Fri., 10/5/12 Foot & Ankle, PAPER #47, 10:58 am OTA-2012
The Effect of Syndesmosis Screw Removal on the Reduction of the Distal Tibiofibular Joint
CPT Daniel J. Song, MD; CPT Joseph T. Lanzi, MD; MAJ Adam T. Groth, MD;
MAJ Matthew Drake, MD; LTC Joseph R. Orchowski, MD; COL Kenneth K. Lindell, MD;
Tripler Army Medical Center, Honolulu, Hawaii, USA
Background/Purpose: Injury to the tibiofibular syndesmosis is frequent with rotational ankle injuries. Although there is controversy regarding the treatment of these injuries (size of screws, number of cortices, composition of screws, postoperative weight bearing, need and timing for screw removal), many studies show statistically significant improvements in subjective and objective outcomes with anatomic reduction of the syndesmosis. In a retrospective radiographic study in 2006, Gardner et al reported a 52% syndesmotic malreduction rate in their 25-patient cohort. The purpose of this study is to prospectively evaluate syndesmotic reduction with CT, and determine the effect of screw removal on both the anatomically reduced and malreduced syndesmosis.
Methods: This is an IRB-approved prospective radiographic study. Patients over 18 years of age treated at one institution between August 2008 and December 2011 with intraoperative evidence of syndesmosis disruption were enrolled. Postoperative CT scans were obtained within 2 weeks of operative fixation of the injured and uninjured ankle. A second CT scan was then obtained 30 days after syndesmosis screw removal. All CT scans were evaluated by a single musculoskeletal radiologist to evaluate the reduction of the syndesmosis. Using axial CT images, differences of more than 2 mm between the anterior and posterior fibula-incisura distances were considered malreduced in accordance with the standard established by Gardner et al.
Results: 25 patients were enrolled in this prospective study. The average age was 25.7 (range, 19-35), with 3 females and 22 males. Eight patients (32%) had evidence of tibiofibular syndesmosis malreduction on their initial postoperative axial CT scans. In the postsyndesmosis screw removal CT scan, seven of eight (87.5%) of malreductions showed adequate reduction of the tibiofibular syndesmosis.
Discussion/Conclusions: Tibiofibular syndesmosis injuries are common with ankle fractures and require surgical fixation. In 2006, Gardner et al showed an alarming 52% tibiofibular syndesmosis malreduction rate on immediate postoperative CT scans. In 2004, Weening and Bhandari reported a much lower 16% malreduction rate using plain radiographs, and also showed that adequate reduction of the syndesmosis was the only statistically significantly predictor of functional outcome. To our knowledge, this study is the only prospective study to report the effect of syndesmosis screw removal on tibiofibular syndesmosis reduction. Similar to Gardner et al, we also found a high rate of tibiofibular syndesmosis malreduction of 32%. Despite this high rate of initial malreduction, 87.5% of the malreduced syndesmoses spontaneously reduced after screw removal. Further correlation with functional outcomes is necessary. Syndesmotic screw removal may be advantageous to achieve final anatomic reduction of the distal tibiofibular joint and continues to be recommended.
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• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.