Association between post-operative lateral soft tissue laxity and clinical outcomes in robotic-assisted bicruciate-stabilized total knee arthroplasty
Year: 2026
Type: article
Study design: Observational Study
Abstract: ABSTRACT Purpose The purpose of this study was to investigate the association between post-operative lateral soft tissue laxity and clinical outcomes in robotic-assisted bicruciate-stabilized (BCS) total knee arthroplasty (TKA). Methods A total of 133 knees that underwent primary robotic-assisted BCS TKA were retrospectively analyzed. Intra-operative gaps were measured under a consistent distraction force of 160 N with only the femoral trial components in place. Post-operative lateral soft tissue laxity, defined as the angle formed between the distal femoral and proximal tibial joint lines under varus stress, was measured. The Knee Society Score (KSS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), Forgotten Joint Score-12 (FJS-12), and patient satisfaction were evaluated. Factors associated with post-operative lateral soft tissue laxity were also investigated. Results Knees were classified into three groups according to post-operative lateral soft tissue laxity: mild (<5°; n = 51), moderate (5–7°; n = 46), and severe (>7°; n = 36). The moderate group demonstrated significantly higher KSS scores than the severe group and better WOMAC, FJS-12, and patient satisfaction scores than the mild group. In the moderate group, the intra-operative lateral gap was 2.9 ± 1.9 mm in extension and 5.9 ± 1.3 mm in flexion. Pre-operative alignment and intra-operative lateral gaps were associated with post-operative lateral soft tissue laxity. Conclusions In robotic-assisted BCS TKA, moderate post-operative lateral soft tissue laxity (5–7°) was associated with more favorable clinical outcomes. Careful management of intra-operative lateral gaps may contribute to achieving post-operative lateral soft tissue laxity associated with favorable clinical outcomes.
Institutions: Gifu University, Ogaki Tokushukai Hospital
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $1,770
OpenAlex ID: W7203910258