Postoperative Knee

Postoperative Knee 1

For post traumatic fixation, learn the terms used to describe general hardware types (plate and screw fixation, intramedullary nail). 

Report on the following during immediate post operative and follow up radiographs: 

  • Hardware alignment
  • Changes in existing fracture alignment
  • Newly identified fracture extent 
  • Signs of hardware loosening (i.e. adjacent lucency, displacement, backout) 
  • Hardware failure
  • Post traumatic and healing complications such avascular necrosis and absence of healing change. 
Postoperative Knee 2

For anterior cruciate ligament reconstruction, learn the common hardware used (interference screws, endobutton) and optimal positioning of tibial and femoral tunnels relative to native anatomy. 

Observe the following during immediate post operative and follow up radiographs: 

  • Position of ACL graft
    • Tibial tunnel: parallel or more steep than Blumensaat line and posterior to intersection of Blumensaat and tibia.
    • Inferior portion of femoral tunnel is near the intersection of Blumensaat line and a line drawn along posterior femoral diaphysis
  • Tibial or femoral tunnel widening (>2 mm from immediate post reconstruction) 
  • Migration of endobutton or interference screws
     
Postoperative Knee 3

Arrows highlight the presence of lucency along the tibial component concerning for loosening.

Learn the common knee arthroplasty prosthesis types (total knee, unicompartmental, constrained) and components (femoral, tibial, patellofemoral, polyethylene insert)
Report on the following during immediate post operative and follow up radiographs: 

  • Prosthesis alignment 
  • Periprosthetic fractures
  • Signs of loosening: may be mechanical or secondary to infection (periprosthetic lucency, change in position, or subsidence) 
  • Prosthesis component failure or signs of polyethylene wear
  • Signs of infection and/or particle disease:  
    • Cystic changes, erosion, and effusion
Postoperative Knee 4

Example report negative for postoperative complication
FINDINGS:

  • Postsurgical changes of total knee arthroplasty with unchanged alignment of intact appearing prosthesis components. No periprosthetic fracture or lucency. 

IMPRESSION: