Posterior Locking Plate Fixation of Bartoníček Type IV Posterior Malleolar Fracture: A Focus on Die-Punch Fragment Size

Abstract

Die-punch fragments refer to articular cartilage and subchondral bone embedded in cancellous bone as part of an intra-articular fracture. Bartoníček type IV posterior malleolar fractures with associated die-punch fragments are rare, and the appropriate surgical approach remains unclear. We determined outcomes, and the effect of die-punch fragment size on outcomes, for 32 patients with Bartoníček type IV posterior malleolar fractures with die-punch fragments between January 2015 and December 2017. Mean follow-up for all patients was 23.8 (range 20.0-30.0) months. At the final follow-up visit, mean ankle dorsal extension was 24.6° and plantar flexion was 40.0°; American Orthopaedic Foot and Ankle Society ankle-hindfoot score was 88.6 ± 4.3; visual analog scale weightbearing pain score was 1.5 ± 0.6; and Bargon traumatic arthritis score was 0.8 ± 0.4. There were no severe complications. We divided patients into a small-fragment (≤3 mm) group (n=12) and large-fragment (>3 mm) group (n=20). The Bargon scores at final follow-up were 0.5 and 1, respectively (P=.02). There were no statistically significant differences between the 2 groups for the other outcome scores at various time intervals. The posterolateral approach with distal locking plate internal fixation for Bartoníček type IV posterior malleolar fractures with die-punch fragments can result in excellent anatomical reduction of the collapsed articular surface and the displaced fragment from the tibial plafond, recovery of articular surface congruity, and maintenance of joint stability. Die-punch fragment size may not impact clinical and functional outcomes but may contribute to post-traumatic arthritis.