Reported selection criteria for adult acquired flatfoot deformity and posterior tibial tendon dysfunction: Are they one and the same? A systematic review

Association of Fusion of the First Metatarsophalangeal Joint and Pes Planus Deformity Correction

BACKGROUND

There has been scant investigation on the relationship between the distal aspect of the medial longitudinal arch and pes planus deformity. The aim of this study was to investigate whether the reduction and stabilization of the distal aspect of the medial longitudinal arch through fusion of the first metatarsophalangeal joint (MTPJ) can subsequently improve pes planus deformity parameters. This could be useful in both further understanding the role of the distal medial longitudinal arch in patients with pes planus and planning operative intervention in patients with multifactorial medial longitudinal arch problems.

METHODS

A retrospective cohort study was undertaken between January 2011 and October 2021, including patients undergoing first MTPJ fusion with a pes planus deformity on weightbearing preoperative radiographs. These were compared to postoperative images, and multiple pes planus measurements were taken for comparison.

RESULTS

A total of 511 operations were identified for further analysis, with 48 feet meeting the inclusion criteria. There was a statistically significant reduction identified between the pre- and postoperative measurements of Meary angle (3.75 degrees, 95% CI 2.9-6.47 degrees) and talonavicular coverage angle (1.48 degrees, 95% CI 1.09-3.44 degrees). There was a statistically significant increase between the pre- and postoperative measurements of calcaneal pitch angle (2.32 degrees, 95% CI 0.24-4.41 degrees) and medial cuneiform height (1.25 mm, 95% CI 0.6-1.92 mm). Reduced intermetatarsal angle was significantly associated with an increase in first MTPJ angle postfusion. Many of the measurements made were found "almost perfectly" reproducible by the Landis and Koch description.

CONCLUSION

Our results demonstrate that fusion of the first MTPJ is associated with improvement of medial longitudinal arch parameters of a pes planus deformity but not to levels considered to be clinically normal. Therefore, the distal aspect of the medial longitudinal arch could, to some degree, be a feature in the pes planus deformity etiology.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Characterising tibialis posterior tendinopathy using the International Classification of Functioning, Disability and Health: a cross sectional study

BACKGROUND

Tibialis posterior tendinopathy (TPT) is characterised by pain around the medial foot/ankle and difficulties weightbearing.

OBJECTIVE

Compare individuals who have TPT with asymptomatic controls across the International Classification of Functioning, Disability and Health (ICF) domains of body structure and function, activity, participation and personal factors.

METHODS

Twenty-two individuals meeting the selection criteria for TPT (86% female, mean ± SD age:43 ± 13 years; body mass index [BMI]:28 ± 7 kg/m²) were compared to 27 controls (93% female, age:44 ± 16 years, BMI:23 ± 5 kg/m²). Standardised differences (and 95% confidence intervals [CIs]) between groups were estimated for outcomes under each ICF domain using Cliff's delta to allow for comparison of the magnitude of deficits across outcomes (>0.47 considered large).

RESULTS

Impairments in body structure and function in individuals with TPT were accompanied by activity limitations including difficulties due to foot problems (-1.0 (-1.0, -1.0)) and with independent living (-0.8 (-1.0, -0.3)) and greater time to complete stair descent/ascent (-0.6 (-0.8, -0.3)). Considering participation, overall foot-related function (-1.0 (-1.0, -1.0)), ability to participate in activities (-0.7 (-0.08, -0.3)), social restrictions (-0.8 (-1.0, -0.4)) and quality of life (-0.7 (-0.9, -0.5)) were poorer in individuals with TPT.

CONCLUSION

Individuals with TPT have large impairments in body structure and function, activity limitations and participation restrictions, particularly relating to independent living, mental health and pain. Personal factors appear to contribute to a lesser extent to the TPT presentation. Treatment plans should consider activity and participation limitations in addition to body structure and function.

