Does the Sagittal Radiographic Morphology of Subtalar Joint Affect the Alignment of Foot?

OBJECTIVES: The etiology of flatfoot and cavus foot is multicