Methods: A systematic literature search was conducted in June 2021 in the PubMed, Embase, Scopus, CINAHL, and Cochrane CENTRAL databases. Clinical and epidemiological studies that reported quantitative data on the prevalence of coexisting LS and KOA were included. Studies which reported data on only LS or KOA alone were excluded. Odds ratios (ORs) and 95% confidence intervals (CI) for LS or KOA were retrieved or calculated for meta-analysis. Fixed-effects and random-effects models were used, and statistical significance was considered when p<0.05. Heterogeneity was evaluated using Cochran’s Q test and the I2 statistic. Risk of bias was assessed using the MINORs (methodological index for nonrandomized studies) criteria. Results: This review included nine studies (5,758 patients). Four studies (4,164 patients) defined KOA and LS by a Kellgren-Lawrence (KL) grade of ≥2 and were included in the meta-analysis. Two other studies defined KOA and LS by a joint space narrowing grade of ≥2. The remaining three studies reported other outcomes. The combined ORs of having KOA of KL grade ≥2 due to LS was 1.75 (95% CI, 1.22–2.50; p=0.002), while the combined OR of having LS of KL grade ≥2 due to KOA was 1.84 (95% CI, 1.23–2.77; p=0.003). Conclusions In patients with either KOA or LS, the odds of having a concurrent knee-spine presentation are significantly increased. This may have implications for clinical decision-making and treatment strategies. Further high-level studies with larger patient populations are required to confirm these results in specific populations.