MSK
Shoulder
Normal measurements (Radiopaedia)
Normal measurements (Radiopaedia)
- AC joint space: 2-4 mm
- increased: AC joint separation, clavicular erosion/absorption
- decreased: degenerative joint disease
- acromiohumeral interval/space: 7-11 mm (or 8-12 mm 3)
- increased: subluxation, dislocation
- decreased: rotator cuff tear
- coracoclavicular distance/space: 11-13 mm
- increased: AC joint separation
- glenohumeral joint space: 3-6 mm
- increased: posterior dislocation
- decreased: degenerative joint disease, crystal arthropathies, inflammatory arthropathies, anterior or posterior dislocation
Knee
Osteoarthritis (Radiopaedia)
The hallmarks of knee osteoarthritis are the same for most other joints 6:
The initial study of any patient with suspicion of knee osteoarthritis should include a Rosenberg view, a PA radiograph with weight bearing and 45 degrees of flexion, which is more sensitive to detect joint space narrowing 5.
Osteoarthritis (Radiopaedia)
The hallmarks of knee osteoarthritis are the same for most other joints 6:
- joint space narrowing
- usually asymmetric, typically of the medial tibiofemoral compartment, and/or patellofemoral compartment 3
- <3 mm on weight-bearing knee radiographs is considered a finding of absolute joint space narrowing with a normal joint space >5 mm 7
- weight-bearing radiographs will demonstrate more joint space narrowing than non-weight-bearing radiographs, hence affecting the radiographic severity 7,8
- subchondral sclerosis
- marginal osteophytes
- subchondral cysts (geodes)
- altered shape of the femoral condyles and tibial plateau
The initial study of any patient with suspicion of knee osteoarthritis should include a Rosenberg view, a PA radiograph with weight bearing and 45 degrees of flexion, which is more sensitive to detect joint space narrowing 5.