J Korean Orthop Assoc.  2014 Feb;49(1):29-35. 10.4055/jkoa.2014.49.1.29.

Treatment of Isolated Posterior Malleolus Fracture in the Ankle

• Kim JH
• Cha SM
• Jo DY
• Suh JS

• KMID: 2185246
• DOI: http://doi.org/10.4055/jkoa.2014.49.1.29

Abstract

PURPOSE
An isolated posterior malleolar fracture in the ankle is very rare. We treated eight cases of isolated posterior malleolar fracture, and describe the clinical features and outcomes of treatment.
MATERIALS AND METHODS
Between from March 2008 to February 2012, eight cases of isolated posterior malleolar fracture were treated in Ilsan Paik Hospital. The mean age of patients was 30 years (11-49 years); six patients were male and five were right. Slip down (4 cases) was the most common injury mechanism. We treated four cases surgically, three cases by cast and one case by ankle brace. We could not recognize three cases of isolated posterior malleolar fracture at first. The time delay to diagnose unrecognized isolated posterior malleolar fracture was nine days, 56 days and 110 days respectively. We were able to diagnose the unrecognized isolated posterior malleolar fracture using computed tomography (two cases) and magnetic resonance imaging (one case).
RESULTS
The main symptom was painful swelling. The average for articular involvement of the posterior malleolar fragment was average 21.4%, and average displacement was 1.25 mm. We treated three cases surgically using a posterior lateral approach and one case using a posterior medial approach. The average American Orthopaedic Foot and Ankle Society score was 92.5 at the last follow-up.
CONCLUSION
The isolated posterior malleolar fracture is very rare and if it is neglected, persistent ankle pain can remain. Isolated posterior malleolus fracture should be included as one of the differential diagnoses after ankle trauma.

Keyword

ankle; isolated posterior malleolar fracture; result of treatment

MeSH Terms

Ankle Fractures*
Ankle*
Braces
Diagnosis, Differential
Follow-Up Studies
Foot
Humans
Magnetic Resonance Imaging
Male

Figure

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  Figure 1 Initial x-ray did not show any fracture line at the posterior malleolus contour.

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  Figure 2 Posterior malleolus fragment involves approximately 41% of the distal tibia articular surface on computed tomography scan (Haraguchi type I).

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  Figure 3 (A, B) Immediate postoperative x-ray showed anatomical reduction of the posterior malleolus. (C, D) After removal of hardware, the x-ray showed a well-united and well-aligned posterior malleolus.

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  Figure 4 (A, B) Ankle antero-posterior and lateral x-ray showed an undisplaced fracture line at the posterior malleolus. (C, D) Magnetic resonance imaging showed that the minimally displaced isolated posterior malleolar fracture was still not united (Haraguchi type 1).

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  Figure 5 (A, B) Postoperative radiographs showed anatomical reduction of the posterior mallolar fracture. (C, D) After removal of metal, the fracture was found to be well united.

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