Background: Pronation-abduction ankle fractures frequently are
associated with substantial lateral comminution and have been reported to be
associated with the highest rates of nonunion among indirect ankle fractures.
The purpose of the present study was to report the technique for and outcomes
of extraperiosteal plating in a series of patients with pronation-abduction
ankle fractures.
Methods: Thirty-one consecutive patients with an unstable comminuted
pronation-abduction ankle fracture were managed with extraperiosteal plating
of the fibular fracture. The average age of the patients was forty-four years.
There were nineteen bimalleolar and twelve lateral malleolar fractures with an
associated deltoid ligament injury. No attempt to reduce the comminuted
fragments was made as this area was spanned by the plate. The patients were
evaluated functionally (with use of the American Orthopaedic Foot and Ankle
Society score), radiographically, and clinically (with range-of-motion
testing).
Results: Immediate postoperative and final follow-up radiographs
showed that all patients had a well-aligned ankle mortise on the fractured
side as compared with the normal side on the basis of standardized
measurements. All fractures healed without displacement. At a minimum of two
years after the injury, the average American Orthopaedic Foot and Ankle
Society score (available for twenty-one patients) was 82. The range of motion
averaged 13° of dorsiflexion and 31° of plantar flexion, with one
patient not achieving dorsiflexion to neutral. There were no deep infections,
and one patient had an area of superficial skin breakdown that healed without
operative intervention.
Conclusions: Extraperiosteal plating of pronation-abduction ankle
fractures is an effective method of stabilization that leads to predictable
union of the fibular fracture. The results of this procedure are at least as
good as those of other techniques of open reduction and internal fixation of
the ankle, although specific results for pronation-abduction injuries have not
been previously reported, to our knowledge.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.