Intraoperative midflexion medial laxity using navigation affects patient expectations following posterior stabilized total knee arthroplasty

Abstract

Background Patient satisfaction and expectations are now recognized as an outcome measure for successful total knee arthroplasty (TKA). The purpose of this study was to determine which factors including soft tissue balance during surgery affect patient satisfaction and expectations after TKA. Methods A total of 135 patients (157 knees) with knee osteoarthritis who underwent primary TKA with a posterior stabilized design were studied. After implantation of all components, varus/valgus laxity of the knee was measured intraoperatively with the knee at 0°, 30°, 60°, 90°, and 120° guided by an image-free navigation system. Factors that affected patient satisfaction and expectations, including lateral and medial laxities, were evaluated using the 2011 Knee Society score. Results The mean intraoperative lateral laxity was 1.1°, 1.6°, 0.9°, 1.3°, and 1.7° with the knee at 0°, 30°, 60°, 90°, and 120°, respectively. The mean intraoperative medial laxity was 1.1°, 1.4°, 1.1°, 1.1°, and 1.7° with the knee at 0°, 30°, 60°, 90°, and 120°, respectively. Patient satisfaction after TKA correlated positively with symptom (R = 0.61, p < 0.01) and functional activity (R = 0.47, p < 0.01) scores. Patient expectations after TKA weakly positively correlated with symptom (R = 0.29, p < 0.01) and functional activity (R = 0.20, p = 0.01) scores, and weakly negatively with medial laxity at 30° (R = −0.21, p < 0.01). Conclusion Midflexion medial laxity was associated with worse patient expectations after TKA. Avoiding medial laxity could be one of the important techniques during TKA.

The Vega advanced third generation posterior stabilized total knee arthroplasty system enables the restoration of range of motion for high demanding daily activities – A 5-years follow-up study

“…The latter requires resection of the posterior cruciate ligament. The use of PS TKA implants is rising in the German Arthroplasty Registry (EPRD) from 16.6% in 2015 to 25.6% in 2022 [3], whereas it is decreasing in the National Joint Registry of England and Wales from 21.2% in 2010 to 15.3% in 2022 [4] and in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), where PS TKA accounted for only 13.3% of all primary TKA [5].…”

“…The Vega System1 PS is an advanced, third generation fixed implant that aims to mimic natural knee kinematics by optimizing pivotal motion while reducing surface stress. So far, 3-dimensional and biomechanical data [9][10][11], intraoperative analyses [12,13] and shortterm clinical results [14][15][16][17][18][19][20] up to 3 years of this implant were published. The aim of this study was to fill the gap and collect mid-term functional and clinical data of the Vega System1 PS TKA implant.…”