Fri., 10/19/07 Foot & Ankle, Paper #34, 3:27 pm OTA-2007
Should the Syndesmosis Screw Be Removed?
Ajay Manjoo, MD1 (n), David W. Sanders MD, MSc2 (n); Christina Tieszer, MSc2 (n);
Mark MacLeod, MD2 (n);
1University of Western Ontario, London, Ontario, Canada;
2Victoria Hospital, University of Western Ontario, London, Ontario, Canada
Purpose: Screw fixation of the injured syndesmosis restores stability, but may reduce ankle motion. The purpose of this retrospective study was to determine whether functional and radiographic results are improved by removal of syndesmosis screws. In addition, we studied whether large fragment screws have an advantage compared to small fragment screws. We hypothesized that retained intact syndesmosis screws are detrimental to ankle function.
Method: 107 adults with ankle fractures requiring syndesmosis screw fixation between 2001 and 2005 were retrospectively studied. Indications for syndesmosis fixation were a positive intraoperative external rotation stress test or inadequate lateral column buttress. Weight bearing was encouraged 6 weeks postoperatively. Syndesmosis screws were only removed for tenderness, prominence, or ankle dorsiflexion <10°. Functional outcomes (n = 66) were measured using the Lower Extremity Measure (LEM) and the Olerud Molander ankle score (OM) (follow-up 21 ± 12 months). Radiologic review (n = 107) included tibiofibular clear space, tibiofibular overlap, and medial clear space. The outcomes of intact, broken or loosened, and removed screws were compared. We also compared outcomes between large and small fragment screws. Statistical significance was defined as P <0.05.
Results: The LEM score for patients with intact screws was 70 ± 26 compared with 85 ± 20 for broken, loosened, or removed screws (P = 0.05). The OM score for patients with intact screws was 48 ± 36 compared with 63 ± 27 for broken, loosened, or removed screws (P = 0.12). There was no difference in outcome comparing broken, loosened, and removed screws. The tibiofibular clear space for intact screws was 3.3 ± 1.3 compared with 4.1 ± 1.7 for removed, broken, or loosened screws (P = 0.02). There was no difference in clinical or radiographic outcome comparing large and small fragment screws.
Conclusions: Patients with broken, loosened, or removed syndesmosis screws have better functional outcome compared to intact screws. The syndesmosis allows fibular rotation, shortening, and translation during gait; the presence of an intact syndesmosis screw may restrict this motion. There was no disadvantage to leaving broken or loosened screws in situ.
Significance: Broken, loosened, or removed syndesmosis screws resulted in a better functional outcome compared to intact retained screws. The syndesmosis normally facilitates rotation and shortening of the fibula during gait; intact retained screws may restrict this motion. This study suggests that surgeons should consider removal of intact retained syndesmosis screws, whereas broken or loosened screws do not require routine removal.
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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.