Imaging of adult flatfoot: correlation of radiographic measurements with MRI

Radiological characteristics of hallux valgus with metatarsus adductus: A matched case-control study

BACKGROUND

No evidence has been found to support the hypothesis that there is a correlation between hallux valgus (HV) and intermetatarsal (IM) angles in HV with metatarsus adductus (MA) and that IM angle in HV with MA is lower than that in HV without MA. The present study aimed to analyze the radiographic characteristics of HV with MA compared to matched controls and to clarify the differences between HV with MA and without MA.

METHODS

Preoperative radiographs of 126 female patients (164 feet) who underwent hallux valgus surgery were reviewed. The HV, IM, and MA angles were measured. The MA was defined as MA angle of 20° or greater. Of all the feet, 37 (22.6%) had HV with MA (MA group). Control A (111 feet) having HV without MA was matched by age, gender, and BMI to MA group; Control B (79 feet) having HV without MA was matched by age, gender, BMI, and HV angle to the sub-MA group (31 feet) having HV with MA.

RESULTS

The correlation coefficient between the HV and IM angles in the MA group was considered negligible (r = 0.08, p = 0.63), whereas the correlation coefficient in Control A was considered moderate (r = 0.57, p < 0.00001). The correlation coefficient in the MA group was significantly smaller than in Control A (p < 0.01). There was no significant difference in the HV angle between the sub-MA group and Control B (p = 0.23), but the IM angle was significantly smaller than in Control B (p = 0.002).

CONCLUSION

There is no significant correlation between the HV and IM angles in HV with MA, as there is in HV without MA. HV with MA has a significantly smaller IM angle for the HV angle compared to HV without MA.

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.

Proximal Supination Osteotomy for Hallux Valgus: Comparison of Clinical and Radiologic Outcomes for the Most Severe Deformities

BACKGROUND

There is little available information regarding the difference in outcomes between severe hallux valgus (S-HV), defined as 40 degrees ≤ hallux valgus angle (HVA) < 50 degrees, and what we consider to be "super-severe HV" (SS-HV), defined as >50 degrees, following a proximal metatarsal osteotomy. We aimed to retrospectively compare the outcomes of a proximal metatarsal osteotomy in S- and SS-HV.

METHODS

The series consisted of 57 female patients (57 feet) treated with a proximal supination osteotomy for symptomatic S- and SS-HV (33 and 24 feet, respectively). The outcome measures included radiographic parameters and for 45 patients included the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) score, and a visual analog scale pain score (VAS-PS) preoperatively and at a minimum follow-up of 12 months with a median of 26 months. No significant differences were found in age, body mass index, and the duration of follow-up between patients with S-HV and SS-HV (P > .10 for all comparisons) with the numbers available.

RESULTS

Preoperative HVA in patients with S- and SS-HV was significantly improved at the final follow-up (P < .0001 for both comparisons). No significant differences in postoperative HVA and IMA were observed between patients with S- and SS-HV (P = .51 and .50, respectively). All 5 preoperative subscale scores of SAFE-Q in patients with S- and SS-HV significantly improved postoperatively (P < .01 for all comparisons). Preoperative VAS-PS in patients with S- and SS-HV significantly improved postoperatively (P < .0001 and <.009, respectively). There were no significant differences in preoperative and postoperative scores of all the SAFE-Q subscales and VAS-PS between patients with S-HV and SS-HV (P > .10 for all) with the numbers available.

CONCLUSION

We found for this patient group that a proximal supination osteotomy can achieve a large correction for SS-HV as well as S-HV and significantly improve radiologic and clinical outcomes in SS-HV. The outcomes between patients with S- and SS-HV were not different in this series.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Unique shape variations of hind and midfoot bones in flatfoot subjects-A statistical shape modeling approach

Flatfoot deformity is a prevalent hind- and midfoot disorder. Given its complexity, single-plane radiological measurements omit case-specific joint interaction and bone shape variations. Three-dimensional medical imaging assessment using statistical shape models provides a complete approach in characterizing bone shape variations unique to flatfoot condition. This study used statistical shape models to define specific bone shape variations of the subtalar, talonavicular, and calcaneocuboid joints that characterize flatfoot deformity, that differentiate them from healthy controls. Bones of the aforementioned joints were segmented from computed tomography scans of 40 feet. The three-dimensional hindfoot alignment angle categorized the population into 18 flatfoot subjects (≥7° valgus) and 22 controls. Statistical shape models for each joint were defined using the entire study cohort. For each joint, an average weighted shape parameter was calculated for each mode of variation, and then compared between flatfoot and controls. Significance was set at p < 0.05, with values between 0.05 ≤ p < 0.1 considered trending towards significance. The flatfoot population showed a more adducted talar head, inferiorly inclined talar neck, and posteriorly orientated medial subtalar articulation compare to controls, coupled with more navicular eversion, shallower navicular cup, and more prominent navicular tuberosity. The calcaneocuboid joint presented trends of a more adducted calcaneus, more abducted cuboid, narrower calcaneal roof, and less prominent cuboid beak compared to controls. Statistical shape model analysis identified unique shape variations which may enhance understanding and computer-aided models of the intricacies of flatfoot, leading to better diagnosis and, ultimately, surgical treatment.

