Session VII - Tibia

*Intramedullary Nailing of Distal Metaphyseal Tibial Fractures

Alexandra K. Schmitt, MD; Sean E. Nork, MD; Robert A. Winquist, MD (c-Zimmer), Harborview Medical Center, Seattle, WA

Purpose: The treatment of distal metaphyseal tibial fractures remains controversial. The purpose of this study is to evaluate the treatment of distal tibial fractures within 5 centimeters of the ankle joint with intramedullary nailing.

Materials and Methods: Over a 16-month period, 243 skeletally mature patients with tibial shaft fractures were treated operatively at 2 institutions. Thirty-seven fractures involved the distal 5 centimeters of the tibia. Thirty-six patients were treated with reamed intramedullary nailing for their distal tibia fracture. One of the 37 patients was treated with plate fixation for an extensive open fracture with an exposed distal tibia and was therefore excluded. There were 24 male and 12 female patients, ranging in age from 18 to 82 years (mean, 30 years). Mechanism of injury included an accidental fall from height in 13 patients, sports injury in 7, motor vehicle accident in 6, motorcycle accident in 5, auto versus pedestrian accident in 3, explosion in 1, and crush injury in 1 patient. Six patients had multiple ipsilateral lower extremity fractures. All fractures were classified according to OTA guidelines as 43A1 (n=8), 43A2 (n=5), 43A3 (n=13), 43C1 (n=6), 43C2 (n=2), and 43C3 (n=2). Fourteen fractures (39%) were open and classified as type I (n=1), type II (n=2), type IIIA (n=10), and type IIIB (n=1). Four patients developed a compartmental syndrome and had fasciotomies. Ten fractures (28%) had articular extension, all of which were amenable to reduction and percutaneous fixation; 54% of patients had fixation of their fibular fractures to assist with obtaining length and rotation. Postoperative management included splinting until the wounds were dry. Patients with intra-articular fractures or significant comminution were non-weightbearing for 8 to 12 weeks, while patients with stable extra-articular fractures were allowed toe-touch weight bearing. Biplanar radiographs were reviewed to assess length and alignment postoperatively and at the time of final follow-up. Malalignment was defined as 5 degrees of angulation in any plane. Patients were evaluated with a Short Form 36 (SF-36) and the Musculoskeletal Function Assessment (MFA) for clinical outcome.

Results: Average follow-up was 11.2 months. The average distance >from the distal extent of the tibial fracture to the plafond was 35 millimeters (range 0 to 45 mm). The average distance between the distal nail tip and the articular surface of the plafond was 6.2 mm (range 2 - 10 mm). Three distal interlocking screws were used in 23 patients while 2 distal interlocking screws were used in 13 patients. Average sagittal plane deformity was 0.9 degrees (range 0 - 5 degrees). Average coronal plane deformity was 0.3 degrees (range 0 - 5 degrees). Acceptable alignment was obtained in 33 patients (92%), and no patient had a malalignment greater than 5 degrees. Two patients had a 5-degree recurvatum deformity, and 1 patient had a 5-degree valgus deformity. No patient had any change in alignment at final evaluation. Three patients with open fractures and associated bone loss developed clinical and radiographic signs of nonunion, and they were treated with iliac crest autograft. Four patients underwent dynamization of the nail at 3 months postoperative. Complications included a deep infection of an open fibular fracture and an iatrogenic proximal tibial fracture at the time of medullary nailing.

Discussion: Intramedullary nailing offers an attractive alternative for distal tibial metaphyseal fractures. This technique avoids the extensive soft tissue dissection associated with open reduction and internal fixation and avoids complications associated with external fixators. Certain nail designs allow for multiple points of distal fixation, which may contribute to the overall stability of the construct. The varying planes of distal interlocking screws may even be used for interfragmentary fixation in such distal fractures. In this series, no patients had loss of alignment or length. The 10 intra-articular fractures healed without displacement. Bone graft was needed only in open fractures with bone loss that developed nonunion.

Conclusion: Intramedullary nailing is effective in the treatment of very distal tibial fractures. The technique minimizes the soft tissue dissection required for plating and eliminates complications associated with external fixation. Alignment can be achieved and maintained despite the short segment of the distal tibia. Nail designs and nail modifications allow for control of the distal segment by placement of multiple distal interlocking screws within a small distance above the tibial plafond. Simple articular fracture extensions secured with screws prior to nailing are not a contraindication to intramedullary fixation.