Validation of patient-specific flatfoot models on finite element analysis.

Adult-acquired flatfoot causes various deformities. If a patient-specific foot model can be created using the finite element method, it can be used to study the appropriate surgical technique for each patient. Nine patient-specific flatfoot models were created, and loading simulations were performed. To validate the models, the patients' weight-bearing radiographs were compared with the parameters of the models. The CCC values ranged from 0.917 to 0.993 , all exceeding the moderate threshold according to the McBride criteria. Our model reproduces the biomechanics of a patient's foot under loading conditions, which may be useful for investigating patient-specific surgical procedures.

Determining the changes in morphology and loading status following medial displacement calcaneal osteotomy for flatfoot using patient-specific finite element models.

Medial displacement calcaneal osteotomy (MDCO) is the standard procedure for flatfoot. We investigated the effect of MDCO on the foot using a finite element analysis. Foot models were created from computed tomography data of 8 patients with flat feet. MDCO was performed on each model with bone translation distance of 4, 8, and 12 mm. The morphological changes, plantar pressures, and stress percentage on the talocrural and subtalar joints were evaluated before and after surgery. Morphological evaluation showed improvement in the medial longitudinal arch. The stress percentage of plantar pressure in the medial area decreased, and the stress percentage of plantar pressure in the mid- and lateral forefoot area increased. At the talocrural joint, the medial and middle stress percentage increased, while the lateral and posterior stress percentage decreased. In the subtalar joint, the stress percentage in the middle subtalar joint increased and that in the posterior subtalar joint decreased. Within the posterior subtalar joint, the anterior and medial stress percentage increased, while the posterior and lateral stress percentage decreased. Preoperative simulation using the finite element analysis may be useful in understanding postoperative morphological changes and loading conditions to perform patient-specific surgery.

Relationship between arthritis of the second and third tarsometatarsal joints and incongruity of the first tarsometatarsal joint in patients with hallux valgus.

OBJECTIVES: Hallux valgus is associated with tarsometatarsal arthritis; its pathophysiology remains unknown. Therefore, we aimed to elucidate the relationship between arthritis of the second and third tarsometatarsal joints and incongruity of the first tarsometatarsal joint in the sagittal plane. METHODS: Forty-three patients (64 feet) with hallux valgus who underwent surgery at University Hospital Kyoto Prefectural University of Medicine were included and divided into two groups: control (without second and third tarsometatarsal joint degeneration) and osteoarthritis (with second and third tarsometatarsal joint degeneration). Intergroup comparisons of the incongruity of the first tarsometatarsal joint in the sagittal plane, age, body mass index, hallux valgus angle, first-second intermetatarsal angle, metatarsus adductus angle, Meary's angle, and calcaneal pitch angle were performed. RESULTS: The proportion of patients with incongruity of the first tarsometatarsal joint was significantly higher in the osteoarthritis group than in the control group. Logistic regression analysis identified incongruity of the first tarsometatarsal joint and metatarsus adductus angle as significant related factors for arthritis of the second and third tarsometatarsal joints. CONCLUSIONS: Incongruity of the first tarsometatarsal joint in the sagittal plane was involved in the development of arthritis of the second and third tarsometatarsal joints in patients with hallux valgus.

The inter-prefectural regional disparity of healthcare resources and representative surgical procedures in orthopaedics and general surgery: a nationwide study in Japan during 2015-2019.

BACKGROUND: Few reports have examined the localized regional disparity in representative surgical procedures in orthopaedics and general surgery globally. This study aimed to clarify the inter-prefectural regional disparity and relationships between healthcare resources and representative surgical procedures using a nationwide database in Japan. METHODS: The number of medical specialists in orthopaedics, general surgery, and anaesthesiology, as well as the number of hospitals, and the incidence of representative surgical procedures in orthopaedics and general surgery were evaluated annually per 100,000 inhabitants/people by prefecture in Japan during 2015-2019. Medium-sized regional disparities were evaluated using the Gini coefficient. Correlation coefficients were calculated for the defined variables and ageing rate. We also compared the urban and rural regional disparities in all study variables. RESULTS: The annual average number/incidence and Gini coefficients were 110.6 and 0.11 for femur fracture surgery, 106.3 and 0.09 for cholecystectomy, 14.2 and 0.11 for orthopaedic surgeon specialists, 17.6 and 0.09 for general surgeon specialists, 5.9 and 0.13 for anaesthesiology specialists, and 8.1 and 0.21 for hospitals, respectively. The correlation coefficients by the incidence of femur fracture surgery were 0.74 for orthopaedic surgeon specialists (p < 0.001), 0.63 for hospitals (p < 0.001), and 0.62 for the ageing rate (p < 0.001); those by the incidence of cholecystectomy were 0.60 for general surgeon specialists (p < 0.001) and 0.59 for hospitals (p < 0.001). The number/incidence of orthopaedic surgeon specialists, hospitals, femur fracture surgery, and cholecystectomy, as well as the ageing rate, were significantly higher in rural prefectures than in urban prefectures (p < 0.05). CONCLUSIONS: Inter-prefectural regional disparity was small, although certain items were unevenly distributed in the rural prefectures, which is contrary to our expectations. Higher prevalence was recognised in rural prefectures due to the higher ageing rate; however, supply and demand are balanced. This study provides basic data for healthcare policy development in a medium-sized community. LEVEL OF EVIDENCE: III.

