Correlates of foot pain severity in adults with hallux valgus: a cross-sectional study

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.

One- and Two-Year Analysis of a Five-Year Prospective Multicenter Study Assessing Radiographic and Patient-Reported Outcomes Following Triplanar First Tarsometatarsal Arthrodesis With Early Weightbearing for Symptomatic Hallux Valgus

We report one- and 2-year results of a prospective, 5-year, multicenter study of radiographic, clinical, and patient-reported outcomes following triplanar first tarsometatarsal arthrodesis with early weightbearing. One-hundred and seventeen patients were included with a mean (95% confidence interval [CI]) follow-up time of 16.6 (15.5, 17.7) months. Mean (95% CI) time to weightbearing in a boot walker was 7.8 (6.6, 9.1) days, mean time to return to athletic shoes was 45.0 (43.5, 46.6) days, and mean time to return to unrestricted activity was 121.0 (114.5, 127.5) days. There was a significant improvement in radiographic measures with a mean corrective change of -18.0° (-19.6, -16.4) for hallux valgus angle, -8.3° (-8.9, -7.8) for intermetatarsal angle and -2.9 (-3.2, -2.7) for tibial sesamoid position at 12 months (n = 108). Additionally, there was a significant improvement in patient-reported outcomes (Visual Analog Scale, Manchester-Oxford Foot Questionnaire, and Patient-Reported Outcomes Measurement Information System) and changes were maintained at 12 and 24 months postoperatively. There was 1/117 (0.9%) reported recurrence of hallux valgus at 12 months. There were 16/117 (13.7%) subjects who experienced clinical complications of which 10/117 (8.5%) were related to hardware. Of the 7/117 (6.0%) who underwent reoperation, only 1/117 (0.9%) underwent surgery for a nonunion. The results of the interim report of this prospective, multicenter study demonstrate favorable clinical and radiographic improvement of the HV deformity, early return to weightbearing, low recurrence, and low rate of complications.

The effect of osteotomy technique (flat-cut vs wedge-cut Weil) on pain relief and complication incidence following surgical treatment for metatarsalgia in a private metropolitan clinic: protocol for a randomised controlled trial

BACKGROUND

Weil osteotomies are performed to surgically treat metatarsalgia, by shortening the metatarsal via either a single distal oblique cut with translation of the metatarsal head (flat-cut) or through the removal of a slice of bone (wedge-cut). The wedge-cut technique purportedly has functional and mechanical advantages over the flat-cut procedure; however, in vivo data and quality of evidence are currently lacking. This study aims to investigate whether wedge-cut Weil osteotomy compared to traditional flat-cut Weil is associated with increased pain relief and fewer complications up to 12 months postoperatively.

METHODS

Patient, surgical and clinical data will be collected for 80 consecutive consenting patients electing to undergo surgical treatment of propulsive metatarsalgia in a randomised control trial, embedded within a clinical registry. The primary outcome is patient-reported pain as assessed by the Foot and Ankle Outcome Score (FAOS) - Pain subscale, and the secondary outcome is the incidence of procedure-specific complications at up to 12 months postoperatively. The groups will be randomised using a central computer-based simple randomisation system, with a 1:1 allocation without blocking and allocation concealment. A mixed-effects analysis of covariance will be used to assess the primary outcome, with confounders factored into the model. A binary logistic regression will be used to assess the secondary outcome in a multivariable model containing the same confounders.

DISCUSSION

To the best of the authors' knowledge, the trial will be the first to examine the clinical efficacy of the wedge-cut Weil osteotomy compared to the flat-cut technique with a prospective, randomised control design.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12620001251910. Registered on 23 November 2020.

Identification of radiographic characteristics associated with pain in hallux valgus patients: A preliminary machine learning study

Objective

To investigate the association between the structural deformity and foot pain in hallux valgus (HV) patients using a multi-variate pattern analysis (MVPA) approach.

Methods

Plain radiographic metrics were calculated from 36 painful and 36 pain-free HV feet. In analysis 1, univariate analyses were performed to investigate the clinical and radiographic differences between painful and pain-free HV. In analysis 2, we investigated the pattern differences for radiographic metrics between these two groups using a MVPA approach utilizing a support vector machine. In analysis 3, sequential backward selection and exhaustive search were performed as a feature-selection procedure to identify an optimal feature subtype. In analysis 4, hierarchical clustering analysis was used to identify the optimal radiographic HV subtype associated with pain in HV.

