Does It Matter the Fixation Method of The Posterior Malleolar Fragment in Trimalleolar Fractures?

PURPOSE OF THE STUDY The purpose of this study was to evaluate if the fixation method of a posterior fragment in trimalleolar ankle fractures affects the surgical outcomes. MATERIAL AND METHODS A retrospective evaluation was made of all the cases of trimalleolar fractures over a 9-year period in a trauma center. Patients aged 18 - 70 years were enrolled in the study. Patients were separated into 2 groups according to the fixation method (A - P percutaneous screw, and posterior open reduction - internal fixation). The fractures were classified according to the AO classification system and the Haraguchi posterior malleolar fracture classification system. The FAOS and SF-36 scores, postoperative reduction quality, arthritis scores and minor - major complications were evaluated. RESULTS 86 patients were found to eligible for the study. The PMF was fixed using anteroposterior percutaneous screw in 50 (58.1 %) patients and with posterior open reduction-internal fixation in 36 (41.9 %) patients. AO 44 B type fracture was determined in 89.5 % of the patients, AO 44 C type was seen in 10.5 %. There were 27 patients (31.4 %) with Haraguchi type 1 fracture and 59 patients (68.6 %) with type 2 fracture. The mean step-off of the articular surface was statistically greater in Group 1 than in Group 2. No statistically significant difference was determined between the two groups in respect of syndesmosis malreduction. The mean arthritis score was higher in Group 1 than in Group 2. Mean scores of the SF-36 and FAOS questionnaire was statistically significantly improved in the patients with open reduction and internal fixation. DISCUSSION Although there is no consensus on the treatment of posterior malleolar fractures, the indication for surgery is mainly based on posterior fragment size in the literature. The anatomic articular reduction has been emphasized recently. In this study, it was determined that the anatomic articular reduction was correlated with better surgical outcomes. CONCLUSIONS The study results demonstrated that better functional and radiological outcomes was observed with direct open reduction and fixation of the posterior fragment than indirect reduction and percutaneous fixation in the patients with trimalleolar fracture. The arthritis risk and patient satisfaction were seen to be correlated with the anatomic reduction of the articular surface. Key words: trimalleolar fracture, posterior malleolar fracture, percutaneous screw, open reduction and fixation, ankle fracture.