Table 1 Morphologic comparison of synovial structure, cellularity, macrophage content, and bone marrow involvement between the Dual-Modular Neck and the Metal-on-Metal (MoM) total hip arthroplasty (THA) groups
Morphologic characteristic | Dual-Modular Neck THA (N = 55 hips) | MoM THA (N = 18 hips) | P value |
|---|---|---|---|
Synovial structure | Cases (%) | Cases (%) | Â |
Synovial layer loss | 96.4 | 100.0 | Â |
Synovial layer hyperplasia | 78.2 | 77.8 | Â |
Cell exfoliation | 87.3 | 94.4 | Â |
Necrosis | 65.5 | 61.1 | Â |
Vascular wall changes | 18.2 | 16.7 | Â |
High endothelial cell venules | 14.5 | 16.7 | Â |
Granulomas | 18.2 | 11.1 | 0.482 |
Cellularity | Â | Â | Â |
Macrophages | Â | Â | 0.016* |
  Grade 1 | 16.4 | 5.6 |  |
  Grade 2 | 30.9 | 5.6 |  |
  Grade 3 | 50.9 | 88.9 |  |
Lymphocytes | Â | Â | 0.066# |
  Grade 1 | 1.8 | 16.7 |  |
  Grade 2 | 9.1 | 5.6 |  |
  Grade 3 | 52.7 | 61.1 |  |
  Grade 4 | 34.5 | 16.7 |  |
Stromal Cells | Â | Â | 0.593 |
  Grade 1 | 27.3 | 38.9 |  |
  Grade 2 | 50.9 | 44.4 |  |
  Grade 3 | 16.4 | 11.1 |  |
Neutrophils | 10.9 | 11.1 | Â |
Plasma cells sparse | 32.7 | 38.9 | Â |
Plasma cells numerous | 20.0 | 22.2 | Â |
Eosinophils | 32.7 | 33.3 | Â |
Macrophage content | Â | Â | Â |
Polyethylene particles | 1.8 | 0.0 | Â |
Metallic particles | 1.8 | 33.3 | <0.005* |
Corrosion products | 100 | 100 | Â |
  Intracellular distribution | Sparse | Diffuse |  |
  Intracellular morphology | Irregular | Globular + Irregular |  |
Extracellular corrosion aggregates | 72.7 | 66.7 | 0.662 |
Bone/bone marrow | Â | Â | Â |
Necrosis | 47.1 | 28.6 | Â |
Macrophage infiltration | 47.1 | 100.0 | Â |
Benign lymphocytic aggregates | 35.3 | 28.6 | Â |
Germinal centers | 17.6 | 0.0 | Â |