OTA 1999 Posters

Fractures of the Proximal Third of the Tibial Shaft Treated with Intramedullary Nails and Blocking Screws

William M. Ricci, MD; Joseph Borrelli, Jr., MD; Carlo Bellabarba, MD; Michael O'Boyle, MD; Roy W. Sanders, MD, Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO

Introduction: The goal of this study was to evaluate the technique of using IM nails and blocking screws to obtain and maintain alignment of fractures of the proximal third of the tibial shaft.

Methods: Twelve fractures of the proximal third of the tibial shaft were treated with IM nails and blocking screws. Blocking screws were placed into the distal portion of the proximal fragment prior to nail insertion to decrease the effective diameter of the medullary canal and facilitate reduction. Blocking screws placed posterior to the nail control apex anterior angulation. Blocking screws placed either medial or lateral to the nail control varus or valgus angulation, respectively.

Results: Post-operative fracture angulation was less than 5° in 11 of 12 cases. In the remaining case, a posterior blocking screw corrected a 32° apex anterior mal/nonunion to zero degrees. No lateral blocking screw was used and 6° of valgus angulation was present. All twelve fractures united. At the last follow-up examination (average follow-up 25 weeks), 11 of 12 cases had maintained alignment. In one case where no lateral blocking screw was used to control valgus, angulation progressed from 6° of valgus postoperatively to 10° of valgus at union.

Discussion and Conclusion: The use of IM nails to treat fractures of the proximal third of the tibial shaft has been associated with high rates of malunion. A proximal and lateral starting point, anterior-directed insertion angle and a semi-extended position of the knee have been advocated to reduce the incidence of angular malunion. We describe a simple and effective technique for obtaining and maintaining angular alignment when treating proximal third fractures of the tibial shaft with IM nails. The indications for this technique may be extended to other long bone fractures where angular deformity complicates nail insertion.