Botulinum Toxin type A injections for patients with painful hallux valgus: a double-blind, randomized controlled study

Botulinum toxin in the rehabilitation of painful syndromes: multiperspective literature analysis, lexical analysis and systematic review of randomized controlled trials

Pain represents a common symptom of several diseases and is often associated with a reduction in rehabilitation outcomes and recovery. The effectiveness of pain alleviation by botulinum toxin has been recently demonstrated. We searched in PubMed the papers about this topic published in the last ten years, and we selected clinical trials, guidelines, meta-analyses, reviews, and systematic reviews. We used different approaches: multiperspective presentation, lexical evaluation, and systematic review. The systematic review was only performed for the randomized controlled trials. We predominantly found reviews and trials about the rehabilitation of stroke/brain injury and epicondylitis. The most common outcome measures were pain, function, and spasticity. Among the common words, pain was the most frequent and the terms were grouped into different families, especially concerning the outcomes. Rehabilitation showed a relatively low frequency. Finally, the systematic review showed moderate-low levels of bias which confirms the effectiveness of botulinum toxin for pain treatment. The current literature about botulinum toxin is wide and globally diffuse but with some limitations in study strategies and clearness in the formal presentation. The evidence justifies the use of botulinum toxin in treating pain in different diseases.

Use of botulinum toxin as a non-surgical treatment option for idiopathic hallux varus: a case report

Hallux varus presents with midline deviation of the hallux at the first metatarsophalangeal joint. If left untreated, it may lead to pain and difficulty with normal daily activities. Here, we present a case of spontaneous hallux varus in an 84-year-old female treated non-operatively with injection of botulinum toxin in the Abductor Hallucis Brevis. Ultrasound guidance with electromyography was used to assist in all injections. Near total symptomatic relief and resumption of daily activities was obtained for up to 12 weeks at a time. Radiographic correction seen was improvement from 14° to 7° on weight bearing radiographs. After five rounds of treatment, no adverse reactions had been observed.

Pain Reduction With AbobotulinumtoxinA for the Treatment of Hallux Valgus in Adult Participants: Results of a Randomized and Placebo-Controlled Phase 2 Trial

AbobotulinumtoxinA (aboBoNT-A, Dysport® [Ipsen, Paris, France]) inhibits acetylcholine release at the neuromuscular junction and may modulate pain signaling in hallux valgus (HV). This randomized study (NCT03569098) included a double-blind phase (aboBoNT-A 300U, 500U or placebo injections into forefoot muscles) and an open-label aboBoNT-A treatment period in participants with an HV diagnosis and no HV surgery. The primary endpoint was change from baseline in numeric pain rating scale (NPRS) score at week 8. Secondary endpoints included change in NPRS (other time points) and proportion of participants with ≥20% reduction from baseline NPRS (responders). Post-hoc analyses assessed number of days in a 7-day evaluation period that participants spent in a lower pain state than at baseline. Participants received aboBoNT-A 300U (n = 63), 500U (n = 60) or placebo (n = 63). Superiority to placebo was not observed with either aboBoNT-A dose at week 8, thus the primary endpoint was unmet. At week 12, a trend toward efficacy was observed with aboBoNT-A 500U versus placebo and the proportion of participants with ≥20% reduction from baseline NPRS was greater with aboBoNT-A 500U versus placebo (p = .006). Participants in the aboBoNT-A 500U group spent more days with lower NPRS than their lowest baseline score, and with NPRS ≥2 points lower than their mean baseline NPRS at weeks 8 and 12 versus placebo (all p < .05; post-hoc). AboBoNT-A was well tolerated. Although the primary endpoint was unmet, other endpoints showed a nominal advantage for aboBoNT versus placebo for treatment of HV-related pain, particularly at week 12. Further clinical evaluation is needed to establish whether botulinum toxins represent a viable non-operative treatment option for HV-associated pain. PLAIN LANGUAGE SUMMARY: Hallux valgus is the medical name for a bunion, a foot deformity that can worsen over time. Patients with bunions experience pain and walking can become difficult, which can affect their quality of life. Foot support aids (e.g., braces, splints and inserts) are available, but surgery is the standard treatment. This study looked at how injections of a specific type of botulinum toxin, called abobotulinumtoxinA or "aboBoNT-A", into the foot may help to reduce pain in patients with bunions. The study included 186 patients aged 18 to 75 years who had not had surgery on their bunion. The researchers looked at how well the injections worked using scales that measure the pain levels the patient experienced. The main outcome was whether patients who had aboBoNT-A injections had less pain after 8 weeks than they did before treatment. The study included patients who were injected with saltwater (no treatment) to check that any treatment effect was real. Researchers also looked at the results after 12 weeks, as well as how many patients had less pain after treatment than before and how many days in a given week patients experienced less pain after treatment than they did before. There was no reduction in pain levels with aboBoNT-A injections after 8 weeks compared with no treatment. However, the other study outcomes suggested that aboBoNT-A resulted in a small benefit compared with no treatment, especially after 12 weeks. Further medical research is needed to establish whether botulinum toxins represent an alternative treatment to surgery for the pain associated with bunions.

