SLR - July 2019 - Nicholas R. Thompson

Talar-Sided Osteochondral Lesion of the Subtalar Joint Following the Intra-Articular Calcaneal Fracture: Study Via A Modified Computed Tomography Mapping Analysis

Reference: Angthong, C., Veljkovic, A., Angthong, W. and Rajbhandari, P. (2019). Talar-Sided Osteochondral Lesion of the Subtalar Joint Following the Intra-Articular Calcaneal Fracture:
Study Via A Modified Computed Tomography Mapping Analysis. European Journal of Orthopaedic Surgery & Traumatology. https://doi.org/10.1007/s00590-019-02445-z

Scientific Literature Review

Reviewed By: Nicholas R. Thompson, DPM
Residency Program: East Liverpool City Hospital – East Liverpool, OH

Podiatric Relevance: The limited visualization to the underside surface of the talus in conventional open reduction internal fixation or percutaneous reduction of the calcaneus stresses the importance of utilizing available preoperative imaging to assist the surgeon with operative planning.

Methods:
Preoperative CT scans were performed on 30 patients with intra-articular calcaneal fractures. Mapping of underlying articular surface of the talus were recorded utilizing the Akiyama classification, with the Ferkel classification used to assess lesion severity, and Sanders’ classification for fracture severity of the calcaneus. Patients were excluded if they were found to have diminished bone stock secondary to osseous disease such as Paget’s, osteopetrosis, neoplasm, osteodystrophy, or simply incomplete data to contribute.

Results: Of the 30 included patients, 28 patients (93.3 percent) were found to have a total of 30 osteochondral lesions on the sub-talus surface, with two patients displaying no lesion. The posterior facet of the talus had the majority of lesions in the study, with 16 occurring anterior (57.1 percent) and 13 occurring central (46.4 percent). Mean patient age was 46.2 years, with 23 (76.7 percent) male and 7 (23.3 percent) female, and 29 (96.7 percent) occurring from falls over the patient’s standing height. Two patient’s developed two lesions on the posterior facet of the talus, which was found to correlate with a higher lesion severity (P value=0.005). In regards to severity, 80 percent of patient’s experienced a grade one lesion (intact roof/cartilage with cystic lesion beneath) with only several patients experiencing more advanced fragmentation of the lesion. Sanders’ fractures were mostly grade three or four, with 12 patients in each group, and six patient’s experiencing grade two fractures. A follow-up study by the same authors was also included in which patients were evaluated by plain radiographs to assess for the presence of post-traumatic subtalar osteoarthritis. Of the follow-up patients, 32 percent were found to display post-traumatic subtalar osteoarthritis and 62 percent of those with osteochondral lesions of the posterior talar facet were found to develop definite or possible osteoarthritic changes.

Conclusions: This article shines light on a unique identification of osteochondral lesion that has largely been ignored. The article is practical in mentioning the difficulty of addressing these lesions due to their location; however, they do make a valid argument for the additional use of arthroscopic measures to treat these lesions at the time of initial calcaneal repair, which would likely result in greater patient outcomes rather than waiting to address later sequelae. There are several glaring values left out that I would have been interested in knowing: the initial number of patients identified prior to those meeting their inclusion criteria, total patients in follow-up group, and what CT images resulted in the highest number of identified lesions. Unfortunately, this study had a limited number of patients. I also find it odd that they cited their own paper addressing the addition of CT to outcomes in intra-articular calcaneal fractures with the same patients utilized in this present study that was published five years earlier. 

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