Aberrant OCIAD2 demethylation in lung adenocarcinoma is associated with outcome.

Overexpression of OCIAD2 in lung adenocarcinoma has already been reported in several research articles, but the molecular mechanism involved remains unknown. Promoter CpG methylation is a representative form of epigenetic gene regulation, and a considerable number of tumor suppressor genes show hypermethylation in many cancers. In contrast, promoter CpG hypomethylation causes oncogene overexpression, resulting in carcinogenesis and malignant progression. In the present study, we investigated the CpG methylation and expression status of OCIAD2 using tumor tissues and adjacent normal tissues from seven cases of lung adenocarcinoma. We also examined the relationship between CpG methylation status and outcome in 58 patients with adenocarcinoma. Pyrosequencing showed that CpG sites in OCIAD2 promoter regions were more frequently demethylated in tumor tissues than in adjacent normal tissues, and reverse transcription-quantitative polymerase chain reaction revealed overexpression of OCIAD2 in lung adenocarcinoma. There was a correlation between OCIAD2 CpG demethylation and the level of mRNA expression, and statistical analysis showed that CpG hypomethylation of OCIAD2 was associated with poor outcomes. Our results suggest that overexpression of OCIAD2 might be caused mainly by CpG hypomethylation and that OCIAD2 methylation status might be a useful prognostic indicator in lung adenocarcinoma.

Early stage and small medial osteochondral lesions of the talus in the presence of chronic lateral ankle instability: A retrospective study.

BACKGROUND: In chronic lateral ankle instability (CLAI), the instability of the ankle joint results in repeated microtrauma to the articular cartilage. How the lesion condition or stage is affected by the presence of lateral instability in medial osteochondral lesions of the talus (OLT) is unclear. We aimed to examine whether CLAI is associated with the size and staging of medial OLT on radiographs, magnetic resonance (MR) images, and arthroscopy. METHODS: Forty-five patients with medial OLTs in 45 ankles were reviewed. Radiographs were assessed for damage and lesion classification. The tibio-talar tilting angle (TTA) was measured. The patients were divided into two groups: the CLAI group and the stable group. The lesion classification on radiographs, MR images, and arthroscopy, and size on MR images were statistically compared. RESULTS: The CLAI group had a mean TTA of 8.15 ± 3.41°, whereas the stable group had a mean TTA of 2.24 ± 1.64°. The CLAI group had a lower clinical score than the stable group at the initial visit to our clinic. The CLAI group presented with lesions of significantly shorter longitudinal and transverse diameters. Stages of medial OLT on radiographs, MR images, and arthroscopic evaluation were earlier in the CLAI group than those in the stable group. CONCLUSIONS: Patients with CLAI presented in the early stages of OLT and had significantly smaller lesions than those without CLAI. The patients without CLAI may be selected for surgery at an early phase.

The influence of hallux valgus and flatfoot deformity on metatarsus primus elevatus: A radiographic study.