Exploring the Relationship Between Clinical Presentation in Hallux Valgus and Response to AbobotulinumtoxinA Treatment

The relationship between pain/disability and angular deviation of the hallux valgus (HV), and the impact of orthotic use, laterality, and pain variability on treatment outcomes remain unclear. This was explored in post hoc analyses of a placebo-controlled trial of abobotulinumtoxinA (aboBoNT-A; Dysport®) for HV-associated pain (NCT03569098). The primary endpoint was not met in this study (change from baseline Numeric Pain Rating Scale [NPRS] score vs placebo at week 8); however, there was a greater reduction from baseline in mean NPRS score at week 12 with aboBoNT-A 500U versus placebo (p = .06). Adults with painful HV without surgery were randomized (1:1:1) to aboBoNT-A 300U, aboBoNT-A 500U, or placebo. NPRS was completed for 7 days before baseline and weeks 4, 8, and 12. Over-the-counter orthoses were permitted. Participants (N = 186) had a mean [standard deviation, SD] age of 48.2 [13.1] years, 18% (33/186) used orthotics, and 67% (124/186) had bilateral HV. No associations between baseline pain severity and angular deviation were identified. Participants with high pain variability at baseline (SD > 2) had a poorer response to aboBoNT-A treatment than those with less variability. In conclusion, no relationship between HV-related pain/disability and angular deviation was observed. PLAIN LANGUAGE SUMMARY: A bunion (medical term: hallux valgus) is a common adult foot problem in which the big toe points inward toward the other toes, and this can be painful. How much the big toe points inward (how deformed the foot is) has been linked to the amount of pain the patient experiences. A better understanding of this foot deformity and bunion pain will help doctors and patients to make the right treatment decisions. A study was completed looking at how injections of a type of botulinum toxin (abobotulinumtoxinA) into specific muscles in the foot may help to reduce bunion pain in patients without surgery. This subsequent analysis of the study data looked at the amount of foot deformity in patients, the bunion pain they experienced, and which factors affected how well abobotulinumtoxinA worked to reduce bunion pain. The results of this study showed that the amount of foot deformity was not linked to the level of bunion pain. When deciding the best treatment option to relieve bunion pain, it is important that doctors not only consider how deformed the foot is, but also other important factors such as foot pain levels.

Impact of First Metatarsal Hyperpronation on First Ray Alignment: A Study in Cadavers

BACKGROUND

There is increased evidence of first metatarsal hyperpronation in patients with hallux valgus, but its impact on the stability of the first metatarsophalangeal and metatarsosesamoid joints is unknown. A previous biomechanical study showed that an increase in hallucal pronation might lead to medial soft tissue failure of the first metatarsophalangeal joint. Conversely, dynamic studies on hallux valgus have shown that the first tarsometatarsal joint moves in supination during weightbearing, and supination was associated with an increase in the intermetatarsal angle (IMA) and hallux valgus angle (HVA).

QUESTIONS/PURPOSES

(1) Does an increase in first metatarsal pronation cause an increase in hallucal pronation? (2) Can an intrinsic increase in first metatarsal pronation lead to first ray supination during weightbearing? (3) Can a combination of intrinsic first metatarsal hyperpronation and first metatarsophalangeal medial soft tissue failure increase supination of the first ray during weightbearing? (4) Is first ray supination during weightbearing associated with an increase in the IMA and HVA?

METHODS

Twelve transtibial, nonpaired cadaver specimens without deformities were used. Each specimen underwent six weightbearing CT scans under different conditions. The first three CT examinations were performed without any osteotomy of the first metatarsal. The first was a simulated nonweightbearing condition. The second was a simulated weightbearing condition. The third was a simulated weightbearing condition with medial soft tissue release. Subsequentially, a 30° pronation osteotomy of the first metatarsal was performed, and the same sequence of weightbearing CT images was obtained. On each weightbearing CT image, the HVA, IMA, sesamoid rotation angle, metatarsal pronation angle (MPA), metatarsosesamoid rotation angle, and hallucal pronation (HP) were measured. Motions were calculated based on the differential values of these angular measurements produced by the six different conditions (weightbearing, medial soft tissue release, 30° pronation osteotomy, and combinations of these conditions). We compared means using a t-test for normally distributed variables and the Mann-Whitney U test for nonnormally distributed variables. Correlations were assessed with Pearson product-moment correlation coefficients.

