ABSTRACT
PURPOSE: The purpose of this study was to identify predictive factors for the occurrence of complications in a consecutive series of patients who underwent step-cut tibial tubercle osteotomy (TTO) and subsequent screw refixation in primary total knee arthroplasty (TKA). METHODS: Using standardised conventional radiographs, critical parameters including TTO length and depth, proximal abutment width (OT), and orientation and placement of fixation screws were measured in 422 patients (mean age of 71 years and a follow-up time range of one to five years) with two screw fixations. RESULTS: Medial spatial orientation in the distal screw (11 %, p=0.046), the TTO length (<55.4 mm, p=0.013), the OT width (<14 mm, p=0.002) and the distance of the distal refixation screw from the TKA (<51.7 mm, p=0.003) were significant factors for the occurrence of complications. CONCLUSIONS: Age, gender, comorbidities, height, weight and/or the body mass index had no significant influence on the occurrence of complications. The TTO-related complication rate was 3 %. Consideration of these key surgical factors leads to improved outcomes.