BACKGROUND: Metatarsus primus elevatus (MPE), a dorsal elevation of the first metatarsal in relation to the lesser metatarsals on lateral-view radiographs, is an indicator of hallux rigidus. The angle between the articular surfaces of the base of the first metatarsal and the anterior part of the medial cuneiform (M1C1A) reflects the sagittal instability of the first tarsometatarsal (TMT) joint. MPE may also indicate instability of the first metatarsal. The purpose of this study was to identify the influence of hallux valgus (HV) and flatfoot (FF) deformities on measurements obtained from first metatarsal-related radiographic images. METHODS: Standing radiographic images of 134 feet were investigated. In dorsoplantar-view radiographs, HV and intermetatarsal angles were evaluated. The position of the medial sesamoid was classified with a grading system (Hardy score). In lateral-view radiographs, MPE, M1C1A, and Meary's angle were measured. The subjects were divided into 4 groups: the normal group (G1), HV(-)FF(-); the HV group (G2), HV(+)FF(-); the FF group (G3), HV(-)FF(+); and the dual group (G4), HV(+)FF(+). The radiographic parameters were compared among the groups. RESULTS: MPE in the HV patients (G2 and G4) was less than that in the non-HV participants (G1 and G3). MPE in G4 was less than that in G3. The odds ratios of the Hardy score were higher in G2, G3 and G4 than in G1. The ratios were higher in the FF patients (G3 and G4) than in the non-FF participants (G1 and G2) and were higher in G4 than in G2. CONCLUSIONS: FF affects sesamoid dislocation, and the combination of HV and FF further increases sesamoid dislocation. Combined with M1C1A and the Hardy score, MPE may be a useful indicator of three-dimensional instability of the first TMT joint. First TMT joint-related operations may be considered for severe HV treatment in G4 patients.

Reproducibility of radiographic methods for assessing longitudinal tarsal axes Part 2: Severe cavus or flatfoot study.

INTRODUCTION: Calcaneal pitch angle and Meary's angle are commonly used to assess longitudinal foot arches on lateral-view radiographs. The aim of this study was to examine and evaluate the radiographic longitudinal foot arch measurement methods with the best intraobserver and interobserver reliabilities for patients with (1) severe cavus deformity and (2) severe flatfoot deformity. METHODS: Standing radiographic images of 22feet with severe cavus foot deformity and 49feet with severe flatfoot deformity were obtained to measure the longitudinal axes of the talus, first metatarsal, calcaneus and plantar surface, which were defined using six, five, four and three different methods, respectively, selected from previous reports. Intraobserver and interobserver correlation coefficients were calculated. RESULTS: The results are generally consistent with those of Part 1. The best intraobserver and interobserver correlation coefficients for the tarsal axes were obtained using methods involving a line bisecting the angle formed by the lines tangential to the superior and inferior margins of the talus, a line connecting the centre of the first metatarsal head and the midpoint of the visualized base of the first metatarsal, and a line drawn tangential to the inferior surface of the calcaneus. For the plantar axis, a method that used the horizontal plane (as a reference axis) was regarded as the best approach. CONCLUSIONS: The aforementioned methods were considered to be optimal for the radiographic assessment of longitudinal foot arches in patients with severe cavus or flatfoot deformity. This study may contribute to the more accurate assessment of any foot deformity.

Reproducibility of radiographic methods for assessing longitudinal tarsal axes: Part 1: Consecutive case study.

INTRODUCTION: Calcaneal pitch angle and Meary's angle are commonly used to assess longitudinal foot arches on lateral-view radiographs. However, the methods used to obtain the talar, first metatarsal, calcaneal, and plantar axes differ across multiple reports, and no study has evaluated the reproducibility of these approaches. The aim of this study was to determine the most reproducible methods for radiographically evaluating longitudinal axes. METHODS: Standing radiographic images of 40 feet from 21 consecutive outpatients were obtained to measure longitudinal axes of the talus, first metatarsal, calcaneus and plantar surface, which were defined using six, five, four and three different methods, respectively, selected from previous reports. Intraobserver and interobserver correlation coefficients were calculated. RESULTS: The best intraobserver and interobserver correlation coefficients for the talar, first metatarsal, and calcaneal axes were obtained using methods involving a line bisecting the angle formed by the lines tangential to the superior and inferior margins of the talus, a line connecting the centre of the first metatarsal head and the midpoint of the visualized base of the first metatarsal, and a line drawn tangential to the inferior surface of the calcaneus, respectively. For the plantar axis, a method that used the horizontal plane (as a reference axis) was regarded as the best approach, although intraobserver and interobserver correlation coefficients could not be calculated because all values were zero. CONCLUSIONS: The aforementioned methods were considered to be optimal for the radiographic assessment of longitudinal foot arches. This study could contribute to more accurate assessments of foot deformities.

Extracorporeal Shock Wave Therapy for an Adolescent Patient with Calcific Tendinopathy of Posterior Tibial Tendon: A Case Report.

BACKGROUND: We report a rare case of calcific tendinopathy in the posterior tibial tendon (PTT) at the navicular insertion. CASE: Conservative treatments other than extracorporeal shock wave therapy (ESWT) were ineffective. Calcium deposition disappeared from the PTT on plain radiographs at 6 months after ESWT. DISCUSSION: In this case, a 14-year-old boy with calcific tendinopathy of the PTT who had not benefited from conservative treatments was effectively treated using ESWT.

