Onabotulinumtoxin A injections: a safety review of children with clubfoot under 2 years of age at BC Children's Hospital

Interventions for congenital talipes equinovarus (clubfoot)

BACKGROUND

Congenital talipes equinovarus (CTEV), also known as clubfoot, is a common congenital orthopaedic condition characterised by an excessively turned-in foot (equinovarus) and high medial longitudinal arch (cavus). If left untreated it can result in long-term disability, deformity and pain. Interventions can be conservative (such as splinting or stretching) or surgical. Different treatments might be effective at different stages: at birth (initial presentation); when initial treatment does not work (resistant presentation); when the initial treatment works but the clubfoot returns (relapse/recurrent presentation); and when there has been no early treatment (neglected presentation). This is an update of a review first published in 2010 and last updated in 2014.

OBJECTIVES

To assess the effects of any intervention for any type of CTEV in people of any age.

SEARCH METHODS

On 28 May 2019, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL Plus, AMED and Physiotherapy Evidence Database. We also searched for ongoing trials in the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov (to May 2019). We checked the references of included studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs evaluating interventions for CTEV, including interventions compared to other interventions, sham intervention or no intervention. Participants were people of all ages with CTEV of either one or both feet.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risks of bias in included trials and extracted the data. We contacted authors of included trials for missing information. We collected adverse event information from trials when it was available. When required we attempted to obtain individual patient data (IPD) from trial authors for re-analysis. If unit-of-analysis issues were present and IPD unavailable we did not report summary data, MAIN RESULTS: We identified 21 trials with 905 participants; seven trials were newly included for this update. Fourteen trials assessed initial cases of CTEV (560 participants), four trials assessed resistant cases (181 participants) and three trials assessed cases of unknown timing (153 participants). The use of different outcome measures prevented pooling of data for meta-analysis, even when interventions and participants were comparable. All trials displayed high or unclear risks of bias in three or more domains. Twenty trials provided data. Two trials reported on the primary outcome of function using a validated scale, but the data were not suitable for inclusion because of unit-of-analysis issues, as raw data were not available for re-analysis. We were able to analyse data on foot alignment (Pirani score), a secondary outcome, from three trials in participants at initial presentation. The Pirani score is a scale ranging from zero to six, where a higher score indicates a more severe foot. At initial presentation, one trial reported that the Ponseti technique significantly improved foot alignment compared to the Kite technique. After 10 weeks of serial casting, the average total Pirani score of the Ponseti group was 1.15 points lower than that of the Kite group (mean difference (MD) -1.15, 95% confidence interval (CI) -1.32 to -0.98; 60 feet; low-certainty evidence). A second trial found the Ponseti technique to be superior to a traditional technique, with mean total Pirani scores of the Ponseti participants 1.50 points lower than after serial casting and Achilles tenotomy (MD -1.50, 95% CI -2.28 to -0.72; 28 participants; very low-certainty evidence). One trial found evidence that there may be no difference between casting materials in the Ponseti technique, with semi-rigid fibreglass producing average total Pirani scores 0.46 points higher than plaster of Paris at the end of serial casting (95% CI -0.07 to 0.99; 30 participants; low-certainty evidence). We found no trials in relapsed or neglected cases of CTEV. A trial in which the type of presentation was not reported showed no evidence of a difference between an accelerated Ponseti and a standard Ponseti treatment in foot alignment. At the end of serial casting, the average total Pirani score in the accelerated group was 0.31 points higher than the standard group (95% CI -0.40 to 1.02; 40 participants; low-certainty evidence). No trial assessed gait using a validated assessment. Health-related quality of life was reported in some trials but data were not available for re-analysis. There is a lack of evidence for the addition of botulinum toxin A during the Ponseti technique, different types of major foot surgery or continuous passive motion treatment following major foot surgery. Most trials did not report on adverse events. Two trials found that further serial casting was more likely to correct relapse after Ponseti treatment than after the Kite technique, which more often required major surgery (risk differences 25% and 50%). In trials evaluating serial casting techniques, adverse events included cast slippage (needing replacement), plaster sores (pressure areas), and skin irritation. Adverse events following surgical procedures included infection and the need for skin grafting.

