Weight-bearing Lateral Radiographs Research Articles

Evaluation of Anterior Tibial Translation Under Physiological Axial Load After ACL Reconstruction With Lateral Extra-articular Tenodesis.

Postoperative laxity correlates with negative clinical outcomes after anterior cruciate ligament reconstruction (ACLR). The influence of lateral extra-articular tenodesis (LET) on anteroposterior translation is unclear. This study aimed to evaluate the reduction in radiographic static anterior tibial translation (SATT) and dynamic anterior tibial translation (DATT) after LET as an adjunctive procedure to ACLR. It was hypothesized that adding a LET procedure would have no effect on postoperative SATT and DATT. Cohort study; Level of evidence, 3. Patients who underwent primary ACLR with hamstring tendon autografts between 2020 and 2022 were reviewed, and those who underwent ACLR and LET as an anterolateral associate procedure were paired 1 to 1 with those who underwent isolated ACLR (control) based on age, sex, preoperative SATT, and posterior tibial slope (PTS). The indications for LET were age <18 years and anterolateral rotary instability (grade ≥2 pivot shift). A previously validated technique was used to measure SATT, DATT, and PTS on lateral weightbearing and lateral stress knee radiographs. Preoperative and 9-month postoperative radiographs were compared between the 2 groups. A total of 72 patients were included in the analysis (n = 36 patients in each group). The inter- and intraobserver reliability of the SATT, DATT, and PTS measurements was excellent (intraclass correlation coefficients, 0.88-0.99). The mean pre- and postoperative SATT in the ACLR+LET group was 2.44 ± 2.90 mm and 2.44 ± 2.38 mm, respectively, compared with 2.60 ± 2.99 mm and 2.12 ± 2.74 mm, respectively, in the control group. The mean pre- and postoperative reduction in side-to-side DATT in the ACLR+LET group was 5.44 ± 4.65 mm and 1.13 ± 2.95 mm, respectively, compared with 5.03 ± 3.66 mm and 2 ± 3.12 mm, respectively, in the control group. There was no pre- to postoperative difference in SATT (P = .51). However, the side-to-side DATT was reduced by 3.66 ± 3.37 mm postoperatively (P < .001), without significant differences between groups (P = .24). Including a LET procedure for patients undergoing ACLR did not reduce SATT; that is, it did not decrease the amount of tibial translation due to physiological axial load.

First Tarsometatarsal Instability Corrects Itself After Triple Arthrodesis in Progressive Collapsing Foot Deformity

Introduction/Purpose: Triple arthrodesis is commonly used to correct severe or rigid progressive collapsing foot deformity (PCFD). In many cases of PCFD, patients have associated first tarsometatarsal instability demonstrated by plantar gapping or dorsal subluxation on the lateral weight-bearing radiographs. During flatfoot reconstruction this is usually addressed with a first tarsometatarsal fusion to realign the joint and to restore the medial column height. However in the setting of triple arthrodesis it has not been well established if it is necessary to add a first tarsometatarsal fusion to the procedure in order to adequately correct the overall deformity. This study retrospectively examined pre- and post-operative radiographs of patients that had first tarsometatarsal instability as a component of their PCFD and who were managed by triple arthrodesis alone. Methods: All triple arthrodesis cases were searched for a single surgeon between 2013 and 2021. Inclusion criteria were patients who had a diagnosis of PCFD and had an isolated triple arthrodesis without first tarsometatarsal joint fusion. Pre-operative radiographs were then examined for the presence of first tarsometatarsal joint instability on the lateral weight-bearing view only. This was demonstrated by either plantar gapping or first metatarsal dorsal subluxation at the tarsometatarsal joint. Those patients who were a minimum of 21 months post-op were called to obtain current radiographs. Measurement of the sagittal first metatarsal-medial cuneiform angle as well as a the first metatarsal lift as described by King and Toolan (FAI 2004) was performed. Results: Twenty patients satisfied the inclusion criteria and were included in the study. Of these patients, five had no correction of their first tarsometatarsal joint instability postoperatively and were considered failures. The remaining fifteen patients demonstrated early correction of their first tarsometatarsal joint instability and were called back for longer term follow-up radiographs. Average follow-up was 4.8 years (range 1.8 - 9.4 years). The sagittal first metatarsal-medial cuneiform angle (plantar gapping) improved significantly from 3.8 degrees to 1.0 degrees (p=0.00002). The first metatarsal lift (dorsal subluxation) corrected from 4.0 mm to 1.5 mm (p=0.000001). Only one patient showed radiographic evidence of arthritis in the first tarsometatarsal joint at final follow-up. Conclusion: First tarsometatarsal joint fusion to correct medial column instability is well established in flatfoot reconstruction cases. However less is known about whether this is required when performing a triple arthrodesis for PCFD. In this study, 75% of patients had their first tarsometatarsal joint instability correct itself after isolated triple arthrodesis and maintained this correction at 4.8 year follow-up. In many cases of PCFD with medial column instability, triple arthrodesis alone may be adequate to restore overall alignment thereby avoiding the additional operative time and risk for complication associated with a first tarsometatarsal joint fusion. First tarsometatarsal joint instability correction following isolated triple arthrodesis. Pre-operative radiographs demonstrate plantar gapping and dorsal subluxation at the first tarsometatarsal joint consistent with medial column instability. At 2.8 year post-operative follow up after isolated triple arthrodesis, radiographs show maintained correction of the instability.

