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DOS Kongressen 2016 ·
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Can easily identifiable radiographic features predict
component malpositioning in measured resection Total
Knee Arthroplasty?
Roshan Latifi, Kirill Gromov, Thomas Kallemose, Henrik Husted, Anders Troelsen
Orthopaedics, Hvidovre Hospital; Orthopaedics, Hvidovre Hospital
Background:
Malalignment of the primary Total Knee Arthroplasty (TKA)
components has been shown to be a risk factor for implants failure and infe-
rior patient reported outcomes. We hypothesised that surgeons are reluctant
to deviate from the preoperative anatomical state of the knee and therefore
easily identifiable preoperative radiographic features can predict postoperative
implant positioning
Purpose / Aim of Study:
To investigate whether preoperative features can
predict the overall alignment of the knee, tibia and femoral components
Materials and Methods:
We identified 772 consecutive and unselected pa-
tients undergoing primary unilateral or bilateral total knee arthroplasty between
March 2013 and December 2014. All surgeries were performed using meas-
ured resection technique. Pre- and postoperative radiological parameters as
well as BMI, age, sex and implant types were registered. Standard safe zones for
postoperative tibia and femoral alignment were determined. Logistic regression
analysis was performed to identify independent preoperative risk factors for
each postoperative misalignment
Findings / Results:
K-L grade 4 compared to 2 was an independent
risk factor for placement of the tibia component outside the coronal safe
zone(OR:1.55,CI:1.05-2.29,P:0.029). Male gender was an independent
risk factor for placement of the femoral component outside the coronal safe
zone(OR:0.68,CI: 0.50-0.93,P:0.018). Preoperative femoral coronal align-
ment outside the safe zone was an independent risk factor of postoperative
femoral component placement outside of the safe zone(OR: 1.65,CI:1.18-
2.32,P:0.004)
Conclusions:
Surgeons tend to place the tibia component outside the safe zone
more often in patients with severe osteoarthritis. This could be explained by al-
tered bone morphology and inability to make sufficient lateral resection in varus
knees with medial osteoarthritis
No conflicts of interest reported
48.