Adductor Canal Block Versus Femoral Block on Pain and Quadriceps Strength

University of California San Francisco (UCSF)

Status and phase: Completed; Phase 4

Conditions: Anterior Cruciate Ligament Tear; Knee Meniscus Tear

Treatments: Drug: Preoperative Adductor canal block with 0.75%% ropivacaine 13.3ml.; Procedure: Adductor Canal Nerve Block; Procedure: Femoral Nerve Block; Drug: preoperative Femoral Nerve Block using 20ml of 0.5% ropivacaine

Study type: Interventional

Funder types: Other

Identifiers

NCT05190120

14-13071

Details and patient eligibility

About

The purpose of this study is to compare the effects of a femoral nerve block vs. an adductor canal block on pain and quadriceps muscle strength for knee arthroscopy surgery.

Full description

Patients undergoing arthroscopic knee surgery (ACL and non-ACL surgery) typically receive an ultrasound-guided femoral nerve block or an adductor canal block in the pre-operative phase for post-operative pain control. While an effective method for post-operative analgesia, the femoral nerve block is associated with profound quadriceps weakness for the duration of the nerve block, which can impair ambulation, rehabilitation, and increase the risk of falls. The more distal adductor canal block, however, contains primarily sensory branches of the femoral nerve and has been been purported by small volunteer studies to provide equally effective analgesia with minimal motor block and quadriceps weakness (as compared to femoral nerve block).

The investigators will prospectively randomize patients undergoing knee arthroscopy at the UCSF Orthopaedic Institute to receive either a single-shot femoral nerve or adductor canal block pre-operatively after taking baseline measurements of quadriceps strength (quantified by maximum voluntary isometric contraction). The quadriceps muscle strength will be checked 20 minutes after the nerve block to assess strength. All patients will subsequently undergo a general anesthetic. The primary outcome variable will be post-block quadriceps strength as a percentage of baseline from pre-block values. Secondary outcome variables that will also investigated include: VAS pain score in the post anesthesia recovery unit and post-operative day 1, duration of nerve blockade, and perioperative opioid consumption.

Enrollment: 132 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• American Society of Anesthesia I-III classification,
• Scheduled for arthroscopic knee surgery (meniscal debridement/repair, ACL reconstruction)

Exclusion criteria

• Age younger than 18 years
• Non-English speaking
• Any contraindication for regional anesthesia, such as allergy to local anesthetics or opioids, -Coagulopaty or severe thrombocytopenia
• Infection at puncture sites
• Pre-existing neuropathy in operative limb
• Need for post-operative nerve function monitoring
• Dementia
• Patient refusal
• High pre-operative opioid requirements

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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132 participants in 2 patient groups

Femoral Block

Active Comparator group

Description:

Patients scheduled for knee arthroscopy will have a femoral nerve block done using 0.5% ropivacaine 20ml before surgery.

Treatment:

Drug: preoperative Femoral Nerve Block using 20ml of 0.5% ropivacaine

Procedure: Femoral Nerve Block

Adductor Canal Block

Experimental group

Description:

Patients scheduled for knee arthroscopy will have an adductor canal block done using 0.75% ropivacaine 13.3ml before surgery.

Treatment:

Procedure: Adductor Canal Nerve Block

Drug: Preoperative Adductor canal block with 0.75%% ropivacaine 13.3ml.