Session VII - Foot / Ankle

Sat., 10/12/13 Foot/Ankle, PAPER #85, 11:15 am OTA 2013

Anatomical Fixation of Supination–External Rotation Type IV Equivalent Ankle Fractures

Milton T.M. Little, MD; Marschall B. Berkes, MD; Patrick C. Schottel, MD;
Matthew Garner, MD; Lionel E. Lazaro, MD; Jacqueline F. Birnbaum, BA;
David L. Helfet, MD; Dean G. Lorich, MD;
Hospital for Special Surgery/New York Presbyterian-Cornell, New York, New York, USA

Background/Purpose: Ankle fracture fixation continues to challenge orthopaedists despite the plethora of research into novel fixation strategies. Outcomes vary with these novel strategies, but discrepancies continue to exist regarding the most successful means of fixation. We have previously published our fracture-specific treatment strategy for supination–external rotation (SER) ankle fractures, which has exhibited equivalent outcomes between boney and ligamentous injuries as well as between geriatric and nongeriatric populations. These results have been contrary to previously published literature and previously held dogma. The goal of this study is to extend that anatomical treatment strategy to supination type IV equivalent (SER IV E) ligamentous injuries and compare our previous patients with our current strategy of deltoid and posterior inferior tibiofibular ligament (PITFL) repair. We hypothesize that our radiographic and functional outcomes will be improved with the addition of ligamentous repair.

Methods: This is an IRB-approved evaluation of a prospectively collected database of a single surgeon from a Level I trauma center. All MRI-confirmed SER IV E (45 patients) ankle fractures treated between 2004 and 2011 with at least 1-year clinical follow-up were included in this cohort. Prior to 2010 all SER IV E ankle fractures were treated with lateral malleolus fixation and transsyndesmotic screws in the setting of a positive intraoperative stress test. Since 2010 all SER IV E ankle fractures have undergone PITFL fixation with a soft-tissue washer and 3.5-mm cortical screw followed by an intraoperative stress test. Deltoid ligament repair with a medial malleolus or talus suture anchor was reserved for intraoperative stress showing increased talar tilt or increased medial clear space (MCS). All patients underwent immediate postoperative bilateral CT scans to evaluate articular reduction and syndesmotic reduction. Postoperative radiographs measuring tibiofibular clear space (TCS) and MCS were performed. Change in TCS or MCS >2 mm from initial radiographs was considered a loss of reduction. Greater than 2 mm difference in anterior or posterior syndesmotic width when compared to the uninjured side was considered a syndesmotic malreduction. Functional outcome scores as measured by the Foot and Ankle Outcome Score (FAOS) were compared for patients with at least 1-year functional outcome score follow-up.

Results: There was no significant difference in mean postoperative TCS, MCS, or change in TCS or MCS between the cohorts. The anatomical treatment group had significantly better postoperative syndesmotic reduction compared to the nonanatomical cohort (7.4% vs 21.4%; P = 0.02). The mean difference in syndesmotic width for the nonanatomical cohort was 1.8 mm compared to 0.9 mm in the anatomical cohort. All transsyndesmostic screws were removed at 4 months in the nonanatomical cohort (14 patients). The nonanatomical cohort had slightly better dorsiflexion of ankle (mean 19° vs 17°; P = 0.02). The nonanatomical group had significantly better functional outcome scores in all categories of the FAOS outcomes score (quality of life, return to sports, activities of daily living, pain, and symptoms) despite worse syndesmotic reduction.

Conclusion: This comparison of treatment strategies for SER IV E ankle fractures has shown an improvement in immediate postoperative syndesmotic reduction and the elimination of reoperation for removal of transsyndesmotic screws, but this does not translate to improved functional outcomes in this cohort. While short-term outcomes (1 year) appear worse, longer-term investigation of these patients is necessary to determine the impact of the anatomical treatment strategy on posttraumatic osteoarthritis and poorer future outcomes.

Alphabetical Disclosure Listing

• 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.