Friday Teaching. Bones

Transcription

1 Friday Teaching Bones

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3 Regarding slipped femoral capital epiphysis It represents Salter Harris type V injury 20% are bilateral There is slight widening of the joint space Slip is typically posteromedial US is useful to confirm the diagnosis

4 Answers F -V= crush injury. I is a slip T F - Joint space widening in Perthes. In SUFE see widening and irregularity of epiphyseal growth plate. T need frog leg view. AP is normal in 10% F

5 Questions on SUFE 2/x people x% bilateral Associated with- x Presentation- x Who is affected?

6 SUFE 2/10000 people 25-50% bilateral Associated with- malnutrition, endocrine abnormalities, DDH. Presentation- hip pain 50%, knee pain 25%, OVERWEIGHT 13YR OLD BOYS

7 Phases Preslip widening of epiphyseal growth plate irregular blurred physis demineralization of neck metaphysis

8 Acute slip Decrease in neck-shaft angle, growth plate moves to more vertical orientation Line of Klein- line along superior edge of femoral neck fails to intersect the femoral head. Posterior slippage causes epiphysis to appear smaller

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11 Chronic slip Sclerosis and irregularity of widened physis Metaphyseal blanch sign (healing response) area of increased opacity in the proximal part of the metaphysis. Grade - mild, moderate, severe. (displacement by how many 1/3rds of metaphyseal diameter)

12 Complications Chrondrolysis 10% AVN of femoral head 10% (risk increase with grade and delay of surgery) Deformity (including limb length discrepancy) Degenerative OA 90%

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15 Findings Right femoral head is large (Coxa magna) and flattened. The Right femoral neck is short and wide (coxa plana). The Right hip shows evidence of degenerative joint disease.

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17 Perthe s disease Females have poorer prognosis Bilateral hip involvement more common in males Usually a family history Older age better prognosis Widening of the joint space is seen early in Perthe s disease?

18 Perthes answers T - females have earlier onset, more common in males. T F - no increase incidence in families F - poor prognostic factors are female sex, older onset, metaphyseal involvement, uncovering of lateral femoral neck T - late sequela, remodelled femoral head, wider and flatter with mushroom configuration True (Waldenstroms sign)

19 Perthes Idiopathic AVN of femoral head 5-10% bilateral M5:1 Peak 4-8 years

20 Early signs smaller femoral epiphysis (96%), sclerosis of femoral head epiphysis (82%), Widening of joint space (60%) (thickening of cartilage) Bone demineralization (46%) NEVER destruction of articular cortex (bacterial arthritis)

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22 Waldenstrom's sign Widening of medial joint space, with a properly positioned AP pelvis view, a 2 mm difference is significant, and should be followed up. This increased medial joint space is termed Waldenstrom s sign.

23 Waldenstroms sign

24 Waldenstrom's sign is non- specific Also observed in hip trauma a joint space infection slipped capital femoral epiphysis.

25 Late signs Delayed osseous maturation Radiolucent crescent line of subchondral fracture (32%) Femoral head fragmentation Femoral neck cysts Loose bodies (only in males)

26 Fragmentation and lateral displacement in Perthes

27 Crescent sign on the right hip Note the curvilinear lucency just beneath the subchondral surface. Collapse of the femoral head at this point is inevitable.

28 Regenerative signs Coxa Plana flattened collection of sclerotic fragments (over 18 months) Coxa Magna - remodelled femoral head, wider and flatter with mushroom configuration

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31 Questions on DDH More common in females and Caucasians Associated with oligohydramnios Most common in first born infants Usually bilateral Premature OA occurs typically between 10 and 20yrs

32 T 8x more common in females. (more sensitive to maternal oestrogen that blocks cross linkage of collage fibrils) T - also breech presentation, FHx, foot and skull deformities, congenital torticollis T 2/3 F 2/3 unilateral. L:R:bilateral 11:1:4 F 40-60yrs

33 DDH Deformity of acetabulum due to disrupted relationship with femoral head. Classification Normal Lax (subluxability up to 6mm decreasing to 3mm by 2nd day of life) Concentric dislocatable hip (Barlow positive), 60% stable by 1/52 Decentered subluxed hip - loss of femoral head spherity, shallow acetabulum, femoral anteversion, early labral inversion Eccentric dislocated hip (if reducible ortolani+ve) - Shallow acetabulum, flattening of femoral head, hypertrophy of labrum.

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35 Centre edge angle <25 o suggests instability

36 Plain film only reliable after 3 months Proximal and lateral migration of femoral neck acetabular angle >30 o Shortening of distance from femoral ossific nucleus to Hilgenreiner s line

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38 An ultrasound evaluation is typically performed either by assessing the alpha and beta angles or by a performing a dynamic evaluation. Alpha >60 o considered normal. Beta angle considered normal if less than 55. depicts the cartilaginous component of the acetabulum

39 Alpha angle (coronal view) between straight lateral edge of ilium and bony acetabular margin. (<43 o = dislocated) Beta angle between straight lateral edge of ilium and fibrocartilaginous acetabulum. >77 o is subluxed

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44 Giant cell tumours of the bone are associated with pagets disease? True