Table 1.

Upper section: Kellgren–Lawrence osteoarthritis (OA) grades of the included patients; Grades I and II are classified as early OA, grade III as moderate OA, and grade IV as severe OA. Lower section: Tönnis OA grades of the included patients; Grade 0 no signs of OA, grade 1 as mild OA grade 2 as moderate OA, and grade 3 as severe OA. + study that included patients with the corresponding OA grade but did not specify the numbers; − study that did not include patients with the corresponding OA grade.

Studies Using Kellgren–Lawrence Scale	Grade I	Grade II	Grade III	Grade IV
Battaglia M. et al., 2011 [22]	−	4	8	8
Singh JR. et al., 2019 [24]	7	11	9	9
Battaglia M. et al., 2013 [26]	−	39	44	17
Di Sante L. et al., 2016 [28]	−	12	31	−
Doria C. et al., 2017 [29]	+	+	+	−
Villanova-López MM. et al., 2020 [30]	27	37	10
Kraeutler MJ. et al., 2021 [31]	−	9	14	−
Palco M. et al., 2021 [32]	−	24	28	−
Emadedin M. et al., 2015 [34]	−	−	+	+
Burnham R. et al., 2021 [39]	+	+	+	+
Heidari N. et al., 2022 [41]	25	28	33	61
Studies Using Tönnis Scale	Grade 0	Grade 1	Grade 2	Grade 3
Sánchez M. et al., 2012 [23]	−	−	12	28
Ortiz-Declet V. et al., 2020 [25]	3	6	2	−
Mazzotta A. et al., 2022 [33]	−	11	42	43
Mardones R. et al., 2017 [35]	−	2	9	2
Rodriguez-Fontan F. et al., 2018 [36]	−	+	+	−
Dall’Oca C. et al., 2019 [37]	+	+	+	−
Whitney KE. et al., 2020 [38]	−	−	6	12
Meadows MC. et al., 2021 [40]	−	3	6	−