Answer for BIR CoW 01 Oct 2023
Avascular Necrosis of bilateral femoral heads
RADIOGRAPHIC VIEWS – Xray AP view of Pelvis and Frog Leg’s View
Findings
Sclerosis with irregularity noted in bilateral femoral head. Subchondral cysts noted in bilateral femoral head. Mild cortical collapse noted.
Discussion
Avascular necrosis is also referred to as osteonecrosis Osteonecrosis occurs most frequently in the immediate subchondral regions of the proximal femur, distal femur, and the proximal humerus. Most common causes include spontaneous (idiopathic), trauma (fracture, dislocation), alcoholism, and corticosteroid therapy. Using plain radiograph, the sensitivity for detecting early stages of the disease is as low as 41% . Plain film does not detect stage 0 and 1 AVN. MRI is the most sensitive imaging modality for detection of osteonecrosis, especially at the early stages of the disease.
PLAIN RADIOGRAPHY IN AVASCULAR NECROSIS
A staging system using radiographic findings has been developed by Ficat and Arlet and has been used widely. In stage 0 (preclinical and preradiologic) avascular necrosis can be suggested only if it has already been diagnosed in the contralateral hip. Stage 1 (preradiologic) - represents the early resorptive stage.Plain radiographs may show minimal osteoporosis and/or blurring and poor definition of the bony trabeculae. Stage 2 (reparative) represents the reparative stage before flattening of the femoral head occurs. Demineralization now is evident. It may be generalized or patchy or appear in the form of small cysts within the femoral head. Patchy sclerosis appears after demineralization develops, usually in the superolateral aspect of the femoral head. Stage 3 (early collapse of the femoral head). A linear subcortical lucency, representing a fracture line, is present immediately beneath the articular cortex. This is termed the crescent sign. Stage 4 (progressive degenerative disease) is represented by further flattening of the femoral head. Severe collapse and destruction of the femoral head leads to progressive degenerative joint disease (DJD) with joint space narrowing, marginal osteophyte formation, and subchondral cyst formation.
REFERENCES
Imaging of Avascular Necrosis of Femoral Head: Familiar Methods and Newer Trends Curr Health Sci J. 2009 Jan-Mar; 35(1): 23–28 Published online 2009 Mar 21. Yochum T, Rowe L. Essentials of skeletal radiology. 2. Baltimore: Williams & Wilkins; 1996. pp. 260–263. Lee MJ, Corrigan J, Stack JP, et al. A comparison of modern imaging modalities in osteonecrosis of the femoral head. Clin Radiol. 1990;42:427–432.
RADIOGRAPHIC VIEWS – Xray AP view of Pelvis and Frog Leg’s View
Findings
Sclerosis with irregularity noted in bilateral femoral head. Subchondral cysts noted in bilateral femoral head. Mild cortical collapse noted.
Discussion
Avascular necrosis is also referred to as osteonecrosis Osteonecrosis occurs most frequently in the immediate subchondral regions of the proximal femur, distal femur, and the proximal humerus. Most common causes include spontaneous (idiopathic), trauma (fracture, dislocation), alcoholism, and corticosteroid therapy. Using plain radiograph, the sensitivity for detecting early stages of the disease is as low as 41% . Plain film does not detect stage 0 and 1 AVN. MRI is the most sensitive imaging modality for detection of osteonecrosis, especially at the early stages of the disease.
PLAIN RADIOGRAPHY IN AVASCULAR NECROSIS
A staging system using radiographic findings has been developed by Ficat and Arlet and has been used widely. In stage 0 (preclinical and preradiologic) avascular necrosis can be suggested only if it has already been diagnosed in the contralateral hip. Stage 1 (preradiologic) - represents the early resorptive stage.Plain radiographs may show minimal osteoporosis and/or blurring and poor definition of the bony trabeculae. Stage 2 (reparative) represents the reparative stage before flattening of the femoral head occurs. Demineralization now is evident. It may be generalized or patchy or appear in the form of small cysts within the femoral head. Patchy sclerosis appears after demineralization develops, usually in the superolateral aspect of the femoral head. Stage 3 (early collapse of the femoral head). A linear subcortical lucency, representing a fracture line, is present immediately beneath the articular cortex. This is termed the crescent sign. Stage 4 (progressive degenerative disease) is represented by further flattening of the femoral head. Severe collapse and destruction of the femoral head leads to progressive degenerative joint disease (DJD) with joint space narrowing, marginal osteophyte formation, and subchondral cyst formation.
REFERENCES
Imaging of Avascular Necrosis of Femoral Head: Familiar Methods and Newer Trends Curr Health Sci J. 2009 Jan-Mar; 35(1): 23–28 Published online 2009 Mar 21. Yochum T, Rowe L. Essentials of skeletal radiology. 2. Baltimore: Williams & Wilkins; 1996. pp. 260–263. Lee MJ, Corrigan J, Stack JP, et al. A comparison of modern imaging modalities in osteonecrosis of the femoral head. Clin Radiol. 1990;42:427–432.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!