Obligatory medical device diagnostics
- Radiographs of the affected joint [radiographic signs of arthritic joint remodeling: osteophytes, narrowed joint space, increased subchondral sclerosis, and deformity; see below Kellgren and Lawrence score].
Optional medical device diagnostics – depending on the results of the history, physical examination, laboratory diagnostics and obligatory medical device diagnostics – for differential diagnostic clarification.
- Computed tomography (CT; sectional imaging procedure (X-ray images from different directions with computer-based evaluation), particularly well suited for the depiction of bony injuries) of the affected joint – findings correspond to the X-ray images, but earlier depiction possible; better depiction of complex structures.
- Magnetic resonance imaging (MRI; computer-assisted cross-sectional imaging method (using magnetic fields, that is, without X-rays); particularly well suited to the representation of soft tissue injuries) of the affected joint.
- Arthrosonography (ultrasound examination of joints) – this also reveals joint effusions, soft tissue processes and fluid accumulation in the joint. This examination is also performed before a puncture or injection. The joint effusions or fluid accumulations can then be treated with medication – if necessary also by puncture. Does not count among the methods of choice for osteoarthritis!
Nativradiological classification of osteoarthritis according to the Kellgren and Lawrence score
| Osteophytes | Joint space | Sclerosis | Deformation | Points |
| none or questionable | none or questionable narrowed | none | none | 0 |
| unique | unique | light | light | 1 |
| large | advanced | light with cysts | distinctly | 2 |
| cancelled | strong with cyst formation | 3 |
Interpretation
According to the Kellgren-Lawrence score, the radiological expression of osteoarthritis is divided into five grades:
- Grade 0 = 0 points
- Grade 1 = 1-2 points
- Grade 2 = 3-4 points
- Grade 3 = 5-9 points
- Grade 4 = 10 points
Grade 1: Minor subchondral sclerosis, no joint space narrowing or osteophytesGrade 2: Minor joint space narrowing and incipient osteophyte formation, indicated joint surface irregularitiesGrade 3: Marked osteophyte formation, marked joint surface irregularitiesGrade 4: Marked joint space narrowing to complete destruction, deformity/necrosis of joint partners.
