Acquired flatfoot in adults due to dysfunction of the posterior tibial tendon

Diagnostic efficacy of posterior tibialis tendon dysfunction: a systematic review of literature

OBJECTIVE

To perform a systematic review to examine the diagnostic accuracy of magnetic resonance imaging, ultrasonography, and radiography in the evaluation of posterior tibial tendon dysfunction (PTTD).

MATERIALS AND METHODS

Medline, Scopus, Embase, and The Cochrane Central Register of Controlled Trials (CENTRAL) were searched for relevant studies through April 2023. The study quality was assessed using the QUADAS-2 scoring system.

RESULTS

Of the initial 634 studies, 12 studies met the quality criteria and were included, with 645 PTTs evaluated with MRI, 133 with US, and 97 with radiography. MRI was found to be more sensitive and specific than ultrasound, radiography, and clinical evaluation for detecting PTTD, with a sensitivity of up to 95%, specificity of up to 100%, and accuracy of 96% for detecting PTT tears. US showed a sensitivity of 80% and specificity of 90% for diagnosing tendinopathy, and a sensitivity of 90% and specificity of 80% for diagnosing peritendinosis when compared to MRI. Weight-bearing radiographs had a sensitivity of 71.4%, specificity of 88.9%, and diagnostic accuracy of 81.3% when diagnosing PTT ruptures. Various radiologic measurements were also found to have a significant relationship with PTT tears but were poorly correlated with PTT tendinosis and isolated tenosynovitis.

CONCLUSION

Magnetic resonance imaging is the preferred imaging tool for evaluating patients with posterior tibial tendon dysfunction, with higher diagnostic accuracy, sensitivity, and specificity compared to ultrasound and radiographic imaging. However, initial imaging with ultrasound and radiographs may be used due to their availability and cost-effectiveness.

CLINICAL RELEVANCE

PTTD affects 3% of women ≥ 40 years and 10% of adults ≥ 65 years globally. Using the appropriate imaging study, MRI ensures that patients suffering from PTTD are diagnosed and treated in a timely manner.

KEY POINTS

• This review aimed to determine the diagnostic accuracy of MRI, ultrasonography, and radiography in evaluating PTTD. • MRI outperformed ultrasound and radiography, with higher sensitivity, specificity, and accuracy in detecting PTT tears. • MRI is the preferred imaging modality for the initial diagnosis of PTTD.

Spring Ligament Reconstruction for Progressive Collapsing Foot Deformity: Contemporary Review

The spring ligament is one of the main stabilizers of the medial arch of the foot and the primary static supporter of the talonavicular joint. Attenuation or rupture of this ligament is thought to play a central role in the pathophysiology of progressive collapsing foot deformity. Traditional correction of flexible flatfoot consists of posterior tibial tendon augmentation along with various osteotomies or hindfoot fusions. Repair or reconstruction of the spring ligament has not been as widely pursued. In recent years, newer techniques have been explored and may improve outcomes of traditional procedures, or possibly entirely replace some osteotomies. Combined spring-deltoid ligament reconstruction is also gaining traction as a viable technique, particularly as the ankle begins to deform into valgus. This review summarizes the variety of nonanatomic and anatomic reconstruction techniques that have been described, including autologous tendon transfers, allografts, and synthetic augmentation. Although many have only been characterized in biomechanical cadaver studies, this article reviews preliminary clinical studies that have shown promising results. There is a need for more high-quality studies evaluating the clinical, radiographic, and patient-reported outcomes following spring ligament reconstruction.

Addressing Medial Column Instability in Flatfoot Deformity

A stable medial column is important to the normal function of the foot and ankle. Medial column instability and forefoot varus can result in compensatory hindfoot motion leading to stress along the medial soft-tissue structures. Medial column stabilization should therefore be considered when (1) forefoot varus deformity is identified following hindfoot realignment; (2) pronounced medial column instability is present, even in the absence of forefoot varus; and (3) when degenerative changes are present within the medial column articulations. Common surgical procedures include arthrodesis of the talonavicular joint, naviculocuneiform joint, and first tarsometatarsal joint, as well as osteotomy of the medial cuneiform (Cotton osteotomy).

Sinus tarsi and sinus tarsi syndrome: An imaging review

The sinus tarsi is a funnel-shaped region at the junction of mid-foot and hind-foot which contains fat, vessels, nerves and ligaments. The ligaments help stabilise the subtalar joint and maintain the longitudinal arch of the foot. The nerve endings contain proprioceptive fibres indicating a role for the sinus tarsi in movement of the foot. Sinus tarsi syndrome is a clinical entity characterised by lateral hind-foot pain with worsening on palpation and weight-bearing, and perceived instability. It is associated with both traumatic and non-traumatic causes. Magnetic resonance imaging is the imaging modality of choice for assessment of the sinus tarsi and sinus tarsi syndrome. In this review article, we review the anatomy and various aetiologies of sinus tarsi syndrome, along with the imaging appearances.

Diagnostic accuracy of measurements in progressive collapsing foot deformity using weight bearing computed tomography: A matched case-control study

BACKGROUND

We aimed to investigate the diagnostic accuracy of known two-dimensional (2D) and three-dimensional (3D) measurements for Progressive Collapsing Foot Deformity (PCFD) in weight-bearing computed tomography (WBCT). We hypothesized that 3D biometrics would have better specificity and sensitivity for PCFD diagnosis than 2D measurements.

METHODS

This was a retrospective case-control study, including 28 PCFD feet and 28 controls matched for age, sex and Body Mass Index. Two-dimensional measurements included: axial and sagittal talus-first metatarsal angles (TM1A and TM1S), talonavicular coverage angle (TNCA), forefoot arch angle (FFAA), middle facet incongruence angle (MF°) and uncoverage percentage (MF%). The 3D Foot Ankle Offset (FAO) was obtained using dedicated semi-automatic software. Intra and interobserver reliabilities were assessed. Receiver Operating Characteristic (ROC) curves were calculated to determine diagnostic accuracy (Area Under the Curve (AUC)), sensitivity and specificity.

RESULTS

In PCFD, mean MF% and MF° were respectively 47.2% ± 15.4 and 13.3° ± 5.3 compared with 13.5% ± 8.7 and 5.6° ± 2.9 in controls (p < 0.001). The FAO was 8.1% ± 3.8 in PCFD and 1.4% ± 1.7 in controls (p < 0.001). AUCs were 0.99 (95%CI, 0.98-1) for MF%, 0.96 (95%CI, 0.9-1) for FAO, 0.90 (95%CI, 0.81-0.98) for MF°. For MF%, a threshold value equal or greater than 28.7% had a sensitivity of 100% and specificity of 92.8%. Conversely, a FAO value equal or greater than 4.6% had a specificity of 100% and a sensitivity of 89.2%. All other 2D measurements were significantly different in PCFD and controls (p < 0.001).

CONCLUSIONS

MF% and FAO were both accurate measurements for PCFD. MF% demonstrated slightly better specificity. FAO better sensitivity. A combination of threshold values of 28.7% for MF% and 4.6% for FAO yielded 100% sensitivity and specificity.

Supramalleolar Lateral Opening-Wedge Osteotomy in Conjunction With Progressive Collapsing Foot Deformity Reconstruction for PCFD With Ankle Instability

BACKGROUND

Reconstruction of progressive collapsing foot deformity (PCFD) with ankle instability (PCFD class E) remains a substantial challenge to orthopaedic surgeons. We report the outcomes of PCFD class E treated by means of a relatively standard PCFD foot reconstruction approach with the addition of a supramalleolar lateral opening-wedge osteotomy.

METHODS

We conducted a retrospective study of 13 patients (15 ankles) who underwent this procedure for PCFD class E between 2010 and 2021. Mean follow-up time was 3.8 (range, 2-6.3) years. Clinical assessment was based on the Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scale as well as a Self-Administered Foot Evaluation Questionnaire (SAFE-Q). Radiographic assessments, including identification of the mechanical ankle joint axis point and a modified valgus Takakura-Tanaka osteoarthritis grade, were recorded.

RESULTS

The mean JSSF score improved significantly from 45.2 preoperatively to 83.9 postoperatively (P < .001). SAFE-Q scores at the final follow-up were 70.1 for the pain and pain-related subscale, 75.4 for the physical functioning and daily living subscale, 83.0 for the social functioning subscale, 74.4 for the shoe-related subscale, and 78.1 for the general health and well-being subscale. Radiographic measurements showed improvement in the tibiotalar tilt angle (average improvement: 5.4 degrees); orientation of the talus joint line relative to the ground (average improvement: 14.0 degrees); anteroposterior talus-first metatarsal angle (average improvement: 11.2 degrees), talonavicular coverage angle (average improvement: 21.6 degrees), and lateral talus-first metatarsal angle (average improvement: 17.0 degrees). Postoperatively, the mechanical ankle joint axis point moved medially for all patients and into the medial half of the ankle joint for 7 patients. The modified osteoarthritis stage improved postoperatively in most cases.

