Additional effect of neuromuscular electrical stimulation in a conservative intervention on morphology and strength of abductor hallucis muscle and correction of hallux valgus deformity: a randomized controlled trial

BACKGROUND

In hallux valgus, morphological changes and functional weakness of intrinsic foot muscles occur, especially in the abductor hallucis muscle.

OBJECTIVES

This study aimed to investigate how a conservative treatment with the addition of neuromuscular electrical stimulation affects the volume and strength of the muscle, the correction of deformity, passive range of motion, pain, and disability.

METHODS

Twenty-eight female participants (48 feet) were randomly assigned to two groups. The interventions included orthoses and exercise (Ortho) in both groups. One group received additional neuromuscular electrical stimulation of abductor hallucis muscle to activate it. Each group received the treatments for one month and was assessed two times, at baseline before starting and after one month of treatment. Mixed within-between ANOVA, analysis of covariance, and nonparametric tests were used for data analysis.

RESULTS

The muscle volume, abduction strength, goniometric angle, and passive hallux dorsi/plantar flexion showed significant changes in both groups (p < .001). Subscales of the foot and ankle ability questionnaire, significantly changed (p ≤ .05). Pain decreased significantly in the two groups (p < .001 and p = .02). Intermetatarsal angle did not significantly differ between the two groups (p = .86, partial eta effect size = 0.001). But, the hallux valgus angle mean (on MRI) in the Ortho group was less than that of the orthoNMES group (p = .007, partial eta effect size = 0.15).

CONCLUSION

Both groups showed nearly identical treatment effects in the primary volume and hallux valgus correction outcome measures. In this study, adding neuromuscular electrical stimulation did not have an additional effect compared to conservative in the treatment of hallux valgus.

TRIAL REGISTRATION NUMBER

The RCT Code is IRCT20200915048725N1.

Multiplanar, Multivariate Analyses of Hallux Valgus Radiographic Parameters

Hallux valgus is a complex condition understood to involve pathomechanics in all 3 of the cardinal planes. Despite this, the bulk of its historical evaluation has been in the transverse plane, and one might argue that the traditional and more commonly performed univariate and bivariate analyses within the literature do not comprehensively describe the potential interrelationships between the planes during perioperative assessment. Therefore this investigation aimed to evaluate relationships between common radiographic parameters measured in the three cardinal planes by means of a multivariate regression analysis. Serial analyses utilizing the first intermetatarsal angle, hallux valgus angle, tibial sesamoid position, proximal articular set angle, Engel's angle, first metatarsal inclination angle, and the sesamoid rotation angle were performed with varying dependent and independent variables. The tibial sesamoid position (p < .001) and proximal articular set angle (p = .014) were found to be independently associated with the first intermetatarsal angle, while the hallux valgus angle (p = .712), Engel's angle (p = .646), first metatarsal inclination angle (p = .097), and sesamoid rotation angle (p = .099) were not. The tibial sesamoid position (p = .003), proximal articular set angle (p < .001), Engel's angle (p = .006), and sesamoid rotation angle (p = .003) were found to be independently associated with the hallux valgus angle, while the first intermetatarsal angle (p = .712) and first metatarsal inclination angle (p = .400) were not. The first intermetatarsal angle (p < .001), hallux valgus angle (p = .003), and proximal articular set angle (p = .015) were found to be independently associated with the tibial sesamoid position, while Engel's angle (p = .400), the first metatarsal inclination angle (p = .088), and the sesamoid rotation angle (p = .649) were not. These findings appear to question a direct relationship between the first intermetatarsal angle and hallux valgus angle, as well as potentially infer a relationship between the frontal plane with the hallux valgus angle.

The accessory tendon of extensor hallucis longus muscle and its correlation to hallux valgus deformity: a cadaveric study

PURPOSE

The accessory tendon (AT) of the extensor hallucis longus (EHL) is a common anatomic variation, whose clinical significance remains debatable. The purpose of this study was to investigate the incidence and morphology of accessory EHL tendons in cadavers and to examine any possible correlation to the occurrence and severity of hallux valgus (HV) deformity.

METHODS

We examined any possible correlation between the AT presence and the cadavers' age and the HV deformity in 98 female adult cadaveric feet. The HV and intermetatarsal (IMA) angles were measured and compared with the relative angle between the primary EHL tendon and AT as well as the length of the AT.

RESULTS

AT was present in 26.5% and HV deformity existed in 36.7% of all feet. There was a high prevalence (65.4%) of HV deformity in feet with AT, but the HV angle and IMA were similar in feet with AT and without AT. No significant correlations were found between AT morphological characteristics and the cadavers' age or the HV angle and IMA.

CONCLUSIONS

In conclusion, there is a high incidence of HV deformity in cadaveric feet with AT of EHL (almost 2/3), but there is no correlation between the severity of the HV deformity and the presence or characteristics of the AT.

Proximal phalangeal osteotomies for hallux abductovalgus deformity

The primary indication for an osteotomy of the hallux proximal phalanx to correct hallux abductovalgus (HAV) deformities is increased hallux interphalangeus. The typical osteotomy is the Akin osteotomy or a variation. The Akin is a medial closing wedge osteotomy in the proximal phalanx. An Akin-type osteotomy is usually used as an adjunctive procedure for HAV to correct deformity within the great toe. When first metatarsal procedures and soft tissue balancing are not sufficient for realigning the first metatarsophalangeal joint, an Akin can be useful. A hallux proximal phalanx osteotomy is not indicated as the primary correction for HAV deformities.