Effect of Adductor Canal Nerve Block Compared to a Simulated Block on Quadriceps Strength Following Knee Arthroplasty

Summary

Total knee arthroplasty (TKA) is a frequent and effective surgery for knee osteoarthritis. This major surgery is associated with a reduction in knee extensor muscle strength persisting several weeks after surgery. This decrease in strength correlates with poor functional recovery. Its cause is multifactorial, including a deficit of the quadriceps activation, an acute postoperative atrophy of the muscle and an important limitation related to postoperative pain.

Peripheral nerve blocks using local anesthetics are frequently used for postoperative analgesia following TKA. Femoral nerve blockade reduces pain and opioid consumption and allows early passive mobilization after surgery. This block also facilitates functional recovery and allows early discharge from the hospital. However, blocks involving the proximal femoral nerve contribute to quadriceps weakness for the duration of nerve blockade. Quadriceps weakness, in turn, results in functional impairment and increases recovery time. A possible long-term quadriceps weakness associated with the femoral nerve block has even been suggested in a recently published abstract. Hence, there is a need for an alternative technique that could minimize postoperative pain as well as the femoral nerve block without causing weakness of the quadriceps muscle.

Femoral nerve block performed at the level of the adductor canal seems to be a promising alternative to the classic inguinal approach of the femoral nerve block. Studies comparing femoral nerve block performed at the canal adductor level to the inguinal approach reported a similar quality of analgesia, a reduction in motor block and a better functional recovery in the early postoperative period in the canal adductor block group. The long-term effect of femoral nerve block performed at the level of the adductor canal on knee extensor strength after surgery remains to be studied.

This study will assess knee extensor muscle strength (principally quadriceps muscle) at 24h, 48h and 6 weeks following TKA in patients having a femoral nerve block at the adductor canal level compared to a simulated block.

Hypothesis: The adductor canal block will allow superior recovery of knee extensor muscle strength when compared to a simulated block at 6 weeks after total knee arthroplasty.

Conditions

• Knee Arthroplasty

Interventions

DEVICE

Adductor canal femoral nerve block

A 18 Gauge Tuohy needle will be inserted and its position will be confirmed using ultrasound guidance. Once the adequacy of the position is confirmed, the anesthesiologist will administer 15 mL of bupivacaine 0.25% with epinephrine in divided doses and examine the quality of its spread. A 20 Gauge polyamide catheter will be inserted at 2 cm in the space. The needle will then be withdrawn and the catheter will be fixed in place. Three mL of the same mixture of local anesthetics will be administered through the catheter and the anesthesiologist will observe the quality of its distribution. Bupivacaine 0.125% will be administered through the catheter using an infusion pump for 48 hours. Knee extensor muscle strength, pain and side-effects will be assessed at different time-points.

DEVICE

Simulated nerve blockade

The insertion of the Tuohy needle and the injection of 15 mL of bupivacaine 0.25% with epinephrine will be simulated. The insertion of the polyamide catheter, the withdrawal of the needle and the injection of local anesthetics through the catheter will also be simulated. The infusion of bupivacaine 0.125% will also be simulated for 48 hours. Knee extensor muscle strength, pain and side-effects will be assessed at different time-points.

Sponsors & Collaborators

• Centre hospitalier de l'Université de Montréal (CHUM)

  lead OTHER

Principal Investigators

• François Girard, MD, FRCPC · Centre hospitalier de l'Université de Montréal (CHUM)

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

90 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2015-01-31

Primary Completion

2016-12-31

Completion

2016-12-31

Countries

• Canada

Study Locations