CONCLUSION

In this select and relatively small group of patients who had a supramalleolar lateral opening-wedge osteotomy combined with PCFD reconstruction, we measured general improvement in JSSF scores and radiographic variables. Long-term durability of the procedure remains unknown. This procedure may be an option for preserving the ankle joint in treatment of PCFD class E with osteoarthritis of the ankle.

LEVEL OF EVIDENCE

Level IV, therapeutic.

Deep learning-based tool affects reproducibility of pes planus radiographic assessment

Angle measurement methods for measuring pes planus may lose consistency by errors between observers. If the feature points for angle measurement can be provided in advance with the algorithm developed through the deep learning method, it is thought that the error between the observers can be reduced. A total of 300 weightbearing lateral radiographs were used for the development of the deep learning-based algorithm, and a total of 95 radiographs were collected for the clinical validation test set. Meary angle (MA) and calcaneal pitch (CP) were selected as measurement methods and measured twice by three less-experienced physicians with the algorithm-based tool and twice without. The intra- and inter-observer agreements of MA and CP measures were assessed via intra-class correlation coefficient. In addition, verification of the improvement of measurement performance by the algorithm was performed. Interobserver agreements for MA and CP measurements with algorithm were more improved than without algorithm. As for agreement with reference standard, combining the results of all readers, both MA and CP with algorithm were greater than those without algorithm. The deep learning algorithm tool is expected to improve the reproducibility of radiographic measurements for pes planus, especially by improving inter-observer agreement.

A Novel Anatomic Reconstruction for Posterior Tibialis Tendon in Treatment of Flexible Adult-Acquired Flatfoot Deformity

OBJECTIVE

To present a novel approach for the anatomic reconstruction of the posterior tibialis tendon (PTT) in restoring plantar insertions and evaluate its efficiency in treating flexible adult-acquired flatfoot deformity (AAFD) caused by PTT dysfunction.

METHODS

For AAFD treatment, a novel PTT reconstruction method was presented. The current study involved 16 patients, including three men, and 13 women, from August 2017 to July 2019. The mean age was 43.2 ± 15.1 years (21-64 years). The innovative PTT repair method was used on all patients. The treatment involved performing a traditional Flexor Digitorum Longus (FDL) transfer in the navicular tuberosity and suturing the plantar insertions to FDL as tension was applied to tighten the plantar structures of the foot. The results were retrospectively analyzed. The clinical outcome was assessed using the pain visual analogue scale (VAS), the satisfaction VAS, and the American Orthopedic Foot and Ankle Society ankle-hindfoot scale (AOFAS-AH). Isokinetic testing was performed using a dynamometer at 60°/s and 120°/s for inversion/eversion and plantarflexion/dorsiflexion, respectively, to determine the mean peak torque. Radiographic measurements were employed to assess the outcomes.

RESULTS

Bone surgeries combined with the modified anatomic PTT reconstruction were performed on patients with medializing calcaneal osteotomy in 12 (75%) patients and subtalar joint fusion in four (25%) patients. The branch linking to the plantar insertions was detected in every case, with an average width of 3.5 ± 0.8 mm (3.1-4.3 mm). All patients were followed up for the mean of 16.8 ± 1.8 months (range, 15-20 months). The average postoperative functional scores, including pain VAS, satisfaction VAS, total AOFAS-AH, and all AOFAS-AH sub-scales, steadily improved during the follow-up. In the last follow-up, isokinetic testing revealed no loss of plantarflexion strength (p = 0.350 and 0.098) and significant improvement in the inversion strength (p = 0.007 and 0.008) in the operated ankles at 60°/s and 120°/s. Radiographic outcomes, particularly the talar head uncovering, improved significantly after more than a year (p < 0.001 for all).

CONCLUSIONS

The novel technique for PTT reconstruction in restoring the plantar insertions serves as an effective procedure in treating AAFD caused by PTT dysfunction in terms of delivering a consistent improvement in ankle inversion strength, medial longitudinal arch restoring, and satisfactory clinical outcomes.

Outcomes of 2B Adult Acquired Flatfoot Deformity Correction in Patients With and Without Spring Ligament Tear

BACKGROUND

It is currently unclear how injury to the spring ligament (SL) affects the preoperative presentation of adult acquired flatfoot deformity (AAFD) or the outcome of operative reconstruction. The purposes of this study were to assess the preoperative features and pre- or postoperative function of patients who underwent direct operative repair of an SL tear compared to those without a tear.

METHODS

86 patients undergoing operative correction of grade 2B AAFD by a single fellowship-trained foot and ankle orthopaedic surgeon were reviewed at an average follow-up of 45.9 months. There were 35 feet found to have an SL tear that underwent concomitant debridement and direct repair of the SL. Patient charts were reviewed for demographic information, preoperative visual analog scale (VAS) pain level, and their Foot and Ankle Ability Measure (FAAM) activities of daily living (ADL) and sports subscales. Preoperative radiographic parameters were assessed. Patient outcomes of VAS pain, FAAM-ADL, and FAAM-Sports were collected and compared between groups.

RESULTS

Those with an SL tear had significantly lower FAAM-ADL and sports scores, with higher VAS pain scores preoperatively. Patient age, talonavicular uncoverage percentage, and talonavicular angle were found to be associated with spring ligament degeneration. At final follow-up, patients demonstrated a significant improvement in all outcome parameters, with no statistical difference found with patient satisfaction, final postoperative VAS pain, FAAM-ADL, or FAAM-Sports in those requiring a repair of their SL as compared to the control group.

CONCLUSION

Increasing patient age, increasing talonavicular uncoverage percentage, and decreasing talonavicular angle are all independently associated with increased likelihood of patients with AAFD having an SL tear. At follow-up for operative treatment of grade 2B AAFD flatfoot with our approach, we found no clinical outcomes difference between those without SL tears and those with SL tears treated with concomitant SL debridement and repair.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Effect of soft inflatable orthosis on the medial longitudinal arch in patients with flexible flatfoot deformity

BACKGROUND

Orthoses can stabilize the foot and restore the medial longitudinal arch for symptomatic flexible flatfoot. However, the effectiveness of orthoses remains controversial. The purpose of this study was to evaluate effectiveness of a customized soft inflatable orthosis on the medial longitudinal arch of flexible flatfoot patients under load.

METHODS

We obtained CT scans of the feet of 14 healthy volunteers and 14 patients with flexible flatfoot under non- and simulated weight-bearing conditions. Then CT scans under the same conditions were taken for patients with flexible flatfoot equipped with soft inflatable orthosis. Three-dimensional models of the medial longitudinal arch and hindfoot were constructed from CT images. The three-dimensional mobility of the medial longitudinal arch joints under load was compared between patients with flexible flatfoot equipped with soft inflatable orthosis or not.

FINDINGS

From non- to simulated weight-bearing condition, the eversion and dorsiflexion of the talocalcaneal joint, the eversion of the talonavicular joint, the abduction and dorsiflexion of the cuneonavicular joint, and the dorsiflexion of the first tarsometatarsal joint were significantly larger in patients with flexible flatfoot than healthy volunteers. The customized soft inflatable orthosis could reduce the eversion of the talonavicular joint and the eversion and dorsiflexion of the talocalcaneal joint.

INTERPRETATION

The soft inflatable orthosis is effective to improve medial longitudinal arch height and reduce excessive mobility of joints for flexible flatfoot deformity. The results of this study could provide evidence for the optimal orthosis design to treat flexible flatfoot in the future.

Extrinsic foot muscle forces and joint contact forces in flexible flatfoot adult with foot orthosis: A parametric study of tibialis posterior muscle weakness

BACKGROUND

The posterior tibialis tendon dysfunction (PTTD) is typically associated with progressive flatfoot deformity, which could be alleviated with foot orthosis. However, the evaluation of tibialis posterior (TP) weakness on lower limb mechanics of flatfoot adults with foot orthoses is scarce and requires further investigation.

RESEARCH QUESTION

This study aimed to examine the effects of TP weakness on lower limb mechanics in flatfoot adults with foot orthosis through gait analysis and musculoskeletal modelling.

METHODS

Fifteen young adults with flatfoot were recruited from University to perform a gait experiment with and without foot orthoses. Data collected from the motion capture system were used to drive the musculoskeletal modelling for the estimation of the joint force and extrinsic muscle forces of the lower limb. A parametric analysis was conducted by adjusting the TP muscle strength from 40 % to 100 %. Two-way repeated measures ANOVA was used to compare the peak extrinsic foot muscle forces and joint forces among different levels of TP weakness and insole conditions.