Two-Dimensional and 3-Dimensional MRI Assessment of Progressive Collapsing Foot Deformity-Adult Acquired Flat Foot Deformity

This article is meant to serve as a reference for radiologists, orthopedic surgeons, and other physicians to enhance their understanding of progressive collapsing foot deformity, also known as adult acquired flat foot deformity. Pathophysiology, imaging findings, especially on MRI and 3-dimensional MRI are discussed with relevant illustrations so that the readers can apply these principles in their practice for better patient managements.

Update on Ankle and Foot Impingement

Ankle impingement syndromes are a well-recognized cause of chronic ankle symptoms in both the elite athletic and general population. They comprise several distinct clinical entities with associated radiologic findings. Originally described in the 1950s, advances in magnetic resonance imaging (MRI) and ultrasonography have allowed musculoskeletal (MSK) radiologists to further their understanding of these syndromes and the range of imaging-associated features. Many subtypes of ankle impingement syndromes have been described, and precise terminology is critical to carefully separate these conditions and thus guide treatment options. These are divided broadly into intra-articular and extra-articular types, as well as location around the ankle. Although MSK radiologists should be aware of these conditions, the diagnosis remains largely clinical, with plain film or MRI used to confirm the diagnosis or assess a surgical/treatment target. The ankle impingement syndromes are a heterogeneous group of conditions, and care must be taken not to overcall findings. The clinical context remains paramount. Treatment considerations are patient symptoms, examination, and imaging findings, in addition to the patient's desired level of physical activity.

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).

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.

The Foot and Ankle Kinematics of a Simulated Progressive Collapsing Foot Deformity During Stance Phase: A Cadaveric Study

BACKGROUND

Progressive collapsing foot deformity (PCFD) is a complex pathology associated with tendon insufficiency, ligamentous failure, joint malalignment, and aberrant plantar force distribution. Existing knowledge of PCFD consists of static measurements, which provide information about structure but little about foot and ankle kinematics during gait. A model of PCFD was simulated in cadavers (sPCFD) to quantify the difference in joint kinematics and plantar pressure between the intact and sPCFD conditions during simulated stance phase of gait.

METHODS

In 12 cadaveric foot and ankle specimens, the sPCFD condition was created via sectioning of the spring ligament and the medial talonavicular joint capsule followed by cyclic axial compression. Specimens were then analyzed in intact and sPCFD conditions via a robotic gait simulator, using actuators to control the extrinsic tendons and a rotating force plate underneath the specimen to mimic the stance phase of walking. Force plate position and muscle forces were optimized using a fuzzy logic iterative process to converge and simulate in vivo ground reaction forces. An 8-camera motion capture system recorded the positions of markers fixed to bones, which were then used to calculate joint kinematics, and a plantar pressure mat collected pressure distribution data. Joint kinematics and plantar pressures were compared between intact and sPCFD conditions.

RESULTS

The sPCFD condition increased subtalar eversion in early, mid-, and late stance (P < .05), increased talonavicular abduction in mid- and late stance (P < .05), and increased ankle plantarflexion (P < .05), adduction (P < .05), and inversion (P < .05). The center of plantar pressure was significantly (P < .01) medialized in this model of sPCFD and simulated stance phase of gait.

DISCUSSION

Subtalar and talonavicular joint kinematics and plantar pressure distribution significantly changed with the sPCFD and in the directions expected from a PCFD foot. We also found that ankle joint kinematics changed with medial and plantar drift of the talar head, indicating abnormal talar rotation. Although comparison to an in vivo PCFD foot was not performed, this sPCFD model produced changes in foot kinematics and indicates that concomitant abnormal changes may occur at the ankle joint with PCFD.

CLINICAL RELEVANCE

This study describes the dynamic kinematic and plantar pressure changes in a cadaveric model of simulated progressive collapsing foot deformity during simulated stance phase.

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.

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.

Functional Activity After Flatfoot Reconstruction With Lateral Column Lengthening

BACKGROUND

The objective of this study was to evaluate return to activity following flatfoot reconstruction with lateral column lengthening (LCL) by assessing functional postoperative data and identifying patient characteristics associated with poor function following surgery.

METHODS

Consecutive patients that underwent operative flatfoot correction including LCL and other necessary procedures from 2014 to 2019 by 3 fellowship trained foot and ankle orthopedic surgeons were retrospectively administered Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and FAAM Sports questionnaires with no preoperative scoring available. Patient demographic factors, comorbidities, and radiographic features were evaluated as predictors of outcome scores to simulate return to activity. Statistical analysis, including student's t-tests and analysis of variance, was performed.

RESULTS

A total of 54 patients were included. A body mass index (BMI) of 30 kg/m2 or greater was associated with a lower ADL score (P = .002) and Sports score (P = .002). Preoperative hindfoot valgus of 9° or higher was associated with higher ADL scores (P = .040). Neither age nor any flatfoot radiographic parameters yielded significant differences in functional scores.

CONCLUSION

This study demonstrated relatively high average FAAM scores in both the ADL and the sports subscales, consistent with previous studies. This study also identified lower BMI and greater preoperative hindfoot valgus as potential predictors of improved functional outcome following reconstruction.

LEVEL OF EVIDENCE

Level III: Retrospective case control.

Injuries to the Spring Ligament: Nonoperative Treatment

The fibrocartilage within the superomedial calcaneonavicular (spring) ligament is part of an interwoven complex of ligaments that span the ankle, subtalar, and talonavicular joints. Acute isolated rupture of the spring ligament has been reported in association with an eversion ankle sprain. Attenuation and failure of the spring ligament causes complex 3D changes called the progressive collapsing foot deformity (PCFD). This deformity is characterized by hindfoot eversion, forefoot supination, collapse of the medial longitudinal arch, and forefoot abduction. Nonoperative treatment of an isolated spring ligament rupture and PCFD using various designs of orthoses have shown promising results.

Clinico-radiological factors predicting the failure risk of conservative management in moderate to severe pediatric idiopathic flexible flatfoot

This study aimed to investigate the clinico-radiological factors of related future surgical treatment in patients with pediatric flexible flatfoot (FFF) who first visited the orthopedic clinic before the age of 10 years. Sixty-five patients diagnosed with moderate/severe idiopathic FFF deformity between the ages of 2-10 years were included. We developed prognostic models for the risk of the surgery during the follow-up period. Twenty (30.8%) patients required surgical treatment, and all of them underwent calcaneal lengthening osteotomy. Among them, 7 (10.8%) patients required concomitant Achilles-lengthening surgery. Unilateral involvement, older age, smaller calcaneal pitch angle, and higher talo-first metatarsal malalignment were considered high-risk factors for pediatric FFF surgery. Prognostic models identified three prognostic risk groups based on those factors, and survival curves revealed significant differences among the groups. Our prognostic models help predict the failure risk of conservative management of pediatric idiopathic FFF. Level of Evidence: Level III, prognostic study.

Understanding Radiographic Measurements Used in Foot and Ankle Surgery

Given the high volume of patient visits for foot and ankle complaints, developing a systematic approach to evaluation of foot and ankle pathology is important for orthopaedic providers. A thorough evaluation of weight-bearing radiographs is essential to differentiate acute and chronic injury from normal findings to dictate treatment. Radiographic changes and varying degrees of deformity can influence surgical considerations. The purpose of this article was to review and define radiographic measurements relevant to surgical decision making for common foot and ankle pathologies and treatment.

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.

Anatomical variants of the medioplantar oblique ligament and inferoplantar longitudinal ligament: an MRI study

Purpose

The spring ligament complex (SL) is the chief static stabilizer of the medial longitudinal foot arch. The occurrence of normal anatomical variants may influence radiological diagnostics and surgical treatment. The aim of this study was to evaluate anatomical variants of the part of SL located inferior to the talar head (i-SL), medioplantar oblique ligament (MPO) and inferoplantar longitudinal ligament (IPL).

Methods

We included 220 MRI examinations of the ankle performed on a 3.0 T engine. Only patients with a normal SL were included. Two musculoskeletal radiologists assessed the examinations and Cohen’s kappa was used to assess agreement. Differences between groups were assessed using the chi-squared test; p < 0.05 was considered as significant. The final decision was made by consensus.

Results

Most commonly, i-SL was composed of the two ligaments IPL and MPO n = 167 (75.9%); in this group, bifid ligaments occurred in 19.2%, most commonly in the MPO. A branch to the os cuboideum was seen in n = 17 (10.2%). Three ligaments were seen in n = 52 (23.6%). In this group, bifid ligaments occurred in 13.5%; most commonly, the IPL was bifid and a branch to the os cuboideum was noted in n = 6 (11.5%). In one case, n = 1 (0.04%), we identified MPO, IPL and two accessory ligaments. No significant relationship was noted between the number of ligaments, the presence of bifid ligaments and side or gender (p > 0.05). Conclusion. More than two aligaments were seen in 24.1% of examined cases, the most common variant was the presence of MPO, IPL and one accessory ligament.