Magnetic resonance imaging findings of chronic plantar fasciitis before and after extracorporeal shock wave therapy.

INTRODUCTION: The objective of this study is to examine the relationships between treatment outcome and changes in magnetic resonance (MR) imaging findings after extracorporeal shock wave therapy (ESWT) for chronic plantar fasciitis. METHODS: The subjects were 23 feet of 23 patients of refractory plantar fasciitis. The mean age was 53.7 years. The thickness of the plantar fascia (PF) and findings of a high-signal intensity area (HSIA) inside the PF, edema around the PF, and bone marrow edema (BME) of the calcaneus were investigated on MR images. The Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale and a visual analogue scale (VAS) were used. Correlations between an improvement in symptoms and one in the MRI findings were analyzed. RESULTS: The mean thickness of the PF was 4.4±1.6mm before ESWT and 4.6±1.8mm six months after ESWT. After ESWT, there was a decrease in the numbers of feet showing HSIA inside the PF from 15 to 6, in edema around the PF from 16 to 2, and in BME of the calcaneus from 11 to 4. Clinical outcomes improved with ESWT from 70.3±5.5 to 88.6±9.1 points (JSSF), 74.1±25.3 to 28.5±24.4 points (VAS), respectively. Improvements in symptoms according to the JSSF and VAS scores and improvement in edema around the PF on MR images showed a significant correlation. CONCLUSIONS: Edema around the PF improved significantly in association with an improvement in symptoms after ESWT.

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

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

Examination of the Correlation Between Foot Morphology Measurements Using Pedography and Radiographic Measurements.

Pedography provides excellent visualization of the footprint. However, the correlation between the footprint images and radiographic measures has not been thoroughly evaluated. Therefore, the objectives of our study were to examine the correlation between the pedography-based measures of foot morphology and radiographic measurements and to propose reference values for the diagnosis of flatfoot using footprint imaging. The plantar footprints of 100 right feet were photographed using a pedography standing platform. The sole and arch areas were measured to calculate the footprint index (FPI). The lateral talar-first metatarsal angle (LTM) and calcaneal pitch angle (CP) were measured on standing lateral radiographs, and the talonavicular coverage angle was measured on frontal radiographs. The Pearson moment correlation between the FPI and radiography-based measures was calculated. The area under the receiver operating characteristic curve was calculated using an LTM of <-4° as the identifying criterion of flatfoot. The sensitivity and specificity of FPI were calculated for LTM values <-4°. The FPI correlated with the LTM (y = -17.964 ± 52.644x, R = 0.588) and CP (y = 9.2304 ± 27.739x, R = 0.659) but not with the talonavicular coverage angle (y = 26.01 ± 15.78x, R = 0.207). The area under the receiver operating characteristic curve was 0.753, with a cutoff FPI of 0.208, yielding a sensitivity of 0.462 and specificity of 0.934 for flatfoot identification. Pedography could provide an easy screening tool for flatfoot, with an FPI cutoff of 0.208, yielding a specificity of 93.4%.

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

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

Weight-bearing three-dimensional computed tomography analysis of the forefoot in patients with flatfoot deformity.

BACKGROUND: The recent classifications for posterior tibial tendon dysfunction (PTTD) stage II are based on forefoot deformity, but there is still no consensus regarding a detailed explanation of the clinical condition. The purposes of this study were to clarify the clinical condition of flatfoot deformity using three-dimensional (3D) computed tomography (CT) imaging under loading on both healthy and flat feet and to compare 3D movement of the forefoot in response to load. METHODS: Ten volunteers and 10 PTTD stage II patients with symptomatic flatfoot deformity were examined. CT scans of 20 healthy and 20 flat feet were performed under non-loading and full weight-bearing conditions. Images of the tibia and foot arch bones (talus, calcaneus, navicular, and first and fifth metatarsal bones) were reconstructed into 3D models. Rotations of individual tarsal bone or metatarsal bone were described by the Eulerian angles. RESULTS: Compared with healthy feet, flat feet experienced plantarflexion of the fifth metatarsal bone relative to the first metatarsal bone under loading conditions. We defined this phenomenon as synonymous with forefoot varus on the coronal plane. CONCLUSIONS: The results of this study have clarified part of the clinical condition of the forefoot in flatfoot deformity and may have applications in basic research of the staging advancement and substage classification of PTTD.

Nonosseous Tarsal Coalition of the Lateral Cuneocuboid Joint: A Case Report.