RESULTS

TP weakness significantly increased ankle joint force superoinferiorly (F = 125.9, p < 0.001) and decreased anteroposteriorly (F = 125.9, p < 0.001), in addition to a significant increase in the muscle forces of flexor hallucis longus (p < 0.001) and flexor digitorum longus (p < 0.001). Besides, the foot orthosis significantly reduced most peak muscle forces whilst significantly reduced the second peak knee force and peak ankle force compared to the control condition (F = 8.79-30.9, p < 0.05).

SIGNIFICANCE

The increased extrinsic foot muscle forces (flexor hallucis longus and flexor digitorum longus) and ankle joint forces in the TP weakness condition indicated that TP weakness may induce compensatory muscle activation and attenuated joint load. The abnormal muscle and joint mechanics in flatfoot adults with TP weakness might be restored by the orthosis.

Relationships Between Relative Ankle Muscle Ratios, Severity of Symptoms, and Radiologic Parameters in Adolescent Patients With Symptomatic Flexible Flat Feet

Objective

To investigate differences in the relative sizes of the ankle-stabilizing muscles in individuals with versus without flexible flat feet and to determine predictors of symptom severity.

Methods

This cross-sectional study included 30 patients with symptomatic flexible flat feet and 24 normal controls. The following were evaluated: foot posture index, resting calcaneal stance position angle, radiographic findings (calcaneal pitch, Meary’s angle, talocalcaneal angle, talonavicular coverage angle [TNCA]), foot function index (FFI), and cross-sectional areas (CSA) of the tibialis anterior (TA), tibialis posterior (TP), and peroneus longus (PL) upon ultrasonographic examination. To address morphometric differences among participants, individual muscle measurements were normalized to proportions of total muscle CSA. Between-group differences were evaluated with independent t-tests. Correlations between muscle ratios, radiographic parameters, and FFI scores were investigated. Logistic regression analysis was performed to determine which parameters predicted severe symptoms.

Results

The relative size of the TP was significantly greater and those of the TA and PL were significantly smaller in patients with flat feet than in normal controls. Correlations were found among relative muscle CSA ratios, radiographic parameters, and FFI score. Linear regression analysis confirmed that the TNCA and the relative CSA of the PL were independent predictors of symptom severity.

Conclusion

This study found significant differences in the relative CSAs of the ankle muscles in patients with flexible flat feet versus individuals without flat feet; these differences were significantly correlated with anatomic abnormalities. Symptoms were more severe in patients with relatively greater forefoot abduction and relatively smaller PL.

American College of Foot and Ankle Surgeons Clinical Consensus Statement: Appropriate Clinical Management of Adult-Acquired Flatfoot Deformity

This clinical consensus statement of the American College of Foot and Ankle Surgeons focuses on the highly debated subject of the management of adult flatfoot (AAFD). In developing this statement, the AAFD consensus statement panel attempted to address the most relevant issues facing the foot and ankle surgeon today, using the best evidence-based literature available. The panel created and researched 16 statements and generated opinions on the appropriateness of the statements. The results of the research on this topic and the opinions of the panel are presented here.

18-Year Operative Incidence and Cost Analysis of the Treatment of Adult Acquired Flatfoot Deformity

Background:

Adult acquired flatfoot (AAFD) is commonly treated by foot and ankle surgeons. Despite how commonly this disease presents, its incidence and economic impact have yet to be defined. We hypothesized that the operative incidence of AAFD and its economic burden would increase over the time period 1996 to 2014.

Methods:

The South Carolina database was queried for data from acute care and ambulatory surgery centers. Bivariate descriptive statistics were used to analyze the data. Operative incidence was calculated and demographics and medical comorbidities of patients who progressed to operative intervention were analyzed. Costs associated with operative care episodes were calculated to determine the economic burden.

Results:

A total of 1299 patients underwent AAFD corrective surgery between 1996 and 2014. Patients who underwent surgery for AAFD were most likely to be white, female, and in their fourth, fifth, and sixth decade of life. Operative incidence for AAFD rose from 0.26 per 100 000 covered lives in 1996 to 3.04 in 2014. The total health care costs associated with patients who underwent surgery for AAFD increased from $57 395.33 in 1996 to $6 859 723.60 in 2014.

Conclusions:

This data demonstrate that patients most commonly undergoing operative intervention for AAFD were white, female, and in their fourth, fifth, or sixth decade of life. There has been a significant increase in operative incidence, which may help direct attention to further exploration of outcome data in these patient populations, associated treatment costs, and preventative treatment options.

Level of Evidence:

Level III, retrospective comparative study.

Orthotic treatment for stage I and II posterior tibial tendon dysfunction (flat foot): A systematic review

OBJECTIVE

To investigate whether orthotic treatment is effective for the treatment of posterior tibial tendon dysfunction stages I and II (flat foot).

DATA SOURCES

Five databases (PubMed, Scopus, PEDro, SPORTDiscus and The Cochrane Library) were searched for potential RCTs from their inception until August 2020.

REVIEW METHODS

Only randomised controlled trials (RCT) that included subjects diagnosed with posterior tibial dysfunction in the initial stage and treated with orthotic treatments were selected. The outcomes assessed were whatever symptom related to posterior tibial tendon dysfunction stage I and II. Included RCTs were appraised using the Cochrane collaboration risk of bias tool.

RESULTS

Four RCT articles and 186 subjects were included. 75% were at high risk of bias for blinding of participants and personnel. Three different types of conservative treatment were used in the studies: foot/ankle-foot orthoses, footwear and stretching /strengthening exercises. Foot orthoses, together with exercise programmes, seemed to improve the effect of orthotic treatment. Foot orthoses with personalised internal longitudinal arch support were more effective than flat insoles or standard treatments in reducing pain.

CONCLUSIONS

The use of orthotic treatment may be effective in reducing pain in the early stages of posterior tibial tendon dysfunction. Further research is needed into individualised orthotic treatment and high-intensity monitored exercise programmes.

Do Not Judge an Ossicle by Its Size: Type 1 Ossicles Associated With Posterior Tibial Tendon Dysfunction

INTRODUCTION

Patients with type II navicular ossicles have traditionally been considered to be symptomatic, whereas patients with type I and III bones are considered asymptomatic without additional relevant imaging findings. The main objective of this study is to investigate the association of type I os naviculare with clinical symptomology and magnetic resonance imaging findings in comparison to types II and III ossicles.

METHODS

Three hundred nine subjects with accessory navicular bone types were identified, and their associations with focal navicular pain, pes planus alignment, ossicle or proximal navicular bone marrow edema pattern presence (BMEP), and posterior tibial tendon (PTT) sheath fluid distension were assessed. Fisher's exact test was used for categorical data and unpaired t tests for continuous data. Intraobserver and interobserver agreement was calculated.

RESULTS

Overall, 28% (85/309) of type I, 57% (176/309) of type II, and 16% (48/309) of type III accessory bones had focal navicular pain (type I vs type II, P = 0.17; type III vs type II, P = 0.001). Thirty-two percent of type I, 38% type II, and 8% type III accessory bones had pes planus (type I vs II, P = 0.3; type III vs type II, P = 0.001). Nine percent of type I, 48% of type II, and 6% of type III accessory bones had BMEP (type I vs II, P < 0.0001; type III vs type II, P = 0.001). Thirty-three percent of type I, 42% of type II, and 6% of type III accessory bones had PTT intrasheath fluid (type I vs II, P = 0.16; type III vs type II, P = 0.001).

CONCLUSIONS

Symptomatic type I navicular ossicle patients demonstrate an increased tendency to present with early findings of PTT dysfunction and morphologic pes planus to a greater degree than previously recognized.

LEVEL OF CLINICAL EVIDENCE

3.

Assessment of lateral hindfoot impingement with weightbearing multiplanar imaging in a flatfoot

Background

Estimation of the lateral hindfoot impingement in the standing position in conventional radiography can be difficult due to superimposition of different bones. Patients with flat feet frequently suffer from pain around the lateral malleolus and sinus tarsi caused by osseous impingement in the lateral hindfoot. Weightbearing multiplanar images (tomosynthesis) yield tomographic images and can be taken while full weightbearing.

Purpose

To assess the availability of tomosynthesis to determine hindfoot lateral impingement.