The awareness of hindfoot malalignment on non-weight-bearing ankle MRI

OBJECTIVE

Hindfoot malalignment is a relatively common clinical finding and several studies have suggested that hindfoot valgus can be identified on non-weight-bearing ankle MRI. The aim of this study was to determine the awareness of hindfoot malalignment on ankle MRI amongst consultant musculoskeletal radiologists.

MATERIALS AND METHODS

All MRI studies referred by Foot and Ankle Unit Consultants reported by one of 14 consultant musculoskeletal radiologists between March 2016 and August 2019 were retrieved from the Hospital Radiology Information System. These were reviewed independently by a radiology fellow and a consultant radiologist. Tibiocalcaneal angle (TCA) was measured, and extra-articular talocalcaneal (EA-TCI) and calcaneofibular impingement (EA-CFI) were recorded. Radiology reports were then analysed for mention of hindfoot malalignment and the presence of EA-TCI and EA-CFI.

RESULTS

The study group comprised 129 patients, 46 males and 83 females with a mean age of 46.8 years (range 8-84 years). Based on review, hindfoot valgus was present in 78-80 cases (60.5-62%), EA-TCI in 30-36 cases (23.2-27.9%) and EA-CFI in 18-21 cases (14-16.3%). By comparison, MRI reports mentioned hindfoot valgus in 18 cases (2 incorrectly), EA-TCI in 8 cases (1 incorrectly) and EA-CFI in 10 cases (1 incorrectly).

CONCLUSION

Hindfoot valgus, EA-TCI and EA-CFI were present relatively commonly on review of ankle MRI studies in patients referred from a specialist Foot and Ankle Unit but were commonly under-reported highlighting a relative lack of awareness of hindfoot malalignment on ankle MRI amongst musculoskeletal radiologists, which could impact negatively on patient management.

Imaging of Peritalar Instability

Undiagnosed medial ankle instability can be a prerequisite for pathogenic progression in the foot, particularly for adult acquired flatfoot deformity. With the complex anatomy in this region, and the limitations of each individual investigational method, accurately identifying peritalar instability remains a serious challenge to clinicians. Performing a thorough clinical examination aided by evaluation with advanced imaging can improve the threshold of detection for this condition and allow early proper treatment to prevent further manifestations of the instability.

Inter-observer and intra-observer reliability in the radiographic measurements of paediatric forefoot alignment

BACKGROUND

Foot bones in children have more rounded shapes in radiograms than adults. Thus, the goal of this work was assessing inter- and intra-observer reliability in paediatric forefoot angle measurements.

MATERIAL AND METHODS

Six forefoot angles in 34 AP standing paediatric foot radiographs were measured by 5 researchers. A classic statistical analysis with use of IBM SPSS Statistics 25 was performed and a new method with two-way analysis of variance was applied.

RESULTS

Results of statistical analysis revealed the properties of a subjective assessment related to specific angles. Kilmartin's angle, calcaneus-fifth metatarsal angle and first ray angle are the most reliable; metatarsus adductus angle should be used with great caution in pediatric population. Engel's angle is the most difficult for measuring and measurement error is the highest.

CONCLUSION

The power of paediatric forefoot measurements is various. Several angles are reliable, while Engle's angle is the most doubtful.

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.

Geometric 3D analyses of the foot and ankle using weight-bearing and non weight-bearing cone-beam CT images: The new standard?

OBJECTIVES

We hypothesize that three-dimensional (3D) geometric analyses in weight bearing CT-images of the foot and ankle are more reproducible compared to two-dimensional (2D) analyses. Therefore, we compared 2D and 3D analyses on bones of weight-bearing and non weight-bearing cone-beam CT images of healthy volunteers.

METHODS

Twenty healthy volunteers (10 male, 10 female, mean age 37.5 years) underwent weight-bearing and non weight-bearing cone-beam CT imaging of both feet. Clinically relevant height and angle measurements were performed in 2D and 3D (for example: cuboid height, calcaneal pitch, talo-calcaneal angle, Meary's angle, intermetatarsal angle). Three-dimensional measurements were obtained using automated software. Intra-observer and inter-observer agreement were evaluated for all 2D measurements.

RESULTS

Overall intraclass correlation coefficients (ICC's) were higher than 0.750 for most 2D measurements, ranging from 0.352 to 0.995. Calcaneal pitch, angle between the first metatarsal (MT1) and proximal phalange 1, between the fifth metatarsal (MT5) and the calcaneus and heights of the sesamoid bones, navicular, cuboid and talus decreased during weight-bearing in both 2D and 3D results (p < 0.01). Meary's angle was not statistically different in 2D (p = 0.627) and 3D (p = 0.765). Higher coefficients of variation in 2D geometric analysis parameters (0.27 versus 0.16) indicate that 3D analyses are more precise compared to 2D (p < 0.01). Results of left and right feet are comparable for 2D and 3D analyses.

CONCLUSION

Although 2D and 3D geometrical analyses are fundamentally different, automated 3D analyses are more reproducible and precise compared to 2D analyses. In addition, 3D evaluation better demonstrates differences in bone configurations between weight-bearing and non weight-bearing conditions, which may be of value to demonstrate pathology.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

Retrospectively registered.

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.

MRI findings of spring ligament injury: association with surgical findings and flatfoot deformity

Background

Spring ligament injury is an important cause for flatfoot deformity; however, reliability of magnetic resonance imaging (MRI) findings of spring ligament injury is still ambiguous.

Purpose

To investigate the reliability of MRI findings for the diagnosis of spring ligament injury.

Material and methods

Forty-three cases with spring ligament injury proven by surgery and 29 control cases were enrolled. The spring ligament complex was demonstrated on proton density-weighted images reconstructed from 3D-isotropic MRI data. The presence of waviness, discontinuity, and abnormally high signal intensity of the spring ligament complex was evaluated by two radiologists in cooperation. Also, injury of the posterior tibial tendon (PTT) on MRI and the lateral talo-1st metatarsal angles on weight-bearing X-rays were evaluated.

Results

Discontinuity and abnormally high signal intensity of the superomedial calcaneonavicular ligament (SmCNL) on MRI were more frequently observed in patients with spring ligament injury than in controls (p < 0.001). Discontinuity and abnormally high signal intensity of the SmCNL were found more often in the PTT injury group than in those without (p < 0.001). The talo-1st metatarsal angle was greater in patients with discontinuity and abnormally high signal intensity of the SmCNL on MRI than in patients without these findings (p < 0.001).

Conclusion

Discontinuity and abnormally high signal intensity are reliable MRI findings for spring ligament injury and related disorders, such as flatfoot deformity and PTT injury.

The symptomatic adult flatfoot: Is there a relationship between severity and degree of pre-existing arthritis in the foot and ankle?

BACKGROUND

The acquired adult flatfoot deformity (AFFD) is a potentially debilitating foot condition with a prevalence thought to be between 3 %-10 %. To the authors' best knowledge, no association has been described between severity of AFFD and degree of pre-existing ankle or foot arthritis. The degree and pattern of preexisting ipsilateral arthritis of the foot and ankle was investigated in those with symptomatic AFFD presenting to hospital.

METHODS

Retrospective observational study between May 2015 and May 2018, of patients who presented to our tertiary clinic with symptomatic AFFD. Radiographs of one hundred and forty-eight (n=148) patients were reviewed, excluding those with charcot arthropathy, previous trauma or coalition. The primary outcome measure was severity of OA in the ankle, subtalar, talonavicular and calcaneocuboid joints. Secondary outcome was severity of radiographic planovalgus deformity. The independant variables used were age and severity of planovalgus deformity as measured by the Meary angle, calcaneal pitch and medial cuneiform-fifth metatarsal height. A linear regression model was carried out on the outcomes.

RESULTS

Median age was 60.0 years (IQR 22). There were 56 males to 92 females, with 75 left sided deformities observed and 73 right sided. With increasing severity of planovalgus measurements, there was no significant association observed in severity of arthritis in the ankle joint (p = 0.766), subtalar joint (p = 0.090), talonavicular joint (p = 0.256) and calcaneocuboid joint (p = 0.091). With increasing age, there was significance observed in degree of ankle arthritis, subtalar, talonavicular and calcaneocuboid joints (p = 0.001). There was no significant correlation observed with age for the angular break of Meary's line (p = 0.73), calcaneal pitch (0.262) and medial cuneiform-fifth metatarsal height (p = 0.937).

CONCLUSION

This observational study shows no significant association between severity of radiographic planovalgus deformity and pre-existing arthritis of the ankle, hindfoot and midtarsal joints.

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.

Update on Investigation Methods for Lower Extremity Biomechanics

Imaging with biomechanical analysis augments the clinical examination and improves outcomes by correlating imaging findings with the examination. Plain film radiographs are the gold standard to assess osseous alignment. The biomechanical examination provides information to formulate an accurate assessment. Weightbearing computed tomography scanning is a potentially valuable for functional information about joint biomechanics. True alignment of the lower extremity can be appreciated on weightbearing computed tomography scanning. Soft tissue structures can be assessed with diagnostic ultrasound examination. Acute and chronic injuries that compromise joint stability can be identified.

