Posterior facet cartilage injury in operatively treated intra-articular calcaneus fractures

Background: Direct visualization of the posterior facet in displaced intra-articular calcaneus fractures (DIACF) frequently shows partial or full thickness cartilage delamination. This is felt to be secondary to the depression of an osteoarticular segment of the posterior facet within the calcaneal body and the subsequent contact with fracture edges as it impacts caudally. The purpose of this study was to determine the frequency of cartilage injury and if it correlates with fracture classification.

Methods: A single surgeon prospective, observational series of 28 patients with 28 DIACFs was reviewed for patient demographic and injury data, radiographic fracture characterization, and intraoperative observation of articular injury size, depth, and location over the time period of February 2010 to December 2012. Observations were correlated with the OTA and Sanders classification systems.

Results: Age, sex, mechanism of injury, and depth and location of cartilage injury were not significantly different between the 13 OTA/Sanders type 2 and 15 type 3 DIACFs evaluated in this study. Posterior facet articular cartilage delamination was found in 77% of type 2 and 100% of type 3 fractures (P = .09). Location of cartilage injury was common (56%) along the distal, lateral aspect of the posterior facet (P < .05). The percentage area of cartilage injury was significantly larger in type 3 fractures (3.1%) then type 2 (1.3%) (P < .02).

Conclusions: DIACFs had a consistent location of posterior facet articular cartilage delamination along the distal lateral aspect of the osteoarticular fragment. This lesion was larger in OTA/Sanders classification type 3 fractures compared to type 2 fractures.

Level of Evidence: Level IV, prospective, observational series.