Diagnosis and treatment of adult flatfoot

Medial column fusion for degenerative pesplanovalgus deformity. Report of 9 patients

Degenerative pesplanovalgus is a progressive disabling condition; there are more than one surgical procedure used in the treatment with varied outcomes. The aim of the current study is to highlight the benefits of the medial column fusion surgery in the treatment of this condition. Nine adult patients with rigid degenerative pesplanovalgus (without significant valgus heel deformity) underwent medial column fusion between January 2015 to December 2020. The procedure was combined with subtalar fusion in four patients and lateral column lengthening in one patient. The mean follow-up period was 19.5 months (range, 15-27). Regular clinical and radiological reviews was carried out in the postoperative period. The mean Manchester Oxford foot score was good in 7 patients, and fair in two patients. The mean Meary angle was 5.8 ± 5.4° preoperatively and improved to 0.9 ± 7.7° at final follow-up, and the mean Pitch angle also improved from 12.5 ± 3.7° preoperatively to 23.2 ± 4.1° (P < .001). In a patient, and at a different stage, talo-navicular fusion was added to the medial column fusion.The outcome of this series of cases was encouraging and medial column fusion continues to be a good option in the management of rigid pesplanovalgus deformity.

Biomechanical effects of Evans versus Hintermann osteotomy for treating adult acquired flatfoot deformity: a patient-specific finite element investigation

BACKGROUND

Evans and Hintermann lateral column lengthening (LCL) procedures are both widely used to correct adult acquired flatfoot deformity (AAFD), and have both shown good clinical results. The aim of this study was to compare these two procedures in terms of corrective ability and biomechanics influence on the Chopart and subtalar joints through finite element (FE) analysis.

METHODS

Twelve patient-specific FE models were established and validated. The Hintermann osteotomy was performed between the medial and posterior facets of the subtalar joint; while, the Evans osteotomy was performed on the anterior neck of the calcaneus around 10 mm from the calcaneocuboid joint surface. In each procedure, a triangular wedge of varying size was inserted at the lateral edge. The two procedures were then compared based on the measured strains of superomedial calcaneonavicular ligaments and planter facia, the talus-first metatarsal angle, and the contact characteristics of talonavicular, calcaneocuboid and subtalar joints.

RESULTS

The Hintermann procedure achieved a greater correction of the talus-first metatarsal angle than Evans when using grafts of the same size, indicating that Hintermann had stronger corrective ability. However, its distributions of von-Mises stress in the subtalar, talonavicular and calcaneocuboid joints were less homogeneous than those of Evans. In addition, the strains of superomedial calcaneonavicular ligaments and planter facia of Hintermann were also greater than those of Evans, but both generally within the safe range (less than 6%).

CONCLUSION

This FE analysis study indicates that both Evans and Hintermann procedures have good corrective ability for AAFD. Compared to Evans, Hintermann procedure can provide a stronger corrective effect while causing greater disturbance to the biomechanics of Chopart joints, which may be an important mechanism of arthritis. Nevertheless, it yields a better protection to the subtalar joint than Evans osteotomy.

CLINICAL RELEVANCE

Both Evans and Hintermann LCL surgeries have a considerable impact on adjacent joints and ligament tissues. Such effects alongside the overcorrection problem should be cautiously considered when choosing the specific surgical method.

LEVEL OF EVIDENCE

Level III, case-control study.

The relationship between pes planus and venous insufficiency

INTRODUCTION

The presence of pes planus may be responsible for the disorder of venous return during ambulation. Our aim in this study is to reveal that the risk of venous insufficiency may be increased in patients with pes planus.

METHODS

A total of 59 patients with 29 bilateral pes planus and 30 normal arches included in the study. Djian Annonier angle measurement, bilateral lower extremity venous Doppler ultrasonography (USG), foot function index (AFI), Comprehensive Classification System for Chronic Venous Disorders (CEAP) clinical scoring and Short Form-36 (SF-36) was evaluated.

RESULTS

There was a statistically significant difference in AFI total, AFI pain, AFI disability and AFI activity limitation scores, bilateral lower extremity doppler USG and CEAP clinical scores in the patient group compared to the control group.

CONCLUSION

These findings suggest that there may be a relationship between pes planus and venous insufficiency. However, large-scale studies with more patient involvement are needed.

Efficacy of Faradic Foot Baths and Short Foot Exercises in Symptomatic Flatfoot: A Review

Flatfoot is a common condition among adults, according to orthopedic experts. Flatfoot is defined in this document as a foot condition that occurs after the completion of skeletal growth and is characterized by either partial or complete reduction of the medial longitudinal arch (MLA). The purpose of this study was to evaluate the effects of short foot exercise (SFE) and faradic foot baths on people who have flat feet. This review focused on comprehensive original primary articles written in English. Numerous studies have been conducted in order to determine the effects of both interventions. The search yielded a wide range of papers, including editorials, review articles, freely available full texts, and abstracts. The results showed that both SFE and faradic foot baths effectively improved flat feet.

Differential contribution of lateral plantar foot ligaments to lateral column stability - A cadaver based sectioning analysis

Lateral column (LC) instability occurs in adult acquired flatfoot deformity (AAFD). Differential ligament contribution to LC stability is unknown. The primary aim was to quantify this by using cadaver sectioning of lateral plantar ligaments. We also determined the relative contribution of each ligament to dorsal translation of the metatarsal head in the sagittal plane. 17 below-knee cadaveric specimens, preserved by vascular embalming method, were dissected to expose plantar fascia, long/short plantar ligaments (L/SPL), calcaneocuboid (CC) capsule and inferior 4th/5th tarsometatarsal (TMT) capsule. Dorsal forces of 0 N, 20 N and 40 N were applied to the plantar 5th metatarsal head after sequential ligament sectioning in different orders. Pins provided linear axes on each bone, allowing relative angular bone displacements to be calculated. Photography and ImageJ processing software were then used for analysis. The LPL (and CC capsule) had the greatest contribution to metatarsal head motion (107 mm) after isolated sectioning. In the absence of other ligaments, sectioning these resulted in significantly increased hindfoot-forefoot angulation (p ≤ 0.0003). Isolated TMT capsule sectioning demonstrated significant angular displacement even when other ligaments remained intact (with intact L/SPL, p = 0.0005). CC joint instability required both LPL and capsular sectioning for significant angulation to occur, whilst TMT joint stability was largely dependent on its capsule. The relative contribution of static restraints to the lateral arch has not yet been quantified. This study provides useful information on relative ligament contribution to both CC and TMT joint stability, which may in turn improve understanding of surgical interventions used to restore arch stability.

Insole Systems for Disease Diagnosis and Rehabilitation: A Review

Some chronic diseases, including Parkinson's disease (PD), diabetic foot, flat foot, stroke, elderly falling, and knee osteoarthritis (KOA), are related to orthopedic organs, nerves, and muscles. The interaction of these three parts will generate a comprehensive result: gait. Furthermore, the lesions in these regions can produce abnormal gait features. Therefore, monitoring the gait features can assist medical professionals in the diagnosis and analysis of these diseases. Nowadays, various insole systems based on different sensing techniques have been developed to monitor gait and aid in medical research. Hence, a detailed review of insole systems and their applications in disease management can greatly benefit researchers working in the field of medical engineering. This essay is composed of the following sections: the essay firstly provides an overview of the sensing mechanisms and parameters of typical insole systems based on different sensing techniques. Then this essay respectively discusses the three stages of gait parameters pre-processing, respectively: pressure reconstruction, feature extraction, and data normalization. Then, the relationship between gait features and pathogenic mechanisms is discussed, along with the introduction of insole systems that aid in medical research; Finally, the current challenges and future trends in the development of insole systems are discussed.

Predicting the outcome of plantar heel pain in adults: a systematic review of prognostic factors

BACKGROUND

Plantar Heel Pain (PHP) is a common disorder with many treatment pathways and is not self-limiting, hence prognostic information concerning recovery or recalcitrance is needed to guide practice. In this systematic review, we investigate which prognostic factors are associated with favourable or unfavourable PHP outcomes.

