Posterior-anterior versus anterior-posterior screws for posterior malleolar fractures: A meta-analysis

BACKGROUND: The incidence of posterior malleolus fractures in ankle fractures ranges from 7% to 44%. Studies have indicated a poorer prognosis for ankle joint function when a posterior malleolar fracture is present, underscoring the significance of active intervention for optimal postoperative ankle function recovery. Hence, the selection of treatment for such fractures holds particular importance. OBJECTIVE: Screw fixation is a key treatment for posterior malleolus fractures (PMFs) or Haraguchi Type 1 fractures involving less than 25% of the distal tibia's articular surface. However, the optimal screw placement direction - anteroposterior (AP) or posterior-anterior (PA) - remains debated. This meta-analysis aims to compare these two approaches for treating posterior ankle fractures, focusing on the efficacy of PA fixation. METHODS: We searched the Cochrane Library, EMBASE, PubMed, SinoMed, and Web of Science databases from their inception to October 20, 2022. Methodological quality was assessed using the Cochrane Collaboration's tool for assessing bias risk in randomized controlled trials (RCTs). Stata MP17 software was used to compare the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, full weight-bearing time, and fracture healing time at the last follow-up between the two fixation methods. RESULTS: A total of 403 patients with posterior malleolar fractures from six RCTs met the inclusion criteria. The meta-analysis revealed a higher AOFAS score at the last follow-up for PA placement compared to AP placement [SMD = 0.512, 95% CI (0.244 to 0.780), z = 3.74, P < 0.001]. Postoperative full weight-bearing time and fracture healing time did not show statistically significant differences between the two groups. CONCLUSION: PA fixation demonstrated a superior AOFAS score compared to AP fixation for posterior malleolar fractures. PA screw placement offers advantages in restoring ankle joint stability and enhancing joint function recovery post-surgery.