Nonoperative Treatment of the Medial Malleolus in Bimalleolar and Trimalleolar Ankle Fractures: A Randomized Controlled Trial

SLR - May 2014 - Sarah Rincker

Reference: Hoelsbrekken SE, Kaul-Jensen K, Morch T, Vika H, Clementsen T, Paulsrud O, Petursson G, Stiris M, Stromsoe K. Nonoperative Treatment of the Medial Malleolus in Bimalleolar and Trimalleolar Ankle Fractures: A Randomized Controlled Trial. Journal of Orthop Trauma. 2013;27:633-637.

Scientific Literature Review

Reviewed By: Sarah Rincker, DPM
Residency Program: Grant Medical Center, Columbus, Ohio

Podiatric Relevance: Ankle fractures are one of the most common injuries that present to the emergency department. Standard of care has changed throughout the years regarding ankle fractures. There have been times when the fibular reduction was considered the most important in bimalleolar and trimalleolar ankle fractures. This later was argued and many felt that the medial malleolus and deltoid were the most important, and most recently, a consensus has been established that all the structures hold importance in maintaining joint congruity and therefore lower the risk of future osteoarthritis (OA). Unfortunately, sometimes patients present with soft tissue compromise to the medial ankle, which raises a question of: “Do you increase the chance of wound dehiscence by going medially or can you only fixate the fibula hoping that the ankle remains stable?” This article looks at the short term prognosis of only fixing the fibula in bimalleolar and trimalleolar ankle fractures when the medial malleolus is well aligned.

Methods: In this prospective randomized study, 100 patients with bimalleolar or trimallolar OTA type 44 ankle fractures with displacement of the medial malleolus less than 2 mm were randomly assigned to ORIF of the lateral malleolus with or without ORIF of the medial malleolus. Standard AO technique was accomplished for the fractures fixed. Regardless of which group, all patients with a posterior malleolar fracture >25 percent underwent ORIF, and all patients with a syndesmotic instability via the Cotton hook test underwent syndesmotic repair either utilizing one 4.5 mm quadricortical screw or two 3.5 mm tricortical screws. Postoperatively all patients were placed in a cast with cast removal and weightbearing after six weeks. All patients also received Lovenox until adequately mobilized. Three observers who were not blinded to the study were assigned to assess the long term follow up of the patients via OMA score, AOFAS, and VAS. A single radiologist was utilized to perform postoperative x-ray examination to determine if any OA had formed.

Results: Of the 100 patients randomized to ORIF versus nonoperative treatment of the medial malleolus, 18 were lost to follow-up. This left 37 patients undergoing ORIF versus 45 patients with no fixation medially. Age, gender, OTA/AO classification, BMI, ASA, and presence of diabetes were not statistically significant between the two groups. However, the group treated with medial malleolar fixation had a higher percentage of patients with obesity and ASA score III. The mean duration of surgery was significantly longer in the group with medial fixation (102 minutes vs 75 minutes), but the number of postoperative infections was comparable. In the non-fixation group, three patients required additional surgery due to complications. Two of these patients were treated for infections and one patient developed Charcot arthropathy. In the fixation group, one patient required repeated surgery due to malposition of the screw on the medial side. Four patients without fixation developed nonunion however the nonunions were not painful and there was no functional disability found in the OMA and AOFAS. None required revisional surgery. Four patients treated with ORIF ended up with malposition of the medial malleolus compared with three in the nonoperative group. Collectively patients with malposition had a lower AOFAS and OMA score. There was no significant difference in post-traumatic arthritis between the two groups (three operative and one nonoperative). There was no significant difference between the groups with regard to VAS, OMA, and AOFAS (good in both groups). Regardless of the group, obese patients and diabetics fared worse.

Conclusions: Fixation of the lateral malleolus alone carries acceptable results if the medial malleolus is reduced with ORIF of the lateral malleolus. VAS, OMA, and AOFAS was comparable in both groups. Post-traumatic arthritis and return to surgery were also similar in both groups. One of the differences between the two groups however was the increased amount of radiographic nonunions present in the nonoperative medial malleolus group. It is important to consider that a malunion of the medial malleolus can lead to a potential for loss of ankle joint congruity. This could be a complication that fails to present with such a short follow-up. Also, the post-traumatic arthritis studied in the patients can also present as a later finding. This study is good in that it provides a stepping stone for further investigation in the future, and hopefully a long-term prospective control study is in the works. Until then, it is likely even with a medial wound, fixation of the medial malleolus in bimalleolar and trimalleolar fractures will remain the standard of care.