The Influence of Tibial Tubercle–Sparing Slope-Reducing Osteotomy on Patellar Height in Patients Undergoing Revision ACL Reconstruction

Background: A posterior tibial slope (PTS) >12° is an independent risk factor for anterior cruciate ligament (ACL) graft rupture, and a high tibial osteotomy (HTO) for slope correction can help avoid it. Management of patellar height is of major concern when performing HTO. Purpose: To evaluate the effect of tibial tubercle–sparing anterior closing-wedge osteotomy on patellar height in revision ACL reconstruction (ACLR). Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent arthroscopic revision ACLR combined with retro–tibial tubercle anterior closing-wedge HTO (ACW-HTO) between January 1, 2016, and March 31, 2021, were assessed for eligibility. Patellar height was measured on full weightbearing lateral radiographs according to the Insall-Salvati index (ISI) and Caton-Deschamps index (CDI) or frontal radiographs using the femoral patellar height index. The PTS was evaluated using the proximal anatomic axis of the tibia on standard short lateral radiographs. The delta (postoperative – preoperative) and the ratio (preoperative/postoperative) of the 3 patellar height indices and PTS were calculated. Preoperative and postoperative patellar heights were compared using independent t tests for each index. Also investigated was whether patients changed patellar height category (baja, normal, or alta) after slope osteotomy. Results: Among 475 revision ACLRs, 47 tibial tubercle–sparing ACW-HTOs were retained for analysis. No significant difference in patellar height was found between pre- and postoperative radiographs regardless of the index (preoperative – postoperative) (ISI: 1.0 ± 0.2 – 0.9 ± 0.2, P = .1729; CDI: 1.0 ± 0.2 – 1.0 ± 0.2, P = .4034; femoral patellar height index: 1.5 ± 0.2 – 1.5 ± 0.2; P = .5130). Fifteen patients (31.9%) exhibited a postoperative change in their patellar height category when measured by the ISI (6 moved up a category, 9 moved down one), and 18 patients (38.3%) changed category according to the CDI (10 moved up a category, 8 moved down one). No significant difference was found between pre- and postoperative patellar height among these patients (ISI: P = .2418; CDI: P = .3005). Conclusion: Changes in patellar height ratio are common after tibial tubercle–sparing ACW-HTO in patients undergoing revision ACLR. The clinical effect of these changes is unknown, and further study is needed to investigate whether they may result in patellofemoral symptoms.

Tibial Axis-to-Talus Distance: A Clinically Reliable Measurement for Sagittal Translation of the Talus in Total Ankle Arthroplasty.

Sagittal talar translation is an important factor influencing the sagittal alignment of total ankle arthroplasty (TAA). Thus, accurate measurement of sagittal talar translation is crucial. This study proposes a simple method (tibiotalar distance [TTD]) that can quantify talar translation without being affected by the ankle and subtalar joint condition or the talar component position in patients with TAA. We enrolled 280 eligible patients (296 ankles) who underwent primary TAA between 2005 and 2019 and retrospectively reviewed them for sagittal talar translation. The TTD was measured for each patient on weight-bearing lateral ankle radiographs by 3 raters. In addition, we analyzed interrater and intrarater reliability for the TTD method. We found that the TTD method could quantify the talar translation and was not affected by the preoperative condition of the ankle joint surface, subtalar joint pathologies, or the postoperative talar component position. The TTD method showed an excellent intraclass correlation coefficient (> 0.9) in all interrater and intrarater reliability analyses. In the analysis of 157 healthy, unoperated contralateral ankles, we identified that TTD showed a Gaussian distribution (p = 0.284) and a mean of 38.91 mm (normal range, 29.63-48.20 mm). The TTD method is a simple and reliable method that could be applied to patients with TAA to assess the sagittal talar translation regardless of the pre-and postoperative joint condition and implantation status.