METHODS

MEDLINE, Web of Science, EMBASE, Scopus and PubMed electronic bibliographic databases were searched for studies evaluating baseline patient characteristics associated with outcomes in prospective longitudinal cohorts or after specific interventions. Cohort, clinical prediction rule derivation and single arms of randomised controlled trials were included. Risk of bias was evaluated with method-specific tools and evidence certainty with GRADE.

RESULTS

The review included five studies which evaluated 98 variables in 811 participants. Prognostic factors could be categorised as demographics, pain, physical and activity-related. Three factors including sex and bilateral symptoms (HR: 0.49[0.30-0.80], 0.33[0.15-0.72], respectively) were associated with a poor outcome in a single cohort study. The remaining four studies reported twenty factors associated with a favourable outcome following shockwave therapy, anti-pronation taping and orthoses. Heel spur (AUC = 0.88[0.82-0.93]), ankle plantar-flexor strength (Likelihood ratio (LR): 2.17[1.20-3.95]) and response to taping (LR = 2.17[1.19-3.90]) were the strongest factors predicting medium-term improvement. Overall, the study quality was low. A gap map analysis revealed an absence of research that included psychosocial factors.

CONCLUSIONS

A limited number of biomedical factors predict favourable or unfavourable PHP outcomes. High quality, adequately powered, prospective studies are required to better understand PHP recovery and should evaluate the prognostic value of a wide range of variables, including psychosocial factors.

Ligament Insufficiency with Flatfoot: Spring Ligament and Deltoid Ligament

The objective of this article was to review the deltoid ligament and spring ligament specifically as they pertain to ligament insufficiency and adult-acquired flatfoot deformity. Discussion includes the normal and abnormal biomechanical forces that extend through these ligaments in normal and flatfoot deformity. Current literature related to spring ligament repair as part of the flatfoot deformity reconstruction is also reviewed.

Cavovarus deformity of one foot with planovalgus deformity of the contralateral foot (Wind-swept heels): A case report

Normal alignment of the arches and adequate stability is essential for the foot to function correctly. Pes planus and pes cavus are fairly common foot deformities, but it is uncommon to see both in the same patient simultaneously. This study aimed to describe the clinical presentation and prognosis of an uncommon combination of bilateral foot abnormalities named “windswept heels” resembling windswept knees. A 43-year-old female employee experienced frequent pain in her right foot and swelling and pain in her left foot, mainly when walking barefoot. She had a severe cavovarus deformity of the right foot with pressure callosities on the lateral side, clawing of the toes, and a positive Coleman’s block test. With the loss of the medial arch, severe heel valgus, and forefoot abduction, the left foot developed a planovalgus deformity. The left foot’s talus-first metatarsal angle and the right foot’s calcaneal inclination angle increased on weight-bearing radiographs. The left foot underwent staged surgical treatments, including medial sliding calcaneal osteotomy, gastrocnemius recession, and cotton osteotomy. For the right foot, lateral sliding calcaneal osteotomy, plantar fasciotomy, and peroneus longus tendon transfer. The American Orthopaedics Foot and Ankle Society Score (AOFAS) was used to measure the clinical and functional outcomes. At 1 year, her AOFAS scale was 85 compared to 59 before surgery. Since this presentation resembles the windswept knee deformity, we propose calling this disorder windswept heel deformity.

Automated diagnosis of flatfoot using cascaded convolutional neural network for angle measurements in weight-bearing lateral radiographs

OBJECTIVES

Diagnosis of flatfoot using a radiograph is subject to intra- and inter-observer variabilities. Here, we developed a cascade convolutional neural network (CNN)-based deep learning model (DLM) for an automated angle measurement for flatfoot diagnosis using landmark detection.

METHODS

We used 1200 weight-bearing lateral foot radiographs from young adult Korean males for the model development. An experienced orthopedic surgeon identified 22 radiographic landmarks and measured three angles for flatfoot diagnosis that served as the ground truth (GT). Another orthopedic surgeon (OS) and a general physician (GP) independently identified the landmarks of the test dataset and measured the angles using the same method. External validation was performed using 100 and 17 radiographs acquired from a tertiary referral center and a public database, respectively.

RESULTS

The DLM showed smaller absolute average errors from the GT for the three angle measurements for flatfoot diagnosis compared with both human observers. Under the guidance of the DLM, the average errors of observers OS and GP decreased from 2.35° ± 3.01° to 1.55° ± 2.09° and from 1.99° ± 2.76° to 1.56° ± 2.19°, respectively (both p < 0.001). The total measurement time decreased from 195 to 135 min in observer OS and from 205 to 155 min in observer GP. The absolute average errors of the DLM in the external validation sets were similar or superior to those of human observers in the original test dataset.

CONCLUSIONS

Our CNN model had significantly better accuracy and reliability than human observers in diagnosing flatfoot, and notably improved the accuracy and reliability of human observers.

KEY POINTS

• Development of deep learning model (DLM) that allows automated angle measurements for landmark detection based on 1200 weight-bearing lateral radiographs for diagnosing flatfoot. • Our DLM showed smaller absolute average errors for flatfoot diagnosis compared with two human observers. • Under the guidance of the model, the average errors of two human observers decreased and total measurement time also decreased from 195 to 135 min and from 205 to 155 min.

Adult Acquired Flatfoot Deformity: A Narrative Review about Imaging Findings

Adult acquired flatfoot deformity (AAFD) is a disorder caused by repetitive overloading, which leads to progressive posterior tibialis tendon (PTT) insufficiency. It mainly affects middle-aged women and occurs with foot pain, malalignment, and loss of function. After clinical examination, imaging plays a key role in the diagnosis and management of this pathology. Imaging allows confirmation of the diagnosis, monitoring of the disorder, outcome assessment and complication identification. Weight-bearing radiography of the foot and ankle are gold standard for the diagnosis of AAFD. Magnetic Resonance Imaging (MRI) is not routinely needed for the diagnosis; however, it can be used to evaluate the spring ligament and the degree of PTT damage which can help to guide surgical plans and management in patients with severe deformity. Ultrasonography (US) can be considered another helpful tool to evaluate the condition of the PTT and other soft-tissue structures. Computed Tomography (CT) provides enhanced, detailed visualization of the hindfoot, and it is useful both in the evaluation of bone abnormalities and in the accurate evaluation of measurements useful for diagnosis and post-surgical follow-up. Other state-of-the-art imaging examinations, like multiplanar weight-bearing imaging, are emerging as techniques for diagnosis and preoperative planning but are not yet standardized and their scope of application is not yet well defined. The aim of this review, performed through Pubmed and Web of Science databases, was to analyze the literature relating to the role of imaging in the diagnosis and treatment of AAFD.

Pressure Properties of Three Different Types of Prefabricated Insoles Related to Plantar Pressure in Asymptomatic Men

BACKGROUND

In clinical fields, many types of insoles are used to not only realign movement patterns, but also treat pressure-related foot diseases. However, the characteristics of and plantar pressure in each type of insole are still unclear. Therefore, the aim of this study was to validate the plantar pressure-relieving effect of three representative types of insoles (metatarsal padding insole [MPI], lateral heel wedge insole [LHI], and arch support insole [ASI]) in asymptomatic men.

METHODS

A total of 35 feet of 35 asymptomatic men with a mean age of 23.4 ± 2.0 years were included. Pedobarographic data were evaluated by dividing the foot into eight designated regions to compare the three types of insoles. Peak plantar pressure (PPP) and pressure time integral (PTI) were assessed using the Pedar-X system. A repeated measures analysis of variance was used for statistical analyses.

RESULTS

In the hallux region, there was no statistically significant difference. MPI showed highest pressure in the 2nd-5th toe and midfoot region, but lowest in the central and lateral forefoot regions. Meanwhile, ASI showed highest pressure in the medial forefoot region but lowest in the lateral heel region. Lastly, pressure in the lateral heel region was highest in LHI. Overall, results of PTI were similar to those of PPP.

