“…Because it was impossible to blind the participants and surgeons who performed the surgery, all outcomes had an unclear risk of bias for this domain [11,12,23,32]. The detection bias was low in 6 studies [11,23,25,28,30], and the rest had unclear risk bias [12,24,26,27,31,32]. Attrition bias, reporting bias and other biases were low in 9 studies [11,12,23,25,28,32] and the remaining 3 studies all had unclear bias [24,26,27].…”