Fluid around the distal tibialis posterior tendon on ankle MRI: prevalence and clinical relevance

OBJECTIVE

It has been stated that the distal 1-2 cm of the tibialis posterior tendon (TPT) does not have a tendon sheath but rather a paratenon, and that any fluid seen around this segment on ankle MRI is considered to represent paratendonitis. The prevalence and clinical significance of isolated TPT paratendonitis diagnosed on ankle MRI is unknown. This study aims to correlate the presence of isolated distal segment TPT paratendonitis on ankle MRI, with the presence or absence of medial midfoot pain.

METHODS

A retrospective database of 195 consecutive 3 T ankle MRI studies was assessed for the presence of isolated TPT paratendonitis. Relevant clinical notes were available in 159 of these cases, and were reviewed for the absence or presence of medial midfoot pain.

RESULTS

Of 133 patients with both ankle MRI studies and clinical notes available, 53 (33.3%) patients had isolated TPT paratendonitis based on MRI. Of these, 37 (69.8%) had reported no medial foot pain on review of clinical records, while medial foot pain was recorded in 16 cases (30.2%). The comparison of TPT paratendonitis with clinically evident medial midfoot pain showed no statistically significant association (p = 0.19).

CONCLUSION

Fluid signal intensity around the distal 1-2 cm of the TPT is a relatively common finding on ankle MRI. Therefore, care should be taken when reporting ankle MRI studies not to overstate the relevance of this finding.

ADVANCES IN KNOWLEDGE

There was no statistically significant relationship between medial midfoot pain and the presence of isolated TPT paratendonitis.

Influence of investigator experience on reliability of adult acquired flatfoot deformity measurements using weightbearing computed tomography

BACKGROUND

Our purpose was to assess the reliability of measurements of adult-acquired flatfoot deformity (AAFD) taken by investigators of different levels of clinical experience using weightbearing computed tomography (WBCT).

METHODS

Nineteen AAFD patients underwent WBCT. Three investigators with different levels of clinical experience made AAFD measurements in axial, coronal, and sagittal planes. Intra- and interobserver reliability were assessed. Mean values for each measurement were compared between investigators.

RESULTS

After a training protocol, substantial to perfect intra- and interobserver reliability was observed for most measures, regardless of the investigator's experience level. Significant differences between investigators were observed in 2 of 21 measured parameters: medial cuneiform-first metatarsal angle (P=0.003) and navicular-medial cuneiform angle (P=0.001).

CONCLUSIONS

AAFD radiographic measurements can be performed reliably by investigators with different levels of clinical experience using WBCT.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Adult-Acquired Flatfoot Deformity

Adult-acquired flatfoot deformity (AAFD) comprises a wide spectrum of ligament and tendon failure that may result in significant deformity and disability. It is often associated with posterior tibial tendon deficiency (PTTD), which has been linked to multiple demographic factors, medical comorbidities, and genetic processes. AAFD is classified using stages I through IV. Nonoperative treatment modalities should always be attempted first and often provide resolution in stages I and II. Stage II, consisting of a wide range of flexible deformities, is typically treated operatively with a combination of soft tissue procedures and osteotomies. Stage III, which is characterized by a rigid flatfoot, typically warrants triple arthrodesis. Stage IV, where the flatfoot deformity involves the ankle joint, is treated with ankle arthrodesis or ankle arthroplasty with or without deltoid ligament reconstruction along with procedures to restore alignment of the foot. There is limited evidence as to the optimal procedure; thus, the surgical indications and techniques continue to be researched.

Automated Spatial Pattern Analysis for Identification of Foot Arch Height From 2D Foot Prints

Arch height is an important determinant for the risk of foot pathology, especially in an aging population. Current methods for analyzing footprints require substantial manual processing time. The current research investigated automated determination of foot type based on features derived from the Gabor wavelet utilizing digitized footprints to allow timely assessment of foot type and focused intervention. Two hundred and eighty footprints were collected, and area, perimeter, curvature, circularity, 2nd wavelet moment, mean bending energy (MBE), and entropy were determined using in house developed MATLAB codes. The results were compared to the gold standard using Spearman's Correlation coefficient and multiple linear regression models with significance set at 0.05. The proposed approach found MBE combined with foot perimeter to give the best results as shown by ANOVA (F_(2,211) = 10.18, p < 0.0001) with the mean ±SD of low, normal, and high arch being, respectively, 0.26 ± 0.025,.24 ± 0.021, and 0.23 ± 0.024. A clinical review of the new cut off values, as set by the first and the third quartiles of our sample, lead to reliability up to 87%. Our results suggest that automated wavelet-based foot type classification of 2D binary images of the plantar surface of the foot is comparable to current state-of-the-art methods providing a cost and time effective tool suitable for clinical diagnostics.

