Discussion to Chap. 12: Chronic Pain Due to Metallosis After TKR

Fig. 1

Radiographs (anterior, lateral radiographs, skyline view) of the right knee showing a femoral and tibial cemented TKR (Emotion, Aesculap, B.Braun Medical AG, Sempach, Switzerland). A pseudo-patella baja was found, which was due to joint line elevation

Fig. 2

Radiographs (anteroposterior, lateral) of the right knee after PFJ. On the skyline view, obvious patella maltracking and a conflict of the metal-backed patella with the metallic trochlea were noted

These findings were confirmed by the surgical report at TKR, in which it was stated that the entire intra-articular joint space appeared black due to metal wear. On the removed implant, deep fissures were found in the trochlear and patellar component.

Questions

What is your differential diagnosis now?

What are your next steps in diagnostics?

SPECT/CT was performed to accurately determine TKR component position and investigate loosening or infection (Figs. 3 and 4). SPECT/CT showed no signs of loosening or infection. Using a customized software (Orthoexpert v1.15©, OrthoImagingSolutions Ltd., London, UK), 3D-CT revealed an overall correctly positioned TKR (femoral component, 2° internally rotated, 6° flexed, and 0° varus; tibial component, 6° external rotated, 5° posterior, and 1° valgus).