Clinical Presentation
The study found that small extra-articular avulsion fragments were more common in pronation injuries (80%), whereas large pilon intra-articular fragments were predominantly seen in supination injuries [PMID:30773057].
Diagnosis
The study found a negative correlation between the sagittal angle and relative displacement, suggesting that a higher sagittal angle correlates with reduced displacement under load, which can be a diagnostic indicator of stability [PMID:31430548].
Preoperative CT scans identified two subtypes of posteromedial fragments: large pilon intra-articular fragments and small extra-articular avulsion fragments, providing critical information for surgical planning [PMID:30773057].
Management
Finite element analysis revealed a positive correlation between the sagittal angle of posterior malleolus fractures and contact area, indicating greater stability with higher angles [PMID:31430548]. Surgeons may consider this angle to optimize fixation strategies for improved joint stability post-fracture.
Knowledge of the morphological variability in posteromedial fragments (large pilon vs. small avulsion) can guide surgeons in selecting appropriate surgical techniques and planning [PMID:30773057].
Prognosis & Follow-up
Greater sagittal angles were associated with increased contact area and decreased maximum contact stress and relative displacement, implying potentially better stability and prognosis [PMID:31430548]. Follow-up assessments should consider these biomechanical factors.
References
1 Guan M, Zhao J, Kuang Y, Li G, Tan J. Finite element analysis of the effect of sagittal angle on ankle joint stability in posterior malleolus fracture: A cohort study. International journal of surgery (London, England) 2019. link 2 Vosoughi AR, Jayatilaka MLT, Fischer B, Molloy AP, Mason LW. CT Analysis of the Posteromedial Fragment of the Posterior Malleolar Fracture. Foot & ankle international 2019. link
2 papers cited of 3 indexed.