CONCLUSIONS

This study demonstrated that the three types of insole each could reduce and redistribute pressure of specific part of the foot to help select an appropriate insole for each purpose.

Diagnostic Accuracy of Various Radiological Measurements in the Evaluation and Differentiation of Flatfoot: A Cross-Sectional Study

Arch angle is used to indicate flatfoot, but in some cases, it is not easily defined. The presence of flatfoot deformity remains difficult to diagnose due to a lack of reliable radiographic assessment tools. Although various assessment methods for flatfoot have been proposed, there is insufficient evidence to prove the diagnostic accuracy of the various tools. The main purpose of the study was to determine the best radiographic measures for flatfoot concerning the arch angle. Fifty-two feet radiographs from thirty-two healthy young females were obtained. Five angles and one index were measured using weight-bearing lateral radiographs; including arch angle, calcaneal pitch (CP), talar-first metatarsal angle (TFM), lateral talar angle (LTA), talar inclination angle (TIA) and navicular index (NI). Receiver-operating characteristics were generated to evaluate the flatfoot diagnostic accuracy for all radiographic indicators and Matthews correlation coefficient was calculated to determine the cutoff value for each measure. The strongest correlation was between arch angle and CP angle [r = −0.91, p ≤ 0.0001, 95% confidence interval (CI) (from −0.94 to −0.84)]. Also, significant correlations were found between arch angle and NI [r = 0.62, p ≤ 0.0001, 95% CI (0.42 to 0.76)], and TFM [r = 0.50, p ≤ 0.0001, 95% CI (from 0.266 to 0.68)]. Furthermore, CP (cutoff, 12.40) had the highest accuracy level with value of 100% sensitivity and specificity followed by NI, having 82% sensitivity and 89% specificity for the cutoff value of 9.90. In conclusion, CP angle is inversely correlated with arch angle and considered a significant indicator of flatfoot. Also, the NI is easy to define radiographically and could be used to differentiate flat from normal arched foot among young adults.

Effects of the Short-Foot Exercise on Foot Alignment and Muscle Hypertrophy in Flatfoot Individuals: A Meta-Analysis

This study aimed to conduct a meta-analysis of randomized controlled trials to examine the effects of the short-foot exercise (SFE) compared to foot orthosis or other types of interventions. Eligibility criteria involved participants with flatfoot engaging in the SFE compared to other forms of intervention or control groups without specific intervention. Relevant studies published before the end of June 2022 were identified from databases. A meta-analysis was performed by calculating the mean differences (MD) and standard MD (SMD) using the random effects model. Six trials with 201 patients (out of 609 records) that met selection criteria were reviewed. Five of the six trials implemented distinct interventions in the control group such as shoe insoles and muscle strengthening exercises, while in the remaining trial, controls received no intervention. The SFE group significantly reduced the navicular drop test (NDT) values (MD: -0.23; 95% confidence interval: -0.45 to -0.02; p = 0.04) and the foot posture index (FPI-6) score (MD: -0.67; 95% confidence interval: -0.98 to -0.36; p < 0.0001) when compared to the control group. The muscle hypertrophy did not differ significantly between the groups. The SFE may contribute more benefits than other intervention as it affects flatfoot individuals' foot alignment. Hence, the SFE is recommended as a beneficial dynamic support when facing flatfoot problems.

Examining the Relationship between Pes Planus Degree, Balance and Jump Performances in Athletes

The foot absorbs shocks with its arches, muscles, ligaments and joints, and bodyweight transmission and it pushes the body forward during all movement patterns. Pes planus is more important in sports activities that include balance and sports performance, such as walking, running, jumping, or transferring weight to a single lower limb. This study, conducted with this information in mind, aims to examine the effects of pes planus deformity on balance and vertical jump performance. Fifty athletes were included in the study. The presence of pes planus was evaluated according to the Feiss line. Balance measurements were performed with a Balance System SD Biodex. Vertical jump performance was recorded using an Omegawave jumping mat. The relationship between the pes planus grades of the participants and their balance and jump performances was analyzed using the Spearman correlation method. Vertical jump and Limit of stability (LOS) was significantly correlated with pes planus.

Evaluation of the relationship between hallux valgus and foot measurements in radiographic images of adult female

PURPOSE

In the present study, we aimed to determine the relationship of HV angle with angles and measurements obtained from lateral and anteroposterior (AP) radiological images of the foot in individuals with HV.

METHODS

The present study had a retrospective design, and the participants consisted of 66 female patients between the ages of 19 and 64 who applied to Orthopedics and Traumatology and were diagnosed with Hallux valgus. Metatarsus adductus angle, metatarsus primus adductus angle, hallux valgus angle, hallux interphalangeal angle, metatarsal break angle, first metatarsal protrusion distance, metatarsal width, talocalcaneal angle, AP Meary's angle were measured on AP view and calcaneal inclination angle, talar declination angle, lateral talocalcaneal angle, first metatarsal declination angle, fifth metatarsal declination angle, navicular height, lateral Meary's angle, tibiotalar angle were measured on a lateral radiograph. The IBM SPSS 21.0. program was used for statistical analysis, and the level of significance was taken as p < 0.05.

RESULTS

There were statistically significant differences between the right and left feet in MPA and AMA measurements. The results showed that HV angle (HVA) had a weak relationship with MAA and MW, as well as a moderately positive relationship with MPA. However, it had a moderately negative relationship with AMA and a weak negative relationship with HIPA.

CONCLUSION

We believe that in addition to the HVA angle, MPA and AMA angles should be considered in the diagnosis of HV, especially as the HVA angle is moderately positively correlated with the MPA angle and moderately negatively correlated with the AMA angle.

Outcomes Following the Use of Subtalar Arthroereisis in the Correction of Adult Acquired Flatfoot: A Systematic Review

BACKGROUND

Adult acquired flatfoot deformity (AAFD) is a condition affecting approximately 3% of the adult population. It can lead to severe morbidity, and therefore, prompt treatment is of the upmost importance in maintaining and restoring function. Recently, the use of subtalar arthroereisis has become more widespread in the treatment of AAFD. The purpose of this systematic review is to examine the clinical and radiological outcomes of AAFD when treated with subtalar arthroereisis.

METHODS

Studies involving the use of subtalar arthroereisis for the management of AAFD were reviewed, and appropriate studies selected based on inclusion and exclusion criteria. Studies were reviewed for both clinical and radiological outcomes following the use of subtalar arthroereisis as well as reported complications.

RESULTS

Nine studies met our inclusion criteria, with most of these involving stage II AAFD. A total of 190 subtalar arthroereisis procedures were performed with all studies demonstrating improvement in both clinical and radiological scores with a low rate of complications.

CONCLUSION

Subtalar arthroereisis may have benefits when used as an adjunct to treat stage II AAFD. However, more high-quality studies are needed to establish its best use.

LEVELS OF EVIDENCE

Level IV: Systematic review.

