Article

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

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Abstract

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 methodsAll 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.ResultsThe 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.

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The term progressive collapsing foot deformity (PCFD) is currently recommended as the replacement to adult-acquired flatfoot deformity and posterior tibial tendon dysfunction to better reflect its pathology, which consists of a complex three-dimensional deformity involving the foot and ankle. The new consensus has also provided a new classification that requires clinical and radiographic findings for patient stratification into each class. However, conventional radiographs are susceptible to errors resulting from the inadequate positioning of patients, incorrect angulation of the X-ray tube, and overlapping of bone structures. Weightbearing cone beam computed tomography (WBCBCT), which has greater diagnostic accuracy than conventional radiograph, is useful for evaluating progressive collapsing foot deformity to determine medial arch collapse, hindfoot alignment, peritalar subluxation, posterior subtalar joint valgus, intrinsic talus valgus, and lateral extra-articular bone impingement. The present review aimed to discuss the new recommendations for nomenclature, classification, and imaging evaluation of PCFD, with an illustrative and quantitative focus on the measurements used in conventional radiography and WBCBCT. The measurements presented here are important criteria for decision-making.
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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.
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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.
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Hindfoot malalignment is a recognized cause of foot and ankle disability. For preoperative planning and clinical follow-up, reliable radiographic assessment of hindfoot alignment is important. The long axial radiographic view and the hindfoot alignment view are commonly used for this purpose. However, their comparative reliabilities are unknown. As hindfoot varus or valgus malalignment is most pronounced during mid-stance of gait, a unilateral weight-bearing stance, in comparison with a bilateral stance, could increase measurement reliability. The purpose of this study was to compare the intra- and interobserver reliability of hindfoot alignment measurements of both radiographic views in bilateral and unilateral stance. A hindfoot alignment view and a long axial view were acquired from 18 healthy volunteers in bilateral and unilateral weight-bearing stances. Hindfoot alignment was defined as the angular deviation between the tibial anatomical axis and the calcaneus longitudinal axis from the radiographs. Repeat measurements of hindfoot alignment were performed by nine orthopaedic examiners. Measurements from the hindfoot alignment view gave intra- and interclass correlation coefficients (CCs) of 0.72 and 0.58, respectively, for bilateral stance and 0.91 and 0.49, respectively, for unilateral stance. The long axial view showed, respectively, intra- and interclass CCs of 0.93 and 0.79 for bilateral stance and 0.91 and 0.58 for unilateral stance. The long axial view is more reliable than the hindfoot alignment view or the angular measurement of hindfoot alignment. Although intra-observer reliability is good/excellent for both methods, only the long axial view leads to good interobserver reliability. A unilateral weight-bearing stance does not lead to greater reliability of measurement.
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To compare the results of sonographic (US) and magnetic resonance (MR) imaging in detecting pathology of the posterior tibial tendon (PTT) in patients with PTT dysfunction. Twenty-two ankles that were clinically suspected by the orthopedic surgeon to have PTT dysfunction were evaluated with US (10 MHz linear-array transducer) and 1.5 T MR examinations within the same day. The US and MR studies were conducted and interpreted by two sonologists and two musculoskeletal radiologists who were masked to the results of the other study. Four patients had bilateral studies. Classic clinical findings were utilized as a standard reference in staging PTT dysfunction. Eighteen women (mean age 61 years, age range 39-86 years). Based on a commonly accepted staging system for PTT dysfunction, 6 ankles were classified as stage I, 11 ankles as stage II, and 5 ankles as stage III. All stage I ankles were interpreted as having an intact PTT by both MR imaging and US. In the stage II and III tendons, MR imaging demonstrated PTT tears in 12 of 22 examinations, including 11 partial tears and 1 complete tear. US demonstrated PTT tears in 8 of 22 examinations, including 8 partial tears and no complete tears. The findings of US and MR imaging were consistent in 17 of 22 cases (77%). The five inconsistencies were as follows: in 4 cases, US reported tendinosis when MR imaging interpreted partial tears (no change in management); in one case, US diagnosed a partial tear when MR reported a complete tear of the PTT (no change in management because the clinical findings were more consistent with a partial tear). In this study, US and MR imaging of the PTT were concordant in the majority of cases. US was slightly less sensitive than MR imaging for PTT pathology, but these discrepancies did not affect clinical management.
