Answer for BIR CoW 25 Aug 2024
Slipped femoral capital epiphysis
Findings
Evidence of marked medial slip of left femoral epiphysis over the metaphysis. The metaphysis of left femur is displaced laterally and does not overlap the posterior lip of the acetabulum. Evidence of superposition of the femoral neck and the medially displaced capital epiphysis. The relation of epiphysis to metaphysis is that the lateral edge of the epiphysis is within the halfway point of the metaphysis - degree of slippage - moderate. Slip angle between the left femoral epiphysis with the metaphysis is 125° (Southwick Head shaft angle - severe). No evidence of osteonecrosis of bilateral femoral head.
Discussion
Slipped femoral capital epiphysis (SFCE), also known as adolescent coxa vara, epiphyseal coxa vara, and epiphysiolisthesis, occurs during the adolescent rapid growth period (10–15 years) and is the result of a slipping of the neck on the femoral head as the head remains in the acetabulum. There is upward displacement, external rotation, and adduction of the neck on the head. The result is a varus deformity, adduction, and external rotation of the femur. Males are more commonly affected than females, with the peak incidence in males occurring at age 13 and in females at age 12. Blacks are more commonly affected than whites. The left hip is more often involved than the right, and both hips are involved in 20–30% of cases. Bilateral involvement is more common in females. The lower extremity gradually develops an adduction and external rotation deformity, with a shortening of leg length. When the slippage is extreme, the gluteus medius is rendered inadequate, and the Trendelenburg test is positive. SFCE can be considered a special form of the type I SalterHarris epiphyseal fracture, a a displacement without visible fracture of either the epiphysis or the metaphysis Differential diagnosis Legg-Calvé-Perthes disease septic arthritis transient synovitis developmental dysplasia (late presentation) Radiologic Features of Slipped Femoral Capital Epiphysis- Decreased vertical epiphyseal height Wide, irregular growth plate Frayed metaphyseal margin Beaked inferior-medial epiphysis Increased teardrop distance Medial buttressing on the femoral neck Lateral buttressing on the femoral neck (Herndon’s hump) On the AP, a line drawn up the lateral edge of the femoral neck (line of Klein) fails to intersect the epiphysis during the acute phase (Trethowan sign). Curved contour of deformed proximal femur (pistol-grip deformity) Grading of SCFE On an AP radiograph a line along the superior margin of the femoral neck (line of Klein) should intersect the lateral corner of the epiphysis. Slip is graded based on the displacement of the epiphysis in relation to the metaphysis : mild: lateral edge of the epiphysis is within the lateral third of the metaphysis moderate: lateral edge between the lateral 1/3 and halfway point of the metaphysis severe: medial third (over the halfway point of the metaphysis) On a true lateral radiograph, the angle (slip angle) which the epiphysis makes with the metaphysis may also be employed (sometimes known as the Southwick head shaft angle) . normal: 0 degrees mild: 0-30 degrees moderate: 30-50 degrees severe: >50 degrees
Findings
Evidence of marked medial slip of left femoral epiphysis over the metaphysis. The metaphysis of left femur is displaced laterally and does not overlap the posterior lip of the acetabulum. Evidence of superposition of the femoral neck and the medially displaced capital epiphysis. The relation of epiphysis to metaphysis is that the lateral edge of the epiphysis is within the halfway point of the metaphysis - degree of slippage - moderate. Slip angle between the left femoral epiphysis with the metaphysis is 125° (Southwick Head shaft angle - severe). No evidence of osteonecrosis of bilateral femoral head.
Discussion
Slipped femoral capital epiphysis (SFCE), also known as adolescent coxa vara, epiphyseal coxa vara, and epiphysiolisthesis, occurs during the adolescent rapid growth period (10–15 years) and is the result of a slipping of the neck on the femoral head as the head remains in the acetabulum. There is upward displacement, external rotation, and adduction of the neck on the head. The result is a varus deformity, adduction, and external rotation of the femur. Males are more commonly affected than females, with the peak incidence in males occurring at age 13 and in females at age 12. Blacks are more commonly affected than whites. The left hip is more often involved than the right, and both hips are involved in 20–30% of cases. Bilateral involvement is more common in females. The lower extremity gradually develops an adduction and external rotation deformity, with a shortening of leg length. When the slippage is extreme, the gluteus medius is rendered inadequate, and the Trendelenburg test is positive. SFCE can be considered a special form of the type I SalterHarris epiphyseal fracture, a a displacement without visible fracture of either the epiphysis or the metaphysis Differential diagnosis Legg-Calvé-Perthes disease septic arthritis transient synovitis developmental dysplasia (late presentation) Radiologic Features of Slipped Femoral Capital Epiphysis- Decreased vertical epiphyseal height Wide, irregular growth plate Frayed metaphyseal margin Beaked inferior-medial epiphysis Increased teardrop distance Medial buttressing on the femoral neck Lateral buttressing on the femoral neck (Herndon’s hump) On the AP, a line drawn up the lateral edge of the femoral neck (line of Klein) fails to intersect the epiphysis during the acute phase (Trethowan sign). Curved contour of deformed proximal femur (pistol-grip deformity) Grading of SCFE On an AP radiograph a line along the superior margin of the femoral neck (line of Klein) should intersect the lateral corner of the epiphysis. Slip is graded based on the displacement of the epiphysis in relation to the metaphysis : mild: lateral edge of the epiphysis is within the lateral third of the metaphysis moderate: lateral edge between the lateral 1/3 and halfway point of the metaphysis severe: medial third (over the halfway point of the metaphysis) On a true lateral radiograph, the angle (slip angle) which the epiphysis makes with the metaphysis may also be employed (sometimes known as the Southwick head shaft angle) . normal: 0 degrees mild: 0-30 degrees moderate: 30-50 degrees severe: >50 degrees
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
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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!