Radiographic Changes in Nonoperative Contralateral Knee After Unilateral Total Knee Arthroplasty

• Published in: The Journal of arthroplasty 2018-07, Vol.33 (7), p.S116-S120
• Main Authors: Parisi, Thomas J., Levy, Daniel L., Dennis, Douglas A., Harscher, Cole A., Kim, Raymond H., Jennings, Jason M.
• Format: Article
• Language: English
• Subjects: bilateral osteoarthritis; osteoarthritis; primary total knee arthroplasty; radiographic review; splinting
• ISSN: 0883-5403; 1532-8406
• DOI: 10.1016/j.arth.2018.02.018

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. 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. 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. 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.