Biomechanical Fixation Analysis of Minimally Invasive Chevron Osteotomy

Category: Bunion Introduction/Purpose: The original fixation for minimally invasive Chevron-Akin ( MICA) was described with two screws: a proximal screw reaching two cortices before fixing the metatarsal head and a distal parallel screw that can reach only one cortical before fixing the head. Despite this, some authors questioned the need for two screws and were able to reproduce good results from this technique using only one screw to fix the osteotomy. Notably, no biomechanical studies evaluate this osteotomy's most stable and safe fixation. This work aims to perform a biomechanical analysis based on finite element analysis (FEM) to compare different MICA fixation configurations using screws. Our hypothesis is that the fixation of the original technique with two screws is the safest. Methods: A Three-dimensional (3D) virtual model of a foot computer tomography (CT) image was made using the Rhinoceros™ program. The element finite analysis was performed with the SimLab™ program using the Optistruct solver. From these 3D virtual models, an extracapsular chevron osteotomy with 130 degrees with 70% of lateral translation was done and fixated. Five internal fixation configurations with screws were used for fixation of MICA and assessed by FEM -: original MICA fixation with 2 screws, 2 intramedullary screws, 2 bicortical screws, 01 intramedullary screw, and 01 bicortical screw. The simulated 150 N and 300 N loads were applied to the middle foot. The FEM evaluated the total and localized displacements of the osteotomy site. For the analysis of stresses, the variables maximum principal (traction) and minimum principal (compression) were used. The equivalent von Mises stress (VMS -S) was used for the metallic implants and for the bone (VMS -O). Results: The classical fixation for MICA showed the lowest values for total and localized displacement, minimum and maximum total stress, and VMS-S and VMS-o in both conditions( 150 and 300 N). The localized displacement was statistically lower for MICA screws compared to the other fixation configurations (p < 0.05) The maximum total stress was statistically lower for MICA screws compared to the other fixation configurations (p < 0.05) Conclusion: The classical fixation for MICA yields better results in terms of total and localized displacement, minimum and maximum total stress, and VMS in both conditions. These results demonstrate that the classical fixation for MICA described in the original technique is biomechanically the most efficient and safe

Evaluation of Automated Coverage and Distance Mapping Selections to Improve Reliability and Clinical Utility of 3D Weightbearing CT Assessments

Category: Other; Hindfoot Introduction/Purpose: Progressive collapsing foot deformity (PCFD) is a complex three-dimensional (3D) deformity where adjacent structures may adopt subtle differences in positioning that result in increased contact or subluxation. Recent studies have highlighted the need for and utility of 3D analyses in PCFD using weightbearing CT (WBCT) and bone segmentation. Beyond the limitations of triplanar imaging, 3D distance and coverage mapping analyses have further highlighted key regional differences like sinus tarsi narrowing ahead of impingement and early middle facet uncoverage ahead of collapse. However, these analyses rely upon manual identification of subregions hindering the utility of 3D mapping clinically. The objective of this study was to compare an automated selection process with manual selections in the context of subtalar regional distance and coverage maps in PCFD. Methods: In this IRB-approved retrospective study, WBCT data of 20 consecutive patients with flexible PCFD and 10 controls were analyzed. Subregions of the peritalar surface (middle and posterior facets of the calcaneus and talus; sinus tarsi area) were manually selected by two experts on manually generated bone surfaces of all 30 feet. An automated algorithm for selecting coverage area was applied to identify the same regions on the semi-automatically generated bones (Figure). A 3D distance mapping (DM) technique was used to create coverage maps (CMs) across the entire peritalar surface where areas with distances less than 4mm were defined as covered. DM and CM percentages were compared using intra-class correlations and t-tests between PCFD and control groups. The Sørensen–Dice index, or Dice coefficient, was used for comparisons of selections on the semi-automated surfaces to evaluate reproducibility of expert selections. Results: The automated process produced identical selections resulting in perfect intra-method ICCs of 1.00 for all regions and Dice coefficients of 1.00. The average Dice coefficient for all manual selections was 0.903 (range: 0.865-0.935) indicating that observers were able to reliably select the same regions with 90% overlap. When assessing reliability of manual selections, intra- observer ICCs ranged from 0.41-0.92 while inter-observer ICCs ranged from 0.47-0.99 were found. Despite strong significant correlations, average coverage was significantly lower in the sinus tarsi region of the automated selections vs the manual selections (34.3±16.8% vs 23.1±12.7%, p< 0.005). However, mean distances in each region were not significantly different in the middle facet or the sinus tarsi regions (p=0.323, p=0.095, respectively). Conclusion: Understanding of the complex 3D deformities that constitute PCFD requires sensitive and reproducible measures. Fully automated 3D assessments of coverage and bone relations can help improve understanding these deformities aiding in diagnosis, staging, and objective evaluation of treatment effects. Prior work with this method has specifically identified the middle facet and sinus tarsi regions as being of particular importance. Compared to manual selections, these regions were well identified by the automated process. This represents a major step toward viable use of fully automated 3D coverage and distance mapping when evaluating PCFD patients