Plantar calcaneal spurs and their connection with lumbar herniating discs

Introduction: Calcaneal spurs are bony triangular projections of varying sizes that are found on the calcaneum. By analyzing the incidence of plantar spurs and lumbar herniated disks, the current research aims to provide a reliable baseline for determining the pathological significance of spurs with herniated disks. Methods: Consecutive patients who had visited a local physiotherapy clinic for plantar calcaneal spurs between October 2022 and February 2023 with no self-reported comorbidities such as diabetes or vascular diseases were qualified for the study. Of the eligible subjects, a total of 84 patients were randomly selected from the clinic’s database. All 84 patients were subjected to weight-bearing lateral foot radiographs and magnetic resonance imaging scans. A Visual Analog Scale (VAS) was used to measure heel pain. Associations between the presence of spurs, herniated disks, sex, body mass index (BMI), and heel pain were then explored. Results: Of the 84 patients, 40 were males (48%) and 44 females (52%), with a mean age of 64.2 ± 5.6 years. The mean BMI was 28.5 ± 5.2 kg/m2. From the analysis of the imaging examination results, of the 84 patients with calcaneal spurs, 40 (48%) had lumbar disk herniation at L5-S1, 38 (45%) at L4-L5, 1 (1%) high lumbar herniations, and 5 (6%) no hernia. Women accounted for 45% of L5-S1 herniations and 41% of L4-L5 herniations. Pearson correlation between the variables speaks for a positive weak (r = 0.33) and significant relationship between VAS and weight and between VAS and BMI (r = 0.436, p &lt; 0.001). Conclusion: Given the high percentage of patients suffering concomitantly from plantar calcaneal spurs and discal hernias (94%), we assume that there might be a probable link between the two disorders.

A modified method for reconstruction of posterior tibial tendon after resection of juvenile painful type II accessory navicular

BackgroundThe surgical treatment of accessory navicular (AN) is divided into simple resection of AN and Kidner surgery used to reconstruct posterior tibial tendon (PTT) after AN resection. However, both of these procedures have certain disadvantages. Herein, we proposed a modified method to reconstruct PTT and compared the short-term clinical effect of our method with the modified Kidner procedure.MethodsWe collected data from 23 adolescent children with painful type II AN treated in our department between January 2015 and June 2020. The American Orthopedic Foot and Ankle Society Ankle-Hind foot (AOFAS-AH) Scores, the Meary Angle, and Pitch Angle of the lateral weight-bearing plain radiographs status were recorded before and after the operation to evaluate the treatment outcomes.ResultsIn the modified Kidner surgery (MK) group, the median AOFAS-AH increased from 61 (59–68) to 87 (83–91) (P < 0.05); the Pitch angle of the lateral weight-bearing plain radiographs increased from 13.0 (8–18) to 17.4 (14–22), and the Meary angle decreased from 18.3 (14–24) to 14.2 (8–20) (P < 0.05). In the PTT preservation folded suture (FS) group, the median AOFAS-AH increased from 61 (59–68) to 87 (85–91) (P < 0.05); the Pitch angle of the lateral weight-bearing plain radiographs increased from 12.3 (7–18) to 18.4 (15–26), and the Meary angle decreased from 17.8 (13–23) to 5.7 (3–8) (P < 0.05). There was no significant difference in AOFAS-AH postoperative scores between the FS group and MK group; however, the improvement on Pitch and Meary angle of the lateral weight-bearing plain radiographs was significantly better in the FS group than in MK group (P < 0.05).ConclusionsFor painful type II AN in juvenile patients, the insertion-preserving folding suture procedure had similar short-term results on AOFAS-AH scores but greater improvement in the Meary angle and the Pitch Angle than the modified Kidner method.Level of Evidence: III

“Antero-medial load shift” in unilateral plantar heel pain – A cross-sectional exploratory study