Prevalence of flatfoot among young Korean males and the correlation among flatfoot angles measured in weight-bearing lateral radiographs

Flatfoot causes significant fatigue and pain while walking, and even asymptomatic flatfoot may increase the risk of metatarsal stress fracture during long-distance walking. While most studies have used physical examination or plantar footprints to diagnose flatfoot, a weight-bearing radiograph of the foot provides more objective data. However, data on the prevalence of flatfoot in Asian populations gathered in a nationwide cohort of a specific age group is lacking. We examined the prevalence of flatfoot among 19-year-old male Korean army recruits using a weight-bearing lateral radiograph and evaluated the correlation among flatfoot angles. A total of 560,141 19-year-old Korean males were examined at the regional Military Manpower Administration offices between April 2018 and April 2020. Weight-bearing lateral radiographs of the foot were obtained using an X-ray system while the subjects were standing on a table with their feet in a neutral position. Based on these radiographs, military orthopedic surgeons and radiologists measured the talo-first metatarsal angle (TMA) and calcaneal pitch angle (CPA) for flatfoot diagnosis. Mild flatfoot was diagnosed when the TMA ranged from 6 to 15° or the CPA was <17°, and moderate-to-severe flatfoot was diagnosed when the TMA was 15° or greater or the CPA was <10°. Pearson correlation coefficients and scatter plot matrix were used to evaluate the correlation among the flatfoot angles. Finally, we evaluated the relationship between body mass index (BMI) and flatfoot angles and compared the BMI in subjects with or without self-checked foot deformities including flatfoot and pes cavus. Of the 560,141 subjects, 16,102 (2.9%) were diagnosed as flatfoot, and 5265 (0.9%) were diagnosed with moderate-to-severe flatfoot. The coefficients between TMA and CPA ranged from 0.342 to 0.449 (all P values < 0.001), and those between the 2 sides of TMA and CPA were 0.709 and 0.746 (all P values < 0.001), respectively. BMI had a significant correlation with both TMA and CPA in subjects with flatfoot, and those with self-checked foot deformities had a significantly higher BMI than the group without foot deformities. The prevalence of total flatfoot and moderate-to-severe flatfoot in 19-year-old Korean males based on a weight-bearing lateral radiograph was 2.9% and 0.9%, respectively. The correlation coefficients between TMAs and CPAs showed a low degree of positive correlation. Higher BMI was associated with the likelihood of the presence of flatfoot.

Short- to Intermediate-Term Radiographic Outcomes Following Cotton Osteotomy

The cotton osteotomy or the medial cuneiform opening wedge osteotomy has been a common adjunct procedure in flatfoot reconstruction to correct for forefoot varus or a dorsiflexed first ray. The main goal of the study is to retrospectively review outcomes specifically in the short-intermediate term for the cotton osteotomy. The medical records of a single foot and ankle surgeon (PRB) were reviewed for patients who met inclusion and exclusion criteria. The study period was from January 2006 to October 2018. The analysis was performed using information obtained from chart-review to examine union and complication rates, as well as changes in the cuneiform articular angle based on graft size and type. A total of 71 feet in 61 patients underwent cotton osteotomies for flatfoot reconstruction. Overall complication rate was 5.6% (4/71) with 2 nonunions (2/47) in those that had radiographic follow-up of greater than 9 months. Change in cuneiform articular angle (CAA) showed 0.91° of correction per 1-millimeter increase in graft wedge size from preoperative to 3 weeks. Change for anterior-posterior medial cuneiform bisection dorsal length (AP length) was 0.70 mm per 1 mm of graft used from preoperative to 3 weeks. 6 weeks to 10 weeks showed statistically significant changes in the CAA (p = .01) and the AP length (p = .002). The cotton osteotomy showed statistically significant radiographic loss of correction between the 6- and 10-week time points when patients were allowed to begin weightbearing. Metal grafts may provide maintenance of correction which warrants future studies on their efficacy.

Different Design Feature Combinations of Flatfoot Orthosis on Plantar Fascia Strain and Plantar Pressure: A Muscle-Driven Finite Element Analysis With Taguchi Method

Customized foot orthosis is commonly used to modify foot posture and relieve foot pain for adult acquired flexible flatfoot. However, systematic investigation of the influence of foot orthotic design parameter combination on the internal foot mechanics remains scarce. This study aimed to investigate the biomechanical effects of different combinations of foot orthoses design features through a muscle-driven flatfoot finite element model. A flatfoot-orthosis finite element model was constructed by considering the three-dimensional geometry of plantar fascia. The plantar fascia model accounted for the interaction with the bulk soft tissue. The Taguchi approach was adopted to analyze the significance of four design factors combination (arch support height, medial posting inclination, heel cup height, and material stiffness). Predicted plantar pressure and plantar fascia strains in different design combinations at the midstance instant were reported. The results indicated that the foot orthosis with higher arch support (45.7%) and medial inclination angle (25.5%) effectively reduced peak plantar pressure. For the proximal plantar fascia strain, arch support (41.8%) and material stiffness (37%) were strong influencing factors. Specifically, higher arch support and softer material decreased the peak plantar fascia strain. The plantar pressure and plantar fascia loading were sensitive to the arch support feature. The proposed statistics-based finite element flatfoot model could assist the insole optimization and evaluation for individuals with flatfoot.

Effects of a 6-Minute Fast-Walking Protocol on Changes in Muscle Activity in Individuals with Flatfoot

Flatfoot causes abnormal biomechanics in the lower extremity, resulting in discomfort and excessive burden on lower extremity muscles during functional tasks, and it potentially leads to associated syndromes in the lower extremity. The aim of this study was to investigate how a demanding, repetitive task affects the muscle strength, activities, and fatigue of the lower extremities during function tasks. Nineteen individuals with flexible flatfoot (10M9F, age: 24.74 ± 2.68 years) and fifteen non-flatfoot participants (6M9F, age: 24.47 ± 3.74) took part in this study. All participants performed maximal voluntary isometric contraction and functional tasks, including walking and single-leg standing tests before and immediately after a 6-min fast-walking protocol. A surface electromyography system was used to collect muscle activation data. Our results showed that, after 6 min of fast walking, peroneus longus activity increased only in the non-flatfoot group, and gastrocnemius activity increased in the flexible flatfoot group. In the flexible flatfoot group, greater recruitment in abductor halluces and greater fatigue in the tibialis anterior was observed. Individuals with flexible flatfoot showed altered muscle activation pattern after 6-min fast walking. These findings can provide an evidence-based explanation of associated syndromes in flatfoot populations and lead to potential intervention strategies in the future.

Effect of 3D printed foot orthoses stiffness on muscle activity and plantar pressures in individuals with flexible flatfeet: A statistical non-parametric mapping study

BACKGROUND

The 3D printing technology allows to produce custom shapes and add functionalities to foot orthoses which offers better options for the treatment of flatfeet. This study aimed to assess the effect of 3D printed foot orthoses stiffness and/or a newly design posting on muscle activity, plantar pressures, and center of pressure displacement in individuals with flatfeet.

METHODS

Nineteen individuals with flatfeet took part in this study. Two pairs of foot orthoses with different stiffness were designed for each participant and 3D printed. In addition, the flexible foot orthoses could feature an innovative rearfoot posting. Muscle activity, plantar pressures, and center of pressure displacement were recorded during walking.

FINDINGS

Walking with foot orthoses did not alter muscle activity time histories. Regarding plantar pressures, the most notable changes were observed in the midfoot area, where peak pressures, mean pressures and contact area increased significantly during walking with foot orthoses. The latter was reinforced by increasing the stiffness. Concerning the center of pressure displacement, foot orthoses shifted the center of pressure forward and medially at early stance. At the end of the stance phase, a transition of the center of pressure in posterior direction was observed during the posting condition. No effect of stiffness was observed on center of pressure displacement.

INTERPRETATION

The foot orthoses stiffness and the addition of posting influenced plantar pressures during walking. The foot orthoses stiffness mainly altered the plantar pressures under the midfoot area. However, posting mainly acted on peak and mean pressures under the rearfoot area.

Adult Acquired Flatfoot Deformity

Adult acquired flatfoot deformity (AAFD) is a condition commonly seen by orthopaedic surgeons. Posterior tibial tendon dysfunction is thought to be the initial pathoanatomic etiology that leads to this deformity. Successful resolution of the pain associated with AAFD can be achievable with nonsurgical methods. Patients who continue to have pain or functional limitations despite nonsurgical treatment can find improvement with appropriately selected surgical interventions. This article addresses new advances in treatment based on the stage of AAFD and will identify areas of continued development with a focus on surgical management. The literature continues to evolve as demonstrated by a recent update regarding the nomenclature and treatment of this condition to progressive collapsing flatfoot deformity. Future goals of research include understanding the natural history of the disease, from asymptomatic to symptomatic, and studying a wide array of newer treatments and implants that have not been prospectively evaluated.

