Clinical study

The efficacy of ankle block for foot and ankle surgery – a systematic review with meta-analysis and trial sequential analysis

Systematic review question
To assess the beneficial and harmful effects of ankle blocks versus sciatic nerve block with or without a femoral nerve block for foot and ankle surgery. We will also assess the effects of ankle block compared with sham block/no intervention and narratively report results from observational, non-randomized studies.

Types of study to be included
Randomized clinical trials assessing ankle blocks versus sciatic nerve block with or without femoral nerve block and trials assessing ankle blocks versus no intervention/sham block in patients undergoing surgery of the foot or ankle.

Condition or domain being studied
The efficacy, and the beneficial and harmful effects of ankle blocks versus sciatic nerve block with or without a femoral nerve block for foot and ankle surgery, and the effects of ankle block compared with sham block/no intervention.

Participants/population
Patients of 18 years or more undergoing surgery of the foot or ankle will be included. Patients will not be excluded based on comorbidities og baseline treatment.

Intervention
Ankle block defined as both “blind” or anatomical landmark-guided local infiltration analgesia at the level of the ankle and ultrasound-guided ankle block.

Comparator
Sciatic nerve block with or without a femoral nerve block (e.g. saphenous or adductor canal nerve block) performed with ultrasound-guidance or with peripheral nerve stimulation. We will also include studies using sham block or no intervention.

We will include trials matching the above criteria irrespective of administered co-interventions, if the co-interventions are intended to be delivered similarly to the intervention groups.

Main outcomes
1) Duration of analgesia measured as either time to first pain, time to first request for analgesics or time to first rescue analgesics (if a study reports more than one of these outcomes, the outcome with the shortest duration will be the only one included in the meta-analysis)
2) 24 hours opioid consumption

Additional outcomes
1) Adverse events
2) Serious adverse events (according to the ICH-GCP)
3) Conversion to general anesthesia
4) Pain at rest measured on the visual analogue scale (VAS) or the numerical rating scale (NRS) at 6 hours, at 24 hours, and at 48 hours
5) Dynamic pain measured on the VAS or NRS at 6 hours, at 24 hours, and at 48 hours
6) Duration of motor block as defined by the investigators
7) Duration of sensory block as defined by the investigators

PROSPERO 2022 CRD42022339755