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Category: Ankle Introduction/Purpose: Fibular lag screw placement during ankle fracture fixation is not without risk. The screw placement endangers either the tendons of the peronei or the posterior rim of the incisura if misplaced. Our aim was to identify a predictable safe zone for screw placement. Methods: 45 radiographs of Weber B fractures were reviewed to determine the typical height of lag screw entry and exit points. 63 MRI scans of anatomically normal ankles were reviewed to evaluate tendon position and syndesmosis location. The safe zone could then be determined using composite images. Results: On review of the 45 ankle fracture radiographs; the typical lag screw exit point was found to be 14.2 mm above the ankle joint (95% Confidence Interval: 11.3-17.1 mm). Using the composite MRI images, there was a consistent flat anterior aspect of the fibula at this level. A safe zone trajectory was seen to occur between 31 and 45 degrees taken from the anterior aspect of the flat fibular surface at this level. The minimum distance to at-risk structures using this trajectory was 4 mm. If this consistent entry point is used, the MRI scans demonstrated that if the drill was aimed towards the medial edge of the Achilles tendon, the correct trajectory would be performed. Conclusion: The flat surface of the fibula is a constant landmark on MRI and is visible during surgery. The peroneal tendons and posterior rim of the incisura have a constant predictable position related to this. The safe zone for insertion of a lag screw is between 31 and 45 degrees medial to the anterior aspect of this flat surface. This represents aiming the drill towards the medial aspect of the Achilles tendon.

Category: Trauma Introduction/Purpose: Ankle fractures are one of the most common fractures. Historically these have been frequently treated by non-specialists and junior staff. In 2011 we presented high malunion rates, which have been mirrored in other departments work. We present the results of system changes to improve the results of ankle fracture fixation Methods: Image intensifier films were reviewed on PACS and scored based on the criteria published by Pettrone et al. At least two blinded assessors assigned scores independently. Patients clinical data was collected from medical records. In 2011 we presented the results of fixation in 94 consecutive patients (Group 1) from 2009. Following this there was period of education in the department to allow change. 68 patients (Group 2) were then reviewed from a 7 month period in 2014 Multiple system changes were introduced in the department including; new treatment algorithms, dedicated foot and ankle trauma lists and clinics, and next day review of all intra-operative radiographs by independent attending. Prospective data was collected on 205 consecutive cases (Group 3) from 01/01/15 – 09/30/16 Results: Patients in group 1 had a malreduction rate of 33%. The major complication rate in this group was 8.5% (8 patients); with only one of these occurred in a correctly reduced fracture. These complications included 4 revision fixations, 2 deep infections and 1 amputation. Following the period of re-education, in Group 2, the mal-reduction rate deteriorated to 43.8%. In this group the major complication rate was 10.9%; including 6 revision fixations and 1 ankle fusion. In Group 3, following overall system changes, the malreduction rate was 2.4%. This result is statistically significant. The major complication rate fell to 0.98%; 1deep infection and 1 amputation (in a polytrauma patient with vascular injury). This result is again statistically significant. Conclusion: Our initial results show that very poor results are a consequence when sufficient attention is not given to what are frequently considered to be ‘simple’ fractures. In group 2 we demonstrated that soft educational changes (eg presentations, emails) are ineffective in improving results. We have demonstrated that hard (institutional system) changes in our department provided statistically significant improvements. These changes allowed the correct surgeon for the fracture in both determining the treatment plan and operating. With these changes, malreduction rates fell from 43.8% to 2.4% and major complication rates from 10.9% to 0.98%

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