MSK radiology

conventional (plain) radiography

first line modality that uses X-rays to for evaluating localized MSK pain

• detect

  • acute bone injury

  • gross joint abnormality

• soft tissue abnormalities with calcifications & major swelling

ultrasound (US)

non-invasive imaging modality that uses sound waves to visualize soft tissue structures & abnormalities through guided diagnostic procedures

• no radiation risk

• joint cavity visualization

• allows for

  • multiplanar imaging

  • examination of the joint in motion 

• Doppler can help to differentiate between inflammatory & non-inflammatory changes

CT (computed tomography)

imaging modality that uses X-rays & computer processing to create detailed cross-sectional images of the body

• allows reconstructions

• detect bone abnormalities & bony trauma

• visualize

  • complex joints

  • axial structures

  • entire circumference & internal matrix of bone

MRI (magnetic resonance imaging)

imaging modality that uses strong magnetic fields & radio waves to produce detailed detailed cross-sectional images of the body's internal structures

• no radiation risk

• helps detect occult fractures

• soft tissue & bone marrow abnormalities

  • artho allows detection of subtle joint abnormalities 

• can help differentiate degenerative traumatic, malignant, & inflammatory conditions

conventional X-ray

most examinations of bones starts with this modality 

• obtained with at least 2 views exposed at 90° to each other (orthogonal views)

• cannot visualize entire circumference of a tubular bone

• not particularly sensitive for demonstrating musculoskeletal soft-tissue abnormalities other than significant soft-tissue swelling

conventional radiographs - normal (long) bone

visualized as having a

• dense cortex of compact bone that completely envelopes a less dense medullary cavity

  • containing cancellous bone arranges a trabeculae, separated primarily by blood vessels, hematopoietic cells, & fat 

• shaft is diaphysis, capped on each end by epiphyses

  • joint at epiphyseal growth plate 

• proportion of cortical vs trabecular bone cary in different skeletal locations

radionuclide bone scan

modality of choice in screening for skeletal metastases

• can also be used in avascular necrosis of bone & Paget disease 

• MRI used primarily to solve specific questions related to lesion composition & extent

shoulder - anterior dislocation 

shoulder - posterior dislocation 

light bulb sign

impingement

a condition where the rotator cuff tendons become irritated and inflamed due to compression during shoulder movement

elbow dislocation

second most common in adults & most common in children

radiology - avascular necrosis

involves the bone with poor collateral blood supply such as the femoral head

• most readily detected by MRI

radiology - pelvis

most common avulsion fractures location

radiology - patello-femoral joint

“sunrise tangential projection“

• X-ray done at 30°, 60°, 90° flexion

patellar dislocation - acute traumatic

occurs when the patella shifts out of its normal position

• occurs equally by gender

• may occur from a direct blow 

patellar dislocation - chronic patholaxity

is characterized by recurrent subluxation episodes of the patella due to inherent knee instability

• occurs more often in women

• associated with malalignment 

patellar dislocation - habitual

is a condition where the patella frequently dislocates with minimal trauma

• usually painless

• occurs during each flexion movement

• pathology is usually proximal

  • tight lateral structures

Morton’s neuroma

Lisfranc injury

condition characteristized by disruption between the articulation of the medial cuneiform & base of the second metatarsal

radiology - scoliosis

radiology - vertebral compression

radiology- Paget disease

includes

• thickening of the cortex

• accentuation of the trabecular pattern

• enlargement + increased density of the affected bone 

radiology - osteoporosis 

low bone mineral density

• age-related & post menopausal 

• predisposes to pathological fractures

radiology - osteolytic metastases

well defined ; from

• lung

• thyroid

• kidney

• breast

radiology - plasmacytomas

are precursors to multiple myeloma

• most common tumor of bone

radiology - osteomyelitis

frequently caused by Staphylococcus aureus 

• more often spread to the adjacent joint space in adults rather than children

radiology - arthritis

disease of a joint that invariably leads to joint space narrowing & changes to the bones of both sides of the joint 

• can be divided into 

  • hypertoric

  • erosive (inflammatory)

  • infectious

radiology - hypertrophic arthritis

features

• subchondral sclerosis 

• marginal osteophyte production (bone spurs)

• subchondral cyst formation 

radiology - primary osteoarthritis

most common type of hypertrophic arthritis

• typically occur in weight-bearing surfaces of the hip, knee, & distal interphalangeal joints of finger

radiology - secondary osteoarthritis

a form of arthritis that develops due to trauma or avascular necrosis

radiology - erosive osteoarthritis

has similar finings to primary osteoarthritis but tends to feature more inflammatory changes

• occurs typically centrally located within the joint

• inflammation & synovial proliferation

  • pannus formation

  • produces lytic lesions near joint

• examples:rheumatoid arthritis, gout, psoriasis

radiology - rheumatoid arthritis

affects the carpals 7 proximal joints of the hand

• can widen the predentate space in the cervical spine 

• can lead to fusion of the posterior elements in the cervical spine

radiology - Charcot / neuropathic joints

features fragmentations, sclerosis, & soft tissue swelling

• diabetes = most common cause

radiology - pyrophosphate arthropathy

occurs with the deposition of calcium pyrophosphate (crystals) [chondrocalcinosis]

• can produce large & multiple subchondral cysts

  • narrowing of the patellofemoral joint space

  • metacarpal “hooks“

  • proximal migration of distal carpal row

radiology - gout

most often affects the metatarsal-phalangeal joint of the great toe with the juxta-articular erosions and/or little to no osteoporosis 

• tophi = late manifestations of the disease