Evidence for foot orthoses for adults with flatfoot: a systematic review

Background

Flatfoot is characterised by the falling of the medial longitudinal arch, eversion of the hindfoot and abduction of the loaded forefoot. Furthermore, flatfoot leads to a variety of musculoskeletal symptoms in the lower extremity, such as knee or hip pain. The standard conservative treatment for flatfoot deformity is exercise therapy or treatment with foot orthoses. Foot orthoses are prescribed for various foot complaints. However, the evidence for the provision of foot orthoses is inconsistent. The aim of this systematic review is to synthesize the evidence of foot orthoses for adults with flatfoot.

Methods

A computerized search was conducted in August 2021, using the databases PubMed, Scopus, Pedro, Cochrane Library, and the Cochrane Central Register of Controlled Trials. Intervention studies of any design investigating the effects of foot orthoses were included, apart from case studies. Two independent reviewers assessed all search results to identify eligible studies and to assess their methodological quality.

Results

A total of 110 studies were identified through the database search. 12 studies met the inclusion criteria and were included in the review. These studies investigated prefabricated and custom-made foot orthoses, evaluating stance and plantar pressure during gait. The sample sizes of the identified studies ranged from 8 to 80. In most of the studies, the methodological quality was low and a lack of information was frequently detected.

Conclusion

There is a lack of evidence on the effect of foot orthoses for flatfoot in adults. This review illustrates the importance of conducting randomized controlled trials and the comprehensive development of guidelines for the prescription of foot orthoses. Given the weak evidence available, the common prescription of foot orthoses is somewhat surprising.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-021-00499-z.

Arch-Support Induced Changes in Foot-Ankle Coordination in Young Males with Flatfoot during Unplanned Gait Termination

Objective: The efficacy of arch orthoses in posture adjustment and joint coordination improvement during steady-state gait is well documented; however, the biomechanical changes of gait sub-tasks caused by arch support (AS), especially during gait termination, are poorly understood. Hence, this study aimed to investigate how the acute arch-supporting intervention affects foot–ankle coordination and coordination variability (CV) in individuals with flatfoot during unplanned gait termination (UGT). Methods: Twenty-five male patients with flatfoot were selected as subjects participated in this AS manipulation study. A motion capture system was used for the collection of the metatarsophalangeal joint (MPJ) and ankle kinematics during UGT. MPJ-Ankle coordination and CV were quantified using an optimized vector coding technique during the three sub-phases of UGT. A paired-sample t-test from the one-dimensional statistical parametric mapping of one-dimensional was applied to examine the data significance. Results: Significant differences for the joint kinematics between non-arch-support (NAS) and AS were exhibited only in the MPJ transverse plane during the middle and later periods of UGT (p = 0.04–0.026). Frontal plane MPJ-ankle coordination under AS during stimulus delay significantly decreased from 177.16 ± 27.41° to 157.75 ± 32.54° compared with under NAS (p = 0.026); however, the coordination pattern had not changed. Moreover, no significant difference was found in the coupling angle variability between NAS and AS in three planes during sub-phases of UGT (all p > 0.5). Conclusions: The detailed intrinsic characteristic of AS induced acute changes in lower extremity segment coordination in patients with mild flatfoot has been recorded. This dataset on foot-ankle coordination characteristics during UGT is essential for explaining foot function and injury prediction concerning AS manipulation. Further studies are expected to reflect lower limb inter-joint coordination during gait termination through the long-term effects of AS orthoses.

Calcaneal lengthening using ipsilateral fibula autograft in the treatment of symptomatic pes valgus in adolescents

Background

Evans calcaneal lengthening osteotomy is used to treat symptomatic flexible flatfoot when conservative treatment fails. Grafts such as autologous iliac bone grafts, allografts, and xenografts are implanted at the osteotomy site to lengthen the lateral column of the hindfoot. This study aimed to present the outcomes of an autologous mid-fibula bone graft used for calcaneal lengthening in symptomatic pes valgus in adolescents.

Methods

We retrospectively examined 23 ft of 13 adolescents who underwent surgery between July 2014 and January 2018. The radiological and clinical outcomes (American Orthopaedic Foot and Ankle Society ankle-hindfoot scale scores) were assessed during a mean follow-up of 49.7 (range, 30.9–73.4) months. The mean distance of the lengthening site was measured to evaluate graft sinking or collapse. The Goldberg scoring system was used to determine the degree of union at the donor and recipient sites.

Results

The calcaneal pitch and the anteroposterior and lateral talo-first metatarsal (Meary) angles showed significant correction, from 14.4 to 19.6 (p < 0.001), and from 14.5 to 4.6 (p < 0.001) and 13.5 to 8.5 (p < 0.001), respectively. The mean distance of the lengthening site showed no significant change (p = 0.203), suggesting no graft sinking or postoperative collapse. The lateral distal tibial angle showed no significant difference (p = 0.398), suggesting no postoperative ankle valgus changes. Healing of the recipient and donor sites occurred in 23 and 21 ft, respectively. The American Orthopaedic Foot and Ankle Society ankle-hindfoot scores improved significantly, from 68.0 to 98.5 (p < 0.001).

Conclusions

Evans calcaneal lengthening using an ipsilateral mid-fibula bone autograft resulted in significant improvement in clinical and radiological outcomes without ankle valgus deformity. Hence, it could be a treatment option for lateral column calcaneal lengthening in adolescents.

Kinematic instability in the joints of flatfoot subjects during walking: A biplanar fluoroscopic study

Abnormal foot kinematics is observed in flatfoot subjects with postural foot deformity. We aimed to investigate joint instability in flatfoot subjects by analyzing the abnormal rotational position and speed of their joints while walking. Five flatfoot subjects participated in our study. Three-dimensional motions of the tibia, talus, calcaneus, navicular, and cuboid were obtained during walking using the biplanar fluoroscopic motion analyses. An anatomical coordinate system was established for each bone. The rotations and ranges of motion (ROMs) of the joints from heel-strike to toe-off were quantified. The relative movements on the articular surfaces were quantified by surface relative velocity vector analysis. The data from flat foot subjects were compared with the data from normal foot subjects in previous studies. The average relative speed on the articular surface of the tibiotalar, subtalar, and calcaneocuboid joints for the flatfoot subjects was significantly higher (p < 0.05) than that for the normal foot subjects. The flatfoot subjects exhibited increased movements toward plantar flexion in the tibiotalar joint, and eversion and external rotations in the talonavicular joint during the stance phase, compared to the normal subjects (p < 0.01). Furthermore, the flatfoot subjects had a significantly larger ROM along with the inversion/eversion rotations (5.6 ± 1.8° vs. 10.7 ± 4.0°) and internal/external rotations (7.1 ± 1.5° vs. 10.5 ± 3.5°) in the tibiotalar joint. The flatfoot subjects demonstrated abnormal kinematics and larger joint movements in multiple joints during the mid-stance and terminal stance phases of walking. This demonstrates their high instability levels.

Analysis of the main soft tissue stress associated with flexible flatfoot deformity: a finite element study

A better understanding of soft tissue stress and its role in supporting the medial longitudinal arch in flexible flatfoot could help to guide the clinical treatment. In this study, a 3-Dimensional finite element (FE) foot model was reconstructed to measure the stress of the soft tissue, and its variation in different scenarios related to flexible flatfoot. All bones, cartilages, ligaments and related tendons around the ankle, and fat pad were included in the finite element model. The equivalent stress on the articular surface of the joints in the medial longitudinal arch and the maximum principal stress of the ligaments around the ankle were obtained. The results show that the plantar fascia (PF) is the main tissue in maintaining the medial longitudinal arch. The equivalent stress of all the joints in the medial longitudinal arch increases when the PF attenuation and the talonavicular joint increases, while other joints decreases when all the three tissue attenuation. Moreover, the maximum principal stress variation of calcaneofibular ligament is largest when the PF attenuation and the tibionavicular ligament and posterior tibiotalar ligament are largest when the posterior tibial tendon (PTT) attenuation. The maximum principal stress variation of tibionavicular ligament and posterior tibiotalar ligament are even larger when all the three tissue attenuation. These findings support that the PF is the main factor in maintaining the medial longitudinal arch. The medial longitudinal arch collapse mainly affects the talonavicular joint and the calcaneofibular ligament, the tibionavicular ligament and the posterior tibiotalar ligament. This approach could help to improve the understanding of adult-acquired flatfoot deformity (AAFD).

