OTA 1997 Posters - Foot & Ankle Fractures

The Dorsal Approach - A New Technique for Unstable Fractures of the Ankle

Peter A. W. Ostermann, MD, PhD, Axel Ekkernkamp, MD, PhD, Michael P. Hahn, MD, PhD, Dirk Richter, MD, PhD, Gert Muhr, MD, PhD

Bergmannsheil, Bochum, Germany

Purpose: Unstable fractures of the ankle with bony avulsion (Volkmann's triangle) of the posterior syndesmosis remain a challenge for the orthopaedic trauma surgeon. Closed reduction and indirect lag screw fixation often leads to joint incongruency. Therefore, we developed a new posterior approach to the fibula and the distal tibia to anatomically reduce this posterior tibial fragment under direct vision.

Material and Methods: In an open prospective trial we treated 86 unstable fractures of the ankle since March 1994. There were 29 unstable fractures type Weber B and 57 fractures type Weber C. The average age of the patients was 31.7 years (range: 17-76). There were 61 males and 25 females. All patients were placed in a prone position. A dorsal longitudinal incision laterally to the achilles tendon was made about 12 to 15 cm long. Particular attention was paid to preserve the small saphenous vein and the saphenous nerve. First the fibula was exposed while retracting the peroneal tendons medially. The fibula was then fixed by dorsal application of a 1/3 tubular plate. Then the peroneal tendons were retracted laterally. The underlying muscles were split to expose the dorsal aspect to the distal tibia. The posterior fragment attached to the syndesmosis was identified, anatomically reduced and fixed. Small fragments were fixed with small fragment lag screws with short threads. Large fragments were stabilized with a two or three hole 1/3 tubular plate as an antigliding plate. In cases with additional fractures of the medial malleolus, lag screw fixation was performed via a medial incision.

Results: All fractures healed uneventfully within 6 weeks. Radiologically, there was no loss of reduction of the posterior fragment. There was no remaining instability of the ankle joint. At the last follow up examination all patients ambulated without crutches. So far we could not observe degenerative changes in the posterior part of the ankle joint. Sixty-eight patients regained full ROM of the ankle joint. Eighteen had minor decrease of motion in comparison to the contralateral side.

Discussion and Conclusion: This new posterior approach was effective to anatomically reduce the posterior bony avulsion of the syndesmosis at the distal tibia. It is a combined approach for fracture fixation for the fibula also. There were no side effects of the dorsal metal application. We think that the new approach is superior to closed reduction and indirect lag screw fixation of bony avulsions (Volkmann's triangle) of the syndesmosis in unstable ankle fractures.