naa a22 4500 510760619 CHVBK 20180411083138.0 cr unu---uuuuu 180411e20130701xx s 000 0 eng 10.1007/s11420-013-9340-1 doi (NATIONALLICENCE)springer-10.1007/s11420-013-9340-1 Reduction in Bone Volume Resection with a Newer Posterior Stabilized Total Knee Arthroplasty Design [Elektronische Daten] [Luke Pugh, Allison Ruel, Joseph Lipman, Timothy Wright, Mark Gessell, Geoffrey Westrich] Background: Posterior stabilized total knee arthroplasty requires an intercondylar notch to accommodate the cam housing that articulates with the tibial post to create femoral rollback required for deep flexion. The volume of bone resected for the intercondylar notch varies with implant design, and newer designs may accommodate high flexion with less bone resection. Questions/Purposes: This study aims to analyze the bone volume and density resected from the intercondylar notch for three posterior stabilized implants from a single company: a Posterior Stabilized (PS) system, a Hi-Flex system (HF), and a rounded new box-reamer (RB) system and to further assess whether the newer RB with a cylindrical cutting tool would preserve more native bone. Materials and Methods: Using a computer model, the PS, HF, and RB femoral components were digitally implanted into CT scans of 19 cadaver femurs. Nine cadavers were fit with a size 4 implant, six with size 3, and four with a size 2. The volume of intercondylar bone resected digitally for femoral preparation was measured. Bone density was measured by CT scans in Hounsfield units (HU). A paired t test was used to compare the mean volume of bone resected for each implant. Results: For the size 4 femurs, the newer RB design removed 8% less intercondylar bone than the PS design (7,832 ± 501 vs. 8,547 ± 377mm3, p < 0.001) and 28% less bone than the HF design (7,832 ± 501 vs. 10,897 ± 444mm3, p < 0.001). The average HU for size 4 femurs for RB design was 427 ± 72 (PS = 399 ± 69, p < 0.001; HF = 379 ± 66, p < 0.001). For the size 3 femurs, the RB design removed 12% less intercondylar bone than the PS (6,664 ± 786 vs. 7,516 ± 648mm3, p < 0.001) and 27% less bone than the HF (6,664 ± 786 vs. 9,078 ± 713mm3, p < 0.001). HU for size 3 femurs for the RB design was 452 ± 70 (PS = 422 ± 53, p < 0.1; HF = 410 ± 59, p < 0.01). For the size 2 femurs, the RB design removed 5% less intercondylar bone than the PS (5,730 ± 552 vs. 6,009 ± 472mm3, p < 0.01) and 22% less bone than the HF (5,730 ± 552 vs. 7,380 ± 532mm3, p < 0.001). HU for size 2 femurs for the RB design was 430 ± 48 (PS = 408 ± 55, p < 0.01; HF = 385 ± 56, p < 0.01). Conclusions: The newer RB design removes less bone from the intercondylar notch than the classic PS and HF designs in all sizes tested. The bone-conserving cuts incorporated into this newer implant design appear to preserve native bone without compromising design objectives. Hospital for Special Surgery, 2013 total knee arthroplasty nationallicence bone resection nationallicence posterior stabilized nationallicence Pugh Luke Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut Ruel Allison Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut Lipman Joseph Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut Wright Timothy Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut Gessell Mark Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut Westrich Geoffrey Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut HSS Journal ® Springer US; http://www.springer-ny.com 9/2(2013-07-01), 157-160 1556-3316 9:2<157 2013 9 11420 https://doi.org/10.1007/s11420-013-9340-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11420-013-9340-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Pugh Luke Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut NATIONALLICENCE 700 1- Ruel Allison Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut NATIONALLICENCE 700 1- Lipman Joseph Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut NATIONALLICENCE 700 1- Wright Timothy Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut NATIONALLICENCE 700 1- Gessell Mark Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut NATIONALLICENCE 700 1- Westrich Geoffrey Hospital for Special Surgery, 535 East 70th Street, 10021, New York, NY, USA aut NATIONALLICENCE 773 0- HSS Journal ® Springer US; http://www.springer-ny.com 9/2(2013-07-01), 157-160 1556-3316 9:2<157 2013 9 11420 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer