To analyze the long term follow up results of treatment with posterolateral approach and to investigate its usefulness in the patients of trimalleolar fracture with posterior fragment which is above 25% of articular involvement.

There were 34 cases of trimalleolar fracture in our hospital from May 2004 to April 2008. We investigated 20 patients who underwent operation with the posterolateral approach and over-2 years follow up cases. The mean follow up period was 34 (24~58) months. Preoperative posterior malleolar fragment involved above 25% of articular surface in all cases and displaced more than 2 mm in 11 cases. We analyzed the radiologic type of posterior malleolar fragments and evaluated the function and pain through AOFAS score and complications.

All cases showed primary union at mean 13.1 weeks. The complications are that partial ankylosis result of soft tissue contracture is seen in 2 cases (10%) and post-traumatic arthritis is seen in 1 cases (5%) and 17 cases (85%) of all patients are showed excellent AOFAS score.

The posterolateral approach is a valuable method because that it enables us to easily reduction and internal fixation of the posterior malleolus and lateral malleolus at one time and the results are satisfied for a long time follow up.