Background and purposePlantar foot pressure provides an insightful data in the ankle and foot complex which may aid in the detection of underlying pathology. Since individuals with unilateral plantar heel pain (PHP) tend to develop compensatory loading strategies, this study aimed to observe the foot loading pattern compared to the asymptomatic side and its relationship with the morphological variations in individuals with unilateral PHP. MethodsIt was a prospective cross-sectional study done on 17 participants with unilateral PHP. The calcaneal inclination and calcaneal first metatarsal angles were measured using lateral weight-bearing radiographs for both symptomatic and asymptomatic feet. Static and dynamic plantar foot pressures for both sides were obtained using a “Portable baropodometry platform 0, 5 m Entry Level footscan®. ResultsOn the symptomatic side, the pressure in the lateral heel was reduced by 65% in static and 67% in dynamic measurements, while in the medial heel, it was reduced by 16 % in static and 47 % in dynamic measurements compared to that of the asymptomatic side. There was a transfer of pressure from the hind foot to the forefoot by 44 % in static and 46 % in dynamic measurements resulting in anterior load shift. It was also observed that the prevalence of PHP was higher in the normal arched foot (59%). ConclusionBased on the observations, compared to the asymptomatic side, patients with unilateral plantar heel pain exhibited an anteromedial load shift (AMLS) in their plantar pressures. PHP was reported higher in the foot with normal morphology. Level of evidenceLevel 4.

Evaluation of Hindfoot Alignment on Lateral Weightbearing x-rays: A Novel Prospective In Vivo Study

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: In clinical practice and research, there are several scenarios when a hindfoot alignment view weightbearing XR is not obtained whether as a result of a lack of resources, technology, in retrospective studies when a hindfoot view was not obtained, as well as in many practices where a hindfoot view XR is not considered a routine examination for foot and ankle disorders. A lateral weightbearing radiograph however is almost routinely obtained, and the goal of this study was to correlate the hindfoot alignment angle with measurements on lateral weightbearing images. Methods: Four volunteers (8 feet) with flexible feet and ankles and no symptoms, nor significant trauma &amp; surgical history in their lower limbs were recruited for this study. A portable fluoroscopy machine (Smart C, Turner Imaging, Salt Lake City, USA) was used for imaging. The participant was asked to stand on different custom wooden wedges with the angle changed every 5 degrees from 30 degrees of varus to 30 degrees of valgus and a weightbearing lateral image was taken for each position. The hindfoot alignment was measured using a skin marker which had been drawn prior to initiation of the imaging, and the angular changes of the hindfoot was measured with the placement of each wedge placed. All standardized measurements of the midfoot and hindfoot were obtained on the lateral images. Results: With the hindfoot positional changes between 30o of varus to 30o of valgus, there was a gradual measurable change in the subtalar joint, with corresponding changes in the midfoot and hindfoot. There was a significant linear correlation between the hindfoot alignment angle and all radiographic parameters on lateral images. When the hindfoot alignment angle increased by 1 degree in the valgus direction, there was 0.49o decrease in the pitch angle, 0.58o of decrease in the middle vs posterior facet angle, 0.06o of decrease in the proximal cuneiform/cuboid height, 0.40o of decrease in the proximal cuneiform/5th Metatarsal height, 0.40o of increase in the fifth metatarsal/cuboid height, 0.009o of increase in the sinus tarsi/lateral process height, and 0.015o increase in Cuboid/Anterior Process Height. (Figure 1) Conclusion: The lateral weightbearing XR can be used to predict the status of the hindfoot alignment, and this study has proven that this can be none not only qualitatively but also quantitatively. This novel research can provide our colleagues with linear regression equations to correlate the lateral imaging metrics with the hindfoot alignment angle. Further study with a larger sample size and participants with different types of hindfoot deformities is needed to help develop an algorithm that would help both clinical practice and research.

Midfoot and Hindfoot Charcot Deformity Correction is Well Maintained with Beam Fixation

Category: Midfoot/Forefoot; Diabetes Introduction/Purpose: Charcot arthropathy is a neurotraumatic foot disorder seen in patients with peripheral neuropathy. Surgical reconstruction via medial column arthrodesis with beams can restore plantigrade foot anatomy with decreased soft tissue dissection and improved bony compression. Methods: We identified 12 patients with midfoot (n=7) or hindfoot (n=5) Charcot who underwent medial column beaming arthrodesis between 2015 and 2021 b y one of two fellowship-trained foot and ankle surgeons at an academic medical center. Data collected from patient charts included demographics, medical history, complications, and reoperation rate. Meary’s angle was measured on lateral weightbearing radiographs preoperatively and up to two years postoperatively. Mean follow-up time was 2.50 (range, 1.04-6.98) years. Statistical analysis included correlation, two-tailed Student t-test, and Chi-squared test. Results: Meary’s angle was recorded preoperatively for 12 patients (19.3° ± 6.7°) and postoperatively at three months for 12 patients (4.0° ± 6.7°), at six months for 12 patients (7.1° ± 9.7°), at one year for 11 patients (6.1° ± 9.4°), and at two years for five patients (10.2° ± 6.4°). However, two (16.7%) patients showed a loss of deformity correction, which was demonstrated by a Meary’s angle that was greater at final follow-up than preoperatively. Overall complication, infection, reoperation rates were 50.0%, 41.7%, and 58.3%, respectively. Finally, dependent on preoperative ulceration, those with and without an ulcer did not differ in Meary’s angle at any time point, overall complication, infection, nor reoperation rate. Conclusion: Although the results showed a relatively high complication rate, the use of beaming arthrodesis was generally able to maintain a plantigrade foot and overall alignment, while decreasing the recurrence of plantar ulceration.