AUTHORS' CONCLUSIONS

From the evidence available, the Ponseti technique may produce significantly better short-term foot alignment compared to the Kite technique. The certainty of evidence is too low for us to draw conclusions about the Ponseti technique compared to a traditional technique. An accelerated Ponseti technique may be as effective as a standard technique, but results are based on a single small comparative trial. When using the Ponseti technique semi-rigid fibreglass casting may be as effective as plaster of Paris. Relapse following the Kite technique more often led to major surgery compared to relapse following the Ponseti technique. We could draw no conclusions from other included trials because of the limited use of validated outcome measures and the unavailability of raw data. Future RCTs should address these issues.

Botulinum Toxin Type A Versus Placebo for Idiopathic Clubfoot: A Two-Center, Double-Blind, Randomized Controlled Trial

BACKGROUND

Congenital idiopathic clubfoot is a condition that affects, on average, approximately 1 in 1,000 infants. One broadly adopted method of management, described by Ponseti, is the performance of a percutaneous complete tenotomy when hindfoot stall occurs. The use of onabotulinum toxin A (BTX-A) along with the manipulation and cast protocol described by Ponseti has been previously reported. Our goal was to compare the clinical outcomes between BTX-A and placebo injections into the gastrocnemius-soleus muscle at the time of hindfoot stall in infants with idiopathic clubfoot treated with the Ponseti method of manipulation and cast changes.

METHODS

This was a double-blind, placebo-controlled, parallel-group study with balanced randomization.

RESULTS

At 6 weeks after the study injection (T1), 66% of the 32 feet in the BTX-A arm and 63% of the 30 in the placebo arm responded to the treatment (i.e., obtained ≥15° of dorsiflexion). Seven of the 11 patients in the BTX-A arm and all of the 11 in the placebo arm who had not responded at T1 responded to a rescue BTX-A injection at 12 weeks after the first injection (T2). The combined response rate at T2, which included the first-time responders as well as the patients who did not respond at T1 but did at T2, was 88% in the BTX-A arm and 100% in the placebo arm, culminating in a 94% response rate at T2. At T3 (2 years of age), 89% of the feet continued to respond and there was an 8% surgical rate.

CONCLUSIONS

There was no difference in outcomes between the BTX-A and placebo groups when the injection was performed at the time of hindfoot stall. Overall, 92% of the clubfeet in this study responded to a manipulation and cast protocol alone, with or without BTX-A injection, by 12 weeks after hindfoot stall, or we can say that 92% of the clubfeet did not require percutaneous Achilles tendon lengthening by 2 years of age. The need for tenotomy is limited to those who have not responded to treatment at this point, and the need for surgery is limited to those for whom all attempts at treatment with sequential casts, BTX-A, and percutaneous Achilles tendon lengthening have failed.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures

Injections of botulinum neurotoxins (BoNTs) are prescribed by clinicians for a variety of disorders that cause over-activity of muscles; glands; pain and other structures. Accurately targeting the structure for injection is one of the principle goals when performing BoNTs procedures. Traditionally; injections have been guided by anatomic landmarks; palpation; range of motion; electromyography or electrical stimulation. Ultrasound (US) based imaging based guidance overcomes some of the limitations of traditional techniques. US and/or US combined with traditional guidance techniques is utilized and or recommended by many expert clinicians; authors and in practice guidelines by professional academies. This article reviews the advantages and disadvantages of available guidance techniques including US as well as technical aspects of US guidance and a focused literature review related to US guidance for chemodenervation procedures including BoNTs injection.

Botulinum Toxin in the Treatment of Pediatric Upper Limb Spasticity

Botulinum neurotoxin (BoNT) is one of the mainstays in the treatment of pediatric spasticity and dystonia. When considering initiation of BoNT treatment for spasticity, treatment goals and responses to prior conservative measures such as passive range of motion exercises, splinting, and other medication trials should be reviewed. As a general rule, children should be engaged in therapy services around the time of the injections and have a robust home program in place. When managing spasticity in children with BoNT injections, the practitioner should be well versed in functional anatomy with specialized training in injection techniques. Localization techniques in addition to anatomical landmarks are recommended for improved efficacy and include limited electromyography, electrical stimulation, and/or ultrasound guidance. A follow-up visit for the purpose of reassessment during the peak effect of the drug is advised. It is known that BoNT is effective at reducing spasticity and improving range of motion, but it remains to be determined to what degree this translates into improved function, activity, and participation.