Abstract
Alignment after total knee arthroplasty (TKA) plays an important role with respect
to patient satisfaction and implant survivorship. In patients undergoing ipsilateral
TKA with prior total hip arthroplasty (THA), the femoral intramedullary (IM) guide
cannot be fully inserted into the femoral canal because of the prior THA. The purpose
of this study was to determine the effect of femoral component alignment using a shorter
IM guide during TKA in patients with an ipsilateral THA. We identified 42 patients
undergoing ipsilateral TKA with the use of a short IM guide in the setting of a prior
THA. A matched cohort group was identified from our total joint registry that included
42 patients who underwent primary TKA. The surgical goal was to achieve 5 degrees
of valgus on the femoral side and 0 degree on the tibial side with an overall postoperative
tibial–femoral angle of 5 degrees of valgus. Patients were evaluated clinically using
Knee Society pain scores (KSSs), function scores, and with radiography. Both the tibial–femoral
limb alignment and the femoral component alignment were compared using Student's t-test. There were no significant differences between the two groups with respect to
sex, age, body mass index (BMI), pre- and postoperative KSSs. There was a statistically
significant difference between the two groups with respect to radiographic tibial–femoral
limb alignment, 4.33 degrees of valgus in the short stem THA–TKA group versus 5.4
degrees of valgus in the TKA group (p < 0.04); however, this difference did not correlate to a difference in postoperative
outcomes. An adequate tibial–femoral component alignment was achieved in patients
undergoing ipsilateral TKA with prior THA using a shortened IM femoral guide.
Keywords
TKA - THA - alignment - short femoral guide - knee