Ten-year outcomes of anterior cruciate ligament reconstruction with hamstring tendon autograft and femoral fixation with a cortico-cancellous screw suspension device

PurposeTo evaluate the clinical and radiographic outcomes of anterior cruciate (ACL) reconstruction at minimum 10-year follow-up.MethodsNinety-three patients who underwent primary unilateral ACL reconstruction with hamstring tendon autograft, transtibial technique and femoral cortico-cancellous screw suspension device (Athrax, Leader Medica s.r.l) between 2010 and 2012 were retrospectively reviewed. Mean follow-up was 136 months. Evaluation was performed using the International Knee Documentation Committee score (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Score and Tegner Activity Level Scale. Incidence of OA was determined by comparing standard anteroposterior and lateral weightbearing radiographs of the ACL-reconstructed and contralateral knee. Osteoarthritis severity was graded according to the Kellgren–Lawrence (KL) score.ResultsMedian Tegner activity level was 6 (5–7). Lysholm and IKDC scores were 100 (95–100) and 90 (86–95), respectively, KOOS was 98 (95–100). Of ACL-reconstructed knees, 41 (50%) had radiographic OA, of which 6 (7.3%) had severe OA (KL III). Of the contralateral healthy knees, 28 (34.1%) had radiographic evidence of OA. Of these 22 (26.8%) and 6 (7.3%) patients had, respectively, KL-I and KL-II. 11 patients (11.8%) underwent subsequent knee surgery: 5 (5.4%) revisions, 3 (3.2%) meniscal surgeries, 2 (2.2%) other surgeries, 1 (1.1%) contralateral ACL reconstruction.ConclusionsThe study demonstrates that ACL reconstruction with HT autograft and cortico-cancellous screw suspension device determines satisfying clinical results after 10 years of follow-up. From our cohort, a low rate of graft failure has been reported, even though almost 50% of patients present a knee OA greater or equal to grade II KL.

Ankle Arthroplasty—Does Preoperative Fixed Equinus Affect Patient-Reported Outcomes

Postoperative sagittal range of motion, in particular degree of dorsiflexion, is critical for satisfactory outcomes in total ankle arthroplasty (TAA). Although there is literature discussing techniques to treat a preoperative fixed equinus we are not aware of any papers presenting patient outcomes. We present patient-reported outcomes for our cohort of patients undergoing TAA with preoperative fixed equinus compared to plantigrade ankles. This is a single surgeon, cohort study of consecutive cases. Cases of primary TAA were identified from a local joint registry which prospectively records Foot and Ankle Outcome Scores (FAOS), Short Form-36 (SF-36), and patient satisfaction. Revision cases or those with inadequate data were excluded. Patients were classified as fixed equinus or neutral based on both preoperative weightbearing lateral radiographs and clinical records. Overall 259 cases were identified, 92 were excluded leaving 167 cases for analysis (mean follow-up 81.7 months), 147 were classified as neutral and 20 fixed equinus. The fixed equinus group were significantly younger (neutral 63.9 vs equinus 52.9, p < .001). Stiffness was the only FAOS domain that was detectibly different at baseline (neutral 36.6 vs equinus 25.6, p=.044). Final FAOS scores, change from baseline and patient satisfaction was the same in all domains for both groups. There was no difference in revision rates. With the numbers available we did not demonstrate a postoperative difference in outcomes for patients with preoperative fixed equinus.

