Genetics of Osteogenesis Imperfecta Treatment & Management

Because osteogenesis imperfecta (OI) is a genetic condition, it has no cure.

• Cyclic administration of intravenous pamidronate reduces the incidence of fracture and increases bone mineral density, while reducing pain and increasing energy levels.^[10] Doses vary from 4.5-9 mg/kg/y, depending on the protocol used.
• Current evidence does not support the use of oral bisphosphonates in patients with osteogenesis imperfecta. Alendronate decreases predicted material properties and has detrimental effects on osteoblasts and bone formation in mice with osteogenesis imperfecta. Risedronate may have some effect in reducing fractures in patients with osteogenesis imperfecta.^[11]
• A preclinical study demonstrated that RANKL inhibition improves density and some geometric and biomechanical properties of the oim/oim mouse bone but does not decrease fracture incidence when compared with placebo.^[12]
• Nutritional evaluation and intervention are paramount to ensure appropriate intake of calcium and vitamin D. Caloric management is important, particularly in adolescents and adults with severe forms of osteogenesis imperfecta.
• In utero transplantation of adult bone marrow has been shown to decrease perinatal lethality in a murine model of osteogenesis imperfecta.

Orthopedic surgery is one of the pillars of treatment for patients with osteogenesis imperfecta.^[13] Surgical interventions include intramedullary rod placement, surgery to manage basilar impression, and correction of scoliosis.

• Intramedullary rod placement

  • In patients with bowed long bones, intramedullary rod placement may improve weight bearing and, thus, enable the child to walk at an earlier age that he or she might otherwise. Use of the new extensible Fassier-Duval rods has shown promising results in these patients.
  • In children appropriately treated with bisphosphonates, the percutaneous technique of multiple osteotomy with intramedullary fixation is safe and effective.
  • An experienced team can perform as many as 4 rod procedures in the long bones of the lower extremities in one surgical session.
  • Fractures heal normally in about 85% of patients with osteogenesis imperfecta.
  • Postoperative immobilization is significantly shortened with this technique. Prolonged immobilization after a fracture must be avoided.
• Surgery for basilar impression: This procedure is reserved for cases with neurologic deficiencies, especially those caused by compression of brainstem and high cervical cord. A team of orthopedic surgeons and neurosurgeons is required.
• Correction of scoliosis: Correction of scoliosis may be difficult because of bone fragility. Spinal fusion may be helpful. Pretreatment with pamidronate appears to improve the surgical outcome.

• Care of patients with osteogenesis imperfecta is multidisciplinary. Team members may include an occupational therapist (OT), a physical therapist (PT), nutritionist, an audiologist, an orthopedic surgeon, neurosurgeon, pneumologist, and nephrologist, among others.
• Offer genetic counseling to the parents of a child with osteogenesis imperfecta who plan to have more children. During genetic counseling, the possibility of germline mosaicism must be discussed.

• Adequate calcium, vitamin D, and phosphorus intake are paramount.
• Caloric management is necessary in nonambulatory patients with severe osteogenesis imperfecta.

• Parents need special instructions in handling affected children.
• Parents need to know how to position the child in the crib and how hold the child to avoid causing fractures while maintaining bonding and physical stimulation.