Sat., 10/18/08 Foot & Ankle/Pediatrics, Paper #60, 11:38 am OTA-2008
Long-Term Follow-Up of Posterior Malleolar Ankle Fixation
Anna N. Miller, MD1 (n); Eben A. Carroll, MD1 (n); Sreevathsa Boraiah, MD1 (n);
David L. Helfet, MD1 (n); Keith D. Hentel, MD2 (n); Dean G. Lorich, MD1 (n);
1Hospital for Special Surgery, New York, New York, USA;
2New York Presbyterian Hospital – Cornell Campus, New York, New York, USA
Purpose: Previously, we have shown in a biomechanical study (Gardner et al, 2006) that fixation of unstable ankle fractures via the posterior malleolus with an attached, intact posteroinferior tibiofibular ligament (PITFL) provided more stable fixation of the syndesmosis than standard trans-syndesmotic screw fixation. This study evaluates long-term radiographic follow-up of ankle fractures with syndesmotic instability and concomitant posterior malleolar fractures treated with direct fixation of that fracture to stabilize the syndesmosis via the intact PITFL.
Methods: 21 patients with ankle fractures that had a separate posterior malleolar fracture were evaluated with a preoperative radiograph and MRI that confirmed syndesmotic injury. MRI on all patients also confirmed that the PITFL was intact and attached to the posterior malleolar fragment. These patients underwent open reduction and syndesmotic fixation via meticulous reconstruction of the tibial incisura, regardless of posterior malleolar fragment size, and the syndesmosis was opened and débrided before reduction under direct visualization. Intraoperative stress testing of the syndesmosis was performed under direct visualization and fluoroscopic visualization to confirm ankle stability after bony fixation. All patients had standard radiographic ankle series postoperatively and at follow-up. Radiographs were evaluated for the following measurements of syndesmotic congruence: anteroposterior tibiofibular clear space (TCS) less than 6 mm, anteroposterior tibiofibular overlap (TFO) greater than 6 mm, mortise TFO greater than 1 mm, and medial clear space (MCS) less than 5 mm.
Results: In our cohort, average follow-up was 9.6 months (range, 4.1-27.0 months). Using the criteria for reduction listed above, all had TCS less than 6 mm postoperatively and at follow-up (3.5 and 3.4 mm, respectively). Average TFO was 5.7 mm postoperatively and 5.3 mm at follow-up. Average mortise TFO was 1.5 mm postoperatively and 1.4 mm at followup, and MCS was 3.3 mm, compared with 2.9 mm at follow-up. There were no statistically significant differences between postoperative and follow-up measurements for any of the four measurements.
Conclusion and Significance: Fixation via the posterior malleolus and PITFL allows an “anatomic” reduction, which is maintained at follow-up. Anatomic incisura reconstruction via the posterior malleolus and PITFL obviates the need for syndesmotic screw placement.
If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.
• 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.