Radiological aspects of sprained ankle syndrome

This thesis addresses several problems related to sprained ankle syndrome. The purpose of this thesis is to evaluate the imaging features of sprained ankles, found on new radiological modalities, and to assess the additional diagnostic understanding and treatment planning of helical CT as well as MR imaging compared with conventional radiographic imaging in patients with ankle and hindfoot problems. In addition recommendations for prudent / optimal use of both new modalities are proposed. The objectives of this thesis are: (1.) Review and evaluation of the use of the Broden view in subtalar joint instability; (2.) Study of MR images after ankle sprains, focused on osteochondral lesions in talar dome and tibia plafond; (3.) To report some MR imaging characteristics in detecting talocalcaneal coalitions; (4.) To investigate the accuracy of dynamic gadolinium-enhanced MR imaging in determining the viability of osteochondral lesions in the talar dome after inversion injury; (5) 5. To give an overview of some common sports-related injuries. The outline of the thesis is given hereunder: Chapters 1-4 are introductory; Chapter 1 represents a general introduction. In Chapter 2 a review is given of clinical symptomatology, developmental embryology and anatomy, instability, ligaments, osteochondral plate and articular cartilage. Chapter 3 describes the classification systems of osteochondral lesions with conventional radiography, helical CT and MR imaging. Osteochondral lesions in relation with the talar dome and tibia plafond. The complex vascularisation of the talar dome is described and the nutrition of the articular cartilage. Etiology of bone edema in relation with (repetitive)trauma is reported. Chapter 4 discusses the imaging techniques used after ankle spraining. Conventional radiography, tomography, stress radiology, ultrasound, bone scintigraphy and arthrography. The imaging protocols of helical CT and MR imaging in specific ankle and hindfoot problems are evaluated. Chapters 5-11 pertain to the performed scientific studies. Chapter 5 reports a study of stress radiography and stress examination of the talocrural and subtalar joint on helical CT in 15 patients with unilateral instability. With stress radiography a variable amount of subtalar tilt was demonstrated in all feet. Chapter 6 evaluates the use of the Broden view in subtalar joint instability. Helical CT didn t show tilting in the subtalar joint, except in the subluxated posteromedial part. Chapter 7 includes the results of posttraumatic osteochondral fractures of the talotibial joint in the relation with the tibia plafond. The high occurrence of kissing contusions is described. Chapter 8 viability of osteochondral fragments is an important parameter for healing. In this study dynamic gadolinium-enhanced MR imaging is compared with dynamic bone scintigraphy in OD lesions of the talar dome for evaluating the viability of the OD fragment. Chapter 9 concerns the MR imaging findings around the subtalar joint in 10 patients with talocalcaneal coalitions. A typical pattern of bone marrow hyperintensities in T2-weighted and STIR images is described. Chapter 10 discusses some common traumatic and overuse syndromes of the foot and ankle seen with MR imaging. Chapter 11 contains a general discussion on helical CT as well as MR imaging in patients with ankle and hindfoot problems. Conclusion of the thesis and general directions for proper use of both techniques are given.