Musculoskeletal #28

Prune Belly Syndrome

What are the features?

Features

There are three cardinal features:
– Bilateral undescended testicles
– Dilated urinary tract
– Deficient abdominal wall musculature.

These manifestations place patients with prune belly syndrome at risk for testicular malignancy, infertility, urinary tract infections, and renal failure.

The Prune Belly syndrome is also known as:
– Eagle-Barrett syndrome
– Abdominal musculation syndrome

What is the incidence of PBS?

– PBS has a contemporary incidence of 3.6–3.8 per 100,000 live male births
– It is a predominantly male diagnosis as <5% of those diagnosed are female

What are the major manifestations of PBS, giving rise to its alternative name of the triad syndrome?

– A deficiency of abdominal musculature leading to a wrinkled “prune- like” appearance of the abdominal wall.
– Bilateral intra-abdominal testes.
– Urinary tract dysmorphism. The urinary tract anomalies are characterized by differing degrees of renal dysplasia, hydronephrosis, dilated tortuous ureters, an enlarged bladder and a dilated prostatic urethra.

What percentage of patients with PBS are female? What are the major manifestations of PBS in a female?

– Only 5% of PBS diagnoses are female.
– Females exhibit only deficiency of abdominal wall musculature and the anomalous urinary tract without any gonadal abnormality.

Other abnormalities

– 75% of children with PBS have non-urinary tract abnormalities
– These abnormalities include respiratory (58%, e.g. pulmonary hypoplasia), cardiac (25%, e.g. patent ductus arteriosus, atrial septal defect, ventricular septal defect, tetralogy of Fallot), gastrointestinal (63%, e.g. constipation, incomplete rotation of the midgut) and musculoskeletal anomalies (65%, e.g. talipes equinovarus, scoliosis, hip dysplasia)

What is the incidence of prematurity

The incidence of prematurity in the PBS population is nearly 50%.

What is the perinatal mortality of those born with PBS?

– Perinatal mortality ranges between 10 and 29% in contemporary studies.
– Perinatal mortality is directly connected to the level of prematurity and severity of pulmonary hypoplasia.

What is the most common urinary tract abnormality?

Hydroureteronephrosis is almost always present and most commonly bilateral.
– The distal ureter is usually where massive dilation occurs; however the presentation is variable.
– Hydroureteronephrosis is almost never due to obstruction within the ureter, rather, lower urinary tract obstruction (posterior urethral valves), vesicoureteral reflux, and a histologic deficiency of smooth muscle and preponderance of fibrous tissue in the ureters leading to ineffective peristalsis

Musculoskeletal #27

53-year-old female:

– Chronic sensory polyneuropathy (autoimmune). Long-term corticosteroid therapy.
Forefoot pain for three weeks (acute onset without trauma).
– Physical examination: no haematoma , mild swelling.
X-ray performed on day 2 after initial pain.
MRI performed on day 25 after initial pain.

What are the findings?

X-Ray: No obvious fracture.

MRI:
– Bone marrow heterogeneous oedema within the third metatarsal diaphysis (hypointense on T1W image, hyperintense on Proton Density (PD) FatSat image).
Linear low signal intensity fracture identified in all sequences.
Periosteal reaction due to callus formation. Periosteal thickening and enhancement (contrast administration is not necessary for diagnosis).
– Surrounding soft-tissue oedema (adjacent fat and interosseous muscles).

Metatarsal stress fracture (“march fracture”)

– Stress fractures are caused by overuse and repetitive activity.
– Everyday activities may result in a stress fracture if there is any disease or therapy that weakens the bone such as osteoporosis or long-term use of steroids (bone insufficiency: long-term treatment with steroids in this case).
– Classically affects the 2nd or 3rd metatarsal of the foot “march fracture”: named after its prevalence in soldiers who often undertake repeated and prolonged periods of walking as part of their training or work.
– Bone changes are usually not evident on X-rays before 10 to 21 days following the injury. May not be visible for several weeks later, until callus bone formation (the sensitivity range, for detecting stress fractures on initial examinations, is 15-35%; it increases to 30-70% at follow-up studies due to bone reaction).

MRI findings:
– The fluid-sensitive sequences (T2-weighted images with chemically selective fat suppression or STIR sequences) are very useful for the detection of the earliest changes of stress reaction, such as periosteal reaction, muscle, or bone marrow oedema.
– T1-weighted sequences depict the anatomy and more advanced stress-related findings.

Grading based on MRI (Arendt and Griffiths)🙂
1: Mild – moderate periosteal oedema on STIR, no marrow changes.
2: Moderate – severe periosteal oedema on STIR + marrow changes on T2-weighted.
3: Grade 2+ marrow changes on T1-weighted.
4: Fracture line visible.

Musculoskeletal #26

Describe the abnormality

Bilateral sacroiliac joint space narrowing, subchondral erosions, subchondral sclerosis, and subchondral fatty marrow infiltration.

What is the differential diagnosis?

Bilateral symmetrical:
Ankylosing spondylitis
Inflammatory bowel disease. 

Bilateral asymmetrical:
Psoriasis
Reactive arthritis (Reiter syndrome) 

What is the most likely diagnosis?

Ankylosing spondylitis

What are the markers of active inflammation?

Erosions with high signal intensity on STIR or T2- weighted images, subchondral edema, and enhancement within or adjacent to the sacroiliac joint.

