Figure 3. Ultrasound of an infected hip. (a) There is a large multilocular collection with an echogenic component (arrows). (b) The collection lies just deep to the scar but is seen to extend down to the neck of the femoral component which appears as a well defined echogenic line (arrow).
Figure 4. Loose cemented prostheses. Wide extensive lucency at the bone/cement interface is seen at (a) a femoral and (b) an acetabular component (arrows).
Figure 5. Migration of the prosthesis. (a) Femoral component showing subsidence with wide lucency at the prosthesis cement interface proximally and laterally (arrow). (b) Acetabular migration. The cup and cement has migrated medially into the pelvis.
Figure 8. Loose uncemented femoral component. There is excessive lucency seen around the tip of the uncemented prosthesis indicating loosening (arrows).
Figure 9. Uncemented femoral component. Cortical thickening (arrow) and pedestal formation (arrowhead) at the tip of an uncemented femoral prosthesis. Although associated with loosening these signs can be seen in asymptomatic hips.
Figure 10. Loose uncemented acetabular component. This threaded screw design had a high failure rate. There is extensive lucency around the component (arrows).
Figure 11. Wear of polyethylene liner. There is marked loss of the liner superiorly (arrow). The resulting microscopic fragments may stimulate granuloma formation.
Figure 12. Granuloma formation. (a) Focal endosteal scalloping at the distal end of the prosthesis indicating histiocytic granuloma formation (arrow) and (b) more extensive bony destruction distal to the tip of the femoral prosthesis (arrows).
Figure 15. MRI of periprosthetic abscess. T2 weighted axial image showing a high signal collection adjacent to the femur (arrows). Note that there is only minimal artefact from the prosthesis.
Figure 16. Bone scan showing diffuse uptake around the femoral prosthesis. Although this pattern may suggest infection it is also seen in aseptic loosening.
Figure 17. Bone scan in a patient with a painful uncemented total hip replacement. (a) There is focal uptake at the tip of the uncemented prosthesis. (b) Plain film shows a lucency and sclerotic reactive line adjacent to the tip (arrow).
Figure 19. Failed hemiarthroplasty. The head has migrated medially into the pelvis (arrow). There is also lucency at the cement–bone interface (arrow heads).
Figure 20. Revision total hip replacement. There is a wide lucency around the femoral component (arrows) which may be a normal appearance following revision.
Figure 21. Heterotopic ossification following total hip replacement. There is extensive soft tissue ossification laterally which has fused the hip joint (arrow).
Figure 23. Aseptic loosening of a total knee replacement. (a) Normal immediate post-operative film. (b) 3 years following surgery there is a wide radiolucency under the tibial plate and around the stem at the bone/cement and prosthesis/cement interfaces (arrows).
Figure 25. Unicompartmental knee replacement. There is lucency at the bone/cement interface of the tibial component which is within normal limits for this particular design.
Figure 26. Infected unicompartmental knee replacement. (a) The immediate post-operative pictures show normal replacement. (b) 1 month later there is bone destruction under the tibial plate (arrows) and (c) loss of lateral joint space.
Figure 27. Normal post-operative appearance of a total shoulder replacement. The superior end of the humeral component lies above the superior tip of the greater tuberosity (dotted lines).
Figure 29. Loose total shoulder replacement. There is subsidence with the head positioned below the superior tip of greater tuberosity (dotted lines). There is a wide lucency seen around the prosthesis (arrows).
Figure 31. Loose glenoid component of a total shoulder replacement. (a) Immediate post-operative film showing normal cemented component without lucency. (b) Film 18 months later shows marked lucency around the component indicating loosening.
Figure 32. Loose glenoid component of a total shoulder replacement. The humeral head has migrated superiorly due to rotator cuff tear. The glenoid is loose and tilted due to the eccentric contact with the humeral component. Arrows demonstrate direction of rotation.
Figure 34. Loose Scandinavian Total Ankle Replacement (STAR). Frontal radiograph showing (a) the normal post-operative appearances and (b) marked lucency around the tibial component (arrows) indicating loosening.
