2021 ISAKOS Biennial Congress ePoster
Robotic Unicompartmental Arthroplasty Has Higher Revision Rates With Partial Cartilage Lesions And With Inlay Prosthesis When Compared To On Lay Prosthesis
Gary G. Poehling, MD, Winston-Salem, NC UNITED STATES
Ralph D'Agostino, PhD, Winston Salem, NC UNITED STATES
Anirudh K. Gowd, MS, Winston Salem, NC UNITED STATES
Asher Lichtig, MD, Chicago, IL UNITED STATES
Johannes F. Plate, MD, PhD, Pittsburgh, PA UNITED STATES
Wake Forest Baptist Medical Center, Winston Salem, NC, UNITED STATES
FDA Status Cleared
Summary
Preoperative joint space of more than 2 mm on the operative side increased the odds of conversion to total knee arthroplasty by 5 times.
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Abstract
Purpose
The purpose of this study is to identify patient factors and surgical characteristics predictive of unicompartmental failure to determine perioperative and operative factors associated with poor outcomes following partial knee replacement. We compared medial versus lateral, onlay versus inlay and bicompartmental versus unicompartmental prosthesis.
Methods
A prospectively maintained institutional data base was retrospectively queried between January 2010 to December 2016 for all patients that received unicompartmental or bicompartmental robotically assisted arthroplasty. Survivorship analysis was performed to determine factors associated with conversion to total knee arthroplasty and functional results were measured by Oxford Scores.
Results
A total of 1,867 knees in 1,567 patients underwent arthroplasty. There were 1,445 medial only, 188 lateral only, 131 bicompartmental, and 101 patella femoral only. There were 1,743 knees with 2 years follow up and 1,273 knees with 4 years follow up. At four years there were 67 deaths.
Conclusions
On lay prosthesis outperformed inlay prosthesis in all groups medial, lateral and bicompartmental. Preoperative joint space of more than 2 mm on the operative side increased the odds of conversion to total knee arthroplasty by 5 times. BMI showed no statistical difference. Oxford Scores showed a minimally clinically important difference (MCID) (which is 5 for the Oxford Score) in 86 percent of patients. The mean change of the Oxford Score was 15 points. At four years, 92 percent of patients had their original prosthesis.