Material and Methods

A total of 14 feet (in 13 patients) with acquired flatfoot deformity and lateral hindfoot pain were included (mean age 64 years; age range 55–80 years). All patients underwent tomosynthesis, radiography, and computed tomography (CT) (non-weightbearing). Talofibular, calcaneofibular, and talocalcaneal impingement were determined. To compare the number of impingements or to determine the area between each image, statistical evaluations were analyzed using the Mann–Whitney U-test (P < 0.05).

Results

On tomosynthesis, we clearly found talofibular impingement in three feet, calcaneofibular impingement in seven feet, and talocalcaneal impingement in 11 feet. Therefore, we could identify most impingements as “positive” compared to those on normal radiographs and CT images. The number of impingements in the calcaneofibular and talocalcaneal regions was significantly higher using tomosynthesis than when using CT (P < 0.05).

Conclusion

Tomosynthesis imaging makes it easier to obtain CT-like images in a short period of time, in a free position, including while standing, and provides useful information to assess lateral pain in patients with flatfoot deformity.

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.

Using the Biomechanical Examination to Guide Therapy

In trying to explain the myriad of foot deformities and symptoms that have slow onset and/or are considered to be overuse syndromes, clinicians have been trying to develop quantitative examinations to describe the cause of the patient's problems and to better individualize treatment modalities. This type of examination is called a biomechanical examination. This article discusses some of the more common portions of a biomechanical examination of the foot and lower extremity. It will also point out some ways that the information from a biomechanical examination can be applied in clinically treating patients.

Correlation between three-dimensional medial longitudinal arch joint complex mobility and medial arch angle in stage II posterior tibial tendon dysfunction

BACKGROUND

The purpose of this study was to evaluate correlation between three-dimensional medial longitudinal arch joint complex mobility and medial arch angle in stage II posterior tibial tendon dysfunction flatfoot under loading.

METHODS

CT scans of 15 healthy feet and 15 feet with stage II posterior tibial tendon dysfunction flatfoot were taken both in non- and simulated weight-bearing condition. The CT images of the hindfoot and medial longitudinal arch bones were reconstructed into three-dimensional models with Mimics and Geomagic reverse engineering software. The three-dimensional complex mobility of each joint in the medial longitudinal arch and their correlation with the medial arch angle change were calculated.

RESULTS

From non- to simulated weight-bearing condition, the medial arch angle change and the medial longitudinal arch joints mobility were significant larger in stage II posterior tibial tendon dysfunction flatfoot (p<0.05). The eversion of the talocalcaneal joint, the proximal translation of the calcaneus relative to the talus, the dorsiflexion of the talonavicular joint, the dorsiflexion and abduction of the medial cuneonavicular joint, and the lateral translation of the medial cuneiform relative to the navicular, and the dorsiflexion of the first tarsometatarsal joint were all significantly correlated to the medial arch angle change in stage II posterior tibial tendon dysfunction flatfoot (all r>0.5, p<0.05).

CONCLUSIONS

There is increased mobility in the medial longitudinal arch joints in stage II posterior tibial tendon dysfunction flatfoot and the medial arch angle change under loading causes displacement not only at hindfoot joints but also involve midfoot and forefoot joint.

T2* mapping and subregion analysis of the tibialis posterior tendon using 3 Tesla magnetic resonance imaging

OBJECTIVE

Early detection of tibialis posterior tendon changes and appropriate intervention is necessary to prevent disease progression to flat-foot deformity and foot/ankle dysfunction, and the need for operative treatment. Currently, differentiating between early-stage tibialis posterior tendon deficiency patients who will benefit from conservative vs more aggressive treatment is challenging. The objective of this work was to establish a quantitative MRI T2* mapping method and subregion baseline values in the tibialis posterior tendon in asymptomatic ankles for future clinical application in detecting tendon degeneration.

METHODS

26 asymptomatic volunteers underwent T2* mapping. The tendon was divided axially into seven subregions. Summary statistics for T2* within each subregion were calculated and compared using Tukey post-hoc pairwise comparisons.

RESULTS

Results are reported for 24 subjects. The mean tibialis posterior tendon T2* was 7 ± 1 ms. Subregion values ranged from 6 ± 1 to 9 ± 2 ms with significant between-region differences in T2*. Inter- and intrarater absolute agreement intraclass correlation coefficient (ICC) values were all "excellent" (0.75 < ICC=1.00) except for regions 5 through 7, which had "fair to good" interrater and/or and intrarater ICC values (0.4 < ICC=0.75).

CONCLUSION

A tibialis posterior tendon T2* mapping protocol, subregion division method, and baseline T2* values for clinically relevant regions were established. Significant differences in T2* were observed along the tendon length.

ADVANCES IN KNOWLEDGE

This work demonstrates that regional variation exists and should be considered for future T2*-based research on posterior tibias tendon degeneration and when using T2* mapping to evaluate for potential tibialis posterior tendon degeneration.

Tenosynovial fluid as an indication of early posterior tibial tendon dysfunction in patients with normal tendon appearance

OBJECTIVE

Our primary aim was to quantify the posterior tibial tendon (PTT) sheath fluid volume in individuals with the clinical diagnosis of stage 1 posterior tibial tendon dysfunction (PTTD) and no MRI-detectable intra-substance tendon pathology and compare them with patients with other causes of medial ankle pain, also without MRI-detectable intra-substance PTT pathology and with normal controls. We also wanted to determine if there is a fluid measurement that correlates with the clinical diagnosis of PTTD.

MATERIALS AND METHODS

A total of 326 individuals with medial ankle pain and no intra-substance PTT pathology were studied. Group 1 included 48 patients with a clinical diagnosis of stage 1 PTT dysfunction, group 2 comprised 278 patients with other causes of medial ankle pain, and a third control group consisted of 56 patients without any medial ankle pain. MRI-based geometric measurements included PTT fluid volume, maximum cross-sectional fluid area, and fluid width. Fluid measurements were compared between groups and measurement reliability was tested.

RESULTS

Group 1 showed greater PTT fluid volume, area, and width compared with groups 2 (other causes of medial ankle pain) and 3 (asymptomatic controls) (all p values < 0.001). A 9-mm threshold maximum fluid width was associated with PTTD (sensitivity 84%, specificity 85%). Measurements were reliable (all p values < 0.03) among three observers blinded to the gold standard.

CONCLUSION

Patients with stage 1 PTT dysfunction displayed greater volumes of tendon-sheath fluid than those with other causes of medial ankle pain and compared with asymptomatic controls. A threshold maximum fluid width greater than or equal to 9 mm distinguishes those with PTTD. An association between tendon sheath fluid distension and the clinical diagnosis of stage 1 posterior tibial tendon disease in the setting of no MRI-detectable intra-substance tendon pathology may allow for differentiation of medial ankle pain from other sources and may allow for early intervention aimed at preventing progressive PTTD. The level of evidence was prognostic (level III).

Three-Dimensional Morphometric Modeling Measurements of the Calcaneus in Adults with Stage IIB Posterior Tibial Tendon Dysfunction: A Pilot Study

Background: The pathophysiology of adult-acquired flatfoot deformity (AAFD) is not fully explained by degeneration of the posterior tibial tendon alone. While a shortened or dysplastic lateral column has been implicated in flatfoot deformity in pediatrics, there is no study that has quantified the degree of dysplasia in adults with a stage IIb flatfoot deformity, or if any exists at all. Methods: An institutional radiology database was queried for patients with posterior tibial tendon dysfunction (PTTD) who had computed tomography (CT) performed. Controls were patients receiving CT scan for an intra-articular distal tibia fracture without preexisting foot or calcaneal pathology. Clinical notes, physical examination, and weightbearing radiographs were used to find patients that met clinical criteria for stage IIb PTTD. Morphometric measurements of the calcanei were performed involving the length of the calcaneal axis (LCA), height of the anterior process (HAP), and length of the anterior process (LAP). All measurements were performed independently by separate observers, with observers blinded to group assignment. We considered a difference of ±4 mm as our threshold. Results: 7 patients and 7 controls were available for reconstruction and analysis. On average, the LCA was 3.1 mm shorter in patients with stage IIb PTTD compared with controls (P < .05). The LAP was shorter in PTTD patients compared with controls 3.4 mm (P < .001). Conclusions: Our results support the hypothesis that the calcaneus of adult patients with stage IIb AAFD is dysplastic when compared with healthy controls, which further supports the utility of lateral column lengthening. Levels of Evidence: Level III: Case-control study.

Statistical Validation of the Grand Rapids Arch Collapse Classification

Background:

The Grand Rapids Arch Collapse Classification system was devised in 2011 to assist physicians’ and patients’ understanding of the mechanisms underlying arch collapse. Five types of arch collapse are described, based on which part of the foot or ankle is affected. The purpose of this study was to determine the inter- and intrarater reliability of this classification system when used by physicians with various levels of training.

