The Musculoskeletal System

Common Problems in Ambulatory Care Medicine

A dr Z Lecture

on common traumatic and non-traumatic conditions of the musculoskeletal system in primary care practice…

With a little help…

• From a noted BONE expert

dr Z’s secret formula for success in radiology

• Know what to order

• Know what an optimal imaging series is and accept no less

• Know a good image from a poor one and accept only the good

…and…

• Read by check list

• Know the common lesions

• Know the commonly MISSED lesions

The Musculoskeletal System

• Soft tissues: muscles, ligaments, tendons, bursae, skin and subcutaneous tissue

• Joints: capsule, synovium, articular cartilage

• Bones: cortex, cancelleous, medullary canal

A case-based overview

• Upper extremity

• Lower extremity

• Spine

• Pelvis

But first…

Some general Musculoskeletal imaging principles

Bones: components

• Epiphysis• Physis (growth plate)• Metaphysis• Diaphysis• Apophysis

Joints: components

• Fibrous capsule• Synovial lining• Articular cartilage• Subchondral bone

Some Fracture Terminology

• Nondisplaced

• Displaced

• Comminuted

• Angulated

• Articular: fracture extends to a joint

• Pathologic: fracture through a focal lesion

• Stress: repetitive microtrauma, fatigue and insufficiency types

Osteolytic Patterns

Geographic

Motheaten

Permeative

Osteolytic Patterns

• These refer to degree of aggression of a bone destroying lesion

• Geographic least, motheaten intermediate, permeative most aggressive

• Usually, but not always, refers to neoplasm or infection

The Upper Extremity

• Shoulder

• Humerus

• Elbow

• Forearm

• Wrist

• Hand

The Shoulder

The Case

• 25 y/o female• Sudden onset pain and

loss of ROM after a fall on the shoulder while playing basketball

Anterior Dislocation

• Very common injury• Can be associated with

humerus head and glenoid rim fractures

• Rx: Closed reduction• If repetitive,

stabilization surgery

The Case

• 60 y/o female• Chronic shoulder pain

and limited ROM, increasing over 10 years

• No trauma

Rotator Cuff Disease

• AKA: impingement syndrome

• This is Phase Three: end stage; complete loss of rotator cuff stabilization

• Rx: Symptomatic, PT

The Elbow

The Case

• 55 y/o female• Fell on outstretched

arm at work• Pain and tenderness of

elbow

Radius Head Fracture

• Note: abnormal fat pads=hemarthrosis

• Common injury• Most are treated with

sling and PT and back to full activity in 3 weeks

The Wrist

The Case

• 55y/o female• Fall on outstretched

hand at work (again)• Pain in wrist and

“Snuff Box” tenderness

Scaphoid Fracture

• Risk of AVN• Immobilize in thumb

spica cast for 6 weeks• If fracture uncertain,

immobilize and repeat films in one week

• Oh: What else is fractured?

Answer

• Capitate

• Distal radius

The Case

• 51 y/o female• 20 year hx hand pain,

swelling, erythema• Both hands

symmetrically involved

Rheumatoid Arthritis

• Very common• Females more than

males• Inflammatory arthritis,

Rh factor seropositive• Rx: Several classes of

drugs (DMARDs, steroids), surgery

The Case

• 80 y/o female• 10 year hx hand pain• Both hands involved,

but dominate hand worse

Osteoarthritis

• Extremely common • Middle aged and

elderly• A mechanical wear

and tear arthritis• Rx: symptomatic

The Finger

The Case

• 25 y/o female• Hyperflexed DIP joint

playing basketball• Pain, tenderness and

inability to extend DIP joint

Mallet or “Baseball” finger

• An injury of the extensor tendon and fracture of dorsal base of distal phalanx

• Caused by hyperflexion of DIP

• Rx: Usually splint 4-6 wks, occasionally pin

The Case

• 60 y/o female• Nicked thumb while

cutting vegetables• One week later,

developed erythema, swelling and pain at IP joint

Osteomyelitis

• Both the bone and joint are involved in this bacterial infection

• The destructive process has crossed the joint, typical of infections

The Spine

• Cervical

• Thoracic

• Lumbar

• Sacral/coccygeal

Cervical Spine

• Plain film

• MRI

The Case

• 55 y/o male smoker• Carcinoma of the right

lung, treated by lobectomy surgery

• One year later, insidious onset of neck pain not relieved by rest

Lateral Cervical Spine Film

• Where is the abnormality?

• How would you describe it?

Sagittal MRI

• Where is the osseous abnormality?

• What other structures are involved?

• What is the diagnosis?

Metastasis to Cervical Spine

• Hematogenous spread to spine from the primary carcinoma

• The tumor extends from bone into the spinal canal and compresses the spinal cord.

Thoracic Spine

The Case

• 91 y/o female• Insidious onset mid

back pain• Increasing kyphosis• No trauma

Osteoporosis

• With multiple insufficiency fractures

• RX: Pain control, biphosphonates

• Common conditon, underdiagnosed & undertreated, can cause severe disability

Lumbar Spine

The Case

• 18 y/o female• Insidious onset low

back pain after 3 months of weight lifting

• No trauma

Stress Fracture of the Pars

• SPONDYLOLYSIS:

spondylo=spine

lysis=a defect, break, disruption

The break is of the pars, the bone bridge between the sup and inf facets

Spondylolysis

• Most often due to fatigue stress fracture

• Young gymnasts, hurdlers, weight lifters, cheerleaders are at risk

• If bilateral, the vertebral body can slip

Spondylolisthesis

Spondylolisthesis

spondylo=spine

listhesis=slipping, displacement

With high grade slipping, surgical fusion is considered

The Case

• 34 y/o male• 10 years of

progressive low back pain and restricted ROM

• No trauma

Ankylosing spondylitis

• There is calcification of all ligaments (syndesmophytes) and complete destruction and fusion (ankylosis) of both sacro-iliac joints

• Seronegative, HLA B27 positive inflammatory arthritis

The Pelvis

Normal Pelvis

The Case

• 85 y/o male• Insidious onset of pain

in right pelvis at rest, over 10 days

• No trauma• No history of

malignancy

Paget’s Disease

• Increased density and thickening of right hemipelvis

• Disease of unknown etiology with ‘hot’, mixed and ‘cold’ phases

Why the onset of pain?

• Notice the fracture of the right medial acetabulum margin

• The fractures associated with Paget’s are often incomplete and due to repetitive microtrauma

Paget’s Disease

• Usually asymptomatic• Complications include

pathologic fracture, pain, nerve encroachment, high output heart failure, malignant transformation

The Lower Extremity

• Hip

• Femur

• Knee

• Lower leg

• Ankle

• Foot

The Knee

The Case

• 34 y/o female• “Clipped” on lateral

knee while playing with nephews

• Tender lateral margin• Positive “drawer sign”

Segond Fracture

• An avulsion fracture caused by tension on lateral capsular lig.

• 95% association with ACL tear, as common mechanism

The Ankle

The Case

• 40 y/o female• Inverted ankle on

stairs• Tenderness lateral

malleolus• Can ambulate but with

severe pain

Fracture of Distal Fibula

• Fracture of lateral malleolus below the joint (Weber A)

• Stable, so treated by cast for 6 weeks

The Foot

• “Now you’re talking MY language!”

Sorry: The HUMAN Foot

The Case

• 23 y/o female• Training for LA

Marathon• Insidious onset of heel

pain

Radiograph: Negative

Diagnosis

• Plantar fasciitis?• Rx: Orthotics, ice,

reduce mileage• No improvement next

2 weeks• So, repeat radiograph

Stress Fracture

• Fatigue fracture: Abnormal stress on normal bone

• Radiographs usually negative for first 2-3 weeks

• Often initially thought to be plantar fasciitis

The Case

• 30 y/0 female• Inverted ankle and

foot after stepping on toy

• Pain and tenderness over base of the fifth metatarsal

Fracture of the Base of the Fifth Metatarsal (Jones)

• Inversion puts tension on the peroneous brevis muscle tendon

• This causes a transverse force, fracturing the 5th MT base

• Can be “Dancer’s” or “Jones” type

The Case

• 55 y/o male • Type I diabetes 30 yrs• Painless swelling of

foot 2 months• No trauma

Neuropathic Joint Disease

Charcot joints with destruction, disintegration, debris, density, distension

Due to loss of sensation from peripheral neuropathy, vascular insufficiency and poor healing

Happy OSSEOUS Imaging!

…and I hope you like BONES as much as I do!

Goodbye…

Copyright 2005

Michael Zucker, MD