Objective Analysis of Regional Tibiotalar Joint Changes in Ankle Osteoarthritis Assessed by Semi- Automated 3D Distance Mapping

Category: Ankle Arthritis; Ankle Introduction/Purpose: Ankle osteoarthritis is a degenerative joint disease characterized by the narrowing of the tibiotalar joint space and in late stages, eventual tibiotalar contact and subchondral bone loss. Traditional methods of assessing changes in the joint space (such as assessment on 2D radiographs) are subjective and do not fully consider the three-dimensional nature of articular surfaces. Weight-bearing CT (WBCT) provides a unique perspective by placing the joints of the lower extremity in a loaded, functional position, and may help to better quantify changes in joint space. Determining the presence and progression of ankle arthritis is difficult. It is our hope that novel 3D distance mapping technologies using images acquired from WBCT may assist with the detection and characterization of progression of ankle osteoarthritis. Methods: In this IRB-approved, retrospective case-control study, we analyzed WBCT data of 9 ankle osteoarthritis patients and 20 healthy controls. Patients included in this study had no identifiable talar tilt. Segmentations were created using an automated segmentation software package (DISIOR Bonelogic 2.0) Principal component analysis was used to divide the talar dome into nine subregions. The articular facet of the medial malleolus was also analyzed. We used 3D distance mapping to objectively measure joint space width across the tibiotalar joint and assessed changes in distance in each of the nine subregions of the talar dome articular surface. Overall mean distances for each subregion analyzed were calculated. Comparisons between the control and ankle arthritis cases were performed with independent t-tests, assuming unequal variances. P-values < 0.05 were considered significant. Results: Changes in the mean distances are reported in the attached figure. The medial side of the talar experienced significant decreases in mean joint space width. The middle medial subregion experienced the largest decrease in mean joint space width with a reduction of 35% when compared to controls (p = 0.017). Increases in joint space width were observed on the lateral aspect of the talar dome, However, these increases were not found to be significant. Conclusion: The purpose of this study is twofold: to quantify changes in joint space using 3D distance mapping technique and to evaluate the utility of a commercial automated segmentation software package. In this cohort, there was a significant decrease on the medial side of the talar dome – this change can be attributed to cartilage degeneration. To our knowledge, this is the first study to analyze changes in ankle osteoarthritis using a fully automated segmentation method. Automated segmentation and 3D distance mapping provide a useful tool for the quantification of osteoarthritis-associated joint space changes

The Role of Computed Tomography with External Rotation and Dorsiflexion in Decision Making for Acute Isolated Posterior Malleolar Fractures Bartoníček and Rammelt Type II: A Cross-Sectional Study

