Shape-matching technology provides preoperative three-dimensional templating of total knee arthroplasty (TKA) placement to restore optimal kinematics for the native prearthritic knee. Despite an accurate preoperative plan to construct cutting jigs for placement of the femoral and tibial implants in a TKA, it is hypothesized that the actual implementation or reproduction of this placement of implants remains suboptimal.
A retrospective radiographic review of 67 primary unilateral TKAs performed using the OtisMed™ (OM, Stryker, Kalamazoo, MI) shape-matching technology was conducted to determine how closely the computer-generated OM preoperative plan resembled the postoperative femoral and tibial implant position in both the coronal and sagittal planes.
Preoperative and postoperative measurements were correlated in the coronal (r=0.407, P=0.001), but not the sagittal plane (r=−0.124, P=0.329). Postoperative coronal alignment differed from the preoperative plan more than 3° in 33.3% of cases, while sagittal alignment differed more than 3° in 56.3% of cases.
A significant number of cases did not achieve precise placement of the implants per the OM plan, most notably in the sagittal plane. While these differences are noteworthy, the limiting factor still remains our ability to precisely execute the plan.
aHamilton Arthroplasty Group, Hamilton Health Sciences Juravinski Hospital, Hamilton, Ontaria, Canada
bHamilton Health Sciences, Orthopaedic Program, Hamilton, Ontario, Canada
cMcMaster University Division of Orthopaedic Surgery, Hamilton, Ontario, Canada
dBrantford General Hospital, Brantford, Ontario, Canada
Financial Disclosure: Dr. Winemaker, Dr. de Beer, and Dr. Woolfrey have received payment for lectures and travel from Stryker, Canada. Dr. Woolfrey also declares research support from Stryker, Canada.
Correspondence to Danielle Petruccelli, MLIS, MSc, Hamilton Arthroplasty Group Hamilton Health Sciences Juravinski Hospital Hamilton, Ontario, Canada Tel: +905-527-4322 ext 42296; fax: +905-389-5617; e-mail: firstname.lastname@example.org