Cataldo 2012.

Methods	RCT, parallel design
Participants	70 participants, ASA I ‐ III scheduled for hallux vagus correction Excluded: patient refusal to procedure, neurologic or neuromuscular disease, acquired or congenital coagulopathy, skin infection at needle insertion site.
Interventions	Ultrasound + nerve stimulation (n = 35) versus nerve stimulation (n = 35) Popliteal block of tibial and peroneal nerve; 20 ml LA (10 mL 0.75% ropivacaine and 10 mL 2% lidocaine without epinephrine) ‐ 12 ml close to tibial nerve, 8 ml close to peroneal nerve Ultrasound: 7.5 ‐ 12 Mhz linear probe; nerve stimulator turned on to confirm correct identification of nerves, then switched off for remaining procedure; endpoint ‐ stimulating current increased to obtain motor response Nerve stimulation (Stimuplex): pulse duration 100 µsec, initial current density 1 mA, frequency 2 Hz; endpoint ‐ stimulation at < 0.4 mA
Outcomes	Adequacy of block (defined as loss of ice sensation after LA injection and confirmed by pain absence at surgical incision or intraoperatively) Complications (puncture of popliteal artery) Block onset time (defined as time interval between end of LA administration and onset of sensory block of peroneal and tibial nerve in its distribution territory) Time to perform block Number of block attempts Participant satisfaction
Notes	All participants first given metatarsal osteotomy with ankle tourniquet. Blocks performed by 2 resident anaesthetists with prior experience of regional anaesthesia using nerve stimulator, but novices to ultrasound and to popliteal block
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomized using sealed envelopes.  No further details given
Allocation concealment (selection bias)	Unclear risk	No details
Blinding of participants and personnel (performance bias):adequacy of block, need for supplementation	High risk	Not possible to blind anaesthetists
Blinding of participants and personnel (performance bias):Complications	High risk	Not possible to blind anaesthetists
Blinding of participants and personnel (performance bias): time outcomes	High risk	Not possible to blind anaesthetists
Blinding of participants and personnel (performance bias): Patient discomfort	High risk	Not possible to blind anaesthetists
Blinding of outcome assessment (detection bias): adequacy of block, supplementation of block	Low risk	Sensory block assessed by a blinded investigator
Blinding of outcome assessment (detection bias): time outcomes	Low risk	Block performance time registered by senior staff not blinded to procedure, but blinded observer monitored onset and progression of sensory block
Blinding of outcome assessment (detection bias): Patient discomfort	Unclear risk	Blinded observer collected participant satisfaction levels in post‐op period, but unclear if participant blinded to group allocation
Incomplete outcome data (attrition bias) All outcomes	Low risk	No apparent losses
Selective reporting (reporting bias)	Unclear risk	Published protocol not sought
Baseline characteristics	Low risk	Largely comparable. More women than men, but expected for this surgery
Funding sources	Low risk	No funding
Operator expertise	High risk	Anaesthetists had more experience in nerve stimulation use than ultrasound but none had experience of popliteal block