Fig. 1

Map of approximate tissue collection locations, shown with prosthetic implant illustrated. Seven tissue samples were taken for each patient; (1) the solid circle represents the medial femoral condyle (denoted as F); (2) the dashed circle represents the medial tibial plateau (denoted as T); (3) the solid square represents the lateral gutter (denoted as LG); (4) the dashed square represents the posterior capsule (denoted as PC). Locations 1–4 were taken for the ATL layer, and locations 1–3 were taken for the RTL layer; separation between ATL (closer to joint) and RTL (further from joint) was approximately 5–10 mm, depending on individual patient