Introduction: Complex ankle fractures frequently include the posterior malleolus (PM). Despite advances in diagnostic and treatment strategies, PM fracture involvement still predisposes to worse outcomes. While not incorporated into the most common PM fracture classifications, the presence of an intercalary fragment (ICF) complicates treatment. This study aims to describe the incidence, morphology, and location of ICFs in PM fractures. Materials and methods: A total of 135 patients with a mean age of 54.4 (SD ± 18.9) years and PM fractures were analyzed for the presence of an ICF. Patients with an ICF were compared to those without in terms of age, gender, and treatment received. Characteristics of the ICFs in terms of location and size were assessed. Furthermore, the presence of an ICF in relation to the PM fracture classification according to Haraguchi et al., Bartoníček/Rammelt et al., and Mason et al. was investigated. Results: ICFs presented in 55 (41%) of the 135 patients. Patients with an ICF were younger, and the PM was more often operatively treated when compared to patients without an ICF. A posterolateral approach was used significantly more often in patients with an ICF. Almost all ICFs were found in the posterolateral (58%) and posterocentral (35%) regions. The majority of fragments were found in Bartoníček/Rammelt type 2 fractures, the most common fracture type. Bartoníček/Rammelt type 3 fractures had the highest relative frequency of ICFs. Conclusion: ICFs are frequently found in PM fractures; however, they are not incorporated into any of the common classifications. They are generally found in younger patients and associated with more complex PM fractures. As they can complicate reduction of the main fragment and may require direct exposure to restore joint congruency, ICFs should be considered in PM fracture classifications. Due to their location, the majority of ICFs are able to be accessed using a posterolateral approach.

Introduction: Progressive collapsing foot deformity (PCFD), formally known as “adult-acquired flatfoot deformity” (AAFFD), is a complex foot deformity consisting of multiple components. If surgery is required, joint-preserving procedures, such as a medial displacement calcaneal osteotomy (MDCO), are frequently performed. The aim of this systematic review is to provide a summary of the evidence on the impact of MDCO on foot biomechanics. Materials and methods: A systematic literature search across two major sources (PubMed and Scopus) without time limitation was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria. Only original research studies reporting on biomechanical changes following a MDCO were included. Exclusion criteria consisted of review articles, case studies, and studies not written in English. 27 studies were included and the methodologic quality graded according to the QUACS scale and the modified Coleman score. Results: The 27 included studies consisted of 18 cadaveric, 7 studies based on biomechanical models, and 2 clinical studies. The impact of MDCO on the following five major parameters were assessed: plantar fascia (n = 6), medial longitudinal arch (n = 9), hind- and midfoot joint pressures (n = 10), Achilles tendon (n = 5), and gait pattern parameters (n = 3). The quality of the studies was moderate to good with a pooled mean QUACS score of 65% (range 46–92%) for in-vitro and a pooled mean Coleman score of 58 (range 56–65) points for clinical studies. Conclusion: A thorough knowledge of how MDCO impacts foot function is key in properly understanding the postoperative effects of this commonly performed procedure. According to the evidence, MDCO impacts the function of the plantar fascia and Achilles tendon, the integrity of the medial longitudinal arch, hind- and midfoot joint pressures, and consequently specific gait pattern parameters.

Zusammenfassung Hintergrund Frakturen des posterioren Malleolus finden sich bei fast 50 % aller Sprunggelenkfrakturen. Die hohe klinische Relevanz dieser Gelenkfrakturen erklärt sich durch das deutlich schlechtere klinische sowie funktionelle Outcome. Bis heute mangelt es an einer einheitlichen Lehrmeinung bezüglich Klassifikation und Behandlung dieser Frakturen. Ziel der Arbeit Intention dieser Arbeit war eine systematische Literaturübersicht über klinische Studien, welche posteriore Malleolus-Frakturen untersucht und mit einer der 3 etablierten Klassifikationen nach Haraguchi, Bartonicek/Rammelt oder Mason klassifiziert haben. Material und Methoden Die Datenbank PubMed wurde vollständig am 01.07.2021 durchsucht. Nur Publikationen in englischer und deutscher Sprache wurden eingeschlossen. Die systematische Literatursuche wurde entsprechend den aktuellen Kriterien von „Preferred Reporting Items for Systematic Review and Meta-Analyses“ (PRISMA) durchgeführt. Die methodologische Qualität der eingeschlossenen Studien wurde anhand des modifizierten Coleman-Scores quantifiziert. Ergebnisse Insgesamt 27 Studien mit insgesamt 2220 Patienten konnten in die systematische Literaturübersicht eingeschlossen werden. Trimalleolarfrakturen zeigten dabei eine deutlich ungünstigere Prognose als andere OSG-Frakturen. Prognostisch entscheidend für das klinische Outcome war v. a. die Qualität der Reposition. Diskussion Keine der 3 untersuchten Klassifikationen konnte sich bisher in der Fachliteratur durchsetzen. Speziell im Hinblick auf einen ableitbaren Therapiealgorithmus oder auf eine Prognose hinsichtlich des Outcome sind die untersuchten Klassifikationen schwach oder nicht zu verwenden. Einzig die Klassifikation nach Bartonicek/Rammelt ist geeignet, sich aufgrund des ableitbaren Therapiealgorithmus in der Literatur sowie im klinischen Alltag durchzusetzen.