Abstract
Proper femoral component alignment in the axial plane during total knee arthroplasty
(TKA) depends on accurate bone cuts and soft tissue balancing. Two methods that are
used to achieve this are “measured resection” and “gap balancing.” However, a controversy
exists as to which method is more accurate and leads to better outcomes. Therefore,
the purpose of this study was to evaluate: (1) implant survivorship, (2) patient outcomes,
(3) complications, and (4) radiographic analysis comparing patients who underwent
TKA with either gap-balancing or measured resection techniques. A total of 214 consecutive
patients (221 knees) underwent primary TKA by a single surgeon between 2011 and 2012.
Component alignment was achieved by using measured resection in 116 knees and gap
balancing was used in 105 knees. The patients had a mean age of 66 years (range, 44–86
years) and a mean body mass index of 32 kg/m2 (range, 22–52 kg/m2). Patient range-of-motion (ROM) and Knee Society (KS) function and pain scores, and
radiographic assessment, were assessed preoperatively and postoperatively at ∼6 weeks,
3 months, 1 year, and then annually. The mean follow-up time was 3 years. A Kaplan–Meier's
analysis was performed to calculate the survivorship. The aseptic survivorship was
98% in both the measured resection and gap-balancing groups. The mean ROM was not
significantly different between the measured resection and gap-balancing groups (123
vs. 123 degrees, p = 0.990). There were no significant differences between the two groups in terms of
the KS function scores (86 vs. 85 points, p = 0.829) or the KS pain scores (93 vs. 92 points, p = 0.425). Otherwise, the radiographic evaluation at latest follow-up did not demonstrate
any evidence of progressive radiolucencies or loosening, of any prosthesis. The results
of this study found that at a mean follow-up of 3 years, both the measured resection
and gap-balancing techniques achieved excellent survivorship and postoperative outcomes.
This demonstrates that both methods can be used to achieve accurate femoral component
alignment with similar short-term outcomes.
Keywords
gap balancing - total knee arthroplasty - component alignment - measured resection
