SLR - February 2013 - Miller
Reference: Tornetta P, Axelrad TW, Sibai TA, Creevy WR. Treatment of the Stress Positive Ligamentous SE4 Ankle Fracture: Incidence of Syndesmotic Injury and Clinical Decision Making. J Orthop Trauma. 2012 Nov;26(11):659-61
Scientific Literature Reviews
Reviewed by: Jennifer Miller, DPM
Residency Program: St. John Hospital and Medical Center, Detroit, MI
Podiatric Relevance:
There is much debate for syndesmotic instability for SE-4 ankle fractures and need for definitive syndesmotic fixation. Per the authors in this study, MRI studies have shown an incidence of syndesmotic injury in SE-4 ankle fractures of 39 percent. Questions arise whether syndesmotic instability can be measured on plain film or on manual stress exam.
Methods:
A retrospective case review over a nine year period from a prospectively collected trauma database of 114 patients with isolated stress positive supination external rotation Weber B fibular fractures were identified and classified by one orthopaedic trauma surgeon. Medial clear space was measured on two separate instances by one blinded author for fractures treated with non-weight-bearing cast therapy, fractures treated operatively with stable syndesmosis, and finally, fractures treated operatively with an unstable syndesmosis from radiography at presentation, stress examination, casting and at final union. Initial fibular displacement was also measured. Stress positive fractures were defined as a widening of the medial clear space greater than four millimeters, at least one millimeter greater than the superior joint space, or identifiable talar subluxation. Syndesmotic instability for operatively treated fractures was defined as medial widening or talar subluxation via the Cotton Test or external rotation stress examination after fibular fixation. Manual stress exams were performed by a senior on-call orthopaedic resident with ankle in neutral flexion with eight to 20 lbs of manual abduction-external rotary force. All patients were casted after manual stress testing and closed reduction. Clinical decision making for operative or non-operative treatment was made by two orthopaedic trauma surgeons after risks versus benefits discussion with the patient. Fractures treated non-operatively underwent non-weight-bearing in a cast for six weeks followed by full weighting in a brace for an unspecified number of weeks. Postoperative care of operatively treated fractures was not discussed.
Results:
One hundred fourteen Weber B stress positive supination external rotation isolated fibular fractures were included within this retrospective study. Fifty-four were treated non-operatively while 60 were treated operatively. Twenty-seven of operatively treated fractures were defined as having syndesmotic instability and were treated with syndesmotic screw fixation. Syndesmotic screw fixation consisted of a single screw utilized in 20 cases with seven cases having two to three screws for definitive fixation. No statistical significant difference in medial clear space and fibular displacement was found for each cohort at separate occasions of analysis. Medial clear space was found to be statistically significant upon stress examination for the following: operative 4.8 mm, ORIF stable syndesmosis 6.3 mm, and ORIF unstable syndesmosis 7.6 mm. Post reduction films demonstrated significantly less medial clear spaced widening than those treated operatively. At final radiographic union, no statistically significant difference was found for medial clear space widening for all three groups.
Conclusions:
Greater medial clear space widening found on stress examination may result in a decreased ability to maintain reduction in a cast. Stress positive supination external rotation Weber B fractures with minimal widening of stress exam may be successfully treated with cast therapy.