What are the markers of chronic disease?

Low signal intensity on T1- and T2- weighted images, subchondral sclerosis, narrowing of the joint spaces, bone bridging, and ankylosis.

Emergency #35

61-year-old female:
– Trauma
– Fracture? What do you see?

Showing the supine AP and lateral view, due to the inability to stand on the right leg.

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Diagnosis: Lipohemarthrosis (fat-blood level) indicating intra-articular #
Comminutive though non-displaced tibia plateau fracture Avulsion fracture proximal fibula (Segond fracture – 100% association with ACL injury)
CT: Schatzker type VI

Schatzker tibia plateau classification

Schatzker I: wedge-shaped pure cleavage fracture of the lateral tibial plateau, having less than 4 mm of depression or displacement
Schatzker II: splitting and depression of the lateral tibial plateau; namely, type I fracture with a depressed component
Schatzker III: pure depression of the lateral tibial plateau; divided into two subtypes:
Schatzker IIIa: with lateral depression
Schatzker IIIb: with central depression
Schatzker IV:  medial tibial plateau fracture with a split or depressed component
Schatzker V: wedge fracture of both lateral and medial tibial plateau
Schatzker VI: transverse tibial metadiaphyseal fracture, along with any type of tibial plateau fracture (metaphyseal-diaphyseal discontinuity)

Musculoskeletal #24

48-year-old male:
– Heavy smoker
– Depressive syndrome

Found lying unconscious at home, in lateral position (opioid overdose)
Erythema and limited movement of the left shoulder
Blood test: CK 7949 u/l. Negative blood and aspiration cultures (no infection)

What do you see?

Findings

CT: Low attenuation area involving the posterior aspect of the deltoid muscle and the lateral aspect of the pectoralis major muscle. Superficial and deep fascia edema. No enhancing walls neither gas is seen.

MRI: Postcontrast T1FS images show hypointense unenhancing central muscle fibers surrounded by thick rim enhancement involving the posterior deltoid, teres minor, and pectoralis major muscles . Thickened and hyperenhancing adjacent fascia and reactive muscle edema are also noted.

What is the most likely diagnosis?

Rhabdomyolysis (type 2: myonecrosis)
– Injury to skeletal muscle that involves leakage of large quantities of potentially toxic substances into plasma.
– Type 1: homogeneous signal changes and contrast enhancement. Ischemic or reversible ischemic reaction.
– Type 2: homogeneous or heterogeneous signal changes and rim enhancement. Irreversible muscular necrosis (myonecrosis).

– Deep tissue injury: severe pressure ulcer, characterized by necrotic tissue mass under intact skin.

– CK > 1000 – 5000 iu/l “cut-off”.

– Risk factors: postoperative patients (position), obesity, male gender, diabetes, surgical bleeding…

Musculoskeletal #22

What do you see?

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Vertebral hemangioma with thickened trabeculae and fat foci inside the lesion, without soft tissue component with an associated pathological fracture.

TEACHING POINTS:
Bone hemangiomas are very frequent, atypical presentations and complications (like in this cases with soft tissue component and pathological fracture) are rare but radiologist must be aware of them to be able to make the correct diagnosis.

Musculoskeletal #20

72-year-old alcoholic patient with intractable dorsal pain and legs numbness and weakness.

What do you see?

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IMAGING FINDINGS:

Thoracic spine compression fracture with posterior displacement of the posterior wall of the vertebral body compromising the spinal canal, cord compression and associated myelopathy. T2W image shows fluid and hypointense bubble-like artifact consistent with vacuum cleft in the collapsed anterior vertebral body

DIAGNOSIS:

Kümmel disease (osteonecrosis and collapse of the vertebral body)

TEACHING POINTS:

Intravertebral vacuum cleft and fluid within the collapsed vertebral body is a characteristic feature
Differential diagnosis includes a pathologic (tumoral) fracture, and the presence of air strongly favors osteonecrosis

Would you like to see a complementary case?

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MR T2-weighted and CT images to highlight the characteristic features of Kümmel disease

Intravertebral fluid seen on T2 image and air on CT image

Emergency #26 – Flashcard

A 30-year-old female with right shoulder pain.

4 images of the right shoulder were obtained (axillar, Y-view, internal rotation, external rotation)

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Y-view

Internal rotation
External rotation
Findings:

Findings


Right shoulder: There is a nondisplaced fracture involving the inferior aspect of the glenoid, with involvement of the articular surface. Glenohumeral joint shows normal alignment. Acromioclavicular joint is normal. No soft-tissue calcification. No fracture or dislocation

What is the most likely diagnosis?

The most likely diagnosis is Hill-Sachs lesion

Hill-Sachs lesions are a posterolateral humeral head compression fracture. Typically occurs secondary to recurrent anterior shoulder dislocations. It is often associated with a Bankart lesion of the glenoid

Internal Rotation
External Rotation

These lesions are best seen following relocation of the joint. It appears as a sclerotic line running vertically from the top of the humeral head towards the shaft. A wedge defect may be evident in large lesions. The lesions are better appreciated on internal rotation views

Musculoskeletal #15 – Flashcard

This is the third and last case of the musculoskeletal series. Check the first one and second one on this blog.

What do you see on the following images?

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Osteoblastoma: Osteoblastoma is histologically similar to osteoid osteoma but they are larger (usually accepted more than 1 cm), often involving the posterior column