Total knee arthroplasty (TKA) is an excellent treatment option for patients with end-stage osteoarthritis; however, a significant number of patients are not satisfied postoperatively. Much of this dissatisfaction comes from persistent pain and difficulty regaining range of motion. We retrospectively reviewed 200 patients who underwent a primary unilateral TKA by a single surgeon from 2013 to 2014 at a single institution. All surgery was performed with computer-navigated guides to minimize surgical alignment error. In total, 100 patients underwent a TKA using a standard posterior stabilized (PS) prosthesis and the other 100 patients underwent TKA with an asymmetric bicruciate stabilized (BCS) prosthesis. There was no significant difference between groups in preoperative range of motion (P=0.07). Postoperatively, in the BCS group, average flexion was 119 degrees (range, 95 to 125 degrees) and in the standard PS group average flexion was 96 degrees (range, 85 to 116 degrees). There was a significant and clinically relevant improvement in flexion at 6 weeks in patients who underwent a TKA with a BCS implant (P<0.0001). There was no significant difference in preoperative and postoperative Knee Society Scores between groups (P=0.30) at 6 weeks postoperatively. At 1-year follow-up, patients in the BCS group had significantly better Knee Society Scores compared with patients in the standard PS prosthesis (P<0.001). Our study suggests that an implant design that more closely replicates the normal anatomic joint line and knee kinematic patterns may help reduce some of the dissatisfaction following TKA.
*Mike O’Callaghan Medical Center, Las Vegas, NV
†Hospital for Special Surgery, New York, NY
D.J.M. is a consultant for Smith and Nephew. The other authors declare that they have nothing to disclose.
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