Sat., 10/18/08 Foot & Ankle/Pediatrics, Paper #59, 11:32 am OTA-2008
The Posterolateral Approach to the Tibia for Displaced Posterior Malleolar Injuries
Paul Tornetta III, MD1 (c-Lippincott; a,c,e-Smith + Nephew);
Sean E. Nork, MD2 (a-AO, EBI, Synthes, Smith + Nephew, Stryker, Zimmer);
Cory A. Collinge, MD3 (a-Foundation for Orthopedic Trauma; c-Biomet; c,e-Smith + Nephew);
William M. Ricci, MD4 (a,b-AO, Synthes; a,b,c,e-Smith + Nephew; a,b,e-Wright Medical
Technology, Inc.; e-OrthoVita);
1Boston University Medical Center, Boston, Massachusetts, USA;
2Harborview Medical Center, University of Washington, Seattle, Washington, USA;
3Harris Methodist Fort Worth Hospital, Fort Worth, Texas, USA;
4Washington University St. Louis, St. Louis, Missouri, USA
Introduction: The indications to fix posterior malleolar fractures have become more clear with biomechanical studies of stability and joint reaction force. The method of reduction and fixation of these injuries, however, has been given little attention. The purpose of this study is to report on the use of the posterolateral approach for the reduction and fixation of large displaced posterior malleolar fractures, specifically the ability to reduce and stabilize the fractures and the attendant complications.
Methods: Over a 6-year period, 72 patients at 4 Level 1 centers with large displaced posterior malleolar fractures as part of their bony injury were treated with a posterolateral approach to the distal tibia. There were 26 men and 46 women, aged 18 to 91 years (mean age, 48). The fracture was part of a bi- or tri malleolar indirect ankle fracture in 63 cases and associated with a distal spiral tibial shaft fracture in 9 cases. Pilon fractures were excluded. The indication for fixation was displacement of greater than 30% of the joint surface as assessed on axial CT scans or posterior instability. Eight had associated marginal impaction. The posterior malleolus was reduced first via a standard posterolateral approach between the peroneal and Achilles tendons via elevation of the flexor hallucis longus. The posterior syndesmotic ligaments were preserved. An indirect reduction of the joint by keying in the cortical shearing fracture was aided by fluoroscopy. Fixation was performed with lag screws and underbent plates. The lateral malleolus was fixed in 57 of the ankle fractures, 16 medial and 41 lateral to the peroneal tendons. Tibial nails were used to stabilize the 9 associated shaft fractures. Patients were maintained in neutral to 5° of dorsiflexion when not doing therapy for 4 to 6 weeks to avoid loss of dorsiflexion.
Results: All of the patients had an accurate reduction (<1 mm displaced) of the joint surface and maintained that position through union. No hardware irritation or loosening occurred. Dorsiflexion of the affected ankles at final follow-up was within 5°of the opposite side in 92%, and within 10° in 8% of cases. Complications included 6 patients with erythema treated with antibiotics and 7 patients with some edge necrosis that healed with local care. There were no deep infections. Four patients had some postoperative numbness in the sural distribution, of whom three had complete resolution. One patient developed a fibular nonunion.
Discussion and Conclusion: In complex ankle or tibial injuries associated with large displaced posterior malleolar fractures, its reduction and fixation is essential for the restoration of joint mechanics. While some fractures may be treated percutaneously, larger displaced fragments are more difficult to accurately reduce. As the obliquity of these fractures most commonly circumscribe a posterolateral fragment, the posterolateral approach provides excellent exposure and the ability to use push plates for the reduction and stabilization. Simultaneous reduction and fixation of the lateral malleolus is also possible. Although this approach allows for effective reduction and fixation, we found a slightly higher rate of noninfected healing complications as compared with standard medial and lateral approaches. Orthopaedic surgeons should be aware of this technique, its effectiveness, and complications.
If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.
• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.