Radiology in the Management of OA Flashcards
“People who have persistent, atraumatic movement-related joint pain or aching and/or morning stiffness lasting <30mins are diagnosed w/ OA based on clinical Ax.”
_________ _________ is NOT required to make a diagnosis in people aged 40 years or older if their symptoms are typical of OA
Radiological Imaging
Next to clinical diagnosis, are cost effective & quickly & readily obtained
Augment our understanding and stage OA
Ensure they are load bearing views; must be specified otherwise radiology techs assumer there is a #
Generally need at least 2 views:
- Knee; AP weight bearing, lateral, skyline for PF joint
- Hip; AP weight bearing, true lateral
X-Ray Advantages
Imaging used to differentiate OA from other inflammatory joint disorders or conditions mimicking OA, rule out red flag causes (sepsis, tumour, #, inflammatory conditions)
Differential Diagnosis
GOLD STANDARD
Helps w/ disease ownership, self management & validation
Improves clinician’s understanding of the client
Helps in designing exercise, activity prescription, walking aids, safety, bracing, assistive equipment
Convey meaningful info to other health care professionals
Differential Diagnosis: referred spinal pain, vascular or neurological compromise
Surgical Planning: Dysplasia, measurement of true LLD
Monitor slowly evolving conditions: AVN, Charcot Marie Tooth
X-Rays
Radiation; absorbed by structures in the body differently
Bone absorbs more radiation that soft tissues (creates white opaque image)
Background dose in environment: ~1-3mSV/year
Peripheral X-ray: 0.001-1 sSV or 3 hours to 10 days added exposure
Spine X-ray: 1.5 mSV or 6 months exposure
CAT 20mSV or 7 years exposure
X-Ray Disadvantages
Computed Tomography cross sectional x-rays
Rarely used but useful in surgical planning hip OA when hip dysplasia or structural abnormality a factor or w/ TJR failure
CAT Scan
Not necessary to diagnose OA or required in addition to plain X-ray image
Can visualize articular cartilage, bone edema, meniscal tears, ligament ruptures & effusions
Great cost, not timely, does not stage arthritis NWB reporting focuses on soft tissues. Little info about degree of cartilage invovlement
Clients fixated on menisectomies & arthroscopic solutions to manage OA
MRI
Checklist for pts 40 years or older referred.
One or more MUST apply in order to be eligible for MRI of the hip/knee:
- MRI was recommended on a previous imaging report
- Previous hip/knee surgery
- Suspected infection
- Suspected tumour
- Osteonecrosis
- Fixed locked knee
- Pt has had a weight-bearing X-ray within the past 6 months and referring clinician has confirmed mild or no evidence of OA in the knee/hip
VCH MRI Criteria
Used for guided injections w/ fluoroscopy
Can be used to DDx calf embolus from a Baker’s Cyst
Used in the management of RA to monitor effectiveness of meds in reducing synovial pannus & for early detection synovitis
Ultrasound
Useful in detecting early hand OA
DDx osteomyelitis, bone metastases, metabolic bone disease, implant failure
Bone Scan
When you see symmetrical joint space loss = an _______ condition (can still lead to secondary OA)
Inflammatory
A: Alignment
B: Bone integrity & mineralization
C: Cartilage space
D: Distribution
S: Soft tissue changes
Additional info: Correct patient, correct knee, weigh bearing view?
ABCDS
Radiological descriptors:
- Normal
- Juxtaarticular osteopenia, diffuse osteopenia
- Erosion: marginal aggressive, central aggressive, non aggressive
- Whiskering, excrescence, periosteal reaction, osseous anklyosis overhanding edge
- Osteophytes subcondral sclerosis
Bone Integrity & Mineralization
___ changes on plain x-ray reveal the FINAL COMMON PATHWAY where there is defective articular cartilage & underlying marginal bone changes which eventually lead to:
- Joint space narrowing
- Sclerosis
- Osteophytes
- Subchondral cysts
OA
Grade 0: Normal
Grade 1: Cartilage softening swelling
Grade 2: Partial thickness defect w/ fissures on surface that do not reach subchondral bone or exceed 1.5cm in diameter
Grade 3: Fissuring to a level of subchondral bone in an area w/ a diameter greater than 1.5cm
Grade 4: Exposed subchondral bone
Outerbridge Arthroscopy
Grade 1: Subtle CMC joint space widening
Grade 2: Slight CMC joint narrowing, sclerosis, and cystic changes w/ osteophytes or loose bodies <2mm
Grade 3: Advanced CMC joint narrowing, sclerosis, & cystic changes w/ osteophytes or loose bodies >2mm
Grade 4: Arthritic changes in CMC as for stage 3 w/ scaphotrapezial arthritis
Eaton-Littler Thumb OA Classification
Dx of OA does NOT require radiological imagin: X-ray, MRI, or laboratory investigation
1) Symptoms do not always match visible findings on x-ray/MRI
2) Severe pain can reveal minimal changes on imaging
3) Minimal pain despite normal to severe structural joint changes is also possible
Summary
Interval deterioration, joint space narrowing shows early bone on bone appearance
Heterogenous reactive sclerosis
Tricompartmental osteophyte lipping
Mild thinning
Interval moderate deterioration in degenerative changes
Pertinent OA Descriptors
No osteochondral defect present
No chondrocalcinosis present
No local #
No subluxation
No avulsion
No acute or aggressive osseous lesion identified
Conditions Ruled Out
When conservative management fails
Pain is affecting all aspects of daily life, mobility, and ability to manage other health issues
No further benefit from modifiable factors: weight loss, exercise, pacing, activity modification, weight bearing aids, bracing, PT or adjunct therapy
Non-narcotic medication, and or injections are no longer provide adequate pain relief
Decision making tools:
- Oxford hip/knee score <31 (surgical referral)
Surgery Consideration
Grade 0: No radiographic features of OA
Grade 1: Doubtful joint space narrowing (JSN) & possible osteophytic lipping
Grade 2: Definite osteophytes possibleJSN on AP weight bearing radiograph
Grade 3: Multiple osteophytes, definite JSN, sclerosis, possible bone deformity
Grade 4: Large osteophytes, marked JSN, severe sclerosis & definite bone deformity
Kellgren Lawrence OA Classification System
