Flexing the hip to 90 degrees, adducting, and internally rotating the hip, known as the FADDIR test, should also be performed. It is positive when it causes pain. The FABER test should also be performed, this test involves flexing, abducting, and externally rotating the hip. The FABER test is useful when diagnosing concurrently with a labral pathology and is considered positive if the position elicits pain. Additional non-invasive ways to observe possible FAI is changes in gait that include a lower peak hip extension and internal rotation to compensate for bony growth. X-ray
Projectional radiography ("X-ray")is often considered first line for FAI. Anterior-posterior pelvis and a lateral image of the hip in question should be attained. A 45-degree Dunn view is also recommended. Other modalities
MRI imaging may follow, particularly if there is no specific evidence on radiographs, producing a three-dimensional reconstruction of the joint for better definition, to evaluate the hip cartilage, or measure hip socket angles (e.g. the alpha-angle as described by Nötzli in 2-D and by Siebenrock in 3-D). MR arthrogram had been used in the past, as it was more sensitive for picking up soft tissue lesions; however, due to improvement in technology, MRI is now considered comparable for picking up such lesions. CT is not usually used due to radiation exposure and no benefit above MRI. It is possible to perform dynamic simulation of hip motion with CT or MRI assisting to establish whether, where, and to what extent, impingement is occurring. The diagnosis is often made in conjunction with a labral tear.
Surgical techniques designed to save the leg (limb-sparing procedures) do not improve the prognosis.Some current studies indicate osteoclast inhibitors such as alendronate and pamidronate may have beneficial effects on the quality of life by reducing osteolysis, thus reducing the degree of pain, as well as the risk of pathological fractures. Cats
Osteosarcoma is also the most common bone tumor in cats, although not as frequently encountered, and most typically affect the rear legs. The cancer is generally less aggressive in cats than in dogs, so amputation alone can lead to a significant survival time in many affected cats, though post-amputation chemotherapy is recommended when a high grade is confirmed on histopathology. References
Further reading
Jaffe, N. (2010). Pediatric and Adolescent Osteosarcoma. New York: Springer. ISBN 978-1-4419-0283-2. Osteosarcoma research: past, present and future. External links
National Cancer Institute—patient information on osteosarcoma
Osteosarcoma – An Introduction Archived 2020-10-27 at the Wayback Machine
What is osteosarcoma?