Tibial Plateau Coverage in UKA: A Comparison of Patient Specific and Off-The-Shelf Implants

• Published in: The Journal of arthroplasty 2014-09, Vol.29 (9), p.1694-1698
• Main Authors: Carpenter, Dylan P., MD, Holmberg, Rebecca R., ME, MS, Quartulli, Marc J., BS, Barnes, C. Lowry, MD
• Format: Article
• Language: English
• Subjects: Arthroplasty, Replacement, Knee - instrumentation; Arthroplasty, Replacement, Knee - methods; Computer Simulation; ConforMIS; CT-based imaging; Humans; Knee Joint - diagnostic imaging; Knee Joint - surgery; Knee Prosthesis; Orthopedics; overhang; patient specific implants; Prosthesis Design; Prosthesis Fitting; Tibia - diagnostic imaging; Tibia - surgery; tibial component; Tomography, X-Ray Computed; unicompartmental knee arthroplasty
• ISSN: 0883-5403; 1532-8406
• DOI: 10.1016/j.arth.2014.03.026

Abstract Poor tibial component fit can lead to issues including pain, loosening and subsidence. Morphometric data, from 30 patients undergoing UKA were utilized; comparing size, match and fit between patient-specific and off-the-shelf implants. CT images were prospectively obtained and implants modeled in CAD, utilizing sizing templates with off-the-shelf and CAD designs with patient-specific implants. Virtual surgery was performed, maximizing tibial plateau coverage while minimizing implant overhang. Each implant evaluated to examine tibial fit. Patient-specific implants provided significantly greater cortical rim surface area coverage versus off-the-shelf implants: 77% v. 43% medially and 60% v. 37% laterally. Significantly less cortical rim overhang and undercoverage were observed with patient-specific implants. Patient-specific implants provide superior cortical bone coverage and fit while minimizing overhang and undercoverage seen in off-the-shelf implants.