![]() For fatigue fractures, MRI is the gold-standard imaging modality with the highest sensitivity and specificity, 13 however, specificity of MRI may be low for early changes of fracture. Following which, linear intramedullary sclerosis due to microcallus becomes evident ( Figure 3). The heralding finding is faint blurring and sclerosis of the trabeculae. PDFS, proton density fat saturated.įatigue fractures in femur predominantly affect its cancellous bone dominant parts such as metaphysis, neck and intercondylar region and demonstrate different radiological appearances. ( b) Coronal PDFS image ( c) Coronal T1 image demonstrating marrow edema (dotted arrow), cortical thickening and periosteal reaction (arrow). ( a) Radiograph demonstrating subtle central lucency with cortical thickening and periosteal reaction (arrow). 7 Cortical breaks may be visible in injuries inciting severe bony responses.ģ5-year-old female amateur marathon runner with Fatigue fracture in the femoral diaphysis where cortical bone predominates. 1 As it lags behind the osteoclastic activity by a few weeks, the periosteal reaction is not visible until several weeks into the disease process. Radiographically, the earliest finding is a subtle lucency in the cortex often described as “Grey cortex sign” 12 from microfracture and osteoclastic resorption ( Figure 2) followed by periosteal reaction, and cortical thickening on progression because of periosteal and endosteal remodelling and callus formation. Radiographic findings of the fatigue fracture depend on the location of involvement and chronicity of the injury. ![]() Compressive forces pass through the medial shaft whereas, tensile forces act upon the lateral aspect when one bears the weight – the latter is substantially lesser relieved by the iliotibial tract and vastus lateralis action – in contrast of dynamics of vastus medialis, adductor longus and brevis increasing medial compression force. 9 The medial aspect is at risk and commonly affected due to biomechanical forces exerted on it during weight-bearing and muscle exertion. 8 The femoral neck (50%), the condylar area (24%) and the proximal shaft (18%) are commonly affected anatomical sites and can be bilateral (9% cases). The femur is the fourth common bone affected by stress injuries accounting for approximately 7.2% cases in athletes. Frequent in young, suboptimally conditioned individuals who abruptly engage in strenuous activities such as weekend-warriors with limited physical fitness, military recruits, and athletes who abruptly intensify their training regimen, 6 they are also common after orthopaedic surgery in lower limbs, foot in particular where altered gait and osteopaenia following guarded mobility in post-surgical period implied as causative factors. These are focal fractures in the normal bone due to repetitive stress following sustained microdamage exceeding the bone’s ability to heal employing physiological remodelling. By the same definition, fracture through osteomyelitis is regarded as a pathological fracture. Pathological fractures are insufficiency fractures occurring in a bone weakened by benign or malignant neoplastic lesion affecting its trabecular integrity ( Figure 1). ![]() 3 The term “Fragility fracture” is exclusive for insufficiency fractures in osteoporosis following single minimally traumatic event. 2 Such fractures can be of two types: fatigue fractures – from abnormal repetitive stress causing temporal mechanical failure – in a normal and insufficiency fractures – owing to normal stress on an abnormally weakened bone. Stress fractures, partial or complete, usually result in bones unable to withstand subthreshold stress applied in a rhythmical and repeated manner. 1 This broad category includes pathological, stress, fatigue, insufficiency and atypical femoral fractures. Terminologies used to describe atraumatic fractures are confusing and often overlap.Ītraumatic fracture term donates a fracture caused by a relatively low-energy mechanism that usually considered incapable of producing a fracture.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |