Notes Flashcards
ARTHRITIDES
= Arthritic conditions
Over 100 different conditions
4 Categories
- Inflammatory
- Degenerative
- Metabolic
- Infection
Inflammatory Arthritides
Characteristics:
- Soft tissue swelling, edema
- Uniform loss of joint space
- Erosions
- Cystic changes: juxta-articular osteoporosis/osteopenia
- Monoarticular or polyarticular
- Symmetric pattern
- Greater predisposition to fusion (ankylosis) than degenerative or metabolic
- Ex: Rheumatoid
Degenerative Arthritides
Characteristics:
- Non-uniform loss of joint space
- Osteophytes
- Subchondral clerosis
- Cystic changes
- Asymmetric changes
Metabolic Arthritides
characteristics:
- Notable soft tissue masses within periarticular soft tissues
- Well-marginated bone lesions
- Relative preservation of joint space
- Overlapping degenerative and inflammatory changes is common
- “The lumpy bumpy arthritis”
- ex: gout
Infectious/Septic Arthritis
- Common cause of grossly destroyed and disintegrated joints
- Gereatest incidence is below age 30
- Monoarticular is most common
- Caused by blood borne pathogens and direct implantation (S. aureus is most common organism)
Radiological Assessment of Joints (I)
Plain film shows bone involvement, therefore hard to detect early disease.
Radiological Assessment of Joints (II)
Radiolographic findings lag behind clinical: 30-50% of bone must be destroyed to see it on x-ray, 3% to see on bone scan (= radionuclide scintigraphy).
Radiological Assessment of Joints (III)
Parameters:
- Clinical evaluation
- Age and sex
- Distribution of joint disease
- Readiographic appearance
- Lab tests
- Specialized imaging exams
General Age of Onset
0-20 Juvenile rheumatoid arthritis or other juvenile arthritis
20-40 Seronegative, seropositive joint disease/spondyloarthropathy
over 40 degenerative, DISH, gout, CPPD
ABCDS of Joint Diseases
Alignment Bone Cartilage (joint space) Distribution (consider target joints) Soft Tissues
Law of Parsimony
Taking historical points and physical findings and putting them together into one diagnosis
but patients often have more than one arthropathy.
ABCDS of Joint Diseases
Alignment Bone Cartilage (joint space) Distribution (consider target joints) Soft Tissues
DEGENERATIVE ARTHRITIS
Target joints are weight-bearing articulations of the: spine -hips -knee -AC joint -1st MTP -1st MC-trapezium -DIP joints
DEGENERATIVE ARTHRITIS
Although any joint can be affected) characteristics: - insidious onset - intermittent exacerbaions - aching pain, stiffness - aggravation of symptoms with environmental changes such as cold and drop in barometric pressure
Primary DJD
No evidence of underlying etiology
Secondary DJD
Caused by:
Abnormal forces including obesity, trauma, joint deformity
-Pre-existing cartilage pathology such as rheumatoid arthritis, fractures and meniscal damage
-Collapse of subchondral bone, such as avascular necrosis and osteoporosis
DJD Other names
Osteoarthritis Osteoarthritis Degenerative joint disease Degenerative disc disease Spondylosis Arthritis Arthrosis Kellgren’s arthritis
DJD Risk Factors
- Increases with age
- Females have increase in DJD of hands, kness
- Obesity increases DJD of knees and hips
- Trauma – most significan local factor
- High impact physical activity increases risk
- Increases with inactivity or excessive activity
DJD Clinical Features
- Poor radiographic-to-clinical correlation
- Stiffness, especially with rest
- Normal blood work
- Spinal stenosis
- Vertebrobasilar ischemia
DJD Progression/Development
Abnormal articular forces promote loss of chondroitin sulfate and interfere with normal chondrocyte function, which leads to:
- Cartilage degradation—fissures, flaking, vascularization
- Denudation process secondary to altered joint function
- Synovium hypertrophy
- Cartilaginous debris
- Osteophytes develop from cartilage metaplasia and increased capsular insertion stresses
DJD Radiology Features (I)
Enthesopathy = pathological osseous proliferation at tendon or ligament insertion; degenerative, inflammatory [enthuses=anatomical location of insertion of ligament/tendon into bone via Sharpey’s fibers]
Ankylosis (rare, but joint may look fused)
DJD Radiology Features (II)
Asymmetric distribution Asymmetric loss of joint space Osteophytes at joint margin Subchondral sclerosis Subchondral cysts (geodes) Subluxation Interarticular loose bodies
DJD in the Hands
Common, especially among middle-aged postmenopausal women
osteophytes, sclerosis, loss of joint space, misalignment
DJD in the Hands (I)
Bouchard’s Nodes = enlarged soft tissue nodes of PIPs
DJD in the Hands (II)
Heberden’s Nodes = enlarged soft tissue nodes of DIPs
DJD in the Hands (III)
“Gull wing” – bilateral DJD with central joint erosions; variant of the normal DJD pattern
DJD in the Hands (IV)
Ungula tuft : At distal part of distal phalanges Target Locations: -DIPs -PIPs -1st metacarpal-carpal joints -NOT MPs
DJD in the Hands (V)
Ungula tuft : At distal part of distal phalanges
Erosive Osteoarthritis (I)
Variant of DJD
Erosive Osteoarthritis (II)
Middle aged females
Appears unusually inflammatory
Erosive Osteoarthritis (III)
Middle aged females
Erosive Osteoarthritis (IV)
Appears unusually inflammatory
Erosive Osteoarthritis (V)
DDx: RA, psoriatic arthritis
“gull-wing” DIP joints is classic radiographic finding
pain, redness, swelling, decreased motion
DJD in the Feet (I)
1st MTP joint common
DJD in the Feet (II)
Hallux rigidus when present with symptoms of pain and stiffness.
Metatarsus varus
hallux valgus joint misalignment is common
DJD in the Feet (III)
Bunions – enlarged head of metatarsal with cystic changes
DJD in the Shoulder (I)
- Glenohumoral joint
degenerative changes usually require prior trauma
Osetophytes and joint misalignment should arouse suspicion of significant previous trauma or underlying CPPD
DJD in the Shoulder (II)
- Acromioclavicular joint
Often involved in DJD without prior trauma
Osteophytes extending inferiorly may impinge on rotator cuff tendons leading to tendon calcification and superior migration of humerus
Shoulder Impingement Syndrome
Rotator Cuff Arthropathy = Greater Tuberosity Enthesopathy (greater tuberosity is location of insertion of supraspinatus tendon)
Shoulder Impingement Syndrome
Progression:
1. Degenerative enthesopathic changes of the humeral head, especially greater tuberosity
- Spurring (osteophytes)/erosions of acromion process
- Humerus migrates superior due to unopposed deltoid action, no room for supraspinatus
- Supraspinatus degeneration → rotator cuff tear: see increased signal in supraspinatus tendon on MR in the critical zone where there is less vascularity
HADD (I)
Hydroxyapatite Deposition Disease
HADD (II)
Deposition of calcium within tendons and bursa
HADD (III) MC areas
-Most commonly seen in the supraspinatus tendon then: Shoulder Elbow Wrist Hip Knee Ankle Spine
HADD (IV) AKAs
Calcifying tendinitis, calcifying bursitis, peritendinitis calcarea
HADD (V) Characteristics
Characteristics:
pain, tenderness, localized swelling reduced range of motion
-lab unrewarding
-radiographic diagnosis of calcificaiton of soft tissue involved
-focus of degeneration within tissue follows with hydroxyapatite crystal deposition
*Disc calcification is a form of HADD due to DDD.
DJD of the Knee
3 compartments of the knee:
- Medial tibiofemoral – most common compartment for DJD
- Lateral tibiofemoral
- Retropatellar
Characteristics of DJD in the Knee
- asymmetric loss of joint space
- subchondral sclerosis
- subchondral cysts
- articular deformity and irreglarity
- hypertrophic changes of intercondylar spines
- enthesopathy of anterior (non-articular) surface of patella
- genu varus in case of medial compartment degeneration
Synovial Osteochondrometaplasia
Multiple intra-articular loose bodies/fragments/cartilaginous masses produced by synovial tissue metaplasia (junk in the joint)
may ultimately ossify/calcify to become visible radiographically—joint mice, with joint locking
Synovial Osteochondrometaplasia (II)
Common in the knee and also seen about the
- Hip
- Ankle
- Shoulder
- Wrist
Synovial Osteochondrometaplasia (III)
Seen as laminated, stippled, concentric calcific densities, unlike HADD
Pigmented Villonodular Synovitis (PVNS) (I)
Slow-growing, benign and locally invasive tumor/metaplasia of the synovium
Pigmented Villonodular Synovitis (PVNS) (II)
Most often involves the knee. Also in hip, ankle, elbow
Found in young to middle age adults - consider in younger patient with unexplained hip pain
Pigmented Villonodular Synovitis (PVNS) (III)
DDx: rheumatoid arthritis
Pigmented Villonodular Synovitis (PVNS) (IV)
Characteristics:
- Intraarticular effusions, lobulated masses
- Bony erosions more common in tight joints (hip, elbow, wrist)
- Apple core deformity in hip – Concentric erosions o femoral neck
- Seen on opposing joint surfaces
DJD of the HIP
Compartments of hip joint: medial, axial, superior
DJD of the HIP characteristics:
- loss of joint space – 80% toward the superior compartment
- osteophyte formation
- subchondral cysts/geodes (Eggar’s cysts) – due to intra-osseous synovial intrusion through cartilage fissures along with necrosis; subchondral with sclerotic borders; can be confused with tumor when large (do MR)
- sclerosis
- joint deformity
- buttressing – Thickened cortex at the medial femoral neck as result of biomechanical changes across the joint