Radiographic Technique for Routine Clinical Measurement of Postoperative Total Knee Extension

Introduction: We propose a novel clinical technique to easily obtain a radiographic measurement for terminal passive knee extension based upon a weight-bearing lateral radiograph. Materials and Methods: Lateral radiographs were obtained with the patient in the standing position. The leg was positioned with slight hip flexion and full passive extension of the knee by instructing the patient to bear partial weight through their heel, with simultaneous use of a wooden wedge to dorsiflex the foot to neutral and to aid in balance. A Terminal extension was measured radiographically with digital imaging software. Fifty postoperative knee radiographs were used in assessing inter-observer and intra-observer reliability. Results: Inter-observer reliability yielded an Intraclass Correlation Coefficient of 0.973. The correlation coefficient for intra-observer reliability was 0.980. Conclusion: With the use of weight-bearing extension radiographs and our measurement technique, we present a method that can easily be applied across any setting in total knee arthroplasty to obtain accurate, objective data on patient knee extension.

Distal Tibia Apex Posterior Angulation: A Normal Anatomic Variant Related to Hindfoot Alignment With Side-to-Side Symmetry.

The sagittal plane of the distal tibia has not been well-described. This study sought to characterize sagittal plane morphology, determine symmetry from side to side, and identify differences based on hindfoot alignment. One hundred twelve bilateral lateral weight-bearing ankle radiographs were retrospectively evaluated (224 ankles). Hindfoot alignment was classified as neutral, planus, or cavus using the Meary angle. The angle between the diaphyseal and distal tibia axes was measured, and the apex location relative to the plafond was recorded. A mean distal tibia apex posterior angulation (DTAPA) of 2.0° (range -2° to 7°, SD = 2.06°) was located 8.0 cm proximal to the plafond. No difference was observed from side to side in DTAPA magnitude (P = 0.36) or location (P = 0.90). Planus alignment was associated with a significantly greater DTAPA (3.05°) as compared with neutral (1.89°) (P = 0.002) and cavus (1.25°) (P < 0.001) alignment. The distal tibia has an apex posterior angulation, suggesting that the true anatomic axis of the tibia terminates just posterior to the plafond center. Hindfoot alignment is related to distal tibia morphology. DTAPA symmetry indicates that contralateral imaging can be used to guide reconstruction of patient-specific anatomy and alignment. Knowledge of the DTAPA may help mitigate sagittal malalignment during distal tibia fracture surgery.

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

Diagnosis of flatfoot using a radiograph is subject to intra- and inter-observer variabilities. Here, we developed a cascade convolutional neural network (CNN)-based deep learning model (DLM) for an automated angle measurement for flatfoot diagnosis using landmark detection. We used 1200 weight-bearing lateral foot radiographs from young adult Korean males for the model development. An experienced orthopedic surgeon identified 22 radiographic landmarks and measured three angles for flatfoot diagnosis that served as the ground truth (GT). Another orthopedic surgeon (OS) and a general physician (GP) independently identified the landmarks of the test dataset and measured the angles using the same method. External validation was performed using 100 and 17 radiographs acquired from a tertiary referral center and a public database, respectively. The DLM showed smaller absolute average errors from the GT for the three angle measurements for flatfoot diagnosis compared with both human observers. Under the guidance of the DLM, the average errors of observers OS and GP decreased from 2.35° ± 3.01° to 1.55° ± 2.09° and from 1.99° ± 2.76° to 1.56° ± 2.19°, respectively (both p < 0.001). The total measurement time decreased from 195 to 135min in observer OS and from 205 to 155min in observer GP. The absolute average errors of the DLM in the external validation sets were similar or superior to those of human observers in the original test dataset. Our CNN model had significantly better accuracy and reliability than human observers in diagnosing flatfoot, and notably improved the accuracy and reliability of human observers. • Development of deep learning model (DLM) that allows automated angle measurements for landmark detection based on 1200 weight-bearing lateral radiographs for diagnosing flatfoot. • Our DLM showed smaller absolute average errors for flatfoot diagnosis compared with two human observers. • Under the guidance of the model, the average errors of two human observers decreased and total measurement time also decreased from 195 to 135min and from 205 to 155min.

Distal Tibia Apex Posterior Angulation: A Normal Anatomic Variant with Side-To-Side Symmetry

