Objectives: Clinical effects of the rotational alignment of tibial component on clinical outcomes after a Total Knee Arthroplasty (TKA) are still much debated, whereas an excessive tibial rotation is hypothesized to affect results and a precise cut-off threshold-value for an optimal rotational positioning remains unknown. The aim of this systematic review was to analyze the available literature to examine the effect between rotational alignment of the tibial component and clinical outcomes after TKA, and assess eventual cut-offs for tibial rotation leading to poor results.

Methods: A detailed and systematic search from 1996 to 2017 of the Pubmed, Medline, Cochrane Reviews, Google Scholar databases had been performed using the keyword terms "total knee arthroplasty", "total knee replacement", "tibial alignment", "tibial malalignement", "tibial rotation", "rotational error", "axis", "angle", "tibial malrotation", "clinical outcome", in several combinations. We used modified Coleman scoring methodology (mCMS). All primary TKAs studies analyzing correlation between clinical results and tibial rotation were included.

Results: Five articles met inclusion criteria. A total of 333 arthroplasties were included in this review; 139 had tibial component malalignment, while 194 were in control groups. The mean age of patients was 67,3 (±0,57) years. The mean average postoperative follow-up delay was 34,7 months (range, 21-70). The mean mCMS score was 59,2 points indicating good methodological quality in the included studies. Functional outcomes were assessed through KSS, OKS, KOOS and VAS, negatively related to tibial internal rotation.

Conclusions: Our review confirmed that excessive internal rotation of the tibial component represents a significant risk factor for pain and inferior functional outcomes after TKA (>10° of internal rotation demonstrated the common value), since external rotation doesn't affect results.
However, a universal precise cut-off value has not been found in available literature and debate remains about CT rotation assessment and surgical intraoperative landmarks.