Morphology of the proximal tibiofibular joint does not affect the type of lateral malleolus fracture and syndesmotic ligament injuries: A computed tomography-based study

Abstract

IntroductionThe Proximal Tibiofibular Joint (PTFJ) is a synovial joint with anatomical variations located between the anteromedial surface of the fibula and the posterolateral facet of the tibia. These anatomical variations are believed to contribute to different biomechanical behaviors in both the knee and ankle joint and play a role in both physiological and pathological movements. Therefore, the morphology of the proximal tibiofibular joint may play a decisive role in the characteristics of ankle fractures and syndesmotic ligament injuries. Materials and methodsIn this retrospective comparative our CT database was searched between January 2015 and December 2022. Following inclusion criteria were used: Availability of knee CT scans for the fractured ankle, external rotation-type injuries (pronation external rotation and supination external rotation fractures). After applying the exclusion criteria (Plafond fractures, supination adduction and pronation abduction type fractures, pathological fractures, patients with previous fractures or surgeries around the knee, patients with previous fractures or surgeries around the knee, proximal tibiofibular arthrosis), 44 CT scans (mean age = 42.8 ± 14.1) confirmed eligible for further analysis. On each scan following measurements were performed: Coronal and sagittal PTFJ inclination angle, Joint obliquity, fibula head-tibia joint distance and tibia plateau-fibular axis angle. ResultsThe study consisted of 24 (54.5 %) male and 20 (45.5 %) female patients. According to the proximal fibular inclination, 29 cases (65.9 %) were of the oblique type, and 15 cases (34.1 %) were of the horizontal type. The distribution of PTFJ variations was as follows: 17 (38.6 %) concave, 4 (9.1 %) convex, 7 (15.9 %) atypical, and 16 (36.4 %) flat type. Regarding the PTFJ joint contour, the distribution was 13 (29.5 %) type a, 11 (25 %) type b, and 20 (45.5 %) type c. There was no relationship between measurements of PITFJ morphology and the type of ankle fracture and/or syndesmosis injury (p > 0.05). ConclusionPTFJ morphological features are not associated with rotational ankle fractures and syndesmotic ligament injuries.