MUSCULOSKELETAL RADIOLOGY🗸

• Ultrasonography
• To screen for DDH (developmental dysplasia of hip)
• To look for joint effusion

X-ray features of scurvy:

• Scurvy → Comes with pain

• Rickets → Painless

• Subperiosteal hemorrhage.
• most common
• leading to bilateral knee pain
• Painful pseudo paralysis.
• Crying on touch.

• NOTE: Scorbutic Rosary.
• sharp & tender,
• unlike rachitic rosary

• Trummerfeld zone.
• Seen adjacent to white line of Frankel.

• Diaphysis:
• Ground glass appearance.
• Pencil thin outline cortex.

• Metaphysis:
• White Line of Frankel.
• Helps differentiate from active rickets.
• Seen in healing rickets.
• Scorbutic Zone (Trümmerfeld zone):
• Radiolucent band in the metaphysis.
• Pelkan's Spur
• Metaphysis forms a spur.

• Epiphysis:
• Wimberger Ring Sign: 
• ring shaped epiphysis
• Ring appearance of epiphysis.
• May be d/t bleeding

Differential Diagnosis (D/D) of Scurvy Radiological Findings

• Healing rickets.

• Congenital syphilis.

• Plumbism (lead poisoning).

• Leukemia.

X ray Rickets

• Radiological Features:
• Genu valgum: Knees towards each other - Knock knees.
• Bowing of the legs: Genu varum.

• Metaphysis
• Earliest
• ↓ Zone Provisional calcification - ZPC
• Fraying, ragged edges → Irregular border
• Cupping → Concavity
• Splaying → Widening

• Epiphysis
• Widening → epiphyseal plates/growth plate.

• Diaphysis
• Bowing

• Decreased density.

• Mnemonic: when Looser (Loosers zone) is in malasia () → stress () relieved → parts protrude (protrusio acetabuli) → like a cod fish mouth (cod fish) → Pelvis become radiated (Triradiate pelvis)

• Pseudofractures with surrounding sclerosis.:
• Also known as Milkman's Line or Looser Zone.
• Most common sites:
• Neck of femur >
• clavicle
• ribs
• pubic rami

• Stress fractures
• that have healed with mineral-deficient material.

• Triradiate pelvis

• Codfish or fish mouth vertebrae
• Biconcave vertebral bodies (after >30% bone loss).
• also in osteoporosis

• Protrusio Acetabuli: 
• Head of femur protrudes into the acetabulum.

Osteoporosis

• Dexa Scan → Bone Mineral Density Scan

• Used to measure bone mineral density.

• Important for diagnosing osteoporosis.
• Biochemical tests are normal in osteoporosis.

T-score: 

• Compares bone mineral density
• to a young male/female (30 y.o.)
• with highest bone density.

• Quantitative CT (QCT)
• Not usually done, but can be done
• can also diagnose osteoporosis.

X-ray findings:

• Vertebral fracture.

• Neck of femur fracture.

• Colles' fracture.

• Codfish Vertebrae: 
• Biconcave vertebral bodies (after >30% bone loss).
• Also seen in Osteomalacia

• Fishmouth vertebra in osteoporosis:
• Decreased vertebral height.
• Vertebral collapse with concave end plate.

• Chevron’s sign
• Femur length = Tibia length
• Dont confuse with scurvy/rickets
• Rhizomelic dwarfism
• Rhizomelic shortening of femur
• Metaphyseal dyplasia

Other signs

• Trident/ Starfish hand:
• Increased gap between middle and ring fingers.

• Champagne glass pelvis

• Tombstone appearance of iliac blades

• Flat acetabulum

• Mnemonic: Achondroplasia → Tyrion lannister → carries a trident → drinks champagne → acetabulum got flat due to repeated sex → died in tombstone

Acromegaly radiology

• Spade phalanx
• Overgrowth of distal phalanx.

• Increased heel pad thickness

• Increased growth hormone.

• Increased growth of bones and soft tissue.

• Prognathism

• Expanded sinus

• Causes subperiosteal bone resorption.

• Hand X-ray (middle phalanx) shows the earliest bone changes.

• Radiological Features:
• Concavity of bone due to subperiosteal resorption.
• Salt and pepper appearance in the skull or pepper pot skull.
• Due to lytic lesions.
• Brown tumor or osteitis fibrosa cystica or Von Recklinghausen disease of bone

note: Ochronosis:

• seen in alkaptonuria, Hydroquinone, Carbolic acid ingestion

• IV disc calcification

note: Garrod’s tetrad

• Cystinuria

• Alkaponuria

• Albinism

• Pentosuria

SKULL XRAY PATTERN APPROACH

Clinical Features Hyperparathyroidism

• M/c/c → Parathyroid Adenoma

1. Bones:
• Pathological #.
• Brown tumours (Von Recklinghausen disease of bone).
• Osteitis fibrosa cystica/brown tumors.
• Sub periosteal resorption.
• Salt and pepper skull.

