SLR - January 2023 - Son Tran, DPM
Title: Intercalary fragments in posterior malleolar fractures: incidence, treatment implications, and distribution within CT‑based classification systemsReference: Mueller E, Kleinertz H, Tessarzyk M, Rammelt S, Bartoníček J, Frosch KH, Barg A, Schlickewei C. Intercalary fragments in posterior malleolar fractures: incidence, treatment implications, and distribution within CT-based classification systems. Eur J Trauma Emerg Surg. 2022 Nov 4. doi: 10.1007/s00068-022-02119-2. Epub ahead of print. PMID: 36331574.
Level of Evidence: Level III
Reviewed By: Son Tran, DPM
Residency Program: Medstar Health, Washington DC
Podiatric Relevance: Acute ankle fractures result in significant functional limitations if not appropriately repaired. In instances of posterior malleolar (PM) involvement, functional outcomes are reportedly worse in comparison to other ankle injuries. Moreover, only a paucity of literature exists to account for the presence intercalary fragments (ICF) in PM fractures. Being able to recognize the incidences of ICF involvement and their locations may help surgeon in properly addressing PM injuries.
Methods: A level III retrospective study was performed at a level I trauma center in a major city in Germany, which included 135 patients between October 2018 and September 2021, who sustained ankle fractures with PM involvement. Using computer tomography (CT), the prevalence, location, dislocation, size, approximate volume, and distributions of ICFs were determined. The PM injuries were then grouped in accordance with the Haraguchi, Bartoníček/Rammelt, and Mason CT classifications. Normality testing was performed with the Shapiro–Wilk test. The Mann–Whitney test compare ranked variables with non-normal distributions. Binominal variables from unpaired groups were compared using the Chisquare test. Significance was determined at p ≤ 0.05.
Results: ICF was seen in 41% of all patients with a PM fracture. The ICF was comminuted in 65% of cases, and 87% of ICFs were dislocated from the articular surface. 58% of ICFs were posterolateral and 35% were posterocentral on the tibial plafond. The majority of ICFs were Haraguchi type I (53%), Bartoníček/Rammelt type 2 (49%), and Mason type 2A (53%). Fixation of the PM fracture was performed in 82% (45 patients) of patients with ICF versus 39% (31 patients) without ICF involvement (p < 0.001). PM fractures with ICF were accessed through posterolateral approach in 71% of cases, compared to 26% in cases without ICF (p < 0.001). The ICF was addressed in 84% of cases (n = 46) with removal of the ICF in 39% (n=18) of instances due to interference with anatomic reduction of the PM fragment.
Conclusion: Ankle fractures with PM involvement demonstrates a high likelihood of ICF involvement. A CT is recommended in further evaluating fracture morphology if there is PM injury. The presence of ICF suggests a higher likelihood for repair of the PM fracture, although directly fixing the ICF is not always indicated. With a predilection for posterior tibial plafond involvement, accessing the ICF via a posterior approach is recommended in the majority of cases.