Ultrasound-guided Selective Blockade of the Saphenous and Obturator Nerves Following Total Knee Arthroplasty

Bispebjerg Hospital

Status and phase: Completed; Phase 4

Conditions: Knee Arthroplasty, Total

Treatments: Drug: nerve block with ropivacaine and with saline; Drug: nerve block with ropivacaine; Drug: nerve block with saline

Study type: Interventional

Funder types: Other

Identifiers

NCT02465827

BispebjergH

Details and patient eligibility

About

The investigators aimed to evaluate the efficacy of selective low volume ultrasound-guided blockades of the saphenous and obturator nerves on dynamic and rest pain 24-hours post-operatively for patients undergoing unilateral primary total knee arthroplasty.

Full description

A femoral nerve block is the recommended strategy in many surgical centers to supplement multimodal analgesic regime following total knee arthroplasty (TKA) (i.e. both for spinal and general anesthesia). However, a femoral nerve block will often result in quadriceps paralysis, and this will increase the risk for the patient to fall as long as the femoral block have effect. Thus, the search for sensory nerve blocks to stop pain after TKA is a very interesting topic. The saphenous nerve is a purely sensory nerve, and the posterior branch of the obturator nerve is a mixed nerve, where the motor component only affects part of the adductor major muscle.

Enrollment: 75 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. American Society of Anesthesiologists' physical classification I-III
2. Age ≥ 18 years undergoing primary unilateral total knee arthroplasty

Exclusion criteria

1. Inability to cooperate
2. Inability to speak and understand Danish
3. Allergy to any drugs used in the study
4. Drug or alcohol abuse
5. Pregnancy or nursing
6. Opioid abusers

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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75 participants in 3 patient groups, including a placebo group

Saphenous and obturator nerve block

Active Comparator group

Description:

5 ml of ropivacaine 0.75% for the saphenous nerve and 10 ml of ropivacaine 0,75% for the obturator nerve block. Ropivacaine 0.75% for nerve blockades for both nerves mentioned.

Treatment:

Drug: nerve block with ropivacaine

Saphenous nerve block

Active Comparator group

Description:

5 ml of ropivacaine 0.75% for the saphenous nerve and 10 ml of isotonic saline for the obturator nerve block. Ropivacaine 0.75% for the saphenous nerve block and saline for the obturator nerve block

Treatment:

Drug: nerve block with ropivacaine and with saline

Placebo nerve block

Placebo Comparator group

Description:

5 ml of isotonic saline for the saphenous nerve and 10 ml of isotonic saline for the obturator nerve block. Saline for nerve blockades for both nerves mentioned.

Treatment:

Drug: nerve block with saline