Fewer reoperations after posterolateral plate positioning compared with lateral plate positioning in ankle fractures-a retrospective study on 453 AO/OTA 44-B injuries.

INTRODUCTION

Ankle fractures are commonly treated by open reduction and internal fixation with plate and screws. Unplanned return to theatre is common, in many cases to extract prominent osteosynthesis material from the lateral malleolus as swelling subsides. We hypothesised that patients operated with a posterolateral plate placement on the lateral malleolus would have fewer reoperations, and fewer complications, compared to patients with a lateral plate placement.

MATERIALS AND METHODS

From a prospectively collected database of all orthopaedic surgery performed at our institution, we identified 664 ankle fractures undergoing plate fixation between 2008-01-01 and 2012-04-30. Radiographs were analysed to only include AO/OTA 44-B-fractures (n = 453), and to define study groups based on plate positioning. Hospital files were assessed to identify possible confounding factors, and any unplanned reoperation or complication. Complications were classified according to Dindo-Clavien.

RESULTS

The risk of reoperation was 13% after posterolateral plating, compared with 24% after lateral plating; absolute risk reduction 10% (95% CI: 2.5-18), p = 0.02. After adjusting for possible confounders, the odds ratio of undergoing reoperation after lateral plating was 2.2 (95% CI: 1.17-4.1), p = 0.01. The two surgical methods did not differ with regard to complication frequency: 31% vs 34%, p = 0.6, but complications following lateral plate fixation were more serious, p = 0.03. Plate positioning depended on surgeon preference.

DISCUSSION

The two studied methods are both considered standard treatment of ankle fractures, and relatively simple surgical procedures. High rates of secondary surgery after plate fixation have been reported, but no study comparing plate positioning has been previously published to our knowledge. AO Sweden has recently switched to teaching posterolateral plating in group exercises during the AO Basic Fracture Surgery course, based on the belief that it may be safer than lateral plating. Our findings support this change in practice.

CONCLUSIONS

Posterolateral plate positioning on the lateral malleolus in AO/OTA 44-B-fractures may be preferential to lateral plate positioning, due to a large difference in unplanned secondary surgery.