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Purpose: The authors compared measurements of hindfoot alignment on MR imaging with weight-bearing CT (WB-CT) to establish the degree of correlation. Forty-seven feet in 44 patients had weight-bearing CT and MRI studies performed on the same day. Materials and methods: Hindfoot alignment on MRI was assessed by two radiologists who calculated tibiocalcaneal angle (TCA) and calcaneofibular ligament angle (CFLA). On WB-CT, foot ankle offset (FAO), calcaneal offset (CO) and hindfoot angle (HA) were assessed by a senior Foot and Ankle Surgeon using dedicated software. Pearson correlation coefficient was used to evaluate the correlation between these measurements. Results: The study group comprised 27 males and 17 females with a mean age of 45 years (range 13-79 years). A statistically significant positive correlation was identified between TCA on MRI and all measurements of hindfoot alignment on WB-CT (p = 0.001-0.005). The CFLA on MRI only had significant correlation with CO on WB-CT (p = 0.03). A significant negative correlation was observed between both MRI parameters (p < 0.001). Conclusion: A highly significant correlation between tibiocalcaneal angle on non-weight-bearing ankle MR imaging and hindfoot alignment measurements on weight-bearing CT was identified.
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Background For the diagnosis and treatment of foot and ankle disorders, objective quantification of the absolute and relative orientation angles is necessary. The present work aims at assessing novel techniques for 3D measures of foot bone angles from current Cone-Beam technology. Methods A normal foot was scanned via weight-bearing CT and 3D-model of each bone was obtained. Principal Component Analysis, landmark-based and mid-diaphyseal axes were exploited to obtain bone anatomical references. Absolute and relative angles between calcaneus and first metatarsal bone were calculated both in 3D and in a simulated sagittal projections. The effects of malpositioning were also investigated via rotations of the entire foot model. Results Large angle variations were found between the different definitions. For the 3D relative orientation, variations larger than 10 degrees were found. Foot malposition in axial rotation or in varus/valgus can result in errors larger than 5 and 3 degrees, respectively. Conclusions New measures of foot bone orientation are possible in 3D and in weight-bearing, removing operator variability and the effects of foot positioning.
Article
Objective Hindfoot valgus malalignment has been assessed on coronal MRI by the measurement of the tibio-calcaneal (TC) angle and apparent moment arm (AMA). This study aimed to determine if the calcaneofibular ligament (CFL) angle could be used as a further marker of hindfoot valgus malalignment on routine non-weight-bearing ankle MRI. Material and methods One hundred ninety-five consecutive 3-T ankle MRI studies were identified from the hospital PACS system. The TC and CFL angles could be measured in 155 cases (78%), and the AMA on 153 cases. Results The study group comprised 56 males and 72 females with a mean age of 46 years (range 4–89 years). In 27 patients, both ankles had been imaged. The Pearson correlation between the TC and CFL angles was −0.43, with a corresponding p value of 0.001 indicating a strong negative correlation between the TC and CFL angles. The CFL angle was significantly lower in those with hindfoot valgus (113 ± 14) compared with those without (123° ± 15°) (p = 0.001). The optimal cut-off point of the CFL angle for hindfoot valgus was ≤119°, with a sensitivity and specificity of 66% and 63% respectively. The Pearson correlation between the CFL angle and AMA was −0.10, with a corresponding p value of 0.21 indicating a weak negative correlation that did not reach statistical significance. Conclusion Hindfoot valgus as estimated by the increased TC angle on coronal non-weight-bearing ankle MRI is associated with a reduced CFL angle on sagittal MR images, but is not associated with AMA. Therefore, a horizontal orientation of the CFL on sagittal MR images may be a further useful sign of hindfoot valgus.
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Objective It has been stated that the distal 1–2 cm of the 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 3T 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). Conclusions 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.
Article
Background For the diagnosis and treatment of the foot and ankle, bone alignments have long been evaluated using planar radiographs in weight-bearing conditions and a large number of measurements have been reported. The present survey reviews the major radiographic angles that are currently present in the literature for a possible better comprehension and classification of them. Methods PubMed and Google Scholar were used to retrieve technical and clinical papers related to these angles, and were classified based on five typologies and the three projection planes. These angles were grouped into one definition if they described similar concepts, regardless of their anatomical references and names. A corresponding original definition and diagrammatic representation are offered. Results Thirty-one conceptual radiographic angles were identified across all descriptions from the literature: 18 in the sagittal plane, 9 in the transverse, and 4 in the coronal. Most angular measures represent relative bone orientations; absolute orientations, bone morphology and joint lines are less frequently used or reported. Conclusions The present survey reveals a confused scenario of angular measures, particularly in terms of anatomical references and names. It is therefore recommended to establish common relevant techniques and terminology.
Article
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).
