Salvage of Chronic Instability of the Syndesmosis with Distal Tibiofibular Arthrodesis: Functional and Radiographic Results

Background: Failure to treat an injury of the syndesmosis after an ankle fracture can lead to a poor functional outcome and posttraumatic arthritis. The results after reconstruction of an ankle with an incongruous mortise, chronic diastasis of the syndesmosis, and arthritis remain unknown. The purpose of the present study was to review the radiographic and clinical results of salvaging this condition through reduction and arthrodesis of the distal tibiofibular articulation. Methods: Ten patients (mean age, fifty-four years) with chronic syndesmotic instability who underwent salvage by a single surgeon were evaluated retrospectively. Five parameters of mortise and syndesmotic alignment were measured on weight-bearing radiographs that were made preoperatively and at the time of the latest follow-up. The extent of arthritis in the ankle was graded with use of an established classification system. Clinical rating scores that were recorded preoperatively and at the time of the latest follow-up were culled from the medical records and were compared. Each patient’s stated satisfaction with the operation and willingness to undergo the operation again were retrieved from the medical records. Results: After a mean duration of follow-up of forty-one months (minimum, two years), the medial clear space, talocrural angle, and talar tilt had improved. No ankle demonstrated progression of arthritis on the basis of the radiographic grade. The clinical rating score improved significantly because of improvements in the pain, activity, maximum walking distance, and gait subscales. Two patients had a total of three additional procedures. Both had prominent implants removed, and one subsequently underwent an ankle arthroscopy. All patients reported satisfaction with and a willingness to undergo the procedure again. At the time of the latest follow-up, no patient had undergone an ankle arthrodesis. Conclusions: The significant improvements in the radiographic and functional measures of outcome that were observed in this small cohort suggest that chronic syndesmotic instability after ankle fracture can be salvaged with reduction and arthrodesis of the distal tibiofibular articulation. Furthermore, the reconstruction of an incongruous and arthritic ankle is an alternative to and may postpone the subsequent need for ankle arthrodesis or arthroplasty. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.