Characteristics and Future Direction of Tibialis Posterior Tendinopathy Research: A Scoping Review

Background and Objectives: Tibialis posterior tendon pathologies have been traditionally categorized into different stages of posterior tibial tendon dysfunction (PTTD), or adult acquired flatfoot deformity (AAFD), and more recently to progressive collapsing foot deformity (PCFD). The purpose of this scoping review is to synthesize and characterize literature on early stages of PTTD (previously known as Stage I and II), which we will describe as tibialis posterior tendinopathy (TPT). We aim to identify what is known about TPT, identify gaps in knowledge on the topics of TPT, and propose future research direction. Materials and Methods: We included 44 studies and categorized them into epidemiology, diagnosis, evaluation, biomechanics outcome measure, imaging, and nonsurgical treatment. Results: A majority of studies (86.4%, 38 of 44 studies) recruited patients with mean or median ages greater than 40. For studies that reported body mass index (BMI) of the patients, 81.5% had mean or median BMI meeting criteria for being overweight. All but two papers described study populations as predominantly or entirely female gender. Biomechanical studies characterized findings associated with TPT to include increased forefoot abduction and rearfoot eversion during gait cycle, weak hip and ankle performance, and poor balance. Research on non-surgical treatment focused on orthotics with evidence mostly limited to observational studies. The optimal exercise regimen for the management of TPT remains unclear due to the limited number of high-quality studies. Conclusions: More epidemiological studies from diverse patient populations are necessary to better understand prevalence, incidence, and risk factors for TPT. The lack of high-quality studies investigating nonsurgical treatment options is concerning because, regardless of coexisting foot deformity, the initial treatment for TPT is typically conservative. Additional studies comparing various exercise programs may help identify optimal exercise therapy, and investigation into further nonsurgical treatments is needed to optimize the management for TPT.

Analysis of skeletal characteristics of flat feet using three-dimensional foot scanner and digital footprint

Background

Flat feet increase the risk of knee osteoarthritis and contribute to frailty, which may lead to worse life prognoses. The influence of the foot skeletal structure on flat feet is not yet entirely understood. Footprints are often used to evaluate feet. However, footprint-based measurements do not reflect the underlying structures of feet and are easily confounded by soft tissue. Three-dimensional evaluation of the foot shape can reveal the characteristics of flat feet. Therefore, foot shape evaluations have garnered increasing research interest. This study aimed to determine the correlation between the three-dimensional (3D) features of the foot and the measurement results of footprint and to predict the evaluation results of flat feet from the footprint based on the 3D features. Finally, the three-dimensional characteristics of flat feet, which cannot be revealed by footprint, were determined.

Methods

A total of 403 individuals (40–89 years) participated in this study. The proposed system was developed to identify seven skeletal features that were expected to be associated with flat feet. The loads on the soles of the feet were measured in a static standing position and with a digital footprint device. Specifically, two footprint indices were calculated: the Chippaux–Smirak index (CSI) and the Staheli index (SI). In the analysis, comparisons between male and female measurement variables were performed using the Student’s t test. The relationships between the 3D foot features and footprint index parameters were determined by employing the Pearson correlation coefficient. Multiple linear regression was utilized to identify 3D foot features that were strongly associated with the CSI and SI. Foot features identified as significant in the multivariate regression analysis were compared based on a one-way analysis of variance (ANOVA) with Tukey’s post hoc test.

Results

The CSI and SI were highly correlated with the instep height (IH) and navicular height (NH) of the 3D foot scanning system and were also derived from multiple regression analysis. In addition to the NH and IH, the indicators of the forefoot, transverse arch width, and transverse arch height were considered. In the flat foot group with CSI values above 62.7%, NH was 13.5% (p < 0.001) for males and 14.9% (p = 0.01) for females, and the axis of the bone distance was 5.3% (p = 0.05) for males and 4.9% (p = 0.10) for females. In particular, for CSI values above 62.7% and NH values below 13%, the axis of the bone distance was large and the foot skeleton was deformed.

Conclusions

Decreased navicular bone height could be evaluated with the 3D foot scanning system even when flat feet were not detected from the footprint. The results indicate that the use of quantitative indices for 3D foot measurements is important when evaluating the flattening of the foot.

Trial registration number UMIN000037694.

Name of the registry: University Hospital Medical Information Network Registry.

Date of registration: August 15, 2019.

Foot and ankle functions and deformities focus on posterior tibial tendon dysfunction using magnetic resonance imaging in patients with rheumatoid arthritis

OBJECTIVES

Posterior tibial tendon dysfunction (PTTD) affects the support of the medial longitudinal arch and stability of the hindfoot. The purpose of this study was to assess the relationships of PTTD with foot and ankle functions and foot deformities in patients with rheumatoid arthritis (RA).

