Are there Differences between Osteosynthesis of the Posterior Malleolus with Plates or with Posteroanterior Screws?

Category: Trauma; Ankle Introduction/Purpose: Cadaver studies suggest that the use of a plate allows a biomechanically more stable osteosynthesis than screws alone in posterior malleolus fractures. The objectives of this study are to test the subjective functional outcomes and the development of radiographic signs of early osteoarthritis in a cohort of patients with the two treatment groups. Methods: This is a retrospective study of patients operated on between 2020 and 2022 for ankle fractures with osteosynthesis of the posterior malleolus. Patients without preoperative CT scan, follow-up of less than one year and fractures without posterior malleolus synthesis were excluded. A total of 42 patients with a mean age of 53.39 years (± 17.25) and the median follow-up was 12 months (range: 12-45) were included. The Olerud-Molander Ankle Score (OMAS) subjective scale was used and the last follow-up radiograph was analyzed to assess the presence of early osteoarthritis using the Takakura classification. There were no differences in the immobilization time (p=0.843) or in the moment of loading (p=0.275) between both groups. Results: 65% of the patients were women. 52.4% of fractures corresponded to Bartonicek type 3 fractures, followed by type 2 (35.7%) and type 4 (11.9%). The predominant method of osteosynthesis for the posterior malleolus was posteroanterior screws in 24 patients, compared to 18 patients treated with plate and screws. No differences were found between the two groups when analyzing mean age, Bartonicek classification or the proportion of fragment size measured in the axial plane. The OMAS scale obtained a mean of 64.0 points (± 21.58) in the group treated with screws and 58.75 points (± 21.86) in the group treated with screws and plates, finding no significant differences (p=0.06). Ddifferences were found in the radiological results (p=0.511). No secondary displacements were observed in either group. Conclusion: We found no significant differences in the variables studied between the two methods of osteosynthesis in our cohort. These data suggest that posteroanterior screw synthesis may be a valid treatment alternative, although studies with a higher level of evidence are needed to confirm this theory.