The effect of surgical procedures for the osteoarthritic knee on coronal laxity and patient outcome: A search to optimize patient outcome for medial closed wedge high tibial osteotomy and total knee arthroplasty in the context of stability of the knee

The overall aim of this thesis was to investigate the effect of surgical procedures for the osteoarthritic knee on coronal laxity, subjective instability and patient outcome. The two parts of this thesis consecutively described: 1) the medial closed wedge high tibal osteotomy (HTO) and 2) total knee arthroplasty (TKA).
For the medial closed wedge high tibial osteotomy without MCL-reefingplasty an increased coronal laxity was reported postoperative. Despite good postoperative results, patient reported outcome and stability might improve when MCL-reefingplasty is applied in selected patients. This thesis thus advised that for those patients in which an increase in MCL laxity is observed per-operatively a MCL-reefingplasty should be considered. For total knee arthroplasty this thesis showed a negative correlation between joint line elevation and patient reported outcome. This joint line elevation results in coronal laxity in the mid-flexion range and should therefore be minimized. The new Flexion First Balancer technique presented in this thesis was able to reconstruct the joint line of the knee however, no improvements in patient reported outcome and stability were reported. As is shown in this thesis it remains difficult to correlate objective laxity measurements to patient reported stability. Standardized methods for analysing laxity and subjective stability should be developed as this would make results comparable for future research. With these standardized methods research should be focused on the correlation between per-operative laxity, postoperative laxity and patient reported stability after surgical procedures for the osteoarthritic knee. This knowledge can provide answers that potentially lead to the next step in improving patient outcome after TKA.