Lateral column osteotomy versus subtalar arthroereisis in the correction of Grade IIB adult acquired flatfoot deformity: A clinical and radiological follow-up at 24 months

BACKGROUND

Adult acquired flat foot deformity (AAFD) is a spectrum of conditions which can be progressive if untreated. Surgical correction and restoration of anatomical relationship are often required in the treatment of symptomatic Grade II AAFD after a failed course of conservative treatment. There is a paucity of literature recommending best practice-especially in the adult population. The authors aim to compare radiological and clinical outcomes of two widely employed surgical techniques in the treatment of symptomatic AAFD.

METHODS

A retrospective study of 76 patients with Grade IIB AAFD and had undergone either lateral column lengthening (LCL) or subtalar arthroereisis (STA) surgical correction of their symptomatic AAFD. Each technique was augmented with both bony osteotomy and soft tissue transfer as determined by on table assessment. Clinical and radiological outcomes were reviewed 24 months after surgery.

RESULTS

LCL and STA groups had comparable radiological outcomes at 24 months after surgery. However, LCL group demonstrated superior American Orthopaedic Foot and Ankle Society (AOFAS) midfoot (90.3 ± 12.6 vs 81.1 ± 20.6, p < 0.001) as well as Visual Analogue Scale (VAS) midfoot scores (0.5 ± 1.6 vs 1.3 ± 2.4, p < 0.001) at 24 months compared to the STA group. STA had a higher complication rate (20.6% vs 4.4%), with all cases complaining of sinus tarsi pain requiring subsequent removal of implant.

CONCLUSION

There is a role for either techniques in the treatment of symptomatic AAFD. LCL whilst more invasive has demonstrated superior outcome scores and lower complication rates at 24 months compared to STA. Patients need to be counselled appropriately to appreciate the benefits of each technique.

Posterior Tibial Tendon Allograft Reconstruction for Stage II Adult Acquired Flatfoot: A Case Series

Surgical treatment for a stage II adult acquired flatfoot has consisted of reconstruction of the diseased posterior tibial tendon with flexor digitorum longus tendon transfer, combined with osteotomies to address the underlying deformity. This case series presents an alternative to tendon transfer using allograft tendon for posterior tibial tendon reconstruction. Four patients who underwent stage II flatfoot reconstruction with posterior tibial tendon allograft transplantation were included. All patients had preoperative radiographs demonstrating flatfoot deformity and magnetic resonance imaging showing advanced tendinopathy of the posterior tibial tendon. Allograft tendon transplant was considered in patients demonstrating adequate posterior tibial tendon excursion during intraoperative assessment. Additional procedures were performed as necessary depending on patient pathology. Postoperatively, all patients remained non-weightbearing in a short leg cast for 6 weeks. Radiographs performed during the postoperative course demonstrated well-maintained and improved alignment. No complications were encountered. Each patient demonstrated grade 5 muscle strength and were able to perform a single-limb heel rise at the time of final follow-up. The average follow-up duration was 19.0 months. Flexor digitorum longus transfer has been studied extensively for stage II adult acquired flatfoot. However, the flexor digitorum longus has been shown to be much weaker relative to the posterior tibial tendon, and concern remains regarding its ability to recreate the force of the posterior tibial tendon. Our results demonstrate that posterior tibial tendon allograft reconstruction combined with flatfoot reconstruction is a reasonable option. This alternative has the advantage of preserving the stronger muscle without disturbing regional anatomy.

MRI of lateral hindfoot impingement

Lateral hindfoot impingement (LHI) is a subtype of ankle impingement syndrome with classic MRI findings. Biomechanically, LHI is the sequela of lateral transfer of weight bearing from the central talar dome to the lateral talus and fibula. The transfer occurs due to collapse of the medial arch of the foot, most commonly from posterior tibial tendon (PTT) and spring ligament (SL) insufficiency. Clinical features include lateral hindfoot pain, deformity, and overpronation on gait analysis. MRI changes continuously reflect the altered biomechanics as the syndrome progresses over time, including typical and often sequential changes of PTT and SL failure, increasing heel valgus, talocalcaneal and subfibular impingement, and finally lateral soft tissue entrapment. In addition to diagnosis, MRI is a useful adjunct to plan surgical treatment.

Posterior Tibial Tendinopathy and Osteopenia as Primary Symptoms of Celiac Disease: A Case Report

This case report describes posterior tibial tendon (PTT) tendinopathy, valgus deformity with tenosynovitis, and osteopenia at the medial malleolus as the primary symptoms of a young patient with celiac disease (CD) without gastrointestinal symptoms. CD is an autoimmune condition that is a chronic inflammatory disorder of the small intestine triggered by ingestion of gluten in individuals with a particular genetic background. Without typical gastrointestinal symptoms, CD patients are often misdiagnosed or undiagnosed. The patient was diagnosed with CD by duodenal biopsy. He underwent a surgical procedure, including medial displacement calcaneal osteotomy, tenosynovectomy of the PTT and flexor digitorum longus (FDL), FDL transfer to the navicular for a pes planovalgus deformity, and drilling of the medial malleolus for a stress reaction. The mechanism of the PTT tear and associated heel valgus deformity was assumed to be related to the fact that his heel alignment on the affected side changed gradually from normal to valgus and pes planus owing to CD and mechanical stress, because his normal-side heel alignment was neutral before surgery and at final follow-up. His operated ankle was pain-free, with full range of motion, 1.5 years after surgery. The patient was able to restart running and exercise gradually. Foot and ankle specialists should consider the possibility of CD in patients presenting with a PTT tear without injury or trauma and osteopenia with no obvious reason.

[Adult Acquired Flatfoot Deformity: Diagnosis and Surgical Treatment]

The adult acquired flatfoot is a deformity with slow progression, which may leads to pain and restrictions of activities of daily living if untreated. Various treatment strategies, depending on the clinical and radiological presentation, exist. Therefore, an individual therapy approach is necessary for optimal treatment. This article covers etiopathologic aspects, conservative and operative treatments as well as postoperative mobilization and rehabilitation.

The effects of individually designed insoles on pes planus treatment

The aim of this study was to examine the effects of individually designed insole in pes planus treatment. Designed insoles was adjusted according to height, length and function of the sole of each participant with pes planus in order to improve the physical parameters of them. A total of 34 participants (17 males and 17 females) with pes planus participated in the study. Height, weight, percent body fat, 30-m sprint test, vertical jump, 12-min Cooper test and Visual Analog Scale (VAS) measurement were obtained before the study and after 1 year later. Wilcoxon signed rank test was conducted to examine whether there were any differences between the pre- and post-test measurements. It was determined that individually designed insoles reduced body weight and BMI, made positive improvements in 30-m speed, vertical jump and 12-min Cooper scores, and significant decrease in VAS scores. In conclusion, it is seen that individually designed insoles have beneficial role in normalizing forces acting on the foot and improve the physical performance parameters of individuals with pes planus. Future studies are needed to explore the long-term effects of individually designed insoles and prefabricated insoles.