METHODS

A total of 129 patients (258 feet) who underwent magnetic plain and contrast-enhanced magnetic resonance imaging were enrolled in this study. Positive magnetic resonance imaging findings were defined as tenosynovitis and incomplete and complete rupture of the posterior tibial tendon. Foot and ankle functions were assessed using the Japanese Society for Surgery of the Foot standard rating system for the RA foot and ankle scale (JSSF-RA) and self-administered foot evaluation questionnaire. Plain radiographs were examined for the hallux valgus angle, first metatarsal and second metatarsal angle, lateral talo-first metatarsal angle, and calcaneal pitch angle.

RESULTS

PTTD was associated with motion in the JSSF-RA (p = .024), activities of daily living in JSSF-RA (p = .017), and pain and pain-related factors in the self-administered foot evaluation questionnaire (p = .001). The calcaneal pitch angle was significantly lower in the feet with PTTD than in those without PTTD (median: 16.2° vs. 18.0°; p = .007).

CONCLUSIONS

The present study shows that PTTD was associated with foot and ankle functions and flatfoot deformity. Thus, a better understanding of PTTD in patients with RA is important for the management of foot and ankle disorders in clinical practice.

A Three-Dimensional Printed Foot Orthosis for Flexible Flatfoot: An Exploratory Biomechanical Study on Arch Support Reinforcement and Undercut

The advancement of 3D printing and scanning technology enables the digitalization and customization of foot orthosis with better accuracy. However, customized insoles require rectification to direct control and/or correct foot deformity, particularly flatfoot. In this exploratory study, we aimed at two design rectification features (arch stiffness and arch height) using three sets of customized 3D-printed arch support insoles (R+U+, R+U-, and R-U+). The arch support stiffness could be with or without reinforcement (R+/-) and the arch height may or may not have an additional elevation, undercutting (U+/-), which were compared to the control (no insole). Ten collegiate participants (four males and six females) with flexible flatfoot were recruited for gait analysis on foot kinematics, vertical ground reaction force, and plantar pressure parameters. A randomized crossover trial was conducted on the four conditions and analyzed using the Friedman test with pairwise Wilcoxon signed-rank test. Compared to the control, there were significant increases in peak ankle dorsiflexion and peak pressure at the medial midfoot region, accompanied by a significant reduction in peak pressure at the hindfoot region for the insole conditions. In addition, the insoles tended to control hindfoot eversion and forefoot abduction though the effects were not significant. An insole with stronger support features (R+U+) did not necessarily produce more favorable outcomes, probably due to over-cutting or impingement. The outcome of this study provides additional data to assist the design rectification process. Future studies should consider a larger sample size with stratified flatfoot features and covariating ankle flexibility while incorporating more design features, particularly medial insole postings.

Clinical Tests of Tibialis Posterior Tendinopathy: Are They Reliable, and How Well Are They Reflected in Structural Changes on Imaging?

OBJECTIVE

To determine the reliability of common clinical tests for tibialis posterior tendinopathy (TPT) and to investigate their relationship with grayscale ultrasound findings in individuals who have medial foot/ankle pain.

DESIGN

Prospective cohort.

METHODS

Fifty-two individuals reporting medial foot/ankle pain were clinically examined by 2 physical therapists using 4 clinical tests for TPT: pain on tendon palpation, swelling around the tendon, pain/weakness with tibialis posterior contraction, and pain during or inability to perform a single-leg heel raise (SLHR). Individuals also underwent an ultrasound examination by a sonographer. Physical therapists and the sonographer were blind to each other's findings. Positive ultrasound examination included at least 1 of the following grayscale changes: hypoechogenicity, fibrillar disruption, or thickening of the tendon. For reliability between the 2 physical therapists, we calculated kappa coefficients and 95% confidence intervals (CIs). To assess relationships between clinical and imaging findings, we calculated odds ratios and 95% CIs.

RESULTS

The SLHR was the most reliable test, with substantial agreement between physical therapists (κ = 0.74; 95% CI: 0.54, 0.93), while the other tests had moderate levels of reliability. Of all clinical tests, the SLHR was most related to grayscale findings on ultrasound (odds ratio = 5.8), but was imprecisely so, with a 95% CI of 1.7 to 20.4.

