ArticleKnee surgery, sports traumatology, arthroscopy : official journal of the ESSKA2025
Preoperative quadriceps malalignment is associated with poor outcomes after knee replacement which are avoided by external rotation of the femoral component.
Article in Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers.
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Who cites it
8 citing papers in PubMed.
- Predicting patellar kinematics and contact forces after TKA: a simulation study on quadriceps malalignment.Arthroplasty (London, England) · 2026Article
- Similar secondary patellar resurfacing but higher tibial revision risk with posterior stabilized versus medial pivot total knee arthroplasty: A registry analysis.Journal of experimental orthopaedics · 2026Article
- Rotational Variability in Arthritic Knee Morphometry Predominantly Arises From the Hip and May Warrant Preoperative Consideration Prior to Total Knee Arthroplasty.Arthroplasty today · 2026Article
- Lateral deviation of the prosthetic trochlear angle relative to the quadriceps vector in mechanically aligned total knee arthroplasty: a radiological and clinical analysis.BMC musculoskeletal disorders · 2026Article
- Valgus knee deserves personalized total knee arthroplasty.EFORT open reviews · 2026Review
- Anatomical and component rotational mismatches negatively affect postoperative outcomes in total knee arthroplasty.Journal of experimental orthopaedics · 2025Article
- Preoperative quadriceps malalignment is associated with poor outcomes after knee replacement which are avoided by external rotation of the femoral component.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2025Article
- The Orientation of the Prosthetic Trochlear Angle Is Predictable in Kinematically Aligned Total Knee Arthroplasty.Journal of personalized medicine · 2025Article
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4 authors.
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Abstract
purposeLateralisation of the proximal apex of the quadriceps tendon relative to the mechanical axis or external rotation relative to the femoral shaft can be accurately measured and is strongly associated with patella maltracking. The aim of this study was to first assess the association between preoperative quadriceps tendon alignment (QTA) and the patient-reported outcomes (PROMs) of total knee replacement, and second, determine the influence of component position on outcomes in patients with preoperative quadriceps tendon malalignment (QTM).
methodsA retrospective analysis of prospectively collected data was performed. All patients had preoperative and postoperative CT scans performed. PROMs were collected preoperatively and at 1 year postoperatively. QTA was measured by the quadriceps tendon axial angle (QTAx). The preoperative and postoperative coronal and axial alignment were measured. Femoral component rotation was measured relative to the preoperative posterior condyles.
resultsAnalysis was conducted on 388 cases and the mean preoperative QTAx was 6.2° externally rotated (standard deviation 12.0°). QTM (QTAx > 14°) was identified in 76 (19.8%) patients. The diagnosis of QTM was associated with reduced patient outcomes including Forgotten Joint Score (60.2 vs. 51.2, p = 0.008), EuroQol Visual Analogue Scale (81.3 vs. 75.7, p = 0.009), KOOS-12 (80.3 vs. 73.3, p = 0.001) and reduced PASS percentages for all KOOS subscales. In patients with preoperative QTM, femoral component external rotation >2° was associated with improved PROMs when compared to patients with <2° of femoral rotation. This included a clinically significant difference in the improvement of KOOS-12 (11.7 points, p = 0.013) and improved PASS percentages in all KOOS subscales. There was no association between coronal alignment or tibial axial alignment and outcomes.
conclusionsQuadriceps malalignment is a common cause for poorer patient outcomes following total knee replacement. This can be avoided by externally rotating the femoral component to accommodate the deformity in the extensor mechanism. LEVEL OF EVIDENCE: Level III, case-control study.
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