SLR - September 2012 - Pauline Seymour
Reference: Mohammed R., Syed, S., Metikala, S. and Ali, S.A. Evaluation of the syndesmotic-only fixation for Weber-C ankle fracture with syndesmotic injury. Indian Journal of Orthapaedics. 2011; 45(5): 454 – 58.
Scientific Literature Review
Reviewed by: Pauline Seymour, DPM
Residency Program: St. John Hospital and Medical Center
Podiatric Relevance:
Approximately 10 percent of all patients with an ankle fracture have disruption to the inferior tibiofibular syndesmosis. The mechanism of injury is external rotation causing the talus to rotate externally, leading to potential disruption of the syndesmotic ligaments. Proper realignment of the ankle mortise and stable fixation of the syndesmosis are essential for successful functional outcomes. The classic approach of lengthening the fibula and anatomically reducing the syndesmosis utilizing a plating system may not be necessary in patients with a Weber-C ankle fracture and syndesmotic injury. A new method has been reviewed through a retrospective observational study in patients with a supra-syndesmotic fibular fracture combined with diastasis of the inferior tibiofibular joint by way of syndesmosis-only fixation.
Methods:
Twelve patients with a Weber type-C and syndesmotic injury were treated with syndesmosis-only fixation between April 2007 and September 2008 at a University Hospital’s tertiary trauma center. Demographics, mechanism of injury, and functional and radiological outcomes at follow-up were collected. Patients with open ankle fractures, other associated injuries, delayed presentation or diagnosis greater than six weeks, follow-up less than six months, and incomplete clinical notes or radiographs were excluded from the study. Initial trauma management consisting of plaster immobilization, analgesia, and elevation was performed on all patients. External rotational stress test and/or Cotton “hook test” confirmed syndesmotic injury. Patients were followed only if the fibular length was restored and syndesmosis was anatomically reduced. A single tricortical 3.5mm cortical screw was inserted across the syndesmosis through percutaneous or mini-open reduction and clamp stabilization of the syndesmosis approximately two cm above the tibiotalar joint line. Patients were non-weightbearing for six weeks and clinical evidence, as well as radiographic findings, determined the time for screw removal, which was performed on an average of eight weeks. Outcomes were evaluated using radiographic assessment and an objective ankle scoring system (OMAS – Olerud and Molander ankle scale).
Results:
Mechanism of injury was attained by accidental twisting falls in eight patients, sports-related injury in three cases and road traffic accident in one patient. Nine patients acquired a fracture in the middle one-third of the fibula, while the other three obtained Maisonneuve fractures. Functional outcome using the OMAS was 75 at an average followup of 13 months. Ten patients (83 percent) had excellent to good outcomes. The ankle mortise was reduced in all patients. All cases but one fibular fracture united without loss of fixation. The latter case resulted in late diastasis and revisional surgery with bone grafting and internal fixation of the fibula.
Conclusions:
Anatomic reduction of the syndesmosis and restoration of the fibular length are essential for optimal functional outcomes in patients with an ankle fracture and syndesmotic disruption. Open reduction and internal fixation of the fibula is the classic approach to restore fibular length. Conversely, internal fixation of the proximal and mid-diaphyseal fibular fractures have potential risks associated with additional soft tissue dissection, possible injury to the common peroneal nerve, and difficulty with handling hardware. In this study, the fibular length and rotation were proven to be restored without internal fixation by stable fixation of the syndesmosis as described above. However, this method of fixation is not recommended in any situation where it was not possible to achieve proper reduction and fibular length.