All types of component malrotation affect the early patient-reported outcome measures after total knee arthroplasty

Outcomes following total knee arthroplasty (TKA), whether clinical, radiological or survival analysis, have been well-studied. Still, there are some concerns about patient satisfaction with the outcome of the surgery and factors that might contribute to a suboptimal result. This study aims to determine if there is correlation between primary TKA malalignment and early patient-reported outcome measures (PROMs).

Sixty patients, who had primary TKA and a minimum of 2 years of follow up, were recruited for a detailed clinical and radiological examination. Knee alignment was measured in the coronal, sagittal and axial planes. Normal and the outlier measurements of the patients' knees were defined and the clinical results (PROMs) compared to see if there was a statistically significant difference.

Correlation between postoperative limb malalignment in the coronal and the sagittal planes and PROMs was not significant. Conversely, there was significant negative correlation between all types of malrotation and PROMs.

Although malalignment has been linked to inferior outcome and implant survival, our results showed that coronal and sagittal limb malalignment has no significant effect on early PROMs. However, all types of component rotational malalignment significantly worsen early PROMs.