Lecture 6: Osteoarthritis, Erosive OA and Disc Flashcards
OA radiographic features (8)
Eight universal radiologic features
- Asymmetric distribution
- Non-uniform loss of joint space
- Osteophytes = traction and claw
- Traction: Occur in early phase of disc degeneration, typically originate about 2mm from anterior vertebral margin.
- Claw: Broader base, climb vertically in a curvilinear fashion. Derived from reactive spur once shear forces have reduced to more compressive loads.
- NOTE: Should not be confused with the thin, bridging vertical syndesmophytes
- Subchondral sclerosis (eburnation) (due to trabecular thickening in areas of mechanicals tress)
- Subchondral cysts (geodes): synovial fluid intrudes into subchondral bone.
- Intra-articular loose bodies (joint mice): cartilage fragmentation and subchondral bone flaking or synovial metaplasia with debris
- Articular deformity: remodeling of articular surfaces
- Joint subluxation: instability
- Vacuum phenomenon: Note vacuum cleft: denotes degeneration in spinal DJD but not in other joints. Represents collections of nitrogen gas in nuclear and annular fissures and presents as area of linear radiolucency. Thought to originate from adjacent extracellular fluid. In movements of the spine that produce a lowered pressure in the disc, such as in extension.
What is this? What condition is is commonly seen in?
Claw osteophytes
Seen in OA
What is the condition in image a? how does it differ from the appearance of the joint in condition b and what is condition b?
a = RA
b = OA
Uniform joint deformity and joint space loss in RA compared to asymmetrical joint space loss in OA
What is the arrow pointing to? What is this condition?
Intra-articular loose bodies (joint mice): cartilage fragmentation and subchondral bone flaking or synovial metaplasia with debris
Condition is OA
What is the arrow pointing to? What condition is this?
Subchondral bone cyst
OA
What are the arrows pointing to? What is this indicative of? What conditions it this?
Vacuum phenomenon: denotes degeneration in spinal DJD but not in other joints. Represents collections of nitrogen gas in nuclear and annular fissures and presents as area of linear radiolucency.
OA
OA in the Cx
C1-2 less common, C7 most common.
- Von Lushka joints often involved.
- Neurocentral impingement may occur thru Osteophytes
- IVD narrowing, endplate sclerosis, osteophytes, sometimes vacuum cleft
- Dec Cx. Lordosis
- Intercalary bone may appear, calcification of anterior annulus.
OA in the Tx
- Affected at IVD, apophyseal jnts, costovertebral and costotransverse
- Apophyseal involvement in lower Tx. Spine and pain radiating from this may refer into lumbars (Maignes syndrome).
OA in the Lx
- Apophyseal involvement most common at L4/5.
- Can lead to anterolisthesis
- Most diagnostic film for facet visualization is oblique.
- IVD degeneration most commonly at L4 and 5.
- Synovial cysts (juxta-articular), usually at L4 and L5 facets.
- Anterolisthesis: Caused by reduced disc height and facet remodeling from a more vertical to a more horizontal plane.
- Gives broadened pedicle/ facet angle
- May lead to lateral and or central canal stenosis.
OA in the SIJ
- Visible changes in synovial portion (lower two thirds) of jnt.
- Decreased joint space.
- Osteophytes form at superior or inferior margin of synovial joint area.
- Occasionally iliolumbar ligs ossify.
- Vacuum cleft here is a normal physiologic finding, not a DJD sign.
OA in the Hip
- See decreased joint space most commonly: Decreased superiorly, widened medially, femoral head migrates anterosuperiorly.
- Osteophytes usually form at superolateral acetabular rim or at femoral head.
- Commonly large subchondral cysts appear in superior femoral head or at the supra- acetabular margin (DDX. Avascular necrosis, neoplasm).
- Sclerosis appears in same appears.
- Buttressing occurs: stress reaction, thickens inferomedial femoral head and neck.
OA in the Knee
- Femur-tibial:
- Joint mice loose bodies, often calcified in concentric laminations.
- May see chondrocalcinosis in decreased joint space.
- Patellofemoral:
- Osteophytes can develop form four patellar poles.
- Irregular anterior patellar surface (spiculated: “tooth sign”).
- Chondromalacia patellae:
- Most common in adolescents.
- Idiopathic pain, crepitus, locking, stiffness and swelling
- Best visualization M<ri></ri>
Test for pain with Patellofemoral compression, knee slightly flexed.
OA in the Foot and Ankle
- Tarsals rarely involved, Most common site 1st MTP.
- Osteophytes, remodeling, valgus deformity.
- Produces characteristic bunion.
OA in the wrist and hand
- Most commonly secondary involvement. Primary involvement in PIPs, DIPs and 1st MC trapezial jnts.
- Clinically visible phalangeal joint osseous nodules
- a) DIP joints: Heberden’s nodes
- b) PIP joints: Bouchard’s nodes
- DIP misalignment common (subluxation).
Radiology of erosive arthritis
- Invariably spares ulnar carpals.
- Resembles DJD except it features:
- Periostitis
- Gull wing patterns
- Sometimes bony ankylosis results
How would you describe this type of joint erosion? what condition would you see it in?
Gullwing deformity
Erosive arthritis
What are the different coloured zones?
What is this?
Tarlovs cyst
