Ortho

6/16/99

DJD

• Early—joint space narrowing
• Cartilage begins to break down
• Ligaments get slack
• Fluid dries up in joint
• Joint goes through phase of hypermobility and possibly unstability
• Trauma to cells may lead to cell death which starts the process
• See bone on the x-ray—space b/w bone has articular cartilage
• When decrease the space, problems w/cartilage
• Knee, hip are commonly affected
• Mainly weight bearing joints
• Problems also seen w/in the hands
• SC is not weight bearing and has a lot of motion—w/weight lifting, can become weight bearing which it is not designed to do
• Consequence of direct trauma

Changes seen w/DJD seen on x-ray (don't necessarily have to have all 4)

1. joint space narrowing
2. bony sclerosis (increase in density) (appears whiter, radiopacity) (Wolf's law)
3. osteophytosis (osteophyte formation)—happens around edges, bridging of joint, improve stability
4. subchondral cyst formation—pocket of decreased density—damage to subchondral bone

• DJD is the same as osteoarthritis (not truly inflammatory problem)
• Post traumatic affect (acute or micro/repetitive trauma)
• Chemical effects (dietary, changes w/in the body, acid/base, free radical)

Further erosion

• Cartilage affected
• Spreading out and forming osteophytes
• Occurs in 3D
• Change in density
• Leads to bone on bone
• Pereosteum is highly innervated to pain
• Bone is vascular which is pain sensitive
• Fibrosis of joint capsule
• Decrease function of the joint
• Hard end feel in ROM
• Irregular distribution of cartilage cells

Changes in the Hands

• Distal interphalangeal joints—knobby, hard change, fibrosis of ligaments, bony osteophytes
• Heperind's nodes
• Most commonly affected

• Thumb also affected --Carpal/metacarpal of first digit
• Some familial tendency
• Can have both RA and DJD
• Proximal Interphalangeal
• Bouchard's nodes

• Connective tissue adapts to the changes
• Hip joint
• Labrum—enlarges surface area
• Bony osteophytes enlarge surface area
• When stand up put a lot of pressure on the joint that is only bone on bone
• Minor sign when stand up—protect joint from loading

• Spine
• Facet joints and discs affected
• Lumbar
• Lateral can see IVF's
• Hypertrophy in response
• Takes up part of posterior dimension making it smaller
• Petagogenic stenosis—narrowing of canal and IVF (congenitally short pedicle)
• Not much room left nerve root to exit
• Disc herniation narrows IVF anteriorly
• Enlargement of posterior body narrowing the canals

• Hyperextension injury
• Oblique to see IVF
• Hour glass shape of IVF