Review Question - QID 212945

The patient is presenting with pseudoarthrosis of the tibia after attempted bracing and casting. The ideal treatment would involve pseudoarthrosis takedown with bone grafting and intramedullary nailing.

Neurofibromatosis type 1 is the result of a mutation of the neurofibromin gene on chromosome 17. Patients may present with several orthopedic manifestations such as dystrophic scoliosis and congenital tibial dysplasia. The etiology of these aberrations is unknown but may be attributable to the decreased osteoblast activity and resultant osteopenia. Tibial pseudoarthrosis is challenging to treat as there is usually interposed hamartomatous tissue that prevents the success of non-surgical treatment. In cases of pseudoarthrosis, this tissue must be excised and a bone graft should be placed and stabilized using rigid fixation.

Stevenson et al. reviewed the treatment of neurofibromatosis type 1 associated tibial dysplasia. The goal of surgical treatment is to achieve union by creating a healthy vascular bed and rigid fixation. Many techniques include a combination of debridement of the fibrous hamartoma, vascularized fibular autograft, Ilizarov frame, intramedullary nailing, and bone stimulating medications.

Feldman et al. reviewed the orthopedic manifestations and treatment of neurofibromatosis type 1. They reported that initial nonsurgical treatment of tibial dysplasia involves knee-ankle-foot orthosis; however, in the presence of pseudoarthrosis, intramedullary nailing with bone grafting may be necessary, with nail retention to prevent re-fracture.

Figures A and B demonstrate AP and lateral radiographs of a right tibia and fibula with pseudoarthrosis and anterolateral bowing. Illustrations A and B demonstrate AP and lateral radiographs after the patient has healed the pseudoarthrosis.

Incorrect Answers:
Answers 1 and 2: Pseudoarthrosis already demonstrated failure with nonoperative approach
Answer 3: Intramedullary nailing alone would be insufficient to address the pseudoarthrosis as there is usually hamartomatous tissue interposed in the fracture site.
Answer 5: An amputation is a viable option after several surgical approaches have been attempted and the patient is likely to have a shortened and contracted extremity.