Statistical analysis
Descriptive data were reported as frequencies (percentage, %) or mean ± standard deviation (SD). The Fisher exact test was used to compare categorical data between groups e.g. gender, and affected side. The Oneway-ANOVA test was used for comparisons of continuous variables with normal distribution, and the Kruskal-Wallis’s test was used for continuous variables with non-normal distribution including age, BMI, VAS during local anesthetic injection, VAS during intra-articular injection, radiation exposure, pre-injection mHHS, post-injection mHHS. P < 0.05 was statistically significant. Data were analyzed using Stata version 14.2 (StataCorp, Lakeway, Texas, USA).