Methods:

A senior author identified a stratified selection of 50 patients (10 per classification type) who presented with foot/ankle pain and suitable radiographs. A survey was designed using prediagnosis radiographs and clinical synopses of the patient’s chart. The survey consisted of a description of the classification scheme and the 50 cases in a randomized order. Eight weeks later, they repeated the test to analyze for intra-rater agreement.

Results:

Of the 33 physicians who received the survey, 26 completed the first round (16 attendings, 4 foot and ankle fellows, and 6 residents). Overall, there was substantial agreement among raters in all five types. Kappa scores for each type were 0.72, 0.65, 0.72, 0.70, 0.63, respectively. The combined kappa score was 0.68. After 8 weeks, 13 of the 26 participants repeated the study. A Kappa analysis was once again performed for the 13 respondents, which produced a substantial level of agreement with a value of 0.74 for intrarater reliability.

Conclusion:

The Grand Rapids Arch Collapse Classification system was designed to provide an accessible mechanism for physicians to consistently describe arch collapse, its effects, and the conditions associated with it. The utility of this system is wholly reliant on the repeatability among clinicians. This study has demonstrated that the classification system has substantial rates of reliability among physicians of different levels of experience and training.

Level of evidence:

Level IV.

Severe Flexible Pes Planovalgus Deformity Correction Using Trabecular Metallic Wedges

BACKGROUND:

Lateral column lengthening and plantarflexion dorsal opening wedge osteotomy of the medial cuneiform are 2 commonly used procedures to address the deformity seen in severe flexible pes planovalgus deformity. Traditionally, iliac crest allograft or autograft has been used to fill the osteotomy sites. Porous metallic wedges can be used as an alternative to avoid the concerns associated with both autograft and allograft.

METHODS:

We performed a retrospective review of patients who had corrective osteotomies utilizing metallic wedges to address flexible pes planovalgus with at least 2 years of follow-up data. Preoperative radiographic measurements (anteroposterior [AP] and talo-first metatarsal angle, calcaneal pitch, talocalcaneal angle, and talonavicular uncoverage angle) and functional scores (visual analog scale [VAS] pain, Foot and Ankle Ability Measure [FAAM] Activities of Daily Living [ADL], FAAM Sports) were compared to postoperative radiographic measurements and functional scores.

RESULTS:

There were statistically significant improvements in all radiographic parameters and functional scores. Two nonunions were seen, one of which healed with revision surgery while the other was asymptomatic. At the time of last radiographic follow-up, there were no recurrences of deformity or collapse.

CONCLUSION:

Porous metallic wedges offer an attractive alternative to autograft and/or allograft in the setting of corrective osteotomies for severe flexible pes planovalgus. Patients who underwent corrective osteotomies using these wedges demonstrated reliable, effective, and stable radiographic correction as well as significant improvements in function and pain.

LEVEL OF EVIDENCE:

Level IV, case series.

Pathological kinematic patterns of the tarsal complex in stage II adult-acquired flatfoot deformity

The in vivo kinematic characteristics of the tarsal joints during gait stance phase were still unclear in adult-acquired foot deformity (AAFD). This study included seven healthy subjects (14 feet) and 12 stage II AAFD patients (14 feet). The 3D models of tarsal bones were reconstructed based on CT scan. Each subject took standard gait on the single fluoroscopy system. Continuous lateral fluoroscopic images were collected. The key postures during the stance phase were selected. The 2D-3D registration technique was applied to explore the spatial motions of the tarsal joints in 6 degrees of freedom (DOF). During the whole stance phase, the AAFD talo-navicular joint (TNJ) exhibited ROM of 13 ± 6° in the sagittal plane while the normal subjects showed ROM of 7 ± 3° (p = 0.004). In AAFD, the subtalar joint (STJ) demonstrated 19 ± 8° and 7 ± 3° of motion in coronal and horizontal plane, respectively, while the normal subjects showed 14 ± 4°(p = 0.031) and 11 ± 3° (p = 0.014) of motion, respectively. Additionally STJ of AAFD patients showed significantly less dorsiflexion during the weight acceptance and showed significantly less external rotation both during the weight acceptance and single limb support of stance phase. In conclusion, for stage II AAFD patients, the talonavicular joint and the subtalar joint showed hypermobility in dorsi/planterflexion and inversion/eversion, respectively, during the gait stance phase while the internal/external rotation of the subtalar joint was reduced. The current study improves our understanding of the pathological kinematics of the tarsal complex in AAFD patients. Notice should be taken about these tarsal joints mobility in AAFD during clinical practice. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:477-482, 2019.

Identifying Risk Factors for 30-Day Readmissions After Triple Arthrodesis Surgery

Rigid flatfoot deformity is a debilitating condition that can be managed by triple arthrodesis surgery. Triple arthrodesis has the potential to restore health-related quality of life, but it is also associated with several complications. Few studies have examined the 30-day readmission rates after triple arthrodesis. The objective of this study was to investigate risk factors for 30-day all-cause readmissions after triple arthrodesis. The nationwide readmission database was queried from 2013. By using International Classification of Disease, Ninth Revision, procedure codes, all triple arthrodesis procedures were identified. Demographic factors, comorbidities, insurance status, and hospital characteristics were statistically compared between patients who experienced a 30-day readmission and those who did not. Multivariable logistic regression was used to identify independent risk factors for 30-day readmission. Overall, 1916 triple arthrodesis cases were identified. The overall 30-day readmission rate after triple arthrodesis was 4.6%. Univariate analysis revealed a statistically higher proportion of patients with electrolyte abnormalities (13.8% vs 4.6%; p < .01) in the patients who were readmitted within 30 days compared with those who were not. Multivariable analysis demonstrated Medicaid insurance, relative to private insurance, as the only statistically significant predictor of 30-day readmission with an odds ratio of 4.43 (p < .05). These results suggest that patients of lower socioeconomic status may be at a greater risk for development of a short-term readmission after triple arthrodesis surgery. These findings are important for surgeon and patient communication, counseling, and postoperative care when choosing to pursue triple arthrodesis surgery.

ERα PvuII and XbaI polymorphisms in postmenopausal women with posterior tibial tendon dysfunction: a case control study

Background

Posterior tibial tendon (PTT) insufficiency is considered as the main cause of adult acquired flat foot and is three times more frequent in females. High estrogen levels exert a positive effect on the overall collagen synthesis in tendons. We have previously demonstrated the association between some genetic single-nucleotide polymorphism (SNP) and tendinopathy. In the present study, we investigated the association of PvuII c454-397T>C (NCBI ID: rs2234693) and XbaI c454-351A>G (NCBI ID: rs9340799) SNPs in estrogen receptor alfa (ER-α) gene with PPT dysfunction.

Methods

A total of 92 female subjects with PTT dysfunction, with histopathological examination of the tendon and magnetic resonance image (MRI) evidence of tendinopathy, were compared to 92 asymptomatic females who presented an intact PPT at MRI for PvuII and XbaI SNPs in the ER-α gene. Genomic DNA was extracted from saliva and genotypes were obtained by polymerase chain reaction restriction fragment length polymorphism.

Results

The analysis of PvuII SNPs showed no significant differences in the frequency of alleles and genotypes between control and PTT dysfunction groups. The XbaI SNPs in the ER-α gene showed significant differences in the frequency of genotypes between control and test groups (p = 0.01; OR 95% 1.14 (0.55–2.33).

Conclusions

The XbaI SNP in the ERα gene may contribute to tendinopathy, and the A/A genotype could be a risk factor for PTT tendinopathy in this population. The PvuII SNP studied was not associated with PTT tendinopathy.

First ray mobility and posterior tibial tendon dysfunction (PTTD) in persons with flatfoot: A case control study

BACKGROUND

While posterior tibial tendon dysfunction (PTTD) commonly presents with flat feet and has been thought to be associated with first ray mobility, many flat-footed individuals are asymptomatic and do not experience any symptoms of PTTD. Thus, there is a need to control for foot type when studying factors related to PTTD. This study aimed to clarify if first ray mobility differed between flat-footed individuals with and without symptoms of PTTD. It was hypothesized that PTTD patients would display higher mobility of the first ray than asymptomatic flat-footed controls.

METHODS

Given that PTTD patients were often flat-footed, asymptomatic flat-footed individuals were chosen as controls to remove flatfoot as a potential confounding factor. We recruited 32 flat-footed subjects, of which 16 exhibiting PTTD symptoms and 16 asymptomatic controls matched for age, sex and body mass index. First ray mobility was assessed using subjective classification ("stiff", "normal" or "hypermobile") and maximum dorsal displacement using a ruler indicator. Mann-Whitney U was used to test for between-groups differences.

RESULTS

Subjective classification was similar between PTTD and control groups (both groups: 38% "normal" joint mobility). No significant differences were found between PTTD patients and asymptomatic controls in first ray displacement [median (IQR), PTTD: 6.00 (1.75) mm; control: 6.00 (1.00) mm; P=.31].

CONCLUSIONS

First ray mobility was not associated with PTTD in flat-footed persons. When evaluating symptoms of PTTD, clinicians should pay attention to factors other than first ray mobility.

A kinematic and kinetic analysis of the hip and knee joints in patients with posterior tibialis tendon dysfunction; comparison with healthy age-matched controls

BACKGROUND

The biomechanical abnormalities in patients with posterior tibial tendon dysfunction (PTTD) have been described, but few studies have investigated biomechanical chains of adjacent joints. Therefore, we examined the gait pattern of the lower extremity in subjects with PTTD, focusing on the hip and knee joints.

METHODS

We compared 19 PTTD patients (average age: 67.1) with 30 age-matched control subjects (average age: 65.1). Gait analysis was performed with a nine-camera motion-capture system and four force plates, using the Vicon Plug-In-Gait and Vicon Nexus software. Temporal-spatial parameters were compared between PTTD and control subjects, and motion and ground reaction force data were compared between the affected limb, the contralateral limb, and the right limb in control subjects.

RESULTS

Subjects with PTTD had increased stance phase ratio and decreased stride length, cadence, and gait speed. The limbs of subjects with PTTD showed increased knee internal rotation at lording response, which was biased to abduction in the knee joint during the gait cycle, and irregular hip flexion and knee extension moment in the terminal stance, even under control of gait speed.

SIGNIFICANCE

We believe that the subjects with PTTD have an increased risk of knee osteoarthritis in both the affected and contralateral limbs.

Minimally invasive distal linear metatarsal osteotomy combined with selective release of lateral soft tissue for severe hallux valgus

BACKGROUND

Minimally invasive techniques for hallux valgus have been widely used to treat mild to moderate hallux valgus deformities. The purpose of this study was to evaluate the clinical and radiographic outcomes of distal linear metatarsal osteotomy (DLMO), which is one of the minimally invasive techniques, for severe hallux valgus.

METHODS

95 patients (141 feet) with severe hallux valgus underwent DLMOs. Lateral soft tissue release (LSTR) was performed at the same time for the cases selected by an original manual test. The satisfaction level, the Japanese Society of Surgery of the Foot (JSSF) hallux scale score, and weight-bearing radiographs of the foot were assessed preoperatively and after more than 24 months. In addition, the clinical and radiographic outcomes were compared among three groups divided by the kind of LSTR: no LSTR; manual correction; and open release through skin incision.

RESULTS

Although the first metatarsal bone was significantly shortened, dorsiflexed, and elevated on postoperative radiographs, the rate of satisfaction was 87.2% (123/141), and the mean JSSF hallux scale score improved significantly from 60.4 (44-73) to 90.4 (65-100). The mean hallux valgus and intermetatarsal angles also improved significantly from 45.5° (40.0-60.0°) to 10.3° (-28.0-40.9°) and from 19.9° (14.0-28.7°) to 8.3° (-1.6-18.5°), respectively. Delayed union (18 feet), metatarsalgia (16 feet), recurrence (22 feet), and hallux varus (22 feet) were observed, and they were more obvious in DLMO combined with open release through a skin incision.

CONCLUSIONS

DLMO combined selectively with LSTR is an effective procedure for correcting severe hallux valgus. However, the indication for open release with DLMO should be considered carefully.

Relationship Between Grading With Magnetic Resonance Imaging and Radiographic Parameters in Posterior Tibial Tendon Dysfunction

The objective of the present study was to elucidate the relationship between the state of the posterior tibial tendon (PTT) on magnetic resonance images and foot deformity. The cases included 34 feet in 27 patients with PTT deformity and the controls included 18 feet in 12 patients who had undergone magnetic resonance imaging for other foot diseases. The PTT was closely examined on the magnetic resonance images and classified using the Conti classification. The control feet with no injury to the PTT were classified as grade 0. The talonavicular coverage angle, lateral talo-first metatarsal angle, medial cuneiform to fifth metatarsal height, calcaneal pitch angle, and varus-valgus angle were measured as radiographic parameters for flatfoot deformation, and the relation between the Conti classification and each parameter was examined statistically. A significant difference was observed in the talonavicular coverage angle between grade 0 and the other grades; the lateral talo-first metatarsal angle between grade 0 and the other grades and between grades 1 and 3; the medial cuneiform to fifth metatarsal height among grades 0, 2, and 3 and grades 1, 2, and 3; the calcaneal pitch angle between grades 1 and 3; and the varus-valgus angle among grades 0, 2, and 3 and between grades 1 and 3. Eversion of the forefoot was observed, along with an advanced collapse in the medial longitudinal arch, from an early stage of PTT injury.

Subtalar Joint Pronation and Energy Absorption Requirements During Walking are Related to Tibialis Posterior Tendinous Tissue Strain

During human walking, the tibialis posterior (TP) tendon absorbs energy in early stance as the subtalar joint (STJ) pronates. However, it remains unclear whether an increase in energy absorption between individuals, possibly a result of larger STJ pronation displacement, is fulfilled by greater magnitudes of TP tendon or muscle fascicle strain. By collecting direct measurements of muscle fascicle length (ultrasound), MTU length (3D motion capture and musculoskeletal modelling), and TP muscle activation (intramuscular electromyography) we endeavoured to illustrate that the TP tendinous tissue fulfils the requirements for energy absorption at the STJ as a result of an increase in muscle force production. While a significant relationship between TP tendon strain, energy absorption at the STJ (R² = 0.53, P = < 0.01) and STJ pronation (R² = 0.53, P = < 0.01) was evident, we failed to find any significant associations between tendon strain and surrogate measure of TP muscle force (TP muscle activation together with ankle and subtalar joint moments). These results suggest that TP tendon compliance may explain the variance in pronation and energy absorption at the STJ. Therefore, as the tendinous tissue of the TP is accountable for the absorption of energy at the STJ it may be predisposed to strain-induced injury.

Ultrasound evaluation of adult-acquired flatfoot deformity: Emphasis on the involvement of spring ligament

Adult-acquired flatfoot deformity (AAFD), a condition commonly caused by tibialis posterior tendon (TPT) dysfunction, has recently been recognised to encompass a spectrum of other deformities, including the disruption of the spring ligament complex. This case series reviews eight examples of chronic AAFD, outlines the sonographic assessment of the TPT and spring ligament and depicts various abnormalities of the TPT and spring ligament that are relevant to AAFD. The importance to always include the spring ligament during the assessment of AAFD will be addressed, as misdiagnosis of the involvement of the spring ligament could lead to inappropriate operative management.

Assessment and Diagnosis of Posterior Tibial Tendon Dysfunction: Do We Share the Same Opinions and Beliefs?

BACKGROUND

Posterior tibial tendon dysfunction is a disabling pathologic flatfoot disorder. Evidence supports the notion that this condition is poorly diagnosed by health-care professionals. In addition, opinion is divided as to the most appropriate assessment and diagnostic techniques used to reflect the progression or stage of the condition. Hence, this study intended to explore the views and opinions of health-care professionals who may be involved in its assessment and diagnosis.

METHODS

A two-phase sequential mixed methods design was used that combined a questionnaire survey and a focus group interview.

RESULTS

The questionnaire data were analyzed using the Kendall levels of concordance and the Cohen kappa statistic, and the focus group data were analyzed using thematic analysis, which led to three main themes: resource implications, scope of practice, and awareness of the condition.

CONCLUSIONS

This study highlights what may have been suspected previously but that has never been investigated in a structured manner. One approach to the assessment and diagnosis of posterior tibial tendon dysfunction is not necessarily the best, and depending on the clinical teams, different guidance may be required to ensure that patients are receiving the most appropriate and best care.

Posterior tibial tendinopathy: what are the risk factors?

BACKGROUND

Posterior tibial tendinopathy (PTT) is the most common cause of acquired (progressive) flatfoot deformity in adults. To date, PTT research has mainly focused on management rather than on causal mechanisms. The etiology of PTT is likely to be multifactorial because both intrinsic and extrinsic risk factors have been reported. We sought to critically evaluate reported etiologic factors for PTT and consider the concept of genetic risk factors.

METHODS

A detailed review of the literature published after 1936 was undertaken using English-language medical databases.

RESULTS

No clear consensus exists as to the relative importance of the risk factors reported, and neither has any consideration been given to a possible genetic basis for PTT.

CONCLUSIONS

To date, studies have examined various intrinsic and extrinsic risk factors implicated in the etiology of PTT. The interaction of these factors with an individual's genetic background may provide valuable data and help offer a more complete risk profile for PTT. A properly constructed genetic association study to determine the genetic basis of PTT would provide a novel and alternative approach to understanding this condition.

Spring ligament complex: Illustrated normal anatomy and spectrum of pathologies on 3T MR imaging

The spring (plantar calcaneonavicular) ligament complex connects the calcaneus and navicular bone of the foot and serves as the primary static stabilizer of the medial longitudinal arch of the foot. In this article, we describe the normal anatomy of the spring ligament complex, illustrate 3T magnetic resonance imaging appearances in its normal and abnormal states, and discuss the pathological associations with relevant case examples.

Magnetic Resonance Imaging of Sports Injuries Involving the Ankle

Understanding of ankle injuries has evolved for the past few decades, influenced by capability to visualize ligaments, tendons, and bone marrow on magnetic resonance imaging (MRI). Natural history of injury progression, complications, and healing has also been characterized using MRI. Stress injury is particularly common at the ankle in athletes and "weekend warriors" alike. This article will discuss manifestations of ankle injury on MRI as well as associated findings that should be addressed.

Diagnostic Characteristics of Standard Radiographs and Magnetic Resonance Imaging of Ruptures of the Tibialis Posterior Tendon

The present study aimed to diagnose complete rupture (CR) and longitudinal rupture (LR) of the posterior tibial tendon (PTT) from the magnetic resonance imaging findings in patients with PTT dysfunction and to analyze and compare the radiographs from each group to identify radiographic indicators related to the progression of PTT injury that would allow the radiographic diagnosis of CR. We evaluated 32 feet in 27 patients with PTT dysfunction (mean age 66.5, range 49 to 82, years). Radiographs were used to acquire weightbearing anteroposterior images of the foot, which were used to measure the talonavicular coverage angle. Lateral images of the foot were also acquired with the patients in the standing position. These were used to measure the lateral talometatarsal angle, calcaneal pitch angle, and medial cuneiform-fifth metatarsal height. From the axial MRI findings, the patients were divided into a CR group and an LR group, and the radiographic attributes of the CR group were analyzed. Of the 32 feet in 27 patients, 12 feet (37.5%) in 11 patients displayed CR and 20 feet (62.5%) in 18 patients displayed LR. The talonavicular coverage angle was 48.3° ± 17.3° in the CR group and 33.6° ± 13.6° in the LR group (p = .012), and the talometatarsal angle was -28.8° ± 22.5° in the CR group and -25.4° ± 14.4° in the LR group (p = .596). The calcaneal pitch angle was 10.4° ± 6.7° in the CR group and 10.2° ± 8.0° in the LR group (p = .935). Finally, the medial cuneiform-fifth metatarsal height was -4.2 ± 7.1 mm in the CR group and 2.1 ± 4.7 mm in the LR group (p = .005). When a medial cuneiform-fifth metatarsal height of ≤0 mm or talonavicular coverage angle of ≥50° was used as the diagnostic criterion for CR on weightbearing radiographs, the sensitivity was 71.4%, specificity 88.9%, and diagnostic accuracy 81.3%; hence, we believe these to be satisfactory diagnostic criteria for CR.

Ultrasound elasticity imaging for determining the mechanical properties of human posterior tibial tendon: a cadaveric study

Posterior tibial tendon dysfunction (PTTD) is a common degenerative condition leading to a severe impairment of gait. There is currently no effective method to determine whether a patient with advanced PTTD would benefit from several months of bracing and physical therapy or ultimately require surgery. Tendon degeneration is closely associated with irreversible degradation of its collagen structure, leading to changes to its mechanical properties. If these properties could be monitored in vivo, they could be used to quantify the severity of tendonosis and help determine the appropriate treatment. The goal of this cadaveric study was, therefore, to develop and validate ultrasound elasticity imaging (UEI) as a potentially noninvasive technique for quantifying tendon mechanical properties. Five human cadaver feet were mounted in a materials testing system (MTS), while the posterior tibial tendon (PTT) was attached to a force actuator. A portable ultrasound scanner collected 2-D data during loading cycles. Young's modulus was calculated from the strain, loading force, and cross-sectional area of the PTT. Average Young's modulus for the five tendons was (0.45 ± 0.16 GPa) using UEI, which was consistent with simultaneous measurements made by the MTS across the whole tendon (0.52 ± 0.18 GPa). We also calculated the scaling factor (0.12 ± 0.01) between the load on the PTT and the inversion force at the forefoot, a measurable quantity in vivo. This study suggests that UEI could be a reliable in vivo technique for estimating the mechanical properties of the PTT, and as a clinical tool, help guide treatment decisions for advanced PTTD and other tendinopathies.

Non-surgical treatment of pain associated with posterior tibial tendon dysfunction: study protocol for a randomised clinical trial

Background

Symptoms associated with pes planovalgus or flatfeet occur frequently, even though some people with a flatfoot deformity remain asymptomatic. Pes planovalgus is proposed to be associated with foot/ankle pain and poor function. Concurrently, the multifactorial weakness of the tibialis posterior muscle and its tendon can lead to a flattening of the longitudinal arch of the foot. Those affected can experience functional impairment and pain. Less severe cases at an early stage are eligible for non-surgical treatment and foot orthoses are considered to be the first line approach. Furthermore, strengthening of arch and ankle stabilising muscles are thought to contribute to active compensation of the deformity leading to stress relief of soft tissue structures. There is only limited evidence concerning the numerous therapy approaches, and so far, no data are available showing functional benefits that accompany these interventions.

Methods

After clinical diagnosis and clarification of inclusion criteria (e.g., age 40–70, current complaint of foot and ankle pain more than three months, posterior tibial tendon dysfunction stage I & II, longitudinal arch flattening verified by radiography), sixty participants with posterior tibial tendon dysfunction associated complaints will be included in the study and will be randomly assigned to one of three different intervention groups: (i) foot orthoses only (FOO), (ii) foot orthoses and eccentric exercise (FOE), or (iii) sham foot orthoses only (FOS). Participants in the FOO and FOE groups will be allocated individualised foot orthoses, the latter combined with eccentric exercise for ankle stabilisation and strengthening of the tibialis posterior muscle. Participants in the FOS group will be allocated sham foot orthoses only. During the intervention period of 12 weeks, all participants will be encouraged to follow an educational program for dosed foot load management (e.g., to stop activity if they experience increasing pain). Functional impairment will be evaluated pre- and post-intervention by the Foot Function Index. Further outcome measures include the Pain Disability Index, Visual Analogue Scale for pain, SF-12, kinematic data from 3D-movement analysis and neuromuscular activity during level and downstairs walking. Measuring outcomes pre- and post-intervention will allow the calculation of intervention effects by 3×3 Analysis of Variance (ANOVA) with repeated measures.

Discussion

The purpose of this randomised trial is to evaluate the therapeutic benefit of three different non-surgical treatment regimens in participants with posterior tibial tendon dysfunction and accompanying pes planovalgus. Furthermore, the analysis of changes in gait mechanics and neuromuscular control will contribute to an enhanced understanding of functional changes and eventually optimise conservative management strategies for these patients.

Trial registration

ClinicalTrials.gov Protocol Registration System: ClinicalTrials.gov ID NCT01839669

Joint space width of the tibiotalar joint in the healthy foot

Background

It is important to evaluate dynamic changes in the joint space width of the ankle mortise in detail in order to better understand the pathology of foot and ankle disorders. However, there are few reports on changes in the joint space width of the foot and ankle assessed using 3D images. The purpose of this study was to determine the changes in the joint space width of the ankle (tibiotalar joint) in association with dorsiflexion and plantar flexion of the ankle joint in healthy feet.

Methods

Computed tomography (CT) images of 10 healthy feet were obtained in the neutral, plantarflexed and dorsiflexed positions of the ankle joint, from which 3D virtual models were fabricated of the tibia, fibula and talus. The 3D joint space width in these models was calculated using a custom made software program.

Results

The joint space width increased in the order of dorsiflexion, neutral position and plantar flexion. Regarding the amount of change in dorsiflexion and plantar flexion relative to the neutral position, there were no significant differences in the middle-middle position. On the other hand, there were highly significant differences in the medial-anterior, medial-middle and medial-posterior positions.

Conclusions

The joint space width of the ankle joint can be calculated accurately using 3D reconstruction images. Our findings should assist in clarifying pathology associated with movement of the ankle during the gait cycle based on changes in the joint space width in feet exhibiting disorders.

