Table 2.

Risk of bias of the included studies

Study	A	B	C	D	E	F	G	H	I	J	Total
Wang et al. [22]	√	√	√	√		√			√		6
Lang et al.  [23]	√	√		√						√	4
Gao et al. [24]	√	√	√	√		√			√	√	7
Yang et al. [25]	√	√	√	√		√			√		6
Dong et al. [26]	√	√	√	√					√	√	6
Ren et al. [27]	√		√			√			√	√	5
Yang et al. [28]	√	√		√						√	4
Ren et al. [29]	√		√	√		√			√	√	6
Gao et al. [30]	√	√	√			√			√		5

Studies fulfilling the criteria of the following: A: peer-reviewed publication; B: control of temperature; C: random allocation to treatment or control; D:blinded induction of model (group randomly after modeling); E: blinded assessment of outcome; F: use of anesthetic without significant protective and toxic effects on bones; G: appropriate animal model (aged, hyperlipidemia, hypertensive, or diabetes); H: sample size calculation; I: compliance with animal welfare regulations (including three or more of the following points: preoperative anesthesia, postoperative analgesia, nutrition, disinfection, environment temperature, environment humidity, circadian rhythm, and euthanasia); J: statement of potential conflict of interests