Patient-Specific Total Knees Demonstrate a Higher Manipulation Rate Compared to Off-the-Shelf Implants

Patient-specific total knee replacements have been designed in hopes of providing better functional outcomes compared to off-the-shelf implants in primary total knee arthroplasty (TKA). We prospectively evaluated manipulation rates and clinical outcomes of 21 patient-specific TKAs matched with 42 posterior-stabilized and 11 cruciate-retaining off-the-shelf TKAs. Postoperatively, the patient-specific group had a range of motion significantly less than both control groups (P < 0.01). Six of the 21 (28.6%) patient-specific TKAs required manipulation to improve range of motion. No manipulations were reported in either control groups. At minimum two-year follow-up the patient-specific TKAs had similar motion, but worse satisfaction and KSS pain scores. Radiographic analysis provided no insight to the cause of stiffness. Early manipulation is recommended for stiffness with patient-specific TKA. (C) 2016 Elsevier Inc. All rights reserved.