Article
Lateral hindfoot pain associated with stage 2 to 3 adult-acquired flatfoot is often attributed to subfibular impingement. Preoperative magnetic resonance imaging (MRI) is generally performed to assess the extent of degeneration within the posterior tibial tendon, attenuation of medial soft tissue constraints, and degeneration of hindfoot and/or ankle articulations. The purpose of this study is to determine the incidence of lateral collateral ligament disease/injury associated with stages 2 and 3 adult-acquired flatfoot. The subjects were identified using a searchable computerized hospital database between 2015 and 2017. Stage 2 or 3 adult-acquired flatfoot deformity was confirmed in patients via chart review and MRI analysis. Lateral ankle ligament injury was confirmed using patient MRI results per the hospital radiologist and documented within the patients’ chart. Inclusion criteria required that patients be diagnosed with Johnson and Strom stage 2 or 3 flatfoot deformity with documented lateral ankle pain and that preoperative MRI scans be available with the radiologist's report. Patient exclusion criteria included patients <18 years of age, patients with flatfoot deformity caused by previous trauma, tarsal coalition, neuropathic arthritis, patients with previous surgery, or patients with incomplete medical records. In total, 118 patients were identified with these parameters. Of the 118 patients, 74 patients (62.7%) had documented lateral ankle ligament injury on MRI. Of the 77 patients with stage 2 adult-acquired flatfoot, 55 (71.4%) had confirmed lateral ankle ligament injury on MRI. Of the 41 patients with stage 3 adult-acquired flatfoot, 19 (46.3%) had confirmed lateral ankle ligament injury on MRI. This study demonstrates a relatively high incidence of lateral ligament disease associated with adult-acquired flatfoot deformity. These findings might have long-term implications regarding ankle arthritis after surgical management of adult-acquired flatfoot.
Article
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.
Article
" Adult-acquired flatfoot deformity is a complex process attributed mainly to posterior tibial tendon insufficiency. " Thorough physical examination and radiographs of the foot and ankle are usually adequate to achieve diagnosis. " Nonoperative management is the first line of treatment and has a reported success rate ranging from 67% to 90%. " A multitude of surgical options are available, particularly for stage II, with no consensus on the best options. " Fusions are associated with poor outcomes; hence, there is a trend toward earlier reconstruction before arthritis ensues. . © 2017 by the journal of bone and joint surgery, incorporated..
Article
Objective: To compare the hindfoot alignment measured on standing HAV radiographs (Saltzman view) and on non-weight-bearing coronal MR images. Materials and methods: The apparent moment arm was measured on weight-bearing conventional radiographs (Saltzman views) and on MRIs of the ankle in 50 consecutive patients (mean age, 54 years; age range, 18-77 years). The evaluation was performed independently by three readers using analogous reference points for both methods. Positive values were assigned when the deepest point of the calcaneus was lateral to the tibial axis as valgus, negative values as varus. The intertechnique agreement and correlation for the measurements performed with HAV radiographs and MRI were assessed for each reader using the Bland-Altman method and the Pearson correlation coefficient, respectively. The interobserver agreement was assessed using the intraclass correlation coefficient. Results: The means of apparent moment arms, with the standard deviation (SD) in parentheses, of three readers were +2.0 (±8.4) mm, +1.5 (±6.6) mm and -1.4 (±8.2) mm on HAV radiographs and +4.6 (±7.4) mm, +6.3 (±5.3) mm and +5.4 (±6.4) mm on MRI. The Bland-Altman analysis found a systematic bias for all three readers, corresponding to an overestimation of measurements with MRI (systematic bias ranging from 2.6 to 4.8 mm). The intertechnique correlation was found moderate to high. The Pearson coefficients for the three readers were 0.75, 0.64 and 0.65. The interobserver agreement among the three readers was 0.72, 0.77 and 0.68 for HAV, MRI and both modalities together, respectively. Conclusion: Hindfoot alignment can be estimated on MRI but the correlation between the values on HAV radiographs and MR images is only moderate with a tendency to increased positive values (valgization) on MR images.
Article
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.
Article
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.
Article
Posterior tibial tendon dysfunction is the most common cause of acquired asymmetric flatfoot deformity. The purpose of this study was to determine and compare the diagnostic value of MRI and high-resolution ultrasound (HR-US) in posterior tibial tendon dysfunction (PTTD), and assess their correlation with intraoperative findings. We reviewed 23 posterior tibial tendons in 23 patients with clinical findings of PTTD (13 females, 10 males; mean age, 50 years) with 18MHz HR-US and 3T MRI. Surgical intervention was performed in nine patients. HR-US findings included 2 complete tears, 6 partial tears, 10 tendons with tendinosis, and 5 unremarkable tendons. MRI demonstrated 2 complete tears, 7 partial tears, 10 tendons with tendinosis, and 4 unremarkable tendons. HR-US and MRI were concordant in 20/23 cases (87%). Image findings for HR-US were confirmed in six of nine patients (66.7%) by intraoperative inspection, whereas imaging findings for MRI were concordant with five of nine cases (55.6%). Our results indicate that HR-US can be considered slightly more accurate than MRI in the detection of PTTD. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Article
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. CONCULSION. 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.