Results

We found that: (1) relative to feet with pain-free HV, the painful ones exhibited a higher hallux valgus angle, i.e., the magnitude of distal metatarsal and phalangeal deviation; (2) painful HV could be accurately differentiated from pain-free HV via MVPA. Using sequential backward selection and exhaustive search, a 5-feature subset was identified with optimal performance for classifying HV as either painful or pain-free; and (3) by applying hierarchical clustering analysis, a radiographic subtype with an 80% pain incidence was identified.

Conclusion

The pain in HV is multifactorial and associated with a radiographic pattern measured by various angles on plain radiographs. The combination of hallux valgus angle, inter-phalangeal angle, distal metatarsal articular angle, metatarsal cuneiform angle and metatarsal protrusion distance showed the optimal classification performance between painful and pain-free HV.

Foot structural factors and ground reaction force in hallux valgus grades

BACKGROUND

Little attention has been paid to foot structural factors and ground reaction force in hallux valgus. Investigating the structural factors in detail and determining their biomechanical effects can help to better manage hallux valgus.

METHODS

In this case-control study, 120 females, 90 hallux valgus and 30 healthy, were recruited. Hallux valgus grades (mild, moderate, severe), first metatarsal mobility, foot pronation, hallux rotation, and pain were assessed by clinical tests. Ground reaction forces were measured in barefoot and shod conditions for both feet and analyzed using mixed within-between MANOVA. The association between structural factors and pain with force was analyzed using Spearman correlation coefficient.

RESULTS

The frequency of foot structural factors and pain severity were reported in hallux valgus grades. A significant difference was seen in the force values between groups (P<0.001). Bonferroni post hoc test indicated that the mean of the first peak for the severe group was significantly higher than the mild group (P=0.013) and the mean of second peak for the moderate group was higher than that of the healthy group (P=0.009). The force values were affected by wearing shoe (P<0.001) but not by foot side (P=0.086). There was a medium, positive correlation between the hallux rotation and force in the moderate group (r=0.39, P=0.03) and also between the pronation and force in the severe group (r=0.36, P=0.04).

CONCLUSION

Foot structural factors, pain, and force were different in each hallux valgus grads. Similar force in both feet, and increased force by wearing shoe were seen. The relationship between the pronation and hallux rotation with force revealed the importance of these factors from the biomechanical viewpoint.

Detailed analysis of the transverse arch of hallux valgus feet with and without pain using weightbearing ultrasound imaging and precise force sensors

Background

Hallux valgus is the most common forefoot deformity and affects the transverse arch structure and its force loading patterns. This study aims to clarify the differences in the transverse arch structure and the force under the metatarsal heads individually, between normal feet and hallux valgus feet, and between hallux valgus feet with pain and without pain. We further test the association between the parameters of the transverse arch and hallux valgus angle and between the parameters and pain in hallux valgus.

Methods

Women’s feet (105 feet) were divided into normal group (NORM) and hallux valgus group (HVG); and further into subgroups: hallux valgus without pain (HV Pain (-)) and hallux valgus with pain (HV Pain (+)). Transverse arch height and metatarsal heads height were measured using weight-bearing ultrasound imaging. Force under the metatarsal heads was measured using force sensors attached directly on the skin surface of the metatarsal heads. The measurements were taken in three loading positions: sitting, quiet standing and 90% weight shift on the tested foot. Differences between the groups were compared using Student t-test and Wilcoxon Exact test. Multivariate logistic analysis with adjustment for physical characteristics was also conducted.

Results

Transverse arch height was significantly higher in HVG than in NORM in all positions; there were no significant differences between HV Pain (+) and HV pain (-). Lateral sesamoid was significantly higher in HVG and HV Pain (+) than in NORM and HV Pain (-) respectively when bearing 90% of the body weight unilaterally. There was a trend of higher forces under the medial forefoot without significant difference. Transverse arch height and lateral sesamoid height were associated with the hallux valgus angle, while lateral sesamoid height was associated with forefoot pain in hallux valgus deformity.

Conclusions

This study shows the differences in the transverse arch structure between normal feet and feet with hallux valgus, and between hallux valgus feet with and without pain. This finding is noteworthy when considering future treatments of painful feet, notably the height of the lateral sesamoid which seems to play a role in forefoot pain.

