomatic then specific treatment, there was a favorable clinical response and partial improvement in osteodensitometry. Conclusion: This clinical case illustrates the difficulty of managing multifactorial bone fragility leading to osteoporosis in a girl with chronic neuropathy, in terms of managing the incriminating factors and prescribing bisphosphonates.