Imaging of adult flatfoot: correlation of radiographic measurements with MRI

OBJECTIVE. The purpose of this study is to determine whether radiographic foot measurements can predict injury of the posterior tibial tendon (PTT) and the supporting structures of the medial longitudinal arch as diagnosed on MRI. MATERIALS AND METHODS. After institutional review board approval, 100 consecutive patients with radiographic and MRI examinations performed within a 2-month period were enrolled. Thirty-one patients had PTT dysfunction clinically, and 69 patients had other causes of ankle pain. Talonavicular uncoverage angle, incongruency angle, calcaneal pitch angle, Meary angle, cuneiform-to-fifth metatarsal height, and talar tilt were calculated on standing foot or ankle radiographs. MRI was used to assess for abnormalities of the PTT (tenosynovitis, tendinosis, and tear) and supporting structures of the medial longitudinal arch (spring ligament, deltoid ligament, and sinus tarsi). Statistical analysis was performed using the chi-square and Fisher exact tests for categoric variables; the Student t test was used for continuous variables. RESULTS. There was a statistically significant association of PTT tear with abnormal talonavicular uncoverage angle, calcaneal pitch angle, Meary angle, and cuneiform-to-fifth metatarsal height. PTT tendinosis and isolated tenosynovitis had a poor association with most radiologic measurements. If both calcaneal pitch and Meary angles were normal, no PTT tear was present. An abnormal calcaneal pitch angle had the best association with injury to the supporting medial longitudinal arch structures. CONCLUSION. Radiographic measurements, especially calcaneal pitch and Meary angles, can be useful in detecting PTT tears. Calcaneal pitch angle provides the best assessment of injury to the supporting structures of the medial longitudinal arch.

In vivo three-dimensional analysis of hindfoot kinematics in stage II PTTD flatfoot

BACKGROUND

This study aims to evaluate the rotation and translation of each joint in the hindfoot and compare the differences in healthy foot with that in stage II PTTD flatfoot by analyzing the reconstructive three-dimensional (3D) computed tomography (CT) image data during several extreme positions.

METHODS

CT scans of 20 healthy feet and 20 feet with stage II PTTD flatfoot were taken in maximal positions of plantarflexion, dorsiflexion, inversion, eversion, external rotation and internal rotation conditions. The images of the hindfoot bones were reconstructed into 3D models. The "twice registration" method was used to calculate the spatial changes of the talus relative to the calcaneus in the talocalcaneal joint, the navicular relative to the talus in talonavicular joint, and the cuboid relative to the calcaneus in the calcaneocuboid joint.

RESULTS

Compared with normal participants, with the calcaneus relative to the talus, participants with stage II PTTD flatfoot presented more dorsiflexion (p < 0.05), adduction (p < 0.05), and eversion (p < 0.05) in rotation, and more anterior (p < 0.05) and distal translation (p < 0.05) from maximal plantarflexion to maximal dorsiflexion; more dorsiflexion (p < 0.05), eversion (p < 0.05), and abduction (p < 0.05) in rotation and more lateral translation (p < 0.05) from maximal inversion to maximal eversion; and a greater degree of adduction (p < 0.05) in rotation, and more lateral (p < 0.05) and posterior translation (p < 0.05) from maximal internal rotation to maximal external rotation condition. For navicular relative to the talus, they demonstrated more eversion (p < 0.05) and adduction (p < 0.05) in rotation, and more lateral (p < 0.05), anterior (p < 0.05), and distal translation (p < 0.05) from maximal plantarflexion to maximal dorsiflexion; more eversion (p < 0.05) and adduction (p < 0.05) in rotation, and more lateral (p < 0.05) and proximal (p < 0.05) translation from maximal inversion to maximal eversion; more eversion (p < 0.05) and abduction (p < 0.05) in rotation and more lateral (p < 0.05) translation from maximal internal to maximal external rotation condition. The cuboid position relative to the calcaneus in the calcaneocuboid joint did not change significantly in rotation and translation in different positions (p > 0.05).

CONCLUSIONS

As previous studies shown, regarding both of the cadaveric foot and the live foot, hindfoot joint instability occurred in patients with stage II PTTD flatfoot.

Posterior tibial tendon dysfunction: an overlooked cause of foot deformity

Posterior tibial tendon dysfunction is the most common cause of adult acquired flatfoot. Degenerative changes in this tendon, lead to pain and weakness and if not identified and treated will progress to deformity of the foot and degenerative changes in the surrounding joints. Patients will complain of medial foot pain, weakness, and a slowly progressive foot deformity. A “too many toes” sign may be present and patients will be unable to perform a single heal raise test. Investigations such X-ray, ultrasound and magnetic resonance imaging will help stage the disease and decide on management. The optimal manage may change based on the progression of deformity and stage of disease. Early identification and prompt initiation of treatment can halt progression of the disease. The purpose of this article is to examine the causes, signs, symptoms, examinations, investigations and treatment options for posterior tibial tendon dysfunction.

Correlation between hindfoot joint three-dimensional kinematics and the changes of the medial arch angle in stage II posterior tibial tendon dysfunction flatfoot

BACKGROUND

The aim of this study was to explore the correlation between the kinematics of the hindfoot joint and the medial arch angle change in stage II posterior tibial tendon dysfunction flatfoot three-dimensionally under loading.

METHODS

Computed tomography (CT) scans of 12 healthy feet and 12 feet with stage II posterior tibial tendon dysfunction flatfoot were taken both in non- and full-body-weight-bearing condition. The CT images of the hindfoot bones were reconstructed into three-dimensional models with Mimics and Geomagic reverse engineering software. The three-dimensional changes of the hindfoot joint were calculated to determine their correlation to the medial longitudinal arch angle.

FINDINGS

The medial arch angle change was larger in stage II posterior tibial tendon dysfunction flatfoot compared to that in healthy foot under loading. The rotation and translation of the talocalcaneal joint, the talonavicular joint and the calcanocuboid joint had little influence on the change of the medial arch angle in healthy foot. However, the eversion of the talocalcaneal joint, the proximal translation of the calcaneus relative to the talus and the dorsiflexion of talonavicular joint could increase the medial arch angle in stage II posterior tibial tendon dysfunction flatfoot under loading.

INTERPRETATION

Joint instability occurred in patients with stage II posterior tibial tendon dysfunction flatfoot under loading. Limitation of over movement of the talocalcaneal joint and the talonavicular joint may help correct the medial longitudinal arch in stage II posterior tibial tendon dysfunction flatfoot.

Effect of graft shape in lateral column lengthening on tarsal bone position and subtalar and talonavicular contact pressure in a cadaveric flatfoot model

BACKGROUND

Lateral column lengthening (LCL) has been used for correction of flatfoot deformity. The purpose of this study was to determine the effect of LCL graft shape on tarsal bone position and talonavicular and subtalar joint pressure.

METHODS

A flatfoot model was created in 6 cadaveric specimens. Corrective LCL was performed using a rectangular graft or a trapezoidal graft with the broad surface oriented dorsally, laterally, or plantarly. Bony surface markers were digitized to calculate angular parameters used in the evaluation of flatfoot deformity. Contact pressure and area in the subtalar and talonavicular joints were also recorded. All measurements were carried out under multiple axial loads in the intact and flatfoot conditions, and following LCL with each graft shape.

RESULTS

Flatfoot creation resulted in significant changes in arch collapse and forefoot abduction. LCL with a rectangular graft best corrected these parameters, while a laterally oriented trapezoidal graft provided some correction. Talonavicular contact pressure was unchanged after flatfoot creation, and was significantly less than intact after LCL. Subtalar contact pressure decreased in some conditions after flatfoot creation, and decreased further after LCL.

CONCLUSION

LCL with a rectangular graft best restored tarsal bone orientation in a cadaveric flatfoot model. The decreases in talonavicular pressure likely represent redistribution of force from the medial to lateral foot.

CLINICAL RELEVANCE

When performing LCL for flatfoot deformity, increased bone graft volume medially better restores tarsal bone position. One way of achieving this is through the use of a rectangular graft as opposed to a trapezoidal graft.

Addressing stage II posterior tibial tendon dysfunction: biomechanically repairing the osseous structures without the need of performing the flexor digitorum longus transfer

The clinical presentation of adult flatfoot can range from a flexible deformity with normal joint integrity to a rigid, arthritic flat foot. Debate still exists regarding the surgical management of stage II deformities, especially in the presence of medial column instability. This article reviews and discusses various surgical options for the correction of stage II flatfoot reconstructive procedures. The authors discuss their opinion that is not always necessary to transfer the flexor digitorum longus tendon to provide relief and stability in this patient population. The anatomy, diagnosis, and current treatments of flexible flatfoot deformity are discussed.