A comparison of the hallux valgus angle, range of motion, and patient satisfaction after use of dynamic and static orthoses

BACKGROUND

Conservative treatment is recommended for mild and moderate hallux valgus. The treatment may include two different types of orthoses: a dynamic orthosis and a static orthosis. The aim of this study was to compare the hallux valgus angle, hallux valgus range of motion, and patient satisfaction after the use of a dynamic and a static orthosis for the treatment of hallux valgus.

METHODS

Twenty-four participants contributed to this cross-over study. Participants were randomly allocated to orthotic treatments at the start. The hallux valgus angle and range of motion were measured using a goniometer. Pain, signs and symptoms, function in activities of daily living (ADL), function in sport and recreation, and foot and ankle-related quality of life (QOL) were measured using the Foot and Ankle Outcome Score (FAOS) questionnaire. The participants then switched to using the other orthosis. A one-way repeated measure ANOVA was conducted to compare the measured variables in subjects at 4 conditions before and after of using each orthosis.

RESULTS

There was a significant difference in the hallux valgus angle (p=0.001). The Bonferroni test indicated that both static and dynamic orthoses significantly decrease the angle of hallux valgus, respectively before static, after static (mean difference=-2.67, p=0.001) and before dynamic, after dynamic conditions (mean difference=-2.13, p=0.02). There was also a significant difference in subjects range of motion by using a dynamic orthosis in before dynamic, after dynamic conditions (mean difference=9.77, p=0.01). There was no significant difference in total FAOS score within the conditions (p=0.067).

CONCLUSION

The use of both static and dynamic orthoses for 1 month can reduce the hallux valgus angle up to 2-3°. To achieve better results, it is suggested to wear orthoses for longer time. The dynamic orthosis also increases the passive range of motion of the first metatarsophalangeal joint and it seems to be effective during walking.

Efficacy of foot orthoses as nonoperative treatment for hallux valgus: A 2-year follow-up study

BACKGROUND

The purpose of this study was to clarify the 2-year clinical and radiological outcomes of nonoperative treatment using foot orthosis for hallux valgus patients.

METHODS

Patients who underwent nonoperative treatment using foot orthosis were surveyed prospectively. Foot orthoses were made by one certified orthotist using the standardized method. Pain and quality of life were evaluated using subjective and objective assessment measures at 3, 6, 12, 18, and 24 months. Furthermore, radiological outcomes, patient satisfaction, and adherence to treatment were surveyed.

RESULTS

A total of 53 patients (50 women and 3 men; median age, 63 years) were included for analysis. The pain visual analogue scale score significantly decreased over time, with the lowest score observed at 12 months. The treatment effect was maintained over 24 months (median score, 52, 21, and 27 points at baseline, 12 months, and 24 months, respectively; P < .001). The Japanese Society for Surgery of the Foot hallux scale, American Academy of Orthopaedic Surgeons Foot and Ankle Scale, and 36-Item Short-Form Health Survey bodily pain subscale also improved, although the treatment effects were maximal at 6 months and decreased thereafter. At 24 months, 43 (81%) patients continued to use the orthosis, with the median visual analogue scale score for patient satisfaction of 76 points. The hallux valgus angle and intermetatarsal angle did not change during the 24-month period.

CONCLUSION

Nonoperative treatment using foot orthoses decreased pain in patients with hallux valgus. The effect of treatment was maintained up to 2 years with a relatively high degree of patient satisfaction. However, treating physicians should inform patients to set realistic expectations and be aware that a limited degree of pain reduction is expected.

Analyzing the effect of an arch support functional insole on walking and jogging in young, healthy females

BACKGROUND AND OBJECTIVE

The aim of this study was to explore the effectiveness of arch support functional insoles to prevent metatarsalgia.

METHOD

Twenty-five healthy females participated in the study. A Vicon motion capture system was used to collect kinematics data of the lower limb. An AMTI force plate was used to record the vertical ground reaction force (GRF), and the Novel Pedar-X System was used to measure foot pressure while subjects wore normal insoles or functional insoles with an arch support during walking and jogging.