CONCLUSION

Of all tests, the SLHR was the most reliable between clinicians and best related to imaging findings in individuals presenting with TPT, aligning with contemporary thinking of tendinopathy as a load-related clinical presentation. There was a disconnect between clinical findings and ultrasound grayscale changes in the tibialis posterior tendon in individuals with TPT. J Orthop Sports Phys Ther 2021;51(5):253-260. Epub 28 Mar 2021. doi:10.2519/jospt.2021.9707.

Validity of a simple footprint assessment board for diagnosing the severity of flatfoot: a prospective cohort study

BACKGROUND

A simple, non-quantitative, and cost-effective diagnostic tool would enable the diagnosis of flatfoot without need for specialized training. A simple footprint assessment board that investigates which toe the cord passes through from the centre point of the heel to the most lateral point of the medial contour of the footprint has been developed to assess flatfoot. The purpose of this study was to verify the validity of a simple footprint assessment board for flatfoot.

METHODS

Thirty-five consecutive patients with foot pain, foot injury, or any associated symptoms who underwent computed tomography (CT) were analysed prospectively. At the time of the CT scan, a footprint analysis using a simple footprint assessment board was performed. The navicular index, tibiocalcaneal angle, and calcaneal inclination angle were evaluated by CT to assess flat feet. These three criteria were compared to those evaluated with the simple footprint assessment board by regression analysis. In addition, the same analysis was conducted separately for young, middle-aged, and older patients in order to investigate each age group.

RESULTS

The navicular index and tibiocalcaneal angle generally decreased as the score of the simple footprint assessment board increased. Calcaneal inclination angle generally increased as the score of the simple footprint assessment board increased. As the scores of the simple footprint assessment board decreased by approaching the great toe, the navicular index and tibiocalcaneal angle were higher and calcaneal inclination angle was lower, which is indicative of a higher likelihood of flatfoot. The scores derived from the simple footprint assessment board was correlated with these three criteria measured by CT, not only when the result of simple footprint assessment board was set as a non-continuous variable but also when the result was set as a continuous variable. The results of the age-stratified survey were similar for all groups.

CONCLUSIONS

The findings of this study suggest that a simple footprint assessment board can be potentially useful to detect flatfoot.

TRIAL REGISTRATION

Retrospectively registered.

Isolated fibular stress fractures: Radiographic parameters

BACKGROUND

Fibular stress fractures are uncommon injuries with an incompletely understood pathogenesis and predisposing characteristics. This study investigated the demographic and radiographic risk factors for fibular stress fractures.

METHODS

A retrospective chart review from 2010 to 2018 revealed thirteen patients with isolated fibular stress fractures. Demographics, history of fracture, fracture location, bone quality, and heel alignment were collected.

RESULTS

The cohort consisted of six men and seven women with a mean age of 41.8 years. The average BMI was 28.5kg/m². Three patients used tobacco. 69.2% of fractures were in the distal third, 23.1% proximal third, and 7.7% middle third. No patients had evidence of osteopenia. Distal fibula stress fractures were more common in women (66.7%) and associated with hindfoot valgus.

CONCLUSION

Distal third fibula stress fractures were most common and associated with hindfoot valgus. This could be due to a greater amount of axial force through fibula in this alignment.

LEVEL OF EVIDENCE

Level IV, Retrospective Case Series.

The horizontal calcaneofibular ligament: a sign of hindfoot valgus on ankle MRI

OBJECTIVE

Hindfoot valgus malalignment has been assessed on coronal MRI by the measurement of the tibio-calcaneal (TC) angle and apparent moment arm (AMA). This study aimed to determine if the calcaneofibular ligament (CFL) angle could be used as a further marker of hindfoot valgus malalignment on routine non-weight-bearing ankle MRI.

MATERIAL AND METHODS

One hundred ninety-five consecutive 3-T ankle MRI studies were identified from the hospital PACS system. The TC and CFL angles could be measured in 155 cases (78%), and the AMA on 153 cases.