2. Stones: 
• Multiple + recurrent renal stones (m/c feature).

3. Abdominal Groans:
• Colicky abdominal pain, pancreatitis.

4. Psychiatric Overtunes.

Punched out lytic lesion/ rain drop lesion

• Well defined lytic lesions in the skull.

• Involves outer and inner tables equally.

• Seen in multiple myeloma & LCH

• It is a lytic lesion:
• No new bone formation.
• No increase in ALP.
• No hot spots on bone scan.

Beta Thalassemia Major (Koul's Anemia):

• 'Hair on End' or 'Crew Cut appearance'.
• Lateral Xray skull: -Seen in hemolytic anaemias.
• e.g. sickle cell anemia, thalassemia.
• Hemolysis causes compensatory increase in hematopoiesis.

• Chipmunk faces/ Hemolytic Facies:
• Frontal prominence.
• Depressed bridge of the nose.
• Maxillary prominence.

• Severe anemia.
• Manifest later
• HbF in infants
• Transfusion requirement.

• Hemolytic jaundice.

• Splenomegaly.

• Short stature.

• Features of iron toxicity.

Clinical Features

1. Bone Pain: 
1. Most common symptom.

2. Bone
1. warm
2. thickened/irregular.

3. Banana Fractures 
1. long, oblique fractures
2. common in long bones

4. Cranial foramen stenosis:
1. Compression of cranial nerves (CN 2, 3, 5, 7, 8)
• → hearing disturbances.

5. Otosclerosis:
1. Hardening of the bones in the ear,
2. causing hearing loss.

6. Thickening of the skull:
1. Frequent changes in hat size
• a classic symptom

 

• Can have lytic, blastic, or mixed phase.

Radiological Features

Marble Bone Disease / Albers-Schonberg disease

Q. An 11-month-old girl presented with pancytopenia and hepatosplenomegaly. An x-ray of her limbs showed the following picture. What is the diagnosis?

Pathophysiology

• Defect in gene for carbonic anhydrase 2
• Required by osteoclasts for acidification for bone resorption
• Decreased osteoclast function (↓ Resorption).
• Leads to increased bone formation (↑ Bone formation).
• Erlenmeyer flask deformity

• Resulting in the medullary cavity being obliterated by new bone,
• ↓↓ space for bone marrow.

Clinical Features

• Excessive thickened bone.

• Aplastic Anemia: 
• Due to marrow obliteration,
• → anemia, thrombocytopenia, and leucopenia.

• Multiple infections (due to leukopenia).

• Foramina are small
• Cranial nerve palsies

X-ray

• Bone within a bone appearance/ "Marble Bone Disease"
• Increased density of the bone.
• Mnemonic: Osteo Pettu → Bone vere bone nte ullil pettu

• Rugger Jersey Spine 



• (also seen in Renal Osteodystrophy).

• Dense, sclerotic bones.

Rugger Jersey Spine: 

• Alternating sclerotic and lucent bands,

• [Resemble stripes on a rugby jersey]

• Seen in
• Osteopetrosis
• Renal osteodystrophy - Secondary hyperparathyroidism

• Mnemonic:
• Mnemonic: Rugger jersey → look like rods → ROD → Renal osteodystrophy
• Rugby Jersey ittond marble (Osteopetrosis/marble bone ds) panikk poi → Got CKD ()

H shaped vertebra

• H-shaped Appearance or Lincoln Log Vertebrae.
• Seen in Sickle Cell Anemia.

• Depressed end plate, predominantly in the center.
• Lateral part is flat.

• In later stages: Fish mouth vertebra.

X-Ray Hemangioma:

• Site Preference: Spine > Skull > Pelvis.

• Mnemonic: Hemangioma → hemorrhage → Jail il () kidannavane Police (Polka dots) Spine () um skullum () adich bleed cheyipich → kodathiyil (Cordruoy) kond poi

• Mnemonic: Hema malini → wore polka dot and codroy pants → going to jail ()

• Vertical Striations: 
• "Jail bar/Jail house appearance."
• Corduroy Appearance.

CT Scan Hemangioma:

• "Polka dot sign" (Axial view).