Tibial component sizing and alignment of TKR components does not significantly affect patient reported outcome measures at six months. A case series of 474 participants. (April 2018)

• Record Type: Journal Article
• Authors: Ahmed, Imran; Paraoan, Vlad; Bhatt, Dveej; Mishra, Bhanu; Khatri, Chetan; Griffin, Damian; Metcalfe, Andrew; Barlow, Tim
• Is Part Of: International journal of surgery. Volume 52(2018)
• Page Start: 67
• Page End: 73
• Publication Date: 2018-04
• Subjects: Alignment -- Tibial component sizing -- Patient reported outcome measures -- Total knee replacement; Surgery -- Periodicals; Surgical Procedures, Operative -- Periodicals; 617.005
• DOI: 10.1016/j.ijsu.2018.02.039
• Languages: English
• ISSNs: 1743-9191

Abstract

Abstract: Objectives: Total knee replacement (TKR) is an effective means of alleviating the symptoms of end stage osteoarthritis. However, 20% of patients report dissatisfaction one year post-operatively. Previous literature has demonstrated contradictory evidence regarding the relationship between alignment and tibial component sizing with patient reported outcome measures (PROMs). We aim to investigate the association between alignment of TKR components and effect of tibial component sizing on PROMs. Method: A prospective, multicentre case series was performed at six centres. Baseline characteristics were collected at recruitment. Coronal and sagittal plain films were taken day one post-operatively. Trained medical professionals blinded to outcome measured the alignment and degree of over/underhang of the tibial component in the coronal and sagittal place, with Oxford Knee Score (OKS) measured six months post-operatively. Results: 474 patients were recruited. Malaligned TKRs caused no significant difference in mean OKS change at six months (independent t -test) (p > 0.05). A multivariate regression model taking into account age, gender, body mass index and baseline OKS also demonstrated no significant difference (p > 0.05). With regards to tibial component sizing, 125 (27%) of patients had appropriately sized tibial components, 120 (26%) had overhang and 219 (53%) had underhang with no significant difference in OKS between the groups (p > 0.05). Conclusion: Tibial component sizing and alignment does not significantly affect short-term function, as measured by OKS, after total knee replacement. Dissatisfaction after TKR is likely due to other factors other than alignment of implant. Highlights: 25% of patients remain dissatisfied with the outcome of total knee replacement at one year. Potential contributing factors include implant alignment and tibial component sizing. Our study of 474 patients investigated whether tibial sizing or alignment affected oxford knee score at 6 months. A multivariate analysis factored in confounding factors including age, sex, gender and degree of osteoarthritis. Degree of alignment and tibial component sizing did not significantly affect six month patient reported outcome measures.