Radiographic Changes in Nonoperative Contralateral Knee After Unilateral Total Knee Arthroplasty

J Arthroplasty. 2018 Jul;33(7S):S116-S120. doi: 10.1016/j.arth.2018.02.018. Epub 2018 Feb 15.

Abstract

Background: Some patients perceive symptomatic improvement in the contralateral knee after unilateral total knee arthroplasty (TKA). This so-called "splinting effect" has been observed but has not been radiographically evaluated.

Methods: A retrospective review of patients with bilateral knee osteoarthritis treated with unilateral TKA was performed. Patients were subcategorized into 2 groups based on whether contralateral TKA was performed within the 2-year period. Contralateral radiographic measurements were performed.

Results: Forty-four of 203 patients had contralateral TKA performed within 2 years. Preoperative parameters were significantly worse in the bilateral group. By 6 weeks postoperatively, mechanical axis plumbline improved approximately 1°, with more change in those patients with preoperative varus alignment. Larger delta changes were also present in bilateral group preoperative to 1-year radiographs for tibiofemoral angle and joint space widening.

Conclusion: In patients with bilateral knee osteoarthritis who undergo unilateral TKA, a splinting effect may be present and measurable radiographically with improvement of contralateral mechanical axis plumbline. Further research is necessary to determine whether this improvement may delay contralateral TKA implantation.

Keywords: bilateral osteoarthritis; osteoarthritis; primary total knee arthroplasty; radiographic review; splinting.

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee*
  • Body Mass Index
  • Female
  • Humans
  • Knee / diagnostic imaging*
  • Knee / surgery
  • Knee Joint / diagnostic imaging*
  • Knee Joint / surgery
  • Male
  • Middle Aged
  • Osteoarthritis, Knee / diagnostic imaging*
  • Osteoarthritis, Knee / surgery*
  • Postoperative Period
  • Radiography
  • Range of Motion, Articular
  • Retrospective Studies