Category: Trauma; Ankle Introduction/Purpose: The native sagittal plane alignment of the distal tibia has not been well-described and has implications during the fixation of tibia fractures. Cavovarus foot alignment has been previously thought to influence gastrocsoleus tightness and the potential for anterior talar escape in the setting of an osseous injury in this region. However, the relationship between midfoot alignment and sagittal distal tibia morphology is undescribed. Characterization of this osseous anatomy may be helpful to achieve adequate sagittal alignment during the reduction of distal tibia fractures. The purpose of this study was primarily to characterize distal tibia sagittal morphology and ankle radiographic parameters, determine whether symmetry exists from side-to- side, and secondarily to identify any differences based on midfoot alignment. Methods: 112 patients (60 females, mean age 45.8 years) with bilateral lateral weight-bearing ankle radiographs were retrospectively evaluated (224 ankles). Midfoot morphology was classified as normal, planus, or cavus using Meary's angle (MA) (Planus: MA &lt;-4°, Normal: MA -4°≤x≤4°, Cavus: MA&gt;4°). The angle between the proximal diaphyseal (Line 1) and distal tibia (Line 2) axes was measured, and the location of the center of rotation of angulation (CORA) relative to the plafond was recorded (Figure 1). The horizontal distance (via a line parallel to the floor) from the distal tibia axis (Line 2) to the lateral talar process was measured, as well as the anterior distal tibial angle, and the plafond radius of curvature (ROC). Bilateral ankles and midfoot morphologies were compared using a Mann-Whitney U test and ANOVA, respectively. Correlation was assessed using linear regression. Results: The average distal tibia had 2° of apex posterior angulation with the CORA located 8.0 cm proximal to the plafond. There was no difference by laterality in magnitude of the angulation (p=.358) or distance from the plafond to the CORA (p=.901). The angulation increased as foot alignment transitioned from cavus (1.25°), to normal (1.89°), to planus (3.05°) alignment (r=.32; R2=.102; p&lt;.001). The angulation was larger in men (2.8°) than in women (1.4°) (p&lt;.001) and decreased with increasing patient age (r=.279, R2=.078, p&lt;.001). The lateral talar process was on average 5.9 mm anterior to the distal tibia axis (Line 2), more anterior with cavus versus planus alignment (6.7mm vs. 4.8mm) (p&lt;.001). The average anterior distal tibial angle and plafond ROC were 83.6° and 22.9 mm, respectively, with no significant differences by laterality or midfoot morphology (p&gt;.05 for both). Conclusion: The distal tibia has a consistent apex posterior bow that is symmetric from side-to-side, but variable from patient- to-patient. Distal tibia osseous morphology is related to midfoot alignment, sex, and age. Cavus alignment is additionally correlated with anterior translation of the lateral talar process relative to the distal tibia axis. Surgeons treating distal tibia fractures may consider the use of contralateral imaging as a reduction template to help restore patient-specific sagittal alignment. A tibial nail that ends anterior in the distal segment of a distal tibia fracture should prompt the surgeon to carefully evaluate whether sagittal alignment has been restored.

Effect of Distal Tibial Cortical Bone Coverage in Rates of Total Ankle Arthroplasty Implant Subsidence, Loosening, Heterotopic Bone Formation and Clinical Outcomes

Category: Ankle Arthritis Introduction/Purpose: Total ankle arthroplasty (TAA) has continued to increase in popularity as a treatment modality for ankle arthritis. Despite this increased popularity, continual updates to implant designs strive for improved outcomes. This has led to different implant design changes including an extended length tibial tray to offer more distal tibia cortical coverage. This study compares the rates of tibial component subsidence, tibial component loosening, heterotopic ossification (HO) formation, average post-operative range of motion (ROM), and patient reported outcome measures (PROMs) between two matched groups of patients who underwent TAA with Salto Talaris extended tibial tray components with full distal tibia cortical coverage and a group who underwent TAA with Salto Talaris traditional tibial tray components without full tibia cortical coverage. Methods: Patients who underwent TAA between January 2019 and February 2021 with Salto Talaris implants (Smith &amp; Nephew, Memphis, TN) were included for review. Patients were matched into two groups for age, gender, and Body Mass Index (BMI). Group 1 consisted of patients who received TAA with the extended tibial tray implant and full distal tibia cortical coverage and Group 2 consisted of patients who received the standard tibial tray implant without full distal tibia cortical coverage. Preoperative and postoperative radiographs were analyzed for the presence of subsidence, loosening, HO formation. ROM was measured utilizing plantarflexion and dorsiflexion weight-bearing lateral radiographs. PROMs were also analyzed including the Veterans- RAND 12 (VR-12) Item Health Survey, Ankle Osteoarthritis Scale (AOS), Foot and Ankle Ability Measure (FAAM), Visual Analog Score (VAS), and Patient Satisfaction. Results: Sixty-one patients (36 males; 25 females) were matched between the two groups. The mean age was 66.9 years in Group 1 and 67.1 years in Group 2, with a mean follow-up of 15.6 months and 22.1 months, respectively. Mean BMI was 30.6 in Group 1 and 30.5 in Group 2. The post-operative VR-12 Physical score was significantly higher in Group 1 (49.2 vs 45.1, P=0.025). Group 1 also had a significantly lower post-operative VAS pain score (11.1 vs 21.2, P=0.012) as well as patient satisfaction (93.8 vs 85.2, P=0.018). Radiographically, the rate of subsidence was significantly lower in Group 1 (0% vs 16.4%, P=0.001) as well as the rate of HO formation (26.2% vs 67.2%, P&lt;0.001). Group 1 had significantly greater post-operative plantarflexion (17.7 degrees vs 14.0 degrees, P=0.018). Conclusion: Early short-term results appear to indicate that utilizing TAA implants with an extended length tibial tray with full distal tibia cortical coverage is associated with less subsidence, less heterotopic ossification formation, greater post-operative plantarflexion, less pain and higher patient satisfaction. Future analysis with longer-term follow up as well as a larger patient cohort may help shed even more light into the efficacy of this new implant design.

