This systematic review aimed to determine whether coronal angular corrections correlate with patient reported outcomes following valgus-producing high tibial osteotomy (HTO).
Ovid MEDLINE, Embase, and Web of Science were systematically searched. Studies that reported hip-knee-ankle angles (HKA) or femorotibial angles (FTA), and the Oxford knee score (OKS), visual analogue score (VAS), knee osteoarthritis outcome score (KOOS), or EQ-5D before and after valgus-producing HTO were eligible. Correlation analyses were performed where appropriate to investigate the relationships between variables. PROSPERO ID: CRD42019135467.
This study included 39 articles including 50 cohorts. VAS was reported in 22 studies, OKS in 9, KOOS in 12 and EQ-5D in 2.
The HKA angle was corrected from 7.1±1.7° varus to 2.3±1.7° valgus at final follow-up. The FTA changed from 3.0±2.0° varus to 7.7±1.3° valgus.
Outcome scores improved with clinical and statistical significance post-operatively. Spearman correlations for nonparametric data revealed greater changes in knee alignment were moderately associated with larger improvements in VAS scores (r = 0.50). Furthermore, those who experienced greater changes in alignment showed larger improvements in the KOOS Activity and Quality of Life domains (r = 0.72 & r = 0.51, respectively).
On average, patients did not achieve the ‘ideal correction’ of 3-6° valgus post-operatively. Nevertheless, statistical and clinical improvements in PROM scores were consistently reported. This suggests that the ‘ideal correction’ may be more flexible than 3-6°.