SLR-February 2014- Joseph S. Baker
Reference: Hoelsbrekken SE; KK Jensen, T Morch, et al. Nonoperative Treatment of the Medial Malleolus in Bimalleolar and Trimalleolar Ankle Fractures: A Randomized Controlled Trial. J Orthop Trauma. 2013; 27: 633-637.
Scientific Literature Review
Reviewed By: Joseph S. Baker, DPM
Residency Program: Detroit Medical Center
Podiatric Relevance: The significance of fixation of the medial malleolus in the setting of bimalleolar and trimalleolar fractures is explored, and functional outcomes are assessed. This data is important for physicians involved in foot and ankle surgery or fracture care.
Methods: The study was designed as a randomized controlled trial of medial malleolus fracture fixation in OTA/AO type 44 fractures B2, B3,C2, and C3. Inclusion criteria was further defined as patients >18 years of age and those treated in an orthopaedic clinic between May 2002 and February 2006. All patients were treated operatively within nine days of injury. Exclusion criteria included patients with OTA/AO 43 distal tibia fractures, patients with purely soft tissue injuries involving the medial malleolus, and patients with open or pathological fractures. Secondary characteristics of age, gender, body mass index (BMI), comorbidity and American Society of Anesthesiologists classification were identified.
Operative technique included open reduction and internal fixation of the lateral malleolar fracture as well as ORIF of the posterior malleolar fragment when it involved >25 percent of the articular surface. Standard AO technique and implants were applied. Syndesmotic instability was tested intra-operatively with a hook test, and was addressed with one 4.5-mm quadricortical screw or two 3.5-mm tricortical screws when more than 2-mm of displacement was noted. Lastly, the position of the medial malleolus was addressed using an AP-mortise view with 20 degrees of internal rotation. If there was less than 2-mm of displacement noted of the medial malleolar fragment, the patient was eligible for inclusion in the study. Patients were randomized using computer generated allocation codes, and were delivered to the operating room in a sealed envelope by the nursing staff. Fixation of the medial malleolus was most frequently performed with two 3.5-mm lag screws. However, two patients had their medial malleolar fracture fixated with tension banding techniques due to small fragments. Post-operatively, patients were placed in a short leg cast and placed on bed rest with the limb elevated for 72 hours. The cast was then removed and patients were allowed partial weight bearing for six weeks.
All patients were then evaluated clinically and radiographically at six weeks. Long-term evaluation was carried out at variable and non-standardized amounts of time. Outcomes were measured using the Olerud Molander Ankle (OMA) score, American Orthopaedic Foot and Ankle Score (AOFAS), and Visual Analog Scale (VAS). Post-traumatic arthritis of the talocrural joint was evaluated using Magnussen criteria.
Results: There were 100 patients that met inclusion criteria. Of these, 18 were lost to follow up. This left 37 patients in the group receiving fixation of a medial malleolus fracture, and 45 patients who received non-operative treatment of the medial malleolus fracture. The two groups were similar in age, gender, BMI, OTA/AO classification of fractures, involvement of the syndesmosis in the injury, and presence of diabetes. Development of infections post-operatively was comparable. The rate of nonunion in the group treat non-operatively was statistically significantly higher than in the group treated with fixation. There were four nonunions (9 percent) in the no fixation group and none in the group receiving fixation.
The follow up time for the group receiving operative treatment of the medial malleolar fracture was 44 months (median was 37 months, range 24-72 months). For the patients receiving fixation of the medial malleolus, the mean follow up was 41 months (median was 41 months, range 24-67 months). Functional scores using OMA and AOFAS scoring systems were similar. The VAS scores were also similar between the two groups. The results of both groups were good. Diabetic and obese patients fared worse than other patients.
For the patients with non-unions, no additional surgery was required for revision,and the patients reported above average functional scores. There was no significant difference in thedevelopment of severity of post-traumatic arthritis between the two groups.
Conclusion: The findings of this study suggest that the functional outcomes of bimalleolar and trimalleolar fractures are similar when the medial malleolar fracture is less than 2mm displaced, regardless of whether or not the medial malleolus is fixated. These results should be interpreted with some caution, as the study does have limitations in its design. These limitations include a lack of pre-operative functional testing, a lack of standardized follow-up timelines, a lack of stratification of the fracture pattern of the medial malleolus itself, and a high amount of patients lost to follow up.
Advantages to using a non-operative approach to the medial malleolus include shorter surgery time and prevention of risks inherent with fracture fixation. These include late irritation due to hardware, infections, reaction to hardware, and undue injury to surrounding vital structures. Additionally, malposition of the fracture site may be enhanced with the use of hardware, as in this study.
A disadvantage to non-operative management of medialmalleolar fractures is the relatively high incidence of non-union. While these non-unions did not appear toalter the functional outcomes, it is unclear with the data presented in this study the long-term effects of non-union at this site. Still, the method of non-operative treatment of the medial malleolar fracture may be useful in the presence of soft tissue injury in this area, or if fixation at this site is otherwise contra-indicated.