We describe a rare case of a nonosseous coalition of the lateral cuneocuboid joint with peroneal spasm that we successfully treated with resection. A 60-year-old female had been experiencing constant pain in her right foot, particularly when walking and going up and down stairs. The pain had been present for approximately 1 year after she had experienced a minor injury. Her right ankle showed plantar flexion restrictions (right 20° and left 40°) and was held in an antalgic valgus position. Sudden passive plantar flexion produced pain behind the lateral malleolus of the right ankle. Tenderness was detected in the right peroneus brevis tendon and the right sinus tarsi. On plain radiographs, the oblique view showed an irregularity in the articular surface of the lateral cuneocuboid joint in both feet. On computed tomography images, there was no osseous continuation in the lateral cuneocuboid joint, indicative of a nonosseous bridge between the lateral cuneiform and the cuboid. The nonosseous coalition between the lateral cuneiform and the cuboid was resected and the trabecular surfaces and cortical margins covered with a thin film of bone wax. The patient's recovery was unremarkable, and 1 year after surgery, she was able to walk without pain and was able to perform her usual activities and job.

Joint space width of the tibiotalar joint in the healthy foot.

BACKGROUND: It is important to evaluate dynamic changes in the joint space width of the ankle mortise in detail in order to better understand the pathology of foot and ankle disorders. However, there are few reports on changes in the joint space width of the foot and ankle assessed using 3D images. The purpose of this study was to determine the changes in the joint space width of the ankle (tibiotalar joint) in association with dorsiflexion and plantar flexion of the ankle joint in healthy feet. METHODS: Computed tomography (CT) images of 10 healthy feet were obtained in the neutral, plantarflexed and dorsiflexed positions of the ankle joint, from which 3D virtual models were fabricated of the tibia, fibula and talus. The 3D joint space width in these models was calculated using a custom made software program. RESULTS: The joint space width increased in the order of dorsiflexion, neutral position and plantar flexion. Regarding the amount of change in dorsiflexion and plantar flexion relative to the neutral position, there were no significant differences in the middle-middle position. On the other hand, there were highly significant differences in the medial-anterior, medial-middle and medial-posterior positions. CONCLUSIONS: The joint space width of the ankle joint can be calculated accurately using 3D reconstruction images. Our findings should assist in clarifying pathology associated with movement of the ankle during the gait cycle based on changes in the joint space width in feet exhibiting disorders.

Alteration of hindfoot alignment after total knee arthroplasty using a novel hindfoot alignment view.

This study examined the coronal alignment of the hindfoot in varus osteoarthritis of the knee before and after total knee arthroplasty (TKA) in 100 legs using a novel imaging method. We categorized the preoperative hindfoot alignment into varus (30 legs) and valgus (70 legs) groups; imaging of the hindfoot was conducted preoperatively and postoperatively, and the varus-valgus angle (VVA) was measured as the hindfoot alignment. The femorotibial angle improved significantly after TKA. We found that the VVA improved significantly after TKA in the hindfoot valgus group (P<0.001), but not in the varus group (P=0.554), and we speculate that the hindfoot alignment in the valgus group improved as a result of a residual compensatory capacity in the hindfoot.

Correlation between the outcome of extracorporeal shockwave therapy and pretreatment MRI findings for chronic plantar fasciitis.

BACKGROUND: The purpose of this study was to investigate the relationship between magnetic resonance imaging (MRI) findings before extracorporeal shockwave therapy (ESWT) and the treatment outcome of ESWT. METHODS: This study examined 50 feet with chronic plantar fasciitis. The scores before ESWT and after a six-month follow-up were investigated using the Japanese Society for Surgery of the Foot (JSSF) Ankle-Hindfoot Scale and the Visual Analog Scale (VAS). MRI before ESWT was used for image evaluation. MRI revealed thickening of the plantar fascia (PF), and an investigation was conducted regarding the findings of a high-signal-intensity area (HSIA) inside the PF, edema near the PF, and bone marrow edema (BME) of the calcaneus. RESULTS: The average JSSF score and VAS score improved significantly at follow-up. In total, 44 feet were noted in the improved group. MRI revealed that the average amounts of PF thickening did not significantly differ between the improved group and the non-improved group. HSIA, edema near the PF, and BME were observed in 36, 41, and 11 feet in the improved group, respectively; and 2, 4, and 2 feet in the non-improved group, respectively. CONCLUSIONS: An HSIA in the PF predicted symptom improvement more easily than other MRI findings. LEVEL OF EVIDENCE: IV.