Osteogenesis imperfecta and Ledderhose disease: Is there a link? A report of two Tunisian siblings

Abstract Introduction Osteogenesis imperfecta (OI) or “brittle bone disease” is a rare genetic disorder tissue due to an abnormal production of type I collagen. It can cause hearing loss, dentinogenesis imperfecta, heart failure, spinal cord problems and permanent deformities. Ledderhose’s disease or Plantar fibromatosis (PF) is also a rare condition that may be caused by an abnormal proliferation of collagen tissue. It is a benign fibroblastic proliferative disorder in which fibrous nodules may develop in the plantar aponeurosis, more specifically on the medial plantar side of the foot arch and on the forefoot region. Rare cases of association of polyfibromatosis with keloids or arthritis have been reported. Case report We report two Tunisian brothers aged 17 and 14 years old, from a first-degree consanguineous marriage and with medical history of multiple bone fractures. The elder brother has medical history of juvenile arthritis treated with methotrexate and etanercept. Clinical examination of both patients showed blue sclera, bone deformities with humeral and femoral curvature and unequal leg length. They were diagnosed with OI and received bisphosphonate to prevent further fractures. One year later, they developed lumps under the sole skin of their feet. They were diagnosed with PF and received conservative treatment including non-steroidal anti-inflammatory drugs, physiotherapy and orthotic support. Conclusion To the best of our knowledge, the association of PF with OI has never been reported. Both diseases suggest an association with abnormalities involving collagen. A question remains currently with no answer: is it a fortuitous association?