Summary of findings for the main comparison. Regional anaesthesia compared to conventional pain control for total knee replacement patients: joint functional outcome (Knee Society Score compared to preoperative value), 3 and 6 months after surgery.

Regional anaesthesia compared to conventional pain control for total knee replacement patients
Patient or population: total knee replacement patients Settings: university hospital Intervention: regional analgesia Comparison: conventional pain control
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	No. of Participants (studies)	Quality of the evidence (GRADE)
	Assumed risk	Corresponding risk
	Conventional pain control	Regional analgesia
Knee Society Score compared to preoperative value Follow‐up: 3 months	The mean Knee Society Score compared to preoperative value in the control group was + 42.87 points	The mean Knee Society Score compared to preoperative value in the intervention group was 1.76 points higher	Impossible to estimate as no standard deviation was provided	30 participants (1 study)	⊕⊝⊝⊝ very lowa,b,c,d,e
Knee Society Score compared to preoperative value Follow‐up: 6 months	The mean Knee Society Score compared to preoperative value in the control group was + 44.70 points	The mean Knee Society Score compared to preoperative value in the intervention group was 4.03 points higher	Impossible to estimate as no standard deviation was provided	30 participants (1 study)	⊕⊝⊝⊝ very lowa,b,c,d,e
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval.
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate.

^aUnclear risk of detection bias (unclear outcome observer blinding), especially as pain is a subjective assessment.
 ^bProvider and participants were unblinded, especially as pain is a subjective assessment.
 ^cHigh risk of attrition bias. Nineteen participants were enrolled, then excluded, but were not included in the analysis.
 ^dOnly one study could be included.
 ^eThe quality of the evidence was downgraded from high to very low.