Femoral nerve block does provide significant analgesia after anterior cruciate ligament reconstruction

Local Infiltration Analgesia Versus Femoral Nerve Block for Pain Control in Anterior Cruciate Ligament Reconstruction: A Systematic Review With Meta-analysis

Background:

Anterior cruciate ligament reconstruction (ACLR) is often performed on an outpatient basis; thus, effective pain management is essential to improving patient satisfaction and function. Local infiltration analgesia (LIA) and femoral nerve block (FNB) have been commonly used for pain management in ACLR. However, the comparative efficacy and safety between the 2 techniques remains a topic of controversy.

Purpose:

To compare pain reduction, opioid consumption, and side effects of LIA and FNB after ACLR.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic search of MEDLINE, Embase, and Cochrane Library databases was performed to identify studies comparing pain on the visual analog scale (a 100-mm scale), total morphine-equivalent consumption, and side effects between the 2 techniques after ACLR at the early postoperative period. The LIA was categorized into intra-articular injection and periarticular injection, and subgroup analyses were performed comparing either intra-articular injection or periarticular injection with FNB. Two reviewers performed study selection, risk-of-bias assessment, and data extraction.

Results:

A total of 10 studies were included in this systematic review and meta-analysis. In terms of VAS pain scores, our pooled analysis indicated that FNB was significantly more effective at 2 hours postoperatively compared with LIA (mean difference, 8.19 [95% confidence interval (CI), 0.75 to 15.63]; P = .03), with no significant difference between the 2 techniques at 4, 8, and 12 hours postoperatively; however, LIA was significantly more effective at 24 hours postoperatively compared with FNB (mean difference, 5.61 [95% CI, −10.43 to −0.79]; P = .02). Moreover, periarticular injection showed a significant improved VAS pain score compared with FNB at 24 hours postoperatively (mean difference, 11.44 [95% CI, −20.08 to −2.80]; P = .009), and the improvement reached the threshold of minimal clinically important difference of 9.9. Total morphine-equivalent consumption showed no difference between the 2 techniques, and side effects were unable to be quantified for the meta-analysis because of a lack of data.

Conclusion:

Compared with FNB, LIA was not as effective at 2 hours, comparable within 12 hours, and significantly more effective at 24 hours postoperatively for reducing pain after ACLR. Total morphine-equivalent consumption showed no significant differences between the 2 techniques.

Quadriceps and Hamstring Strength in Adolescents 6 Months After ACL Reconstruction With Femoral Nerve Block, Adductor Canal Block, or No Nerve Block

Background:

Femoral nerve block (FNB) and adductor canal block (ACB) have been used increasingly for pain control during anterior cruciate ligament (ACL) reconstruction in adolescent patients. However, recent evidence suggests that the use of FNB may affect quadriceps strength recovery 6 months after surgery.

Purpose/Hypothesis:

To compare postoperative isokinetic strength in adolescents who received FNB, ACB, or no block for perioperative analgesia during ACL reconstruction. We anticipated lower postoperative quadriceps and hamstring isokinetic deficits in adolescents who received FNB as compared with ACB.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients were included in the study if they had undergone hamstring tendon autograft ACL reconstruction by a single surgeon from July 2008 to January 2018 and if they underwent isokinetic muscle testing at 4 to 8 months postoperatively. The participants were divided into 3 groups (no block, FNB, and ACB), and we compared the deficit in percentages between the affected and unaffected limbs as calculated from the isokinetic quadriceps and hamstring strength testing at 60 and 180 deg/s. Between-group analysis was performed using analysis of variance, with an alpha of .05.

Results:

A total of 98 participants were included in the analysis (31 no block, 36 FNB, and 31 ACB). The mean ± SD age of the patients was 15.26 ± 1.15, 15.50 ± 1.42, and 15.71 ± 1.44, for no block, FNB, and ACB, respectively. At 5.61 months postoperatively, there was no significant difference across the 3 groups in isokinetic quadriceps deficits (P ≥ .99), and the only significant difference in isokinetic hamstring deficit was observed for peak flexion at 180 deg/s, in which the ACB group had lower peak torque than the FNB group (–9.80% ± 3.48% vs 2.37% ± 3.23%; P = .035). The ratio of participants with a deficit exceeding 15% did not differ significantly among the 3 groups.

Conclusion:

Contrary to previous research, our findings indicate only minimal difference in quadriceps strength among the 3 types of perioperative analgesia in adolescents approximately 6 months after ACL reconstruction. The only significant strength deficit was seen in the hamstrings of patients receiving ACB at peak flexion as compared with those receiving FNB.

The Effect of Femoral Nerve Block on Quadriceps Strength in Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To assess the isokinetic, functional, and patient-reported outcomes of femoral nerve block (FNB) compared with traditional multimodal anesthesia for FNB in anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic search of PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature, Cochrane Reviews, and Google Scholar was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Effects of FNB on quadriceps function were evaluated by isokinetic testing, functional scoring systems, range of motion, and patient self-report questionnaires. Heterogeneous reporting of outcomes precluded a formal meta-analysis. The methodologic merit of all studies included was evaluated by the Coleman Methodology Score.

