Kadic 2009.

Methods	Partially blinded, randomized, controlled trial Random allocation to a group by drawing a sealed envelope from a pile Follow‐up: 3 months
Participants	Subjects: 58 participants enrolled (53 analysed, 48 followed up to 3 months) from one university hospital: Radboud University Nijmegen Medical Centre in the Netherlands Operation: primary total knee replacement 2 groups (of 27 and 26 people) Mean age (SD): group 1, 67.4 (± 12); group 2, 66.8 (± 11) Sex: group 1, 7 males and 20 females; group 2, 7 males and 19 females
Interventions	Standardized anaesthetic: spinal using 15 mg of 5 mg/mL isobaric bupivacaine Group 1 (experimental group): continuous femoral nerve block placed using neurostimulation 5 mL of 20 mg/mL of lidocaine given to test the block with ice Then 20 to 25 mL of ropivacaine 7.5 mg/mL given Postoperatively, an infusion of ropivacaine 2 mg/mL was started at 5 mL/h and adjusted as needed to a maximum of 10 mL/h for the next 48 hours Group 2 (control group): no block Standard analgesic regimen using paracetamol, diclofenac and a morphine IV PCA (bolus 1 mg, lockout 6 minutes)
Outcomes	Pain during the first 48 hours Morphine consumption during the first 48 hours Knee flexion in the first week (days 3 through 6) Knee function after 3 months (knee flexion, Knee Society Score and WOMAC pain, stiffness and function subscale) Catheter position was tested immediately after insertion using lidocaine; however, there is no information as to whether any of the blocks needed additional troubleshooting.
Funding source	Not provided
Declarations of interest	None reported
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"For the randomization procedure, 58 sealed envelopes enclosed a note of either the study or the control group. A blinded operating room nurse drew an envelope, which allocated the patient to one of the groups."
Allocation concealment (selection bias)	Low risk	As above: random draw procedure with sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No mention of blinding for participants or personnel assessing participants during their hospital stay
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"The knee function was assessed by a blinded, independent physician, 3 months after surgery at the orthopaedic outpatient centre."
Incomplete outcome data (attrition bias) All outcomes	Low risk	"[F]ive patients were excluded from the analysis due to protocol violations (one study, two control), a severe adverse reaction to morphine (one control) and for not meeting the inclusion criteria (one study)." At the 3‐month assessment, data from only 48 patients are given (21 in the study group, and 17 in the control group), but no explanation is given as to why 5 more patients were lost to follow‐up.
Selective reporting (reporting bias)	Low risk	Knee Score and WOMAC components reported as mean and SD