Is Botulinum Toxin Type A a Valuable Adjunct During Femoral Lengthening? A Randomized Trial

Botulinum toxin type A for lower limb lengthening and deformity correction: A systematic review and meta-analysis

BACKGROUND

Botulinum toxin type A (BTX-A) is the most popular therapeutic agent for muscle relaxation and pain control. Lately, BTX-A injection received great interest as a part of multimodal pain management for lower limb lengthening and deformity correction. This systematic review aimed to determine the role of BTX-A injection in pain management for during lower limb lengthening and/or deformity correction.

METHODS

We searched Medline, Embase, and CENTRAL. We included randomized controlled trials (RCTs) that compared the BTX-A injection to placebo for individuals undergoing lower limb lengthening and/or deformity correction. We sought to evaluate the following outcomes: pain on visual analogue scale (VAS), range of motion parameters, average opioid consumption, and adverse events. The standardized mean difference (SMD) was used to represent continuous outcomes while risk ratio (RR) was used to represent dichotomous outcomes.

RESULTS

A total of 4 RCTs that enrolled 257 participants (337 limbs) deemed eligible. Adjuvant BTX-A injection showed a significant reduction in post-operative pain compared to placebo (SMD = -0.28, 95% CI -0.53 to -0.04). No difference was found between BTX-A injection and placebo in terms of range of motion parameters, average opioid consumption, or adverse events after surgical limb lengthening and/or deformity correction (RR = 0.77, 95% CI -0.58 to 1.03).

CONCLUSIONS

Adjuvant BTX-A injection conferred a discernible reduction in post-operative pain during surgical limb lengthening and/or deformity without increasing the risk of adverse events.

PROSPERO REGISTRATION NUMBER

CRD42021271580.

Efficacy and safety of botulinum toxin type A in distraction osteogenesis of the lower extremities: a meta-analysis of randomized controlled trials

Background

To explore the efficacy and safety of botulinum toxin in patients who received distraction osteogenesis of the lower extremities.

Methods

We searched the PubMed, Medline, Cochrane Library, and Web of Science databases for randomized controlled trials that administered botulinum toxin to individuals who underwent distraction osteogenesis of the lower limbs. The final search was conducted on July 6, 2021. Quality assessments were conducted using the Cochrane risk of bias tool and the Jadad scale. We performed random-effects meta-analysis to calculate the standardized mean differences (SMDs) and confidence intervals (CIs) of the pooled effect sizes, and subgroup analysis and meta-regression were performed for potential moderators.

Results

Our analysis of four randomized controlled trials, which enrolled a total of 257 participants, revealed that the difference in pain during the distraction phase was not statistically significant between groups (SMD, − 0.165; 95% CI, − 0.379 to 0.050, p = 0.133, I² = 0.0%). The meta-regression analyses did not find any influence on the effect size, considering age (β = − 0.0092; p = 0.61) and the amount of lengthening (β = 0.0023; p = 0.99). Subgroup analysis did not reveal difference between different doses of botulinum toxin and single or multi-site study design. An analysis of two randomized controlled trials enrolling a total of 177 individuals demonstrated a limited effect of botulinum toxin in reducing postoperative pain (SMD, − 0.239; 95% CI, − 0.641 to 0.162, p = 0.24, I² = 37.6%), total adverse events (SMD, − 0.207; 95% CI, − 0.505 to 0.090, p = 0.17, I² = 0.0%), and infection of pin site (SMD, − 0.131; 95% CI, − 0.428 to 0.165, p = 0.39, I² = 0.0%). No botulinum toxin–related adverse events were reported.

Conclusions

The current evidence does not support the administration of botulinum toxin in patients who receive distraction osteogenesis of the lower limbs. However, we were unable to draw decisive conclusions because of the limitations of our meta-analysis. Future well-designed, large-scale randomized controlled trials are necessary to confirm our conclusions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05175-2.

Anatomical locations of the motor endplates of sartorius muscle for botulinum toxin injections in treatment of muscle spasticity

PURPOSE

This study aimed to detect the idyllic locations for botulinum neurotoxin injection by analyzing the intramuscular neural distributions of the sartorius muscles.

METHODS

An altered Sihler's staining was conducted on sartorius muscles (15 specimens). The nerve entry points and intramuscular arborization areas were measured as a percentage of the total distance from the most prominent point of the anterior superior iliac spine (0%) to the medial femoral epicondyle (100%).

RESULTS

Intramuscular neural distribution were densely detected at 20-40% and 60-80% for the sartorius muscles. The result suggests that the treatment of sartorius muscle spasticity requires botulinum neurotoxin injections in particular locations.

CONCLUSIONS

These locations, corresponding to the locations of maximum arborization, are suggested as the most suggestive points for botulinum neurotoxin injection.

Complications of Limb Lengthening With Motorized Intramedullary Nails

Intramedullary limb lengthening (LL) is now achievable through motorized intramedullary devices. While this technology mitigates some complications of external-fixation-based lengthening, many complications common to all lengthening procedures persist. New challenges and complications exclusive to this newer technology are also presented. The LL surgeon should be aware of and ready to respond to complications involving device malfunctions, poor local bony and soft-tissue biology, patient compliance, neurovascular compromise, joint instability, regenerate problems, and others. While technology will continue to evolve, study of and adherence to foundational principles of LL will minimize risks and optimize patient outcomes.