RESULTS

With the arch support functional insoles, the first metatarsal (FM) region's contact area was increased and the peak pressure and time-pressure integral of the FM and second and third metatarsal (SATM) were areas decreased. This suggests a lower risk of longitude stress injuries in these areas. The ankle dorsiflexion angle of jogging with the 'arch support functional insoles' (RF) and walking with the 'arch support functional insoles' (WF) were significantly increased at initial contact and the knee and hip flexion angle of RF and WF were reduced. The peak hip extension angle of WF and RF also declined. The vertical loading rate of RF was lower, which would be beneficial in reducing the risk of lower limb injuries during jogging.

CONCLUSIONS

The results demonstrate that arch support functional insoles can be used effectively to prevent and decrease pain and promote a suitable weight-bearing pattern in the foot for promoting the health of young females.

Pressure thresholds and stiffness on the plantar surface of the human foot

A methodology to assess Pressure Discomfort Thresholds (PDT), Pressure Pain Thresholds (PPT) and tissue stiffness on the plantar surface of the foot was developed. Ten male and 10 female participants volunteered for the study. Foot landmarks were used to create a standardised grid-type template of 95 points. For each test point, PPT and PDT values were obtained, and stiffness was calculated for each of the 20 participants. Cluster analyses were performed to determine the regions of similarity for the three dependent variables, PPT, PDT and stiffness. Moran's-I-index was used to determine the spatial auto correlations. The use of k-means clustering showed five distinct clusters while the three dependent variables showed strong correlations to each other. Morisita's similarity index was used to check the similarity of the grid among all participants. Both male and female participants showed a Morisita's index greater than 0.7 confirming the reliability of the foot template. Practitioner Summary: Pressure Discomfort thresholds (PPT), Pressure pain thresholds (PPT) and tissue stiffness were evaluated at 95 points on the plantar surface of the foot. The PPT and related PDT map are useful to design the footbeds of shoes. Based on the data collected, five distinct clusters of locations were identified.

Influence of depression in a sample of people with hallux valgus

Hallux valgus (HV) is a highly-prevalent forefoot deformity associated with progressive subluxation and osteoarthritis of the first metatarsophalangeal joint; it is believed to be associated with depression. The aim of the present study was to determine the association of patients with varying degrees of HV involvement to depression using the Beck Depression Inventory (BDI). The sample consisted of 102 participants (mean age: 45.1 ± 1.6), who attended an outpatient centre where self-report data were recorded. The degree of HV deformity was determined in both feet, and the scores on the BDI were compared. A total of 38.24% of the sample had depression, with an average BDI score of 10.55 ± 12.36 points. There was a statistically-significant association between the degree and presence of HV in both feet (P = 0.0001). People with a greater degree of HV deformity in any foot also have a significant increase in depression based on BDI scores, regardless of sex.

Quality of Life in Patients With Untreated and Symptomatic Hallux Valgus

BACKGROUND

The purposes of this study were to compare the quality of life (QOL) of subjects who had untreated symptomatic hallux valgus with the QOL of the general population and to investigate factors associated with the QOL of the subjects.

METHODS

One hundred sixteen subjects with previously untreated and symptomatic hallux valgus were surveyed. QOL was assessed using the 36-item Short Form Health Survey (SF-36). Additionally, clinical evaluations (the visual analog scale for pain, Japanese Society for Surgery of the Foot Scale, lesser toe pain, and pain in other parts of the body) and radiographic evaluations (hallux valgus angle, intermetatarsal angle between the first and second metatarsals, and dislocation of the second metatarsophalangeal joint) were performed. Differences in the SF-36 between the subjects and the general population were tested using independent t tests. Correlations between the QOL measurements, clinical evaluations, and radiographic evaluations were assessed using Spearman rank correlation coefficient.

RESULTS

All SF-36 subscales and physical component summary scores for the subjects were significantly lower than those of the general population. Notably, the standardized physical function subscale (38.2 ± 15.8, P < .001) and physical component summary scores (38.9 ± 14.5, P < .001) were more than 10 points lower than those of the general population. Most QOL and clinical evaluation parameters were not correlated or were negligibly correlated with radiographic evaluations. Similarly, lesser toe pain or pain in other parts of the body was not correlated with QOL or clinical evaluations.

CONCLUSION

The QOL of untreated and symptomatic hallux valgus subjects was lower than that of the general population. All QOL and clinical evaluation parameters were not significantly or negligibly correlated with the severity of toe deformities. Surgical decision making should not be based on the severity of the deformity alone, but rather patient QOL should also be carefully assessed.

LEVEL OF EVIDENCE

Level III, comparative series.