Session V - Post Traumatic Reconstruction

Exchange Nailing for Aseptic Nonunion or Delayed Union of Tibial Shaft Fractures Treated Originally with Tibial Nailing

William J. Rosenblum, MD; Michael J. Prayson, MD; Gary S. Gruen, MD, Mareus J. Haemmerle, MPT, ATC, University of Pittsburgh Medical Center, Pittsburgh, PA

Purpose: Exchange nailing of the tibia has become the treatment of choice for aseptic nonunions, although reports in the literature supporting this technique are limited. We reviewed our experience with this technique in an effort to demonstrate that exchange nailing leads to bony union.

Methods: The charts and radiographs of 40 consecutive patients with 42 fractures of the tibia with either nonunion or delayed union of the tibial shaft treated initially by tibial nailing were retrospectively reviewed. Excluded were all patients whose preoperative or intraoperative work-up revealed infection. Data collected included: fracture pattern, fracture location in the tibia, Gustillo and Anderson open fracture classification (if applicable), initial mode of locking, time to exchange nailing, presence or absence of concurrent fibulotomy, and time to bony union. Thirty-one fractures were open (6 grade I, 10 grade II, 3 grade IIIA and 15 grade IIIB) and 11 were closed. Forty fractures were originally unreamed, and two were originally reamed. All of the original nails were statically locked. The fractures were all treated with use of a reamed exchange nail.

Results: Fracture union was achieved in all patients, and the mean time to healing after exchange nailing was 4.5 months (134 days). There were no postoperative infections in the study group. At the time of exchange nailing, 23 fracture nonunions underwent fibulotomy. All of the tibias with nonunions were reamed at least 2 mm larger than the original nail. Eight (19%) underwent an additional procedure (dynamization) to achieve union after exchange nailing.

Discussion: Our results showed 100% union at a mean of 4.5 months after the exchange nailing. Contrary to previous reports, none of our patients with exchange nails became secondarily infected, including those with grade-IIIB open fractures. The likely cause of nonunions in the tibia is an interruption of the biologic processes necessary to heal the fracture. All of the original fractures were nailed in nearly anatomic alignment, without an excessive fracture gap. Fifty percent of the fractures were in the distal third of the tibia, an area with limited surrounding soft tissue. Seventy-nine percent of the fractures were open, leading to further disruption of the soft tissue envelope. It is our belief that exchange nailing leads to bony union by providing autogenous bone graft to the fracture site and stimulating the local biologic processes toward healing.

Conclusions: Exchange nailing to achieve fracture union has been shown in this series to be effective if there is no evidence of infection prior to exchange nailing. To our knowledge, this is the largest series of aseptic tibial delayed unions and nonunions treated with exchange nailing. Although previous reports have cautioned against the use of exchange nailing for grade-IIIB open fractures, our data support its use.