Msk -- Hip And Pelvis

Front 1

1. What is the Ficat stage of osteonecrosis?
2. What are the MRI findings of AVN?

Back 1

1.
- Stage 1: normal
- Stage 2: mixed osteopenia and sclerosis
- Stage 3: subchondral collapse or a "crescent" sign
- Stage 4: articular collapse
- Stage 5: degenerative joint disease
2. Irregular rim of low signal intensity on T1W images and double line sign on T2W images which identifies the interface between viable and dying bone marrow. The high signal intensity rim is indicative of granulation tissue.

Front 2

What are the common avulsion injuries around pelvis?

Back 2

1. Ischial tuberosity = attachment of the hamstring muscles (biceps femoris, semitendinosis, and semimembranosus)
2. Pubic symphysis = Adductor muscle group
3. AIIS = Rectus femoris
4. ASIS = Sartorius and Tensor Fascia lata (iliotibial band)
5. Iliac crest = Rectus abdominis muscles
6. Lesser trochanter = Iliopsoas.
6. Greater trochanter = gluteal muscles.

Front 3

What are the different types of acetabular fractures?

Back 3

5 Simple types:
1. Anterior wall fx (obturator ring is not involved)
2. Posterior wall fx (obturator ring is not involved)
3. Anterior column fx (obturator ring is involved)
4. Posterior column fx (obturator ring is involved)
5. Transverse (obturator ring is not involved)

5 associated fracture types:
1. Transverse with posterior acetabular wall fracture (obturator ring is not involved)
2. T-shaped (obturator ring is involved)
3. Anterior column and posterior hemitransverse
4. Posterior colum and posterior acetabular wall
5. Both column fracture

Front 4

Osteitis pubis

Back 4

seen in kicking sports
Bone marrow edema around the pubic symphysis.

Front 5

1. What is the ddx of bone marrow edema in the femoral head?
2. Who is more commonly affected by transient osteoporosis of the hip? Which side is more commonly affected?

Back 5

1.
- Early avascular necrosis
- Bone contusion/fracture
- Transient osteoporosis of the hip
- Reflex sympathetic dystrophy
- Inflammatory arthritis
2. Men are affected 3x as much as women. However, classically described in pregnant women in the third trimester. The left hip is involved more frequently.
- Osteomyelitis

Front 6

1. Name the bursae around the hip joint?
2. Which is the lagest bursa and where is it located?
3. What processes can lead to bursitis?

Back 6

1.
- Iliopsoas bursa
- Trochanteric bursa
- Gluteus medius bursa
- Ischiogluteal bursa
2. Iliopsoas bursa is located anterior to the joint capsule in close proximity to the iliopsoas muscle. The bursa communicates with the
hip joint through a space between the iliofemoral and pubofemoral ligaments in 15% of normal hips.
3. It can become inflamed in the setting of OA, RA, PVNS, synovial chondromatosis.

Front 7

1. Name the bursae around the hip joint?
2. Which is the lagest bursa and where is it located?
3. What processes can lead to bursitis?

Back 7

1.
- Iliopsoas bursa
- Trochanteric bursa
- Gluteus medius bursa
- Ischiogluteal bursa
2. Iliopsoas bursa is located anterior to the joint capsule in close proximity to the iliopsoas muscle. The bursa communicates with the
hip joint through a space between the iliofemoral and pubofemoral ligaments in 15% of normal hips.
3. It can become inflamed in the setting of OA, RA, PVNS, synovial chondromatosis.

Front 8

1. What are the different types of INTRACAPSULAR hip fractures?
2. What are the complications of hip fracture?

Back 8

1.
- Subcapital fractures: occur just distal to the articular margin of the femoral head.
- Transcervical fracture: Fractures that occur through the neck.
- Basocervical fracture: fracture that occurs at the junction of the neck and the shaft.
2. Fracture nonunion and AVN. The more proximal the fracture line, the greater the incidence of both complications.

Front 9

1. What is proximal femoral focal deficiency?
2. What is an associated anomaly?

Back 9

1. Rare congenital anomaly with varying degrees of absence of the proximal femur. Depending on severity, it may result in acetabular dysplasia and leg length discrepancy.
2. Absence of the fibula (fibular hemimelia).

Front 10

1. What is Legg Calve Perthes Disease?
2. What are the imaging features?
3. How does age of onset affect the manifestions of Legg Calve Perthes disease?
4. What are the phases of the disease?
5. What is the treatment?
6. If the AVN is symmetrical in both femoral heads, what should you consider?
7. What is Meyer's dysplasia?