Posterior Tibial Tendon Integrity Can Be Screened With Plain Anteroposterior Foot Radiography

Posterior tibial tendon integrity is an important consideration when treating adult-acquired flatfoot caused by posterior tibial tendon dysfunction. The condition of this tendon traditionally has been evaluated with ultrasonography or magnetic resonance imaging, but recent advances in radiography have increased the resolution of radiographic soft tissue images. The authors examined whether the posterior tibial tendon could be screened with anteroposterior foot radiographs, based on interobserver agreement and accuracy. The authors retrospectively evaluated consecutive patients who underwent weight-bearing foot radiography and ultrasonography based on suspicion of posterior tibial tendinopathy. The integrity of the posterior tibial tendon was evaluated by 2 orthopedic surgeons with foot radiographs and scored as normal or abnormal. The authors evaluated interobserver agreement and compared the findings of ultrasonography and radiography to evaluate diagnostic accuracy. The study included 21 patients with a mean age of 51.5±15.7 years. Ultrasonography showed that 4 patients had normal tendon integrity, 6 patients had tenosynovitis and no tendinopathy, 8 patients had tendinopathy and tendon continuity, and 3 patients had loss of tendon continuity. The surgeons provided consistent radiographic findings for 81.0% of patients (17 of 21). On the basis of the ultrasonographic findings, the surgeons' accuracy was 76.2% (16 of 21) and 61.9% (13 of 21). The results indicate that weight-bearing anteroposterior foot radiography can be used to evaluate posterior tibial tendon integrity, which may allow orthopedic surgeons to predict the prognosis of patients with posterior tibial tendon dysfunction, determine the extent of surgical treatment, and evaluate tendon integrity postoperatively. [Orthopedics. 2020;43(6):e503-e507.].

Prevalence of Abnormal Ultrasound Findings in Asymptomatic Posterior Tibial Tendons

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) is a pathological condition that can cause failure of the posterior tibial tendon (PTT). Initially, patients with PTTD are often asymptomatic, making early identification and treatment challenging. Certain ultrasound (US) characteristics have been implicated in the presence of tendinopathy, but their frequency has yet to be assessed in the PTT. The purpose of this study was to identify and report on the frequency of incidental, or potentially early subclinical, tendinopathic US characteristics in asymptomatic PTTs.

METHODS

Following institutional review board approval, 150 participants underwent a bilateral-comprehensive US assessment. The resulting images were reviewed and assessed to identify the presence of abnormalities demonstrated to represent tendinopathy.

RESULTS

Overall, 266 tendons were assessed and 128 (48.1%) were determined to have at least one tendinopathic trait. Specifically, 51 (19.2%) had circumferential fluid, 69 (25.9%) had noncircumferential fluid, 22 (8.3%) had thickening, 31 (11.7%) had heterogenicity, 19 (7.1%) had hyperemia, and 2 (0.8%) had calcification. Additionally, Caucasian participants were found to be nearly 3 times more likely to have tendinopathic findings when compared with African American participants.

CONCLUSION

Sixty-seven percent of participants and 48.1% of PTTs evaluated had at least one tendinopathic feature identified on US. The prevalence rates of these findings, observed in participants, were as follows: noncircumferential fluid, circumferential fluid, heterogenicity, and thickening. Knowing the frequency of these traits may help clinicians to identify subclinical tendinopathy in the PTT before it progresses to PTTD.

LEVEL OF EVIDENCE

Level IV, case series.

Finite element analysis of secondary effect of midfoot fusions on the spring ligament in the management of adult acquired flatfoot

BACKGROUND

Surgical treatment of adult acquired flatfoot deformity can involve arthrodesis of the midfoot to stabilize the medial column. Few experimental studies have assessed the biomechanical effects of these fusions, because of the difficulty of measuring these parameters in cadavers. Our objective was to quantify the biomechanical stress caused by various types of midfoot arthrodesis on the Spring ligament. To date this is not known.

METHODS

An innovative finite element model was used to evaluate flatfoot scenarios treated with various combinations of midfoot arthrodesis. All the bones, cartilages and tissues related to adult acquired flatfoot deformity were included, respecting their biomechanical characteristics. The stress changes on the Spring ligament were quantified. Both foot arch lengthening and falling were measured for each of the midfoot arthrodeses evaluated.

FINDINGS

Arthrodesis performed for stabilization of the talonavicular joint leads to a higher decrease in stress on the Spring ligament. Talonavicular fusion generated a Spring ligament stress decrease of about 61% with respect to the reference case (without any fusion). However, fusing the naviculocuneiform joints leads to an increase in the stress on the Spring ligament.

INTERPRETATION

This important finding has been unknown to date. We advocate caution regarding fusion of the naviculocuneiform joint as it leads to increased stresses across the Spring ligament and therefore accelerates the development of planovalgus.

Predicting foot orthosis deformation based on its contour kinematics during walking

BACKGROUND

Customized foot orthoses (FOs) are designed based on foot posture and function, while the interaction between these metrics and FO deformation remains unknown due to technical problems. Our aim was to predict FO deformation under dynamic loading using an artificial intelligence (AI) approach, and to report the deformation of two FOs of different stiffness during walking.

METHODS

Each FO was fixed on a plate, and six triad reflective markers were fitted on its contour, and 55 markers on its plantar surface. Manual loadings with known magnitude and application point were applied to deform "sport" and "regular" (stiffer) FOs in all regions (training session). Then, 13 healthy male subjects walked with the same FOs inside shoes, where the triad markers were visible by means of shoe holes (walking session). The marker trajectories were recorded using optoelectronic system. A neural network was trained to find the dependency between the orientation of triads on FO contour and the position of markers on its plantar surface. After tuning hyperparameters and evaluating the performance of the model, marker positions on FOs surfaces were predicted during walking for each subject. Statistical parametric mapping was used to compare the pattern of deformation between two FOs.

RESULTS

Overall, the model showed an average error of <0.6 mm for predicting the marker positions on both FOs. The training setup was appropriate to simulate the range of triads' displacement and the peak loading on FOs during walking. Sport FO showed different pattern and significantly higher range of deformation during walking compared to regular FO.

CONCLUSION

Our technique enables an indirect and accurate estimation of FO surface deformation during walking. The AI model was capable to make a distinction between two FOs with different stiffness and between subjects. This innovative approach can help to optimally customize the FO design.

Adult Acquired Flatfoot Deformity: Anatomy, Biomechanics, Staging, and Imaging Findings

Adult acquired flatfoot deformity (AAFD) is a common disorder that typically affects middle-aged and elderly women, resulting in foot pain, malalignment, and loss of function. The disorder is initiated most commonly by degeneration of the posterior tibialis tendon (PTT), which normally functions to maintain the talonavicular joint at the apex of the three arches of the foot. PTT degeneration encompasses tenosynovitis, tendinosis, tendon elongation, and tendon tearing. The malaligned foot is initially flexible but becomes rigid and constant as the disorder progresses. Tendon dysfunction commonly leads to secondary damage of the spring ligament and talocalcaneal ligaments and may be associated with injury to the deltoid ligament, plantar fascia, and other soft-tissue structures. Failure of multiple stabilizers appears to be necessary for development of the characteristic planovalgus deformity of AAFD, with a depressed plantar-flexed talus bone, hindfoot and/or midfoot valgus, and an everted flattened forefoot. AAFD also leads to gait dysfunction as the foot is unable to change shape and function adequately to accommodate the various phases of gait, which require multiple rapid transitions in foot position and tone for effective ambulation. The four-tier staging system for AAFD emphasizes physical examination findings and metrics of foot malalignment. Mild disease is managed conservatively, but surgical procedures directed at the soft tissues and/or bones become necessary and progressively more invasive as the disease progresses. Although much has been written about the imaging findings of AAFD, this article emphasizes the anatomy and function of the foot's stabilizing structures to help the radiologist better understand this disabling disorder. Online supplemental material is available for this article. ^©RSNA, 2019.

Adult rigid flatfoot: Triple arthrodesis and osteotomy

To analyze the efficacy of arthrodesis combined with osteotomy applied to subtalar, calcaneocuboid, and talonavicular joints for the treatment of adult rigid flatfoot.This retrospective study included 29 adult patients with rigid flatfoot who underwent triple arthrodesis combined with osteotomy from January 2015 to December 2017. All patients suffered from stage III of adult acquired flatfoot. Patients returned for a clinical and radiologic follow-up evaluation at an average of 19.5 (range, 15-27) months postoperatively. Outcomes were assessed by comparing pre- and postoperative AOFAS scores, VAS pain scores, and Karlsson scores, and the radiographic assessment including Meary, Pitch, and Kite angles.Twenty six patients returned for final evaluation. Twenty four patients had an excellent or good outcome on patient subjective self-assessment. All the VAS scores, AOFAS scores, and Karlsson scores at final follow-up showed different extents of improvement. The mean Meary angle significantly decreased from 25.8 ± 5.4 degrees preoperatively to 6.9 ± 7.7 degrees at final follow-up, and the mean Pitch angle improved markedly from 12.5 ± 3.7 points preoperatively to 23.2 ± 4.1 points at final follow-up (P < .001).Arthrodesis combined with osteotomy can effectively correct calcaneal valgus deformity, restore arch structure, and relieve foot pain in adult rigid flatfoot.