RESULTS

Six studies were identified with outcome measures reported between 7 days and 6 months postoperatively. At 6 months, 2 of 4 studies that reported isokinetic testing found significantly greater deficits among patients who received a nerve block; one of the remaining studies showed a deficit at 6 weeks but not 6 months. Limited data showed no significant differences in functional or patient-reported outcomes at 6 months after reconstruction, and data regarding the impact of FNB on return to sport were inconclusive. The mean Coleman Methodology Score for the included studies was 53, indicating poor overall methodologic quality of the available literature.

CONCLUSIONS

The limited data available suggest that FNB causes a measurable deficit in quadriceps isokinetic strength during the early postoperative period but has no effect on functional outcomes or return to sport at 6 months after ACL reconstruction. However, current clinical evidence is not sufficient to draw any valid or definitive conclusions regarding the effect of FNB on postoperative outcomes after ACL reconstruction.

LEVEL OF EVIDENCE

Level IV, systemic review of Level I through IV studies.

Liposomal Bupivacaine Versus Femoral Nerve Block for Pain Control After Anterior Cruciate Ligament Reconstruction: A Prospective Randomized Trial

PURPOSE

To compare femoral nerve block (FNB) versus local liposomal bupivacaine (LB) for pain control in patients undergoing anterior cruciate ligament (ACL) reconstruction.

METHODS

Eighty-five patients undergoing primary ACL reconstruction were assessed for participation. We performed a prospective randomized trial in accordance with the CONSORT (Consolidated Standards of Reporting Trials) 2010 statement. The study arms included either intraoperative local infiltration of LB (20 mL of bupivacaine/10 mL of saline solution) or preoperative FNB with a primary outcome of postoperative pain levels (visual analog scale) for 4 days. Secondary outcomes assessed included opioid consumption (intravenous morphine equivalents), hours slept, patient satisfaction, and calls to the physician. Randomization was by a computerized algorithm. The observer was blinded and the patient was not blinded to the intervention.

RESULTS

One patient declined participation; 2 patients were excluded after randomization. A total of 82 patients were analyzed. Outcomes showed a significant increase in pain in the LB group between 5 and 8 hours postoperatively (mean ± standard deviation, 6.3 ± 2.0 versus 4.8 ± 2.6; P = .01). There were no significant differences between the groups in mean daily pain levels, morphine equivalents, or patient satisfaction when we controlled for graft type, age, body mass index, and sex. Patients receiving an FNB had a nonsignificant increase in number of sleep disturbances on the day of surgery (mean ± standard deviation, 4.4 ± 3.7 v 3.1 ± 2.1; P = .09) and were more likely to call their doctor the following day because of pain (29% v 8%, P = .04). Six patients in the FNB group had either prolonged quadriceps inhibition or sensory disturbance. One patient in the LB group required reoperation for a flexion contracture.

CONCLUSIONS

An increase in acute postoperative pain was found with LB compared with FNB for post-ACL reconstruction pain control. After the acute postoperative period, there were no significant differences in opioid consumption or pain control. The occurrence of nerve irritation postoperatively was found to be higher in the FNB group.

LEVEL OF EVIDENCE

Level I, prospective randomized trial.

Do outcomes of outpatient ACL reconstruction vary with graft type?

BACKGROUND

Studies establishing the feasibility of anterior cruciate ligament (ACL) reconstruction as an outpatient procedure in France were usually conducted with hamstring tendon grafts. The objective of this study was to evaluate the outcomes of outpatient ACL reconstruction according to whether the graft was harvested from the hamstring tendons or patellar tendon.

HYPOTHESIS

Outpatient ACL reconstruction can be performed using any type of graft.

METHODS

A single-centre retrospective study was conducted in consecutive patients older than 16 years who had primary ACL reconstruction using patellar tendon or hamstring tendons, with or without lateral tenodesis. Patients who underwent other procedures on bones or peripheral ligaments and those with a previous history of ACL reconstruction were excluded. The primary evaluation criterion was the occurrence of complications within 45 days after surgery. Secondary evaluation criteria were the visual analogue scale (VAS) for pain during the first 3 postoperative days, patient satisfaction on day 3, and the IKDC and Lysholm clinical scores on day 45.

RESULTS

The analysis included 104 knees (one knee per patient). Hamstring tendons were used in 77 (74%) knees and patellar tendon in 27 (26%) knees. In the hamstring group, 2 (2.6%) patients spent the first postoperative night in the hospital and 2 others were re-admitted. No hospitalisations were recorded in the patellar-tendon group. None of the patients required revision surgery within 45 days of the reconstruction procedure. None of the postoperative criteria studied showed statistically significant differences between the two groups.

DISCUSSION

ACL reconstruction can be performed on an outpatient basis using any type of graft. The main determinants of successful outpatient ACL reconstruction are a standardised clinical management strategy and an appropriate anaesthesia protocol.

LEVEL OF EVIDENCE

Level IV, retrospective study.