Abstract:
This study aimed to investigate the important anatomical structure of the tibiofibular joints and attempted to correlate with function and stability of these joints in Thai cadavers. It was done by dissection and measurement of the capsular and surrounding ligaments. Further measurement of fibular length, inclination of the fibular facets and degree of wedging of the talus was also done. The articular surface area was estimated by means of the image tool analysis program. Three hundred and seventy-two cadaveric specimens were used in this study, were 102 male and 84 female, with age ranging from 30 to 97 years. The superior tibiofibular joint was strengthened by its capsular ligaments and the anterior ligament of the head of the fibula was larger and stronger than the posterior ligament. In addition, the surrounding structures of the superior tibiofibular joint also played an important role in stabilizing and supporting the joint. Among these, the largest cross-sectional area was the popliteofibular followed by the fibular collateral and fabellofibular ligament, respectively. The stability of the inferior tibiofibular joint was ensured by the anterior, posterior and transverse tibiofibular ligaments. It was found that the posterior tibiofibular ligament was the largest and strongest ligament supporting the posterior aspect of the joint. Correlation analysis showed that the inclination of superior fibular facet was negatively correlated with the superior and triangular surface area of fibular facet. The fibular length was also correlated to all the articular surfaces on the fibula. Furthermore, the degree of wedging of trochlea tali was associated with the superior and inferior inclination of fibular facets. These structural features imply that in ankle dorsiflexion, the steeper the superior fibular facet the smaller the articular area leading to limitation on the movement of the joint. Whereas, during ankle plantar flexion the greater the degree of wedging the steeper the plantarflexion axis of the ankle leading to greater mobility of the joint.
In conclusion, the results suggest that strength and stability of the tibiofibular joints are associated with fibula length, articular surface area, inclination of fibular facet and the degree of wedging of trochlea tali. This thesis therefore provides fundamental knowledge for further kinematical or biomechanical studies of the joints of the leg.