Article
Background PedCAT (Curvebeam, Warrington, USA) is a new technology that allows 3D imaging with full weight bearing which is be not influenced by projection and/or foot orientation (as radiographs). The aim of this study was to compare time spent of the image acquisition, and comparison of specific bone position (angle) measurements between three imaging methods (radiographs, CT, pedCAT), and to analyse and compare measurement differences and inter- and intraobserver reliability. Methods In a prospective consecutive controlled study, 30 patients in which standard digital radiographs with full weight bearing in standing position (feet bilateral dorsoplantar and lateral views and Saltzman hindfoot view), CT without weight bearing, and pedCAT scan with full weight bearing in standing position were included, starting July 1, 2013. The following angles were measured for the right foot by three different investigators three times: 1st - 2nd intermetatarsal angle, talo-metatarsal 1-angle (TMT) both dorsoplantar and lateral projection, hindfoot angle, calcaneal pitch. The angles were digitally measured and compared (ANOVA with Post Hoc Scheffe test). Results The angles differed between radiographs, CT and pedCAT (ANOVA, all p≤.01). The angles differed between pedCAT and both radiographs and CT (Post Hoc Scheffe test, each p≤.05 except for TMT dorsoplantar and calcaneal pitch angels versus radiographs). Conclusions The angles differed between radiographs, CT and pedCAT, indicating that only pedCAT is able to detect the correct angles. PedCAT includes weight bearing in contrast to CT. PedCAT prevents inaccuracies of projection and foot orientation in contrast to radiographs due to the 3D dataset which is principally independent from projection and foot orientation.
Article
The posterior tibial tendon (PTT) is the most important dynamic stabilizer of the medial ankle and longitudinal arch of the foot. PTT dysfunction is a degenerative disorder of the tendon, which secondarily involves multiple ligaments, joint capsules, fascia, articulations, and bony structures of the ankle, hindfoot, midfoot, and forefoot. When the tendon progressively attenuates, the patient develops a painful, progressive collapsed flatfoot or pes planovalgus deformity. This comprehensive review illustrates the 3-Tesla magnetic resonance imaging (3T MRI) features of PTT dysfunction. In addition, the reader will gain knowledge of the expected pathologic findings on MRI, as they are related to clinical staging of PTT dysfunction.
Article
Posterior tibial tendon dysfunction with secondary hindfoot valgus can lead to painful extraarticular, lateral talocalcaneal, and subfibular impingements, often necessitating surgical intervention. The purpose of this study was to correlate findings of lateral hindfoot impingement with grading of posterior tibial tendon tears and severity of hindfoot valgus on MRI. MR images from 75 patients (45 women and 30 men) with MRI evidence of posterior tibial tendon tears were evaluated for grade of posterior tibial tendon tear, hindfoot valgus angle, osseous contact or opposing marrow signal changes at the talus-calcaneus or fibula-calcaneus, peroneal tendon subluxation-dislocation, and presence of lateral malleolar bursa. Statistical analyses were performed using Cochran-Armitage, Fisher's exact, and Mann-Whitney tests. Twenty-eight cases (37%) of lateral hindfoot impingement were identified, including six talocalcaneal, eight subfibular, and 14 talocalcaneal-subfibular impingements. The prevalence of impingement was significantly increased with greater MRI hindfoot valgus angle (p < 0.001). The prevalence of talocalcaneal-subfibular impingement significantly increased with grading of posterior tibial tendon tear (p = 0.018). Peroneal tendon subluxation was present only with advanced hindfoot valgus (p = 0.010) and impingement (p = 0.004). There was no significant association between the presence of lateral malleolar bursa and hindfoot valgus severity. Extraarticular lateral hindfoot impingement is associated with advanced posterior tibial tendon tears and increased MRI hindfoot valgus angle. Peroneal tendon subluxation likely represents an end stage of lateral impingement in patients with posterior tibial tendon dysfunction.
Article
Tibialis posterior dysfunction is a complex progressive condition caused primarily by injury to the tibialis posterior tendon, leading to acquired pes planus. The tibialis posterior is the most frequent ankle tendon to be injured, and the disorder commonly occurs in late middle-aged females. Degenerative, inflammatory, functional and post-traumatic aetiologies have all been proposed. Failure of the tibialis posterior tendon causes excessive load stress on the spring ligament and sinus tarsi ligaments. A wide spectrum of bony and soft-tissue abnormalities may be seen on plain radiographs, ultrasound and MRI, including malalignment, anatomical variants, and enthesopathic and tendinopathic changes. Knowledge of the anatomical and biomechanical considerations in tibialis posterior dysfunction allows the radiologist to diagnose injury to key structures and provide prognostic information that may assist with management options to prevent further flat foot deformity.
3D imaging for hindfoot alignment assessment: a comparative study between non-weight-bearing MRI and weight-bearing CT
  • A Haldar
  • A Bernasconi
  • SE Junaid
  • KHB Lee
  • M Welck
  • A Saifuddin