Back 10

1. Idiopathic avascular necrosis of the femoral epiphysis ossification center.
2.
- Earliest manifestations = widened joint space with slight lateral displacement of the femur.
- Localized epiphyseal demineralization
- Loss of height of femoral epiphysis.
- Subchondral fxs
- Fragmentation
- Sclerosis
3. Age of onset correlates well with the degree of deformity of the femoral head. Pts who present younger than 5 years have less femoral head deformation that do pts who suffer the disease later in life as there is minimal potential for acetabular remodeling in contradistinction to the potential for younger pts.
4.
- Avascular phase: characterized by ischemia.
- Revascularization phase: represented by ingrowth of vascular fibrous tissue and formation of new bone.
- Reparative phase: characterized by remodeling of femoral head. The femoral head takes on a characteristic mushroom shaped appearance. Coxa magna (short, thick femoral neck) also develops.
5. Weight relieving treatment and containment of the femoral epiphysis w/n the acetabulum. If surgery = femoral varus osteotomy or shelf acetabuloplasty.
6. Epiphyseal dysplasia.
7. Meyer dysplasia (also known as dysplasia epiphysealis capitis femoris) is a condition that can affect the pediatric hip. It is considered more of a normal hip developmental variation rather than a true dysplasia as there is delay in the ossification of the femoral epiphysis. It can be bilateral in ~ 50% of cases. It can mimic LCP in appearance.

Front 11

1. What is SCFE?
2. Why must the other hip be scrutinized?
3. What is the treatment? What are the complications?
4. What systemic conditions are associated with SCFE?

Back 11

1. Slipped capital femoral epiphysis. Look for medial and posterior displacement of the femoral head and widening of the physis, and metaphyseal irregularity. The key number to remember is 1/6; a line drawn along the lateral aspect of the femoral neck should intersect the femoral epiphysis with 1/6 of the femoral head lateral to the line.
2. It is important to scrutinize the other hip as SCFE is frequently bilateral(50%).
3. Treatment is screws/pin placement to prevent further displacement. SCFE can be complicated by AVN and chondrolysis.
4. Hypothyroidism and growth hormone deficiency.

Front 12

How are the various hip fractures treated?

Back 12

1.
- Subcapital: ???

- Femoral neck fractures are treated with 3 pins. These are at high risk of AVN

- Intertrochanteric fractures are treated with dynamic hip screw.

- Subtrochanteric fractures are treated with intramedullary rod.

Front 13

Eosinophilic granuloma

Back 13

The supratrochanteric region is commonly involved with eosinophilic granuloma.

Front 14

1. What is the etiology of DDH and what are associated conditions?
2. What is the inverted limbus deformity?
3. What are the ultrasound findings?
4. What are the radiographic findings?

Back 14

1.
- Thought to be related to ligamentous laxity (mediated by estrogen).
- Occurs more frequently with breech presentation and oligohydramnios.
- Ligamentous and muscle laxity can also result from neuromuscular diseases resulting in DDH.
2. Pressure of the subluxed femoral head on the hip labrum causes the labrum to invert into the acetabulum preventing reduction of femoral head.
3. Shallow acetabulum ± malposition of femoral head.
- Ultrasound most useful between birth & six months.
- There should be a sharp edge to the ossified acetabular roof (AKA promontory). Look for rounding of the acetabular roof.
- α angle > 60° (drawn on a coronal image of the hip; angle between the iliac line and line drawn parallel to the acetabular roof).
- Capsular laxity: > 50% bony coverage femoral head at rest, with < 50% bone coverage on stress examination or normal movement
- Subluxation: < 50% bony coverage at rest
- Dislocation: Femoral head lies completely outside of bony acetabulum at rest
4.
- Hilgenreiner line: links tops of both triradiate cartilages. The femoral METAphysis should lie below Hilgenreiner line.
- Perkin line: perpendicular to Hilgenreiner through lateral margin of the bony acetabulum. Femoral capital epiphysis should lie within inner lower quadrant of intersection between Perkin and Hilgenreiner line.
- Acetabular index is angle between acetabular roof and Hilgenreiner line. In newborn is 30-32°, becoming smaller in older in children.

Front 15

Liposclerosing Myxofibrous tumor (LSMFT)

Back 15

Geographic round/oval lesion with a thick, well-defined sclerotic margin in the intertrochanteric region of the femur.