Complications of Seidel intramedullary nailing of narrow diameter humeral diaphyseal fractures.

Forty acute blunt fractures of the humeral diaphysis were treated with Seidel nails (9-mm diameter) between April 1988 and August 1992. Follow up was available for 36 patients. Average Injury Severity Score (ISS) was 22. Forty-eight pelvic and lower extremity fractures necessitated humeral weight bearing in 23 patients. Patients were grouped by canal diameter measured at the point of distal humeral fixation: < or = 9 mm or > or = 10 mm. Data were analyzed with regard to complications, fracture pattern, and time to union. Due to difficulties reaming the humeral canal, five different reaming systems were used. In the < or = 9 mm group (N = 12), there were seven complications (58%). Two patients had iatrogenic comminution distal to the nail. The two open fractures in this group (II, IIIA) developed wound infections, and one, osteomyelitis. Three patients had nonunions: one was lost to follow up at 6 months, and two united at 41 and 74 weeks after exchange nailing and bone grafting. Average time to union was 21 weeks. Six of the seven complications occurred in patients who required reaming of a long, tight segment of distal canal. In the > or = 10 mm group (N = 24), there was one complication of iatrogenic comminution (4%). There were four open fractures (three, grade II; one, IIIB) with no infections. All fractures united (average = 10 weeks). The differences in complications (P = .001) and union (P = .04) between groups were significant. Other complications were not associated with canal diameter or union. There were seven radiographic failures of the distal locking device (19%). Four nails (11%) were left prominent in the shoulder due to technical or equipment failures, and were eventually removed. Four patients (11%) had residual shoulder stiffness (three due to neurologic injury). These primary data suggest use of the Seidel nail is associated with a higher complication rate in humeri with canal diameters < or = 9 mm.