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.

Radiographic measurements of the talus and calcaneus in the adult pes planus foot type

OBJECTIVE

A distinctive feature of the modern human foot is the presence of a medial longitudinal arch when weight-bearing. Although the talus and calcaneus play a major role in the structure and function of the human foot, the association between the morphology of these bones and longitudinal arch height has not been fully investigated. A better understanding of this relationship may assist in the interpretation of pedal remains of fossil hominins, where features of the foot and ankle morphology have been described as providing evidence for the presence of a longitudinal arch.

METHODS

For this study, weight-bearing radiographs of 103 patients from an urban US Level 1 trauma center, taken as part of a clinical examination for medical evaluation, were selected. These radiographs were classified as to foot type by arch height as defined using the calcaneal inclination angle. From this group, 68 radiographs were suitable for linear and angular measurements of the talus and 74 of the calcaneus. The relationships between these measurements and arch height were explored using least squared linear regression analysis.

RESULTS

The results demonstrate that angular measurements of the calcaneus (particularly those that reflect the relationship of the talar articular facets to each other and the tilt of the calcaneocuboid joint to the longitudinal axis of the calcaneus) are predictive of arch height (r² = .29-.44 p ≤ .001). All angular measurements of the talus and all examined linear measurements of both the talus and calcaneus were not predictive of arch height.

DISCUSSION

These results suggest that certain angular measurements of the calcaneus are associated with arch height in the modern human foot. While this information is useful in the interpretation of hominin pedal remains, the relationship of the morphology of these bones, as well as other bones of the foot, to arch height is complex, requiring further investigation.

Surgical Biomechanics: Principles of Procedure Choice

Surgical treatment of foot and ankle ailments is common, but in the past the choice of procedures was often dictated principally by positional considerations. This article reviews the use of the 2 primary biomechanical approaches, the kinematic and kinetic methods, and presents a novel unified method to guide surgical procedure choice, the kineticokinematic approach. Decision-making methods and resources are discussed and 2 case studies are presented to elucidate how this method may be used when choosing surgical procedures.

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.

Can short-term effectiveness of anti-pronation taping predict the long-term outcomes of customized foot orthoses: developing predictors to identify characteristics of patients with plantar heel pain likely to benefit from customized foot orthoses

BACKGROUND

Foot orthoses are widely used to manage plantar heel pain (PHP). However, the evidence concerning the effect of foot orthoses on PHP is not conclusive. The study aims to identify the characteristics of patients with PHP likely to achieve a positive outcome after customized foot orthoses and to verify the concept that patients who respond positively to anti-pronation taping would achieve a positive prognosis after wearing foot orthoses for six months.

METHODS

This is a prospective observational cohort study. Seventy-four patients with PHP underwent a baseline examination and received anti-pronation taping to their painful feet. The taping effects on pain and function were assessed at the 7-day follow-up visit. Then, all patients received an intervention for their PHP with customized foot orthoses for six months. Outcome was assessed with a numeric pain rating scale, the patient-specific functional scale, the foot function index, and the global rating of perceived change. Significant reduction of pain, increase of function, and perception of a meaningful improvement were considered a positive response.

RESULTS

Of 74 patients, 49 had a positive response to the customized foot orthosis treatment. Five predictors were identified: (1) the average pain intensity decreased by over 1.5 points with taping, (2) the range of ankle plantarflexion > 54 degrees, (3) the strength of ankle plantarflexors on the symptomatic side was equal to or stronger than that on the other side, (4) the range of hip internal rotation < 39 degrees, and (5) the range of hip external rotation > 45 degrees. The presence of three or more predictors increased the rate of achieving positive outcome from 66 to 89%.

CONCLUSIONS

The predictors of customized foot orthosis outcome in patients with PHP are related to several physical measures of a lower extremity. Findings of the study can be used to screen and select patients with PHP for foot orthosis intervention. Moreover, patients who respond positively to anti-pronation taping would also benefit from the customized foot orthoses. However, since there was no control group in the current study, it is inappropriate to draw conclusions about the effectiveness of the foot orthoses treatment.

TRIAL REGISTRATION

The trial was retrospectively registered with the Australian and New Zealand Clinical Trials Registry (ACTRN 12617000119392 ).

Short- to Mid-Term Outcomes Following the Use of an Arthroereisis Implant as an Adjunct for Correction of Flexible, Acquired Flatfoot Deformity in Adults

BACKGROUND

The use of an arthroereisis implant for the treatment of adolescent flatfoot deformity has been described. However, data that address the outcomes of patients treated with an arthroereisis implant in adults are limited. The purpose of this study was to investigate the radiographic and clinical outcomes and complications following the use of a subtalar arthroereisis implant as an adjunct for correction acquired flatfoot deformity secondary to posterior tibial tendon dysfunction.

METHODS

A retrospective case-control study was performed querying all patients undergoing surgical flatfoot correction between January 1, 2010 and January 1, 2015. The experimental group included patients undergoing arthroereisis augmentation at the time of flatfoot correction. Patients undergoing the same flatfoot correction without the use of an arthroereisis implant were used as controls. Radiographic measurements were evaluated preoperatively and at final radiographic follow-up and included talonavicular (TN) coverage angle, and lateral talar-first metatarsal angle (T1MA). Patient-reported outcomes were assessed using preoperative visual analog scale (VAS) pain scores and postoperative Short Form-36, VAS, and satisfaction at final orthopedic follow-up.

RESULTS

A total of 15 patients underwent flatfoot correction and were augmented with an arthroereisis implant and were matched with 30 controls. Postoperative, mid-term T1MA and regional analysis was found to be improved in the experimental group versus control. Patients undergoing adjunct subtalar arthroereisis demonstrated an increased likelihood of achieving radiographically normal talonavicular coverage <7° compared with our control group at follow-up.

CONCLUSIONS

The adjunct use of an arthroereisis implant resulted in improved and maintained radiographic and clinical measurements in patients undergoing stage II flatfoot.

CLINICAL SIGNIFICANCE

These results suggest utility of a subtalar arthroereisis implant as an adjunct to flatfoot correction with little additional risk of harm to the patient.

LEVELS OF EVIDENCE

Level III: Case-control study.

H-reflex in abductor hallucis and postural performance between flexible flatfoot and normal foot

OBJECTIVE

Morphological changes of the abductor hallucis muscle (AbH) in flexible flatfoot (FF) individuals influence regulations of the medial longitudinal arch (MLA). Prolonged and repeated stretching of AbH in flexible flatfoot may cause changes in muscle reflex properties and further influence postural performance. However, AbH muscle reflex under different postural conditions have never been examined. The purpose of this study was to investigate differences in AbH H-reflex and postural performance between individuals with normal foot (NF) alignment and FF under prone, double-leg stance (DLS), and single-leg stance (SLS) conditions.

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PARTICIPANTS

Individuals with FF (n = 12) and NF (n = 12).

MAIN OUTCOME MEASURES

AbH H-reflex, AbH EMG and center of pressure (CoP) displacement.

RESULTS

Under all postural conditions, AbH H-reflex was significantly lower in the FF group (P < .05). Under the SLS condition, AbH EMG was significantly higher in the FF group (P < .05), and CoP displacement for the medial-lateral and anterior-posterior directions were significantly higher in the FF group (P < .05).

CONCLUSIONS

With increased postural demand, FF individuals maintained their postural stability by recruiting greater AbH activities than through automatic stretch reflex, but FF individuals still showed inferior posture stability.