RESULTS

We found that 30° pronation osteotomy of the first metatarsal increased the MPA and HP by 28° ± 4° and 26° ± 6°, respectively, in the nonweightbearing condition. No differences between the increase in MPA and the increase in HP were noted (mean difference 2° [95% CI -1° to 5°]; p = 0.20). Therefore, an increase in first metatarsal pronation caused an increase in hallucal pronation. When a 30° pronation osteotomy of the first metatarsal was performed, the first ray motion during weightbearing went from pronation to supination (4° ± 2° in pronation without osteotomy versus 4° ± 2° in supination after the osteotomy, mean difference 8° [95% CI 6° to 9°]; p < 0.001). Therefore, an intrinsic increase in pronation of the first metatarsal led to a first ray supination motion during weightbearing. When a first metatarsophalangeal medial soft tissue release was performed in addition to the 30° osteotomy of the first metatarsal, the supination motion of the first ray increased (4° ± 2° without medial soft tissue release versus 11° ± 7° after the release, mean difference 8° [95% CI 3° to 12°]; p = 0.003). Therefore, a combination of intrinsic first metatarsal hyperpronation and first metatarsophalangeal medial soft tissue failure increased supination of the first ray during weightbearing. Regarding static angular measurements, the HVA and IMA were not correlated with the MPA (ρ = 0.20; p = 0.09 and ρ = 0.22; p = 0.07, respectively). Regarding motions, as the HVA and IMA increased from nonweightbearing to weightbearing the pronation decreased, with strong correlations (ρ = -0.82; p < 0.001 and ρ = -0.77; p < 0.001, respectively). Therefore, a first ray supination during weightbearing was associated with an increase in the HVA and IMA.

CONCLUSION

The combination of first metatarsal intrinsic hyperpronation and first metatarsophalangeal medial soft tissue failure led to a hallux valgus deformity in this cadaveric study. The static measurement of first metatarsal head pronation relative to the ground (MPA) did not reflect the real intrinsic pronation of the first ray, and foot and ankle specialists should be careful when interpreting these measurements. Hallux valgus is a dynamic condition, and the deformity could be more correlated with motions during weightbearing than with plain static measurements.

CLINICAL RELEVANCE

First ray supination compensating for first metatarsal intrinsic hyperpronation might be an important factor in the hallux valgus pathogenesis. Further in vivo studies involving nonweightbearing and weightbearing comparative assessments of hallux valgus and controls should be performed to confirm this pathomechanism.

Adjusted Indirect and Mixed Comparisons of Conservative Treatments for Hallux Valgus: A Systematic Review and Network Meta-Analysis

Background: Hallux valgus (HV) deformity is a common, potentially debilitating deformity. And evidence with high-quality for the conservative treatments of HV deformity is still required.; AIMS: To compare the effects of different conservative treatments for hallux valgus deformity by using the method of network meta-analysis.; Study Design: A systematic review and network meta-analysis of randomized controlled trials identified by searching PubMed, EMBASE, MEDLINE, OVID, and CINAHL. The included studies should have the characteristics that: (1) participants with hallux valgus deformity of any age (2) conservative treatments (3) Reported the hallux valgus (HVA), the intermetatarsal angle (IMA), the score of the Visual Analog Scale, and the score of Foot Function Index.; Results: 11 studies were included in this review. The agreement between reviewers reached a kappa value of 0.75. The results of the network meta-analysis showed that a combination of exercise and toe separator, night splints, and dry needling are most likely to be the best choice for reducing the hallux valgus angle (HVA) and intermetatarsal angle, and toe separators (with or without exercise), dry needling, and manipulation (with or without ice treatment) have advantages in improving the subjective feeling of patients.; Conclusions: Multi-disciplinary conservative treatments have a great potential for hallux valgus deformity. More research with high-quality is needed to give a comprehensive and reasonable scheme of a holistic and long-term treatment protocol.

Effectiveness of non-surgical interventions for hallux valgus: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis investigating the effectiveness of non-surgical interventions for hallux valgus (HV).

METHODS

The review protocol was registered with PROSPERO (CRD42019111711). Medline, CINAHL, Embase, and the Cochrane Library were searched to April 2020, including parallel-group and crossover studies investigating non-surgical interventions for HV. Two reviewers independently screened articles for inclusion, extracted data, performed risk of bias and GRADE assessments. Risk of bias was assessed using version 2 of the Cochrane risk of bias tool. Effect sizes (mean differences or risk ratios, and 95% confidence intervals) were calculated and pooled where possible for the primary outcomes, foot pain and HV angle.

