Distal metaphyseal tibial nonunions associated with significant bowing deformity and cortical bone loss: treatment with human bone morphogenetic protein (h-BMP) and internal fixation.

: Distal tibial metaphyseal nonunions with significant posterior bowing deformities are extremely difficult to manage and may require the use of additional healing factors to achieve union. Four patients with complex multiple failed surgically treated distal metaphyseal nonunions were treated with debridement of the nonunion, correction of deformities, internal stabilization, and augmentation with human bone morphogenetic protein implants (h-BMP). All patients had, following resection of the anterior cortical sequestrum, a significant cortical defect extending from a level proximal to the ankle joint to the distal tibial metaphysis. The average number of failed previous surgical procedures were 5.8 and average age was 35.3 years. Symptomatic nonunion averaged 24.8 months. All patients received h-BMP combined with insoluble noncollagenous proteins (iNCP) either in a delivery form of coated polylactic polyglycolic acid strips (1 x 13 cm.) or in gelatin capsules. The h-BMP/iNCP implants were placed within the anterior cortical defects in contact with the residual distal metaphyseal bone. All nonunions were stabilized with internal fixation. Ankle motion was difficult to record preoperatively but good to very good ankle function was obtained at final follow-up evaluation in three of four patients. All fractures healed without further surgical treatment at an average of 4.4 months. h-BMP/iNCP protein implants were felt to be of benefit in the healing of these difficult fracture problems.