Clinical performance of a new medullary humeral nail: antegrade versus retrograde insertion.

OBJECTIVE: A new intramedullary nail system for humeral shaft fractures is evaluated to determine whether retrograde nailing is as reliable as antegrade nailing. STUDY DESIGN: Prospective multicenter nonrandomized clinical study. PATIENTS: Eighty-four patients with acute humeral shaft fractures were nailed with the new unreamed humeral nail (UHN) system. Fifty-seven nails were introduced retrogradely, and twenty-seven antegradely. Bone healing and functional outcome were the follow-up parameters. RESULTS: The ratio of perioperative complications was equivalent for both groups, but one shaft fracture and three fractures or fissures at the entry point occurred in the group with retrograde nail insertion. Five fractures, all with retrograde nail insertion, needed secondary surgery to achieve bony healing. There was no difference in functional outcome after healing in either group. CONCLUSION: Retrograde nailing of humeral shaft fractures is technically more demanding than antegrade nailing. Fractures or fissures at the insertion point must be avoided by adequate preparation of the entry hole and careful nail insertion. Bone healing problems seem more surgeon-related than approach-related. As in every other procedure, an optimal fracture configuration and high fracture stability must be achieved.