RESULTS

Eighteen included studies investigated a wide range of non-surgical interventions for HV. Most studies had small sample sizes and concerns regarding risk of bias. Five separate meta-analyses for foot orthoses, splints, manual therapy, and taping added to foot exercises showed no significant effects on primary outcomes. However, results from eight studies showed a significant pain reduction with the use of foot orthoses, night splints, dynamic splints, manual therapy, taping added to foot exercises, multifaceted physical therapy program and Botox injections. Four studies reported a clinically significant reduction in HV angle with night splints, foot exercises, multifaceted physical therapy and Botox injections.

CONCLUSION

There is a low level of certainty surrounding the effectiveness of non-surgical interventions for HV, however a reduction in pain appears more likely than improvement in HV angle.

Treatment of "plantar fasciitis"/Plantar Heel Pain Syndrome with botulinum toxin - A novel injection paradigm pilot study

Randomized controlled trials over the last two decades, although promising with favorable results, have shown varied efficacy in treatment of "plantar fasciitis" with botulinum toxin injection¹. One reason may be due to conflating the variabilities of plantar heel conditions solely as plantar fasciitis. Plantar Heel Pain Syndrome can be of one or more etiologies and symptoms which refutes the mistaken tendency to categorize all plantar heel pain singularly as either plantar fasciitis or fasciosis. Recognizing that there is likely an interplay of inflammatory, degenerative, and neuropathic etiologic conditions of this often-difficult malady to treat, a novel injection paradigm of botulinum toxin is explored in the treatment of 4 distinct presentations of Plantar Heel Pain Syndrome with encouraging results. Botulinum toxin injection into two intrinsic foot muscles; Abductor Hallucis and Quadratus Plantae at their origins with electrical stimulation is presented as novel method to treat four distinct etiologies of Plantar Heel Pain Syndrome. This method of botulinum toxin injection resulted in significant prolonged improvement of patient function and pain reduction in four variations of Plantar Heel Pain Syndrome. A precise injection paradigm facilitated with direct intrinsic muscle stimulation of the Abductor Hallucis and Quadratus Plantae at their origins may prove to be effective in reducing the disabilities of Plantar Heel Pain Syndrome and its associated pain.

Nonsurgical Treatment for Hallux Abducto Valgus with Botulinum Toxin Type A

BACKGROUND

Hallux abducto valgus (HAV) is a frequently seen abnormality of the first metatarsophalangeal joint. Limited conservative treatment options exist, making surgery the only definitive treatment option for a mild to moderate deformity. Since initially published in 2008, treatment of HAV with botulinum toxin injection has evolved as a potentially effective modality as shown in several subsequent independent studies.

METHODS

Botulinum injection of two intrinsic foot muscles (extensor halluces brevis and flexor hallucis brevis) in addition to adductor hallucis under electrical stimulation is presented as an improvement to the original method.

RESULTS

The additional muscle injections of botulinum resulted in an further reduction of the HAV deformity and associated pain.

CONCLUSIONS

A significant improvement to the injection paradigm developed the author may prove to be more effective in reducing the HAV deformity and its associated pain.

Treatment of hallux valgus deformity

Hallux valgus deformity is a very common pathological condition which commonly produces painful disability. It is characterised as a combined deformity with a malpositioning of the first metatarsophalangeal joint caused by a lateral deviation of the great toe and a medial deviation of the first metatarsal bone.

Taking the patient’s history and a thorough physical examination are important steps. Anteroposterior and lateral weight-bearing radiographs of the entire foot are crucial for adequate assessment in the treatment of hallux valgus.

Non-operative treatment of the hallux valgus cannot correct the deformity. However, insoles and physiotherapy in combination with good footwear can help to control the symptoms.

There are many operative techniques for hallux valgus correction. The decision on which surgical technique is used depends on the degree of deformity, the extent of degenerative changes of the first metatarsophalangeal joint and the shape and size of the metatarsal bone and phalangeal deviation. The role of stability of the first tarsometatarsal joint is controversial.

Surgical techniques include the modified McBride procedure, distal metatarsal osteotomies, metatarsal shaft osteotomies, the Akin osteotomy, proximal metatarsal osteotomies, the modified Lapidus fusion and the hallux joint fusion. Recently, minimally invasive percutaneous techniques have gained importance and are currently being evaluated more scientifically.

Hallux valgus correction is followed by corrective dressings of the great toe post-operatively. Depending on the procedure, partial or full weight-bearing in a post-operative shoe or cast immobilisation is advised. Post-operative radiographs are taken in regular intervals until osseous healing is achieved.

Cite this article: Fraissler L, Konrads C, Hoberg M, Rudert M, Walcher M. Treatment of hallux valgus deformity. EFORT Open Rev 2016;1:295-302. DOI: 10.1302/2058-5241.1.000005.