TY - JOUR
T1 - Varus tibial joint line obliquity
T2 - A potential cause of femoral component malrotation
AU - Pagnano, Mark W.
AU - Hanssen, Arlen D.
PY - 2001
Y1 - 2001
N2 - In 60 consecutive total knee arthroplasties done in 52 patients with primary osteoarthritis and varus or neutral tibiofemoral alignment, the posterior condylar angle was calculated intraoperatively and averaged 3.98° (range, 0°-9°). Eighteen knees had a posterior condylar angle value less than 3° whereas 27 knees had a posterior condylar angle value of 5° or greater. Final rotational alignment of the femoral component was set parallel to the transepicondylar axis. Only one of these 60 knees required a lateral retinacular release for proper patellar tracking during the knee arthroplasty. When compared with three previously defined angles measured on the radiographs taken preoperatively, only the tibial plateau-tibial shaft angle values were correlated significantly with the value of the posterior condylar angle. As the tibial varus joint line obliquity increased, there was a distinct tendency for the transepicondylar axis to be rotated more externally relative to the posterior condylar axis. This variance suggests that the use of the posterior condylar axis as a rotational reference is inappropriate in many knees with arthritis with varus or neutral tibiofemoral alignment. In particular, varus tibial joint line obliquity of more than 4° increases the likelihood of femoral component malrotation when the posterior femoral condyles are used to reference femoral component rotation.
AB - In 60 consecutive total knee arthroplasties done in 52 patients with primary osteoarthritis and varus or neutral tibiofemoral alignment, the posterior condylar angle was calculated intraoperatively and averaged 3.98° (range, 0°-9°). Eighteen knees had a posterior condylar angle value less than 3° whereas 27 knees had a posterior condylar angle value of 5° or greater. Final rotational alignment of the femoral component was set parallel to the transepicondylar axis. Only one of these 60 knees required a lateral retinacular release for proper patellar tracking during the knee arthroplasty. When compared with three previously defined angles measured on the radiographs taken preoperatively, only the tibial plateau-tibial shaft angle values were correlated significantly with the value of the posterior condylar angle. As the tibial varus joint line obliquity increased, there was a distinct tendency for the transepicondylar axis to be rotated more externally relative to the posterior condylar axis. This variance suggests that the use of the posterior condylar axis as a rotational reference is inappropriate in many knees with arthritis with varus or neutral tibiofemoral alignment. In particular, varus tibial joint line obliquity of more than 4° increases the likelihood of femoral component malrotation when the posterior femoral condyles are used to reference femoral component rotation.
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U2 - 10.1097/00003086-200111000-00009
DO - 10.1097/00003086-200111000-00009
M3 - Article
C2 - 11716427
AN - SCOPUS:0035163363
VL - 392
SP - 68
EP - 74
JO - Clinical Orthopaedics and Related Research
JF - Clinical Orthopaedics and Related Research
SN - 0009-921X
ER -