Der Einfluss der Femur- und Tibiakomponentenrotation auf das patellofemorale Versagen beim k�nstlichen Kniegelenkersatz

Abstract

Patellofemoral complications are among the most common causes for revision surgery in total knee arthroplasty. So far no quantitative assessment has been made of the femoral and tibial malalignment or the positioning of the patellar component and the type of patellofemoral complication or failure. In particular, no comparative studies are available that include patients with and without patellofemoral failure in respect to the above-mentioned parameters when implant material, implant design, and fixation technique were identical. Between 1985 and 1992, 171 MG I total knee arthroplasties were performed. Since 1999, 20% of all the implanted MG I knee arthroplasties (all with metal-backed patellar component) had to be revised. Of those 34 patients, 18 were pair matched with 18 control patients based on the criteria of sex, body mass index, and age. The only difference in the control group was that they did not suffer any malfunction of the patellofemoral mechanism. To assess the patella component localization, conventional AP radiographs, patellar merchant view radiographs in 30 degrees, and CT scans were performed. This study has demonstrated a significant difference for the thickness of the patellar component and a trend regarding the rotational malalignment of the tibial component. Potential causes for the malrotation and guidelines to prevent rotational malalignment are discussed.

Clinical value of SPECT/CT for evaluation of patients with painful knees after total knee arthroplasty- a new dimension of diagnostics?

“…Malposition of prosthetic components is one of the most important factors leading to failure of TKA [15,24-28]. Chowdhury et al [29] showed that external rotation of the tibial component of 15° caused posteromedial and anterolateral impingement.…”

Is it possible to re-establish pre-operative patellar kinematics using a ligament-balanced technique in total knee arthroplasty? A cadaveric investigation

“…In a prospective randomised study, Pagnano et al [24] showed that a rotating platform knee design did not decrease the prevalence of lateral retinacular release, patellar tilt or subluxation in comparison to a posterior-stabilised, fixedbearing knee [23]. A few radiological studies ascribe altered patellofemoral kinematics and the appearance of anterior knee pain to combined femoral and tibial component internal rotation [2,5]. In our study different combinations of femoral and tibial component alignment could not show a significant effect of tibial component rotation or combined component rotation on patellofemoral kinematics.…”

“…Several authors emphasise that the appearance of patellar maltracking is caused by rotational malalignment of the femoral and tibial components [4][5][6][7][8][9][10][11]. Furthermore, especially internal rotation of the femoral component seems to contribute to altered patellofemoral kinematics and consequently the occurrence of anterior knee pain [2,12,13]. In a radiological study, Berger et al [12] state that combined internal rotation of the femoral and tibial components correlates directly with the severity of postoperative patellofemoral complications.…”

“…However, anterior knee pain is reported in up to 20 % as a major postoperative complication, whereas maltracking of the patella is considered as the main reason in some recent investigations [1][2][3]. Several authors emphasise that the appearance of patellar maltracking is caused by rotational malalignment of the femoral and tibial components [4][5][6][7][8][9][10][11].…”

Patellanavigation bei computerassistierter Knie-TEP-Implantation

“…Als eine der Hauptursachen wird ein unphysiologischer Patellalauf mit konsekutiv pathologischer Druckerhöhung im Bereich des Patellofemoralgelenkes genannt [9,12].…”