Category: Ankle; Sports Introduction/Purpose: A ligament-centered analysis is currently incorporated in the assessment of joint stability in malleolar fractures. Although several imaging tests are available, in the setting of acute isolated non-displaced posterior malleolar fractures Bartoníček/Rammelt types II and IV diagnosing syndesmotic instability remains challenging. The objective of this multi-center cross- sectional study was to evaluate the syndesmotic and fracture instability using conventional ankle CT with external rotation and dorsiflexion in the setting of acute, isolated non-displaced Bartoníček and Rammelt type II posterior malleolar fractures. Methods: Between March 2018 and September 2022, a consecutive sample of 123 individuals with an ankle sprain were assessed for eligibility. In total, 33 participants met the inclusion criteria. All participants underwent a CT scan (CTSM), comprising a first phase with the ankles in a neutral position, then a stress phase with the ankles in external rotation and dorsiflexion and semiflexed knees. Investigators used the patterns of ligament tear found at MRI and instability at CTSM to classify all participants into West Point grades I, IIA, IIB, or III. Mann-Whitney test was used to test the differences in the numerical variables between injured and uninjured syndesmoses. The Spearman correlation tested the strength of the association between the tibial joint surface involved in posterior malleolus fracture and syndesmotic instability. Results: In MRI reading parameters two patterns of syndesmotic ligament injury predominated. A completely torn AITF and IO ligaments and a completely torn AITF was combined with a partially torn IO. Regarding the deep layer of the deltoid ligament, participants were classified as normal, strained and partially torn. In CT scan reading parameters in the neutral phase, the median difference of 0.2 mm in d measurements between injured and uninjured syndesmoses was not statistically significant (P = 0.057). During the stress phase, the injured and uninjured syndesmoses had distinct behavior, and the 2.3 mm median difference for d measurement was statistically significant (P < 0.0001). Conclusion: The conventional computed tomography with external rotation and dorsiflexion represent a reproducible and accurate diagnostic option for the detection of syndesmosis instability and fracture instability in acute isolated posterior malleolar fractures Bartonícek and Rammelt type II

Prevalence of Progressive Collapsing Foot Deformity in Hallux Valgus Patients

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Hallux valgus (HV) and progressive collapsing foot deformity (PCFD) are very common foot and ankle conditions in the adult population. Both could potentially disrupt the tripod construct of the foot which leads to chronic pain and arthritis. Several procedures were described to address HV deformity depending on deformity characteristics. PCFD could alter the management plan for HV if they occur simultaneously. The aim of this study was to detect the prevalence of PCFD in HV patients and study the frequency of individual PCFD classes. Methods: In this retrospective IRB approved study, patients > 18 years old who were evaluated for symptomatic hallux valgus and had a weight bearing computed tomography (WBCT) imaging were included. Patients were considered for further analysis if they have a hallux valgus angle (HVA) > 15° or inter-metatarsal angle (IMA) > 9°. All relevant demographic data were extracted. Two fellowship trained foot and ankle orthopaedic surgeon measured the following parameters: foot and ankle offset (FAO%) (Class A), talo-navicular coverage angle (TNCA) (Class B), Meary’s angle (Class C) and middle facet subluxation (MFS%) (Class D). Cases that showed FAO% > 4.6% and MFS% > 28.7% were diagnosed as PCFD. The prevalence of PCFD classes (A,B,C and D) was calculated using threshold values for its respective radiographic marker. Descriptive statistics were performed. Results: Thirty-four cases were included. 16 cases were females (46.06%) and 16 (46.06%) were right side. The average age was 52.51 years (SD ± 17.75), the average BMI was 30.14 (SD ± 7.15). The average HVA was 26.82 (SD ± 9.98) and the average IMA was 15.41 (SD ± 3.53). 13 patients (38.24%) had MFS% and FAO% above the threshold values. The average FAO was 4.75% (SD ± 4.92) and the average MFS was 29.17% (SD ± 15.89). Prevalence of Class A (FAO%) was 20 (58.82%), Class B (TNCA) was 12 (35.29%), Class C (Meary’s angle) was 15 (44.12%) and Class D (MFS%) was 16 (47.06%). Conclusion: Progressive collapsing foot deformity is prevalent in the hallux valgus population (38.24%). Class C which indicates medial column instability was prevalent in 44.12% of the cases. Given this high prevalence of PCFD, we believe that in addition to the classic hallux valgus parameters, PCFD classes evaluation could favor a surgical approach over another such as first tarsometatarsal joint procedures over isolated distal first metatarsal procedures to correct the HV deformity and simultaneously halt PCFD progression

Semi-Automatic 3D Assessment of Zadek Osteotomy Effects

Category: Hindfoot; Sports Introduction/Purpose: Zadek's procedure is a surgical option to treat insertional Achilles tendinopathy(IAT). This procedure consists of a closing wedge osteotomy of the calcaneus with biomechanical consequences. Great modifications in the hindfoot alignment can result in poor functional outcomes for athletes. Additionally, some authors stated that Zadek osteotomy is a good choice for patients with IAT associated with cavovarus foot. This study aims to analyze the hindfoot alignment and the parameters related to Haglund's syndrome after Zadek's osteotomy using a virtual surgical simulation by specific software. The authors hypothesize that the Zadek is an effective technique to decompress the Achilles tendon against the Haglund deformity without major modifications in the alignment. Methods: A total of 20 WBCT scans of patients with IAT were included. The WBCT images were run through the Foot & Ankle module of Disior's BonelogicTM software, creating a 3D virtual model. With this 3D model built into this software, 20 virtual Zadeck osteotomies standardized with a 10 mm resection wedge were performed using the virtual osteotomy module of Bonelogic®. The Calcaneal Inclination angle (sagittal view)7; Talocalcaneal angle (sagittal view)8; Talocalcaneal angle (axial view)8; Saltzman angle (45 degrees view)9; Saltzman angle (20 degrees view)9; Hindfoot moment arm angle;10 Hindfoot angle10; Fowler Philips angle11 and the calcaneal length7 were measured before and after the virtual osteotomy. These results were compared and statistically analyzed. Results: A virtual Zadek osteotomy was realized in 20 WBCT from patients with an insertional Achilles tendinopathy. Most of the patients were female, and the mean age was 55 years. There were significant statistical differences in the average of the calcaneal length (79 mm to 73 mm), Fowler Philips angle (57º to 43º), calcaneal pitch ( 24º to 20º ), sagittal talocalcaneal angle (55º to 47º ), and the hindfoot moment arm angle (20 º to 21,8º). The axial talocalcaneal angle, Saltzman view 45 º and 20 º, and Hindfoot moment arm showed subtle modifications. Conclusion: The virtual analysis of Zadek's osteotomy decreased the Fowler Philips angle, shortened the calcaneus, and modified the alignment in the sagittal view. It suggests that Zadek's procedure reduces the bone impingement with Achilles and the Achilles push. The effect of this osteotomy in Hindfoot Alignment was subtle, modifying only the sagittal plane

Multiligament Ankle Instability Following Rotational Ankle Injuries: A Prospective Cohort Study

Category: Sports; Arthroscopy Introduction/Purpose: Rotational ankle injuries are frequent and mostly benign. However, chronic pain and residual instability following an index rotational trauma can happen. The diagnostic elucidation of the pain source is challenging, with ligamentous insufficiency, osteochondral injuries, and impingement/arthritis representing potential causes for symptoms. The prevalence and pattern of the residual isolated or combined ligamentous ankle instability following rotational injuries are not entirely elucidated in the literature. In this prospective cohort study, we aimed to assess the frequency of combined ligamentous instability (lateral, medial, and syndesmotic) in patients with chronic ankle pain (>6 months) following rotational ankle injuries that failed conservative treatment and underwent surgical treatment. We also aimed to assess improvement in patient-reported outcomes (PROs) following treatment of the diagnosed conditions. Methods: IRB-approved prospective cohort study. We included patients with history of chronic pain (>6 months) following a rotational ankle injury, with clinical signs of combined ligamentous instability of at least two ligamentous complexes (lateral, medial, and syndesmotic), and that failed conservative treatment (>3 months). All patients underwent surgical treatment. Diagnostic arthroscopic assessment was performed. Syndesmotic instability was considered positive if a metallic sphere of 3mm could be inserted in the anterior syndesmotic space. Deep deltoid instability was confirmed with a “pass-through sign” when a 4.0mm shaver could be introduced in the medial gutter. Lateral ankle instability was confirmed with a positive rotatory drawer test under fluoroscopic assessment. Presence of isolated or combined ligamentous instability was noted and patients received appropriate open surgical treatment for the confirmed ligamentous insufficiencies. Presence of associated osteochondral injuries, peroneal pathology and anterior bony impingement was also recorded. PROs were collected pre-operatively and at most recent follow-up. Results: A total of 27 patients were included (9 males/18 females), mean age 35.9 years (range, 18-68) and average BMI 31.3kg/m 2 (CI, 28.1-34.5). Eighty-nine percent had ankle sprains, and 11% rotational ankle fractures treated conservatively. Intraoperative assessment demonstrated positive lateral, medial, and syndesmotic instability in respectively 96%, 81%, and 78% of the patients. Most common combined instabilities were: 59% multidirectional (all three complexes), 19% rotational (medial+lateral), 15% anterolateral (lateral+syndesmotic), and 4% anteromedial (medial+syndesmotic). Isolated lateral instability was present in only one patient (4%). Peroneal tendon pathology, osteochondral injuries and anterior bony impingement were found in respectively 67%, 19%, and 26% of the patients. The average postoperative follow-up was 22.2 months (3-39 months). Significant improvements in VAS (P=0.0024), PROMIS Pain Interference (p=0.024), and EFAS scores (p=0.022) were observed. Conclusion: In this prospective cohort study, combined multiligament instability was extremely frequent in patients with chronic pain following rotational ankle injuries. Ninety-six percent of patients had confirmed intraoperative instability of at least two of the three ankle ligamentous complexes. Multidirectional (lateral, medial, and syndesmotic) (49%), rotational (lateral and medial) (19%), and anterolateral (syndesmotic and lateral) (15%) instabilities were the most frequent injury patterns. Following ligamentous repair/reconstruction, significant improvements in PROs were observed at an average follow-up of 22-months. Our study highlights that the diagnosis of residual multiligament ankle instability should be considered in patients with chronic ankle pain following rotational injuries

Comparing Symptomatic and Asymptomatic Flatfeet Using Known Markers of Progressive Collapsing Foot Deformity (PCFD): A Case Control Study

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: Flattening of the longitudinal arch of the foot (Flatfoot) can represent a normal spectrum of foot morphology and alignment. The issue comes when the foot is collapsing progressively, what is now termed Progressive Collapsing Foot Deformity (PCFD). Literature on asymptomatic flatfoot is scarce since asymptomatic patients do not seek medical attention. Alignment differences between asymptomatic flatfoot and PCFD have not been established and might represent a key-step in understanding predictors of PCFD. The objective of this prospective study was to compare established PCFD measures in a cohort of asymptomatic flatfoot, PCFD patients and healthy controls. We hypothesized that asymptomatic flatfeet alignment would differ from both symptomatic PCFD patients and healthy controls. Methods: In this prospective comparative study, patients with asymptomatic flatfeet were recruited to undergo a weight-bearing CT (WBCT) scan. This cohort (22 feet, 10 males, 12 females) was compared to two other prospective cohorts (22 symptomatic PCFD and 22 healthy controls). Along with demographic data, PCFD measurements performed include Foot and Ankle Offset (FAO), Forefoot Arch Angle (FAA), Middle Facet Uncoverage, and the Transverse Arch Plantar (TAP) angle. Normality of variables was assessed using the Shapiro-Wilk test. Chi-squared or analysis of variance (ANOVA) test was performed to compare each parameter between the three groups. A post-hoc Bonferroni test was then performed to assess significance between each group pairing. P-values of >0.05 were considered significant. Results: All three groups were comparable on BMI (p=0.10), Age (p=0.75) and Gender (p=0.78). All measurements taken differed significantly between the symptomatic PCFD and healthy controls (Table 1). FAO was significantly different between controls vs asymptomatic (p < 0.001) and asymptomatic vs symptomatic (p < 0.001). FAA was also significantly different between asymptomatic and both symptomatic (p=0.001) and control groups (p=0.001). Middle facet uncoverage differed between the asymptomatic and control group (p=0.001) but the asymptomatic and symptomatic group were similar (p=0.106). While the TAP angle was significantly different between asymptotic and symptomatic groups (p=0.013), the asymptomatic and control groups failed to reach significance (p=0.061) (Table 1). On average, deformity measurements for asymptomatic flatfeet were in between the values for healthy controls and symptomatic PCFD (Figures 1-3). Conclusion: To our knowledge this is the first prospective study to compare healthy controls, asymptomatic flatfoot and symptomatic PCFD patients. We observed that asymptomatic flatfoot patients usually had measurements of PCFD that would fall in between normal alignment asymptomatic controls and symptomatic PCFD patients. Further, the asymptomatic group differed significantly from both other groups on every measure but two. Our data supports the idea that asymptomatic flatfoot should be considered a risk factor for Progressive Collapsing Foot Deformity. Our data can hopefully shine light in finding predictive markers for the development of PCFD

Relationship between High Heels and Hallux Valgus Deformity. Fact or Fiction? A 3-Dimensional Weight-bearing CT Assessment

