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.

Introduction: Periprosthetic fractures are a devastating complication following total knee arthroplasty. Little is known about the effect of mechanical factors on the incidence of periprosthetic fractures. The aim of this study was to examine the correlation between pre-operative mechanical factors, like side of surgery, coronal alignment and pre-operative range of motion and intra-operative factors, and the incidence of a periprosthetic fracture, following primary total knee arthroplasty (TKA). Materials and Methods: Forty-two patients with periprosthetic fractures (PPF) after primary TKA were identified from our hospital arthroplasty registry. These patients were matched two-to-one for gender and age at primary knee arthroplasty to 84 patients without PPF. The incidence of periprosthetic fracture with regards to laterality, coronal alignment and pre-operative range of motion was analysed. Intra-operative factors like implant type, patellar resurfacing and notching were also analysed using logistic regression. Results: Coronal alignment, pre-operative range of motion and patella resurfacing were not significant predictors of periprosthetic fractures. Anterior femoral notching was found to be significantly higher in the fracture group with an odds ratio of 17. Left sided surgery was also significantly higher in the periprosthetic fracture group. Conclusion: Periprosthetic fractures are 17 times more likely to occur in a knee with anterior femoral notching. Preoperative factors like coronal alignment and poor preoperative range of motion do not seem to increase the risk of periprosthetic fractures after TKA.