Review Question - QID 215831

This patient has an atrophic nonunion. The most appropriate treatment at this time would be revision ORIF with autograft.

A nonunion is an arrest in the fracture repair process. A hypertrophic nonunion is caused by inadequate stability with an adequate blood supply and biology resulting in abundant callous formation without bridging bone. These typically heal once mechanical stability is improved. Conversely, an atrophic nonunion is caused by inadequate immobilization and inadequate blood supply. In addition to mechanical stability, they require bone grafting. Use of autologous iliac crest (osteoinductive) is the gold standard, but bone morphogenetic proteins (BMPs) and osteoconductive agents (ie. crushed cancellous chips, demineralized bone matrix) may also be used. An oligotrohic nonunion is produced by inadequate reduction with fracture fragment displacement.

Sauder et al. reviewed isolated fractures of the ulnar shaft injuries. They reported that these fractures are complicated by nonunion, radioulnar synostosis, and loss of motion. They concluded that stable fractures are managed well with forearm bracing, while unstable fractures are reliably treated with open reduction and internal fixation with compression plating.

Bishop et al. reviewed fracture nonunions. They reported that risk factors for nonunion include medical co-morbidities, age, and the characteristics of the injury. They concluded that a comprehensive evaluation of the patient's immune and endocrine status, biologic capacity of the fracture, presence of infection, and quality of reduction and fixation should be scrutinized.

Figure A is the radiograph of the forearm demonstrating an atrophic nonunion of the ulnar shaft

Incorrect Answers:
Answers 1 and 2: At 6 months following ORIF, this atrophic nonunion requires intervention
Answer 3: While an extremely stiff construct may result in an atrophic nonunion, this is not the case as demonstrated on the radiographs in which the ulna was treated with appropriate fixation. This atrophic nonunion would require some biological component to help with the healing
Answer 4: An atrophic nonunion requires some biological component to help with the healing. Use of autologous iliac crest (osteoinductive) is the gold standard