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Evidence in the literature suggests the negative effects of using High Heels (HH), becoming a challenge for clinicians and researchers since they are welcomed by women worldwide, mainly due to the subjective power of attractiveness given to them. Although some people blame HH as one of the causes of Hallux Valgus (HV), until now, there are no studies in the literature that effectively prove a cause-effect relationship between HH and HV. The objectives of this study are: (1) to analyze whether the increase in heel height can lead to HV and (2) to evaluate whether HV can increase in severity with increasing heels. We hypothesized that an increase in heel height could cause and increase the severity of HV deformity radiographically. Methods: Comparative cross-section4-one feet from twenty-one participants (11 males and 10 females, aged 30.8 ± 8.9 years, and with Body Mass Index 25.5 ± 2.0 m kg2) were recruited. HH shoes were designed for this study with three heights for each participant: 3, 6, and 9 cm. The inclusion criteria were: no regular wearing of heels. The exclusion criteria were: Hallux Valgus diagnosis and/or any orthopedic conditions that affect the Foot and Ankle joints. Hallux Valgus Angle (HVA), Intermetatarsal Angle (IMA), First-Metatarsal Phalangeal Angle, 1st-to-5th Intermetatarsal Angle, First Tarsometatarsal Angle (axial), Second tarsometatarsal angle (axial), Hindfoot Moment Arm (HMA) (mm), Saltzman 45 angle and, Foot Ankle Offset (FAO) were measurement using semiautomated software analysis. Multiple comparisons were performed (Bonferroni's for normal distributions and Wilcoxon test for no normal distributions) when there was a main effect on an outcome (p 0.05). However, heel increases above 6 cm significantly increased HVA and IMA (p > 0.001). Based on Coughlin's classification, a 3 cm heel increase promoted a mild HV, and increases above 6 cm caused a moderate HV. Conclusion: Based on data from our study with patients without Hallux Valgus through analysis with WBCT versus High Heels, we conclude that increasing heel height can radiographically lead to Hallux Valgus deformity and progressively increase the severity. High heels above 6 cm can lead to radiographically moderate Hallux Valgus. These findings may be an essential step toward a better understanding the effects of increasing high heels on Hallux Valgus pathology. More studies are needed to support this data clinically

Deformities Influencing Different Classes in Progressive Collapsing Foot

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: The current classification system of progressive collapsing foot deformity (PCFD) is comprised of 5 possible classes. PCFD is understood to be a complex, three-dimensional deformity occurring in many regions along the foot and ankle. The question remains whether a deformity in one area impacts other areas. The objective of this study is to assess how each one of the classes is influenced by other classes by evaluating each associated angular measurement. We hypothesized that positive and linear correlations would occur for each class with at least one other class and that this influence would be high. Methods: We retrospectively assessed weight-bearing computed tomography (WBCT) measurements of 32 feet with PCFD diagnosis. The classes and their associated radiographic measurements were defined as follows: class A (hindfoot valgus) measured by the hindfoot moment arm (HMA), class B (midfoot abduction) measured by the talonavicular coverage angle (TNCA), class C (medial column instability) measured by Meary’s angle, class D (peritalar subluxation) measured by the medial facet uncoverage (MFU), and class E (ankle valgus) measured using the talar tilt angle (TTA). Multivariate analyses were completed comparing each class measurement to the other classes. A p-value < 0.05 was considered significant. Results: Class A showed a substantial positive correlation with class C (ρ=0.71; R2=0.576; p 0.001). Class B was substantially correlated with class D (ρ=0.74; R2=0.613; p 0.001). Class C showed a substantial positive correlation with class A (ρ=0.71; R2=0.576; p 0.001) and class D (ρ=0.75; R2=0.559; p 0.001). Class D showed a substantial positive correlation with class B and class C (ρ=0.74; R2=0.613; p 0.001), (ρ=0.75; R2=0.559; p 0.001) respectively. Class E did not show correlation with class B, C, or D (ρ=0.24; R2=0.074; p=0.059), (ρ=0.17; R2=0.071; p=0.179), and (ρ=0.22; R2=0.022; p=0.082) respectively. The average values of each class radiographic markers are listed in Figure 1. Conclusion: This study was able to find relations between components of PCFD deformity with exception of ankle valgus deformity (Class E). Measurements associated with each class were influenced by others, and in some instances, with pronounced strength such as between class A and C as well as between Class B and D. Surgical procedures to address certain class deformities could indirectly address other classes as well, which ultimately decreases surgical procedures numbers or complexity. The presented data may support the notion that PCFD is a three-dimensional complex deformity and suggests a possible relation among its ostensibly independent features