RESULTS

The study group comprised 56 males and 72 females with a mean age of 46 years (range 4-89 years). In 27 patients, both ankles had been imaged. The Pearson correlation between the TC and CFL angles was -0.43, with a corresponding p value of 0.001 indicating a strong negative correlation between the TC and CFL angles. The CFL angle was significantly lower in those with hindfoot valgus (113 ± 14) compared with those without (123° ± 15°) (p = 0.001). The optimal cut-off point of the CFL angle for hindfoot valgus was ≤119°, with a sensitivity and specificity of 66% and 63% respectively. The Pearson correlation between the CFL angle and AMA was -0.10, with a corresponding p value of 0.21 indicating a weak negative correlation that did not reach statistical significance.

CONCLUSION

Hindfoot valgus as estimated by the increased TC angle on coronal non-weight-bearing ankle MRI is associated with a reduced CFL angle on sagittal MR images, but is not associated with AMA. Therefore, a horizontal orientation of the CFL on sagittal MR images may be a further useful sign of hindfoot valgus.

Finite element analysis of subtalar joint arthroereisis on adult-acquired flexible flatfoot deformity using customised sinus tarsi implant

Background

Subtalar arthroereisis may cause sinus tarsi pain complications. In this study, we aimed to introduce a customised implant that facilitated treatment effect and less impingement. The biomechanical outcome between the intact and implant conditions was compared using finite element analysis.

Methods

A female patient with flatfoot (age: 36 years, height: 156 ​cm, body mass: 51 ​kg) was recruited as the model patient. The customised implant was designed from the extracted geometry. Boundary and loading conditions were assumed from the data of a normal participant. Four gait instants, including the ground reaction force first peak (25% stance), valley (45%), initial push-off (60%) and second peak (75%) were analyzed.

Results

The navicular height was elevated by 4.2% at 25% stance, whereas the strain of the spring, plantar cuneonavicular and plantar cuboideonavicular ligaments were reduced. The talonavicular joint force decreased and the calcaneocuboid joint increased by half and 67%, respectively, representing a lateralised load pathway. There was a stress concentration at the sulcus tali reaching 15.29 ​MPa

Conclusion

Subtalar arthroereisis using a customised implant may produce some positive treatment effects in terms of navicular height elevation, ligament strain relief and lateralised joint loading pathway. Although the concentrated stress at the sulcus tali did not exceed the threshold of bone breakdown, we could not rule out the potential of vascular disturbance owing to the remarkable elevation of stress. Future study may enlarge the contact area of the bone–implant interface by considering customisation based on the dynamic change of the sinus tarsi during walking gait.

The translational potential of this article

Geometry mismatch of prefabricated implants could be the reason for complications. With the advancement of 3D printing, customising implant becomes possible and may improve treatment outcome. This study implemented a theoretical model approach to explore its potential under a simulation of walking.

Surgical Management of Symptomatic Adult Pes Planovalgus Secondary to Stage 2B Posterior Tibial Tendon Dysfunction: A Comparison of Two Different Surgical Treatments

BACKGROUND

This study compares radiological and functional outcomes of patients with symptomatic Adult Acquired Flat Foot Deformity (AFFD) secondary to stage 2B Posterior Tibial Tendon Dysfunction (PTTD) treated with either a Subtalar Arthroereisis (SA) implant or a Lateral Column Lengthening (LCL) procedure. The aim of the study is to determine if the Subtalar Arthroereisis procedure is an acceptable surgical adjunct in our treatment armamentarium.

MATERIALS AND METHODS

21 patients (22 feet) were evaluated. 12 consecutive patients (n = 12) underwent a Subtalar Arthroereisis procedure while 9 patients (n = 10) underwent a Lateral Column Lengthening procedure. Functional outcomes were evaluated using the American Orthopaedic Foot and Ankle Score (AOFAS) midfoot score, Short Form 36 (SF-36) and Visual Analog of Pain Scale (VAS), preoperatively and at 6 and 12 months postoperatively. 10 radiological parameters were analyzed. All complications were tabulated.

RESULTS

Significant improvements in functional outcomes were noted in both groups of patients. Radiographically, some loss of correction was noted in the SA group and no loss of correction in the LCL group, respectively. In the SA group, 6 patients complained of sinus tarsi pain in the postoperative period and 4 required removal of implants. No implants were removed in the LCL group.

