12 yr. old girl with rapid gain in height since last 11 months has inability to sit with legs crossed and difficulty in squatting. On bending her knee reaches axilla of same side. What’s the most probable diagnosis? (AIPG 2012)
|A||Slipped capital femoral epiphysis|
Slipped Capital Femoral Epiphysis
Limitation of abduction & internal rotation with a tendency to increasing external rotation as the hip is flexedDuring a period of rapid growth, due to weakening of upper femoral physis & shearing stress from excessive body weight, there is upward & anterior movement of femoral neck on the capital epiphysis. So the epiphysis displaces primarily posteriorly relative to the femoral neck.
The cause is unknown in vast majority of patients.
a. Many of the patients are either fat and sexually immature or excessively thin and tall.
b. Endocrinopathies such as Hypothyroidism (most common) treated or not. Growth hormone excess caused by growth hormone deficiency conditions treated by growth hormone administration
i. Chronic renal failure (Hyper parathyroidism)
ii. Primary hyper parathyroidism
iii. Pan hypopituitism associated with intracranial tumors
vii. MEN 2 B
viii. Turner’s syndrome
ix. Klinfelters syndrome
Pathogenesis & Pathology
a. Slip occurs through hypertrophic zone of growth plate classically in obese hypogonadal male (adiposo genital syndrome)
b. Normally, pitutary growth hormone activity stimulates rapid growth and increased physeal hypertrophy during puberty (adolescent growth spurt). This is balanced by increasing gonadal hormone activity, which promotes physeal maturation & epiphyseal fusion. So growth hormone excess or hypogonadism is provocative of SCFE.
c. Physeal disruption causes premature fusion of epiphysis-usually within 2 years of the onset of symptoms.
d. Bone remodeling may cause permanent external rotation deformity and apparent coxa vara
e. Chondrolysis & AVN are possible complications
a. An adolescent child (boys 13-15 & girls 11- 13) typically overweight or very thin and tall presents with pain some times in the groin, but often only in thigh (anteromedial aspect) & knee
b. Antalgic limp, with the affected side held in a position of increased external rotation, (turning out of leg).
c. Restriction of internal rotation, abduction & flexion actually represents a change in location of a relatively preserved arc of motion rather than a loss of motion. So hip extension, external rotation and adduction are increased.
d. A classical sign is tendency of thigh to rotate in to progressively more external rotation, as the affected hip is flexed.
f. 20% cases will have evidence of contralateral slip. 60% of patients will have B/L involvement when associated with endocrinopathies.
• Plain radiography (x- ray)
a. Widening & irregularity physis with rarefaction in its juxta epiphyseal portion (earliest sign)
b. A line drawn tangential to superior femoral neck (klein’s line) on AP view will intersect a portion the lateral capital epiphysis normally. With typical posterior displacement of capital epiphysis this line will intersect a smaller portion of the epiphysis or not at all trethowans sign.
a. SCFE is usually a progressive disease endocrinopathies that requires prompt surgical treatment.
b. Because the changes in the chronic form occurs so slowly it is impossible to manipulate the femoral head into a better position. So treatment consists fixing the slip in its current position & preventing progression
c. This is done by inserting one or more screws or pins across the growth plate (pinning in Situ)
d. Acute slips, if unstable may be gently reduced before fixation but it increases the chances of AVN.