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.

Angle of BRINK - a new way to measure Haglund's deformity.

Haglund's deformity, an abnormality of the postero-superior corner of the calcaneum, is a common, critically debated cause of posterior heel pain. Several radiological indices such as Fowler-Philip angle, Ruch pitch, Chauveaux-Liet angle, calcaneal pitch angle, parallel pitch lines, and X-Y ratio have been described to measure this deformity. However, most of these lack specificity and have variable intra- and inter-observer reliability. The study aims to describe a new radiological "angle of BRINK"(Botchu-Reilly-Iyengar-Nischal-Kakarala)to measure Haglund's deformity. We performed a retrospective cohort analysis, assessing 20 weight-bearing lateral ankle radiographs of patients with Haglund's deformity (Haglund's cohort) and 100 radiographs without the deformity (normal cohort). Demographic details and angle of BRINK to measure Haglund's deformity were measured for each patient. Statistical analysis was performed using t-test and inter-observer reliability was calculated using kappa coefficient. The mean angle of BRINK to measure Haglund's deformity in the normal cohort was 20.04° (SD 4.88), and in the Haglund's cohort was 25.1° (SD 3.3). This was statistically significant with a p-value of less than 0.0001. There was excellent intra- and inter-observer reliability with kappa value of 0.8. Our proposed radiological angle of BRINK to measure Haglund's deformity is simple and easy to calculate on standard weight-bearing radiographs. Contrary to the traditional measurements used to estimate the deformity, it has shown a good intra- and inter-observer reliability and can support surgical decision-making process for management of patients with symptomatic Haglund's deformity.

Automated landmark identification for diagnosis of the deformity using a cascade convolutional neural network (FlatNet) on weight-bearing lateral radiographs of the foot

Landmark detection in flatfoot radiographs is crucial in analyzing foot deformity. Here, we evaluated the accuracy and efficiency of the automated identification of flatfoot landmarks using a newly developed cascade convolutional neural network (CNN) algorithm, Flatfoot Landmarks AnnoTating Network (FlatNet). A total of 1200 consecutive weight-bearing lateral radiographs of the foot were acquired. The first 1050 radiographs were used as the training and tuning, and the following 150 radiographs were used as the test sets, respectively. An expert orthopedic surgeon (A) manually labeled ground truths for twenty-five anatomical landmarks. Two orthopedic surgeons (A and B, each with eight years of clinical experience) and a general physician (GP) independently identified the landmarks of the test sets using the same method. After two weeks, observers B and GP independently identified the landmarks once again using the developed deep learning CNN model (DLm). The X- and Y-coordinates and the mean absolute distance were evaluated. The average differences (mm) from the ground truth were 0.60 ± 0.57, 1.37 ± 1.28, and 1.05 ± 1.23 for the X-coordinate, and 0.46 ± 0.59, 0.97 ± 0.98, and 0.73 ± 0.90 for the Y-coordinate in DLm, B, and GP, respectively. The average differences (mm) from the ground truth were 0.84 ± 0.73, 1.90 ± 1.34, and 1.42 ± 1.40 for the absolute distance in DLm, B, and GP, respectively. Under the guidance of the DLm, the overall differences (mm) from the ground truth were enhanced to 0.87 ± 1.21, 0.69 ± 0.74, and 1.24 ± 1.31 for the X-coordinate, Y-coordinate, and absolute distance, respectively, for observer B. The differences were also enhanced to 0.74 ± 0.73, 0.57 ± 0.63, and 1.04 ± 0.85 for observer GP. The newly developed FlatNet exhibited better accuracy and reliability than the observers. Furthermore, under the FlatNet guidance, the accuracy and reliability of the human observers generally improved.

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

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