CONCLUSION

The results suggest that subtalar arthroereisis may be a reasonable procedure to utilize in the treatment of AAFD, albeit with a relatively high implant-removal rate.

Biomechanics and Orthotic Treatment of the Adult Acquired Flatfoot

The adult acquired flatfoot deformity resulting from posterior tibial tendon dysfunction is the result of rupture of the posterior tibial tendon as well as key ligaments of the ankle and hindfoot. Kinematic studies have verified certain levels of deformity causing hindfoot eversion, lowering of the medial longitudinal arch and forefoot abduction. The condition is progressive and left untreated will cause significant disability. Bracing with ankle-foot orthoses has shown promising results in arresting progression of deformity and avoiding debilitating surgery. Various types of ankle-foot orthoses have been studied in terms of effects on gait as well as efficacy in treatment.

Exercise for posterior tibial tendon dysfunction: a systematic review of randomised clinical trials and clinical guidelines

Objective

To systematically review all randomised clinical trials to determine the efficacy of local strengthening exercises compared with other forms of conservative management for adults with posterior tibial tendon dysfunction.

Design

Systematic review.

Data sources

Four electronic databases (Cumulative Index to Nursing and Allied Health Literature, Cochrane, Embase and PubMed) were searched up to June 2018.

Eligibility criteria for selecting studies

The study included randomised clinical trials investigating individuals with posterior tibial tendon dysfunction where local strengthening was compared with other forms of conservative management with respect to pain, function and/or physical impairment outcome measures. Standardised mean differences (SMDs) were used to compare change scores between groups and descriptors of exercise prescription assessed according to the Template for Intervention Description and Replication and the Toigo and Boutellier recommendations.

Results

3 studies (n=93) were eligible for inclusion in the review. Varying strengthening exercises were compared with stretching and foot orthoses (n=2) or no intervention (n=1). Moderate effects (SMD 0.6-1.2) were found for reducing pain and disability with eccentric strengthening in conjunction with stretching and orthoses compared with concentric exercises, stretching and orthoses combined, and stretching and orthoses alone. Evaluation of exercise prescription parameters demonstrated minimal reporting, with the only consistent parameters being the number of sets and repetitions of the exercises, and the duration of the experimental period.

Conclusion

This review demonstrates the paucity of high-quality research for the conservative management of posterior tibial tendon dysfunction, and highlights the lack of exercise prescription parameters reported in clinical trials.

Trial registration number

CRD42017076156.

Self-reported social and activity restrictions accompany local impairments in posterior tibial tendon dysfunction: a systematic review

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) is a painful, progressive tendinopathy that reportedly predominates in middle-age, overweight women. There is no evidence based guidelines that clinicians can use to guide treatment planning, which leaves clinicians to make decisions on the basis of presenting clinical impairments and self-reported pain and disability. The purpose of this systematic review was to quantify clinical impairments, pain and disability in individuals with PTTD compared with controls.

METHODS

Five databases were searched for terms referring to the posterior tibial tendon and flatfoot up to and including 11 March 2018. The systematic review was registered with PROSPERO (CRD: 42016046951). Studies were eligible if they were published in the English language and contained data on clinical impairments, pain or disability compared between participants diagnosed with PTTD and pain-free individuals. Standardised mean differences (SMDs) were calculated where possible and meta-analysis was performed when homogeneity of outcomes allowed.

RESULTS

Ten eligible studies were identified and pooled in the meta-analyses. Strong effects were revealed for poor heel rise endurance (SMD -1.52, 95% CI -2.05 to - 0.99), less forefoot adduction-inversion strength (SMD -1.19, 95% CI -1.68 to - 0.71) and lower arch height (SMD -1.76, 95% CI -2.29 to - 1.23). Compared to controls, individuals with PTTD also had more self-reported stiffness (SMD 1.45, 95% CI 0.91 to 1.99), difficulties caused by foot problems (SMD 1.42, 95% CI 0.52 to 2.33) and social restrictions (SMD1.26, 95% CI 0.25 to 2.27).

CONCLUSION

There is evidence of impaired tibialis posterior capacity and lowered arch height in individuals with PTTD compared to controls. Further to addressing the expected impairments in local tendon function and foot posture, pain, stiffness, functional limitations and social participation restrictions should be considered when managing PTTD.