Table 3.
Results of the MARS MRI evaluations according to the Anderson classification.
| Articulation | MoM THA/RHA | MoP THA |
|---|---|---|
| Total number of hips | 71 | 63 |
| Total number of pseudotumours | 22 | 25 |
| Grade A “normal or acceptable” | 49 | 38 |
| Grade B “infection” | 0 | 0 |
| Grade C1 “mild MoM disease” | 12 | 14 |
| Male/female | 8/4 | 5/9 |
| Fluid/mixed or solid | 11/1 | 11/2 |
| Location (PL/ILB/AL) | 11/0/1 | 6/8/0 |
| Grade C2 “moderate MoM disease” | 9 | 10 |
| Male/female | 8/1 | 7/3 |
| Fluid/mixed or solid | 8/1 | 5/5 |
| Location (PL/ILB/AL) | 7/0/2 | 5/5/0 |
| Grade C3 “severe MoM disease” | 1 | 1 |
| Male/female | 1/0 | 1/0 |
| Fluid/mixed or solid | 1/0 | 0/1 |
| Location (PL/ILB/AL) | 0/0/1 | 0/1/0 |
In addition to the Anderson classification, pseudotumour appearance (fluid or mixed/solid) and location were recorded.
Location: The anatomical location of the pseudotumour: AL = anterolateral of the greater trochanter; PL = posterolateral of the greater trochanter; ILB = located at the iliopsoas bursa.
MARS = Metal artefact reduction sequence; MoM = metal-on-metal; MoP = metal-on-polyethylene; MRI = magnetic resonance imaging; RHA = resurfacing hip arthroplasty; THA = total hip arthroplasty.