Imaging of the Tibionavicular Ligament, and Its Potential Role in Adult Acquired Flatfoot Deformity

BACKGROUND

The spring ligament is an important medial arch stabilizer. However, when disrupted, it does not cause planovalgus deformity until the foot is cyclically loaded. We propose that the tibionavicular (TN) ligament plays an important role. However, this ligament is not imaged in routine magnetic resonance imaging (MRI) sequences.

METHODS

A prospective case-control study using a novel MRI sequence to image the TN ligament in 20 normal feet creating a baseline appearance of the ligament. We then scanned 20 patients with adult acquired flatfoot deformity (AAFD). All patients had weightbearing anteroposterior and lateral radiographs. We followed up patients, the end point being surgery or 18 months' follow-up.

RESULTS

The normal ligament was reliably identified on the novel sequences. It had a reproducible appearance in 2 views, and consistent length and width. Two groups of patients were identified in the AAFD cohort: Normal TN (11/20) (The mean Meary angle was 6.8 degrees) and Abnormal TN (9/20). The ligament was thickened proximally, with distal attenuation and intrasubstance edema. On sagittal sequence, it had dorsal bulging and high signal. The mean Meary angle was 13.2 degrees ( P = .013). All patients had posterior tibial tendon dysfunction and 8 had spring ligament complex attenuation. Five patients have undergone corrective surgery compared to none in the other group.

CONCLUSION

This study adds to the evidence that AAFD is multifactorial. With this imaging technique, we were able to reliably image the TN ligament. We hope that including this sequence into routine scanning will help us understand its role in flatfoot deformity. This poses the question of whether this structure will play a role in reconstructive surgery in future.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Finite element simulation on posterior tibial tendinopathy: Load transfer alteration and implications to the onset of pes planus

BACKGROUND

Posterior tibial tendinopathy is a challenging foot condition resulting in pes planus, which is difficult to diagnose in the early stage. Prior to the deformity, abnormal internal load transfer and soft tissue attenuation are anticipated. The objective of this study was to investigate the internal load transfer and strain of the ligaments with posterior tibial tendinopathy, and the implications to pes planus and other deformities.

METHODS

A three-dimensional finite element model of the foot and ankle was reconstructed from magnetic resonance images of a 28-year-old normal female. Thirty bones, plantar fascia, ligaments and tendons were reconstructed. With the gait analysis data of the model subject, walking stance was simulated. The onset of posterior tibial tendinopathy was resembled by unloading the tibialis posterior and compared to the normal condition.

FINDINGS

The load transfer of the joints at the proximal medial column was weaken by posterior tibial tendinopathy, which was compromised by the increase along the lateral column and the intercuneiforms during late stance. Besides, the plantar tarsometatarsal and cuboideonavicular ligaments were consistently over-stretched during stance. Particularly, the maximum tensile strain of the plantar tarsometatarsal ligament was about 3-fold higher than normal at initial push-off.

INTERPRETATION

Posterior tibial tendinopathy altered load transfer of the medial column and unbalanced the load between the proximal and distal side of the medial longitudinal arch. Posterior tibial tendinopathy also stretched the midfoot plantar ligaments that jeopardized midfoot stability, and attenuated the transverse arch. All these factors potentially contributed to the progress of pes planus and other foot deformities.

Posterior tibial tendon dysfunction: Clinical and magnetic resonance imaging findings having histology as reference standard

OBJECTIVE

To investigate the correlation between MRI, clinical tests, histopathologic features of posterior tibial tendon (PTT) dysfunction in patients with acquired adult flatfoot deformity surgically treated with medializing calcaneal osteotomy and flexor digitorum longus tendon transposition.

MATERIALS AND METHODS

Nineteen patients (11 females; age: 46 ± 15 year, range 18-75) were pre-operatively evaluated using the single heel rise (HR) and the first metatarsal rise (FMR) sign tests. Two reviewers graded the PTT tears on a I-III scale and measured the hindfoot valgus angle on the pre-operative MRI of the ankle. The specimens of the removed portion of PTT were histologically analysed by two pathologists using the Bonar and Movin score. Linear regression, Spearman's rank-order, and intraclass correlation coefficient (ICC) statistics were used.

RESULTS

ICC for MRI was excellent (0.952). Correlation between FMR and HR tests was at limit of significance (r = 0.454; P = 0.051). The HR and FMR tests were significantly correlated to the Movin score (r = 0.581; P = 0.009 and r = 0.538; P = 0.018, respectively) and were not significantly correlated to the Bonar score (both with a r = 0.424; P = 0.070). PTT tendinopathy grading at MRI was significantly correlated to the FMR test (p = 0.041) but not to the hindfoot valgus angle (p = 0.496), the HR test (p = 0.943), the Bonar score (p = 0.937), and the Movin score (p = 0.436). The hindfoot angle was not correlated to any of the other variables (p > 0.264).

CONCLUSION

For PTT dysfunction, there is high correlation between HR and FMR test and histology evaluated using the Movin score, while no correlation was seen for the Bonar score. Semiquantitative grading of PTT dysfunction at MRI only correlates to the FMR and not to histology. The hindfoot valgus angle is not correlated to any of the considered variables.

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

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) and adult acquired flatfoot deformity (AAFD) are used interchangeably, although both suggest quite different pathological processes.

OBJECTIVE

To investigate key differences in selection criteria used for inclusion into research studies.

METHODS

An electronic database search was performed from inception to June 2016. All primary research articles with clear inclusion/diagnostic criteria for PTTD or AAFD were included in the review. All criteria were extracted and synthesised into one aggregate list. Frequencies of recurring criteria were calculated and reported for each stage of the conditions.

RESULTS

Of the potentially eligible papers, 148 (65%) did not specify inclusion/selection criteria for PTTD or AAFD and were excluded. Eligibility criteria were reported 82 times in the 80 included papers, with 69 descriptions for PTTD and 13 for AAFD. After synthesis of criteria from all papers, there were 18 key signs and symptoms. Signs and symptoms were considered to be those relating to tendon pathology and those relating to structural deformity. The total number of individual inclusion/diagnostic criteria ranged from 2 to 9. The majority of articles required signs of both tendon dysfunction and structural deformity (84% for AAFD and 81% for PTTD). Across both groups, the most frequently reported criteria were abduction of the forefoot (11.5% of total criteria used), the presence of a flexible deformity (10.2%) and difficulty performing a single leg heel raise (10.0%). This was largely the case for the PTTD articles, whereas the AAFD articles were more focused on postural issues such as forefoot abduction, medial arch collapse, and hindfoot valgus (each 16.7%).

CONCLUSION

As well as synthesising the available literature and providing reporting recommendations, this review has identified that many papers investigating PTTD/AAFD do not state condition-specific selection criteria and that this limits their clinical applicability. Key signs and symptoms of PTTD and AAFD appear similar, except in early PTTD where no structural deformity is present. We recommend that PTTD is the preferred terminology for the condition associated with signs of local tendon dysfunction with pain and/or swelling along the tendon and difficulty with inversion and/or single leg heel raise characterising stage I and difficulty with single leg heel raise and a flexible flatfoot deformity characterizing stage II PTTD. While AAFD may be useful as an umbrella term for acquired flatfoot deformities, the specific associated aetiology should be reported in studies to aid consolidation and implementation of research into practice.

TRIAL REGISTRATION

Prospero ID: 42016046943.

Bioabsorbable implants for subtalar arthroereisis in pediatric flatfoot

Flatfoot is a common condition in growing-age patients. Despite its common presentation, nowadays surgical indications and treatments are still debated. Arthroereisis is a widely used technique, and several implants designs have been proposed over time. Despite the good results shown in the literature, the main drawback of these techniques has always been the need for a second surgery for implant removal. Bioabsorbable devices have been introduced to overcome this necessity.Correct approach to the patient, indications and contraindications and available studies on bioabsorbable implants for subtalar arthroereisis in pediatric flatfoot were analyzed in this narrative review. Even if only a few studies have been published in the literature, bioabsorbable implants showed good clinical results comparable to non-absorbable implants and with a rare necessity for implant removal or revision. When correct indications and proper surgical technique are followed, arthroereisis with bioabsorbable implants appears to be an effective solution for the treatment of pediatric flexible flatfoot.

A pictorial review of reconstructive foot and ankle surgery: evaluation and intervention of the flatfoot deformity

This pictorial review focuses on basic procedures performed within the field of podiatric surgery, specifically for elective reconstruction of the midfoot and rearfoot with focus on the flatfoot deformity. Our goal is to demonstrate objective radiographic parameters that surgeons utilize to initially define the deformity, lead to procedure selection, and judge post-operative outcomes. We hope that radiologists will employ this information to improve their assessment of post-operative radiographs following reconstructive foot surgeries. First, relevant radiographic measurements are defined and their role in procedure selection explained. Second, the specific surgical procedures of the Evans calcaneal osteotomy, medial calcaneal slide osteotomy, Cotton osteotomy, subtalar joint arthroeresis, and arthrodeses of the rearfoot are described. Finally, specific plain film radiographic findings that judge post-operative outcomes for each procedure are detailed.