Management of stiff hypertrophic nonunions by distraction osteogenesis: a report of 16 cases.

Objective: Hypertrophic nonunions can be managed successfully with distraction. Hypertrophic changes indicate that the tissue at the nonunion site has a biologic healing potential. The missing component is an appropriate mechanical environment to transform a hypertrophic nonunion into solid bone.

Design: At our institution, the records of 10 male and 6 female patients treated for stiff hypertrophic nonunion with the Ilizarov distraction method were retrospectively analyzed. The average age of the patients was 42.3 years (range 15-69 years). The nonunion time ranged from 8-48 months. All patients had at least 1 cm shortening, 3 patients had a deformity in one plane, and 13 had a deformity in two planes. The pathology was localized to the upper extremity in 5 patients, to the lower extremity in 11 patients, with a periarticular localization in 11 patients. An Ilizarov-type circular external fixator was applied in all patients to correct shortening, to correct deformity, and to achieve a solid union.

Results: All nonunions healed at an average follow-up of 38.1 months (range 24-95 months). The average time spent in the external fixator was 7.1 months (range 5-10 months). The average preoperative length discrepancy was 2.25 cm (range 1-8 cm), which was eliminated in all patients at the time of frame removal. The average coronal plane angulation of 19.7 degrees (range 15-37 degrees) and sagittal plane angulation of 20.8 degrees (range 5-45 degrees), together with translation in one patient, also were corrected to normal anatomic alignment. Complications included minor pin tract infections and hardware problems; recurrence of deformity was observed in one patient who refused to wear a protective brace after frame removal.

Conclusions: Hypertrophic nonunions can be managed successfully with distraction. The Ilizarov device can address every aspect of a stiff hypertrophic nonunion, including shortening and deformity.