Anatomical And Imageological Study Of Tarsometatarsal Joint

Tarsometatarsal joints is also known1as Lisfranc joint, which is acomplex structure and a part of the midfoot.Tarsometatarsal joint plays a rolein weight supporting and the transimission of weight load from metapedes toforefoot during walking. Tarsomatatarsal joint is a major part of foot arc,locates in its highest point, and plays an important role in foot action. Thetarsomatatarsal joint is complex. Firstly, it is composed of multiple stable bonyjoints. Secondly, multiple ligaments can strengthen the stability of the footarch. Thirdly, the muscles around the joint is also important to maintain thestability. There is little information with regard to the comparative study onthe anatomy and image of tarsometatarsal joint. It is sometimes difficult todiagnose tarsometatarsal joint injury only according to routine X-ray films ofthe foot, subsequently resulting in a rate of misdiagnosis as high as20%. Themis-or delay diagnosis of tarsometatarsal joint can delay the treatment,acompanying with serious sequala.The routine X-ray films are often used todiagnose fracture and dislocation of tarsomatatarsal joint, however, it can notbe used to diagnose the ligament injury definitely. Therefore, we haveconducted an anatomical and imageological study to work out how to resolvethe questions regarding the early diagnosis of the injury of tarsometatarsaljoint. In the current study, the routine and lateral radiographs of100normalfeet were taken to analyze the reason of misdiagnosis of tarsometatarsalinjury.We conducted a study to compare the sectional anatomy oftarsometatarsal joint with the coresponding MR images with the aim toprovide evidence for early diagnosis of tarsometatarsal joint injury. This studyconsists of two parts.Part I: The study on routine radiographs of tarsometatarsal joint.Objective: This study aims to eveluate the demonstration andradiological features of tarsometatarsal joint on the routine anteroposterior, oblique and lateral views, and to analyze the reason of the high rate ofmisdiagnosis of tarsometatarsal joint.Method:100volunteers with abnormality or trauma of the feet wereselected, The anteroposterior and oblique radiographs were taken on100feet.including53males and47females with an average age of37.8years (range,18-72years). There were45right feet and55left feet. The lateral radiographswere taken on41feet, including15right feet and26left feet, and there were21males and20females, aging from18to68years. Two senior radiologistswere instructed to assess the demonstration of the five tarsometatarsal jointswith a score from1to5. Simultaneously, the minimal distance between thebases of the first and second metatarsal bone was measured. The anglebetween tarsometatarsal joint surface and feet sole was also measured.Statistical analysis was performed using SPSS13.0.Result: There were no significant differences between the tworadiologists between males and females, between left and right feet and amongdifferent age groups (all p>0.05). The minimal distance of the bases of thefirst and second metatarsal bone is0.15±0.04cm. Based upon theanteroposterior radiographs, less than5%of the first, second, third and fifthtarsometatarsal joints were eveluated with a score2or3. Less than50%of theforth tarsometatarsal joint; none got3socres；. According to the obliqueradiographs, less than50%of the first and third tarsometatarsal joints can beeveluated with a score2or3, and less than35%can obtain3scores. The anglebetween tarsometatarsal joint surface and foot sole is60.87°±1.81°.Conclusion:①The routine anteroposterior and medial obliqueradiographs of midfoot can not demonstrate the tarsometatarsal joint clearlyand can not meet the need for the diagnosis of tarsometatarsal joint injury.Thereforem, it is necessary to investate a new view to illustrate tarsometatrsaljoint.②The minimal distance of the bases of the first and second metatarsalbone is0.15cm and the angle between tarsometatarsal joint surface and footsole is60.87°on average. Part Ⅱ: Comparative study on the sectional anatomy and MR imagesof tarsometatarsal jointObjective: This study aims to eveluate the role of MRI in the analysis ofanatomical relashionship of tarsometatarsal joint via analyzing the MRI andsectional anatomical data of normal tarsometatarsal joint.Method: Six normal foot specimens were selected. Saggital,obliquecoronal and oblique axial views of the feet were scanned using FLASHsequence and T1-vibe sequence with the application of SIEMENS1.5Tsuperconductivity scanner.The six specimens were divided into three groupswith two in each group. Each specimen was embedded, fixed and mill-cut insaggital view, oblique coronal view and oblique axial view, respectively.Each slice is0.5mm in thickness. Digital camera was used to take photoesand store the pictures. The slice pictures of the specimen was compared withthe MR images.Result: MR image can illustrate the bony array of the tarsometatarsaljoint clearly. The medial edge of the second and forth metatarsal bone and themedial edge of intermediate cuneiform bone and cuboid bone was in a smoothline. The dorsal edge of tarsometatarsal joint is also smooth. Lisfranc ligamentis very thick and strong, however, the dorsal tarsometatarsal ligaments arethinnest. The oblique axial image can demonstrate the long axis of Lisfrancligament and intertarsal and inter-metatarsal ligaments clearly. The coronalimage can demonstrate the section of Lisfranc ligament and intertarsal andinter-metatarsal ligaments clearly.The saggital image can not demonstrate theLisfranc ligament well, but it can show the dorsal and metatarsal ligamentsclearly. There is a good congruity between MR iamges and its correspondingsection pictures obtained from foot specimen.Conclusion: MRI can demonstrate the anatomical relationship amongvarious parts of tarsometatarsal joint with its superiority in observation ofligament.