Session IV - Foot & Ankle

Syndesmotic-Only Fixation for Weber-C Ankle Fractures

Paul Tornetta, III, MD; William R. Creevy, MD; Jonathan W. Surdam, MD, Boston University Medical Center, Boston, MA

Introduction: Fibula fractures occurring above the syndesmotic region are accompanied by syndesmotic ligament disruption. The use of syndesmotic screw fixation is recommended to stabilize the ankle mortise if instability exists after bony fixation. The goal of the surgical procedure is to reconstruct the ankle mortise. Thus, fibular fixation in the case of concomitant fibula fracture and syndesmotic disruption may not be necessary if the syndesmosis is reduced and stabilized. Although many surgeons use this technique, there are no published series specifically evaluating its results. The purpose of this study was to evaluate a series of patients with Weber-C fibular fracture and syndesmotic injury treated with syndesmosis-only fixation.

Methods: Intraoperative requirements were that the fibular length was restored and that the syndesmosis was anatomically reduced on the AP, mortise, and lateral radiographs (the lateral radiograph was routinely compared to the normal ankle). Fifty-nine patients had fracture patterns amenable to syndesmosis-only fixation, and the records of the 57 who were treated with this technique were reviewed. There were 28 SE, 19 PA, and 10 PE injuries by the Lauge Hansen classification, and 42 of the patients had a fracture of the medial malleolus that was fixed as the first step in the ankle reconstruction. The operative technique used for the lateral side was percutaneous reduction and clamp stabilization of the syndesmosis followed by static 3.5-mm cortical screw fixation. Patients were treated with a standard postoperative regimen, and the screw(s) were removed at 12 weeks.

Results: Four of the 59 patients required open reduction of the syndesmosis. In two of the patients (not included in results) the fibular length could not be restored, necessitating ORIF of the fibula. A reduced mortise was achieved in all fractures and all united without infection or loss of fixation. Forty-nine patients were followed for a minimum of 6 months (average, 2.7 years). There were 38 excellent, 9 good, and 2 poor results according to the Maryland foot score. One patient developed reflex sympathetic dystrophy and one developed significant stiffness and loss of joint space despite an anatomic reduction. The average range of motion was 90% of that of the normal side. No patient complained of lateral-sided ankle pain. In most patients, there was some displacement of the fibular fracture caused by the rotation of the proximal fragment, as described by Michelson. CT scans in the last 20 patients confirmed anatomic rotation of the distal fibula and a reconstructed mortise.

Discussion: When the fibula and the syndesmosis are both injured, many surgeons believe that restoration of the fibular anatomy is required to successfully reduce the syndesmosis. However, if the syndesmosis is anatomically aligned, then trans-syndesmotic fixation will also stabilize the fibula fracture by fixation into the distal fragment of the tibia. This technique obviates the need for ORIF of the fibula, which is more difficult and carries a greater neurologic risk for proximal fractures. In this series, anatomic reduction was obtained percutaneously in the vast majority of the fractures, aided by initial medial fixation. Good or excellent results were obtained in 96% of the patients. The keys to the reduction are careful evaluation of fibular length and use of radiographs of the normal side, particularly the perfect lateral. We recommend syndesmotic-only fixation for combination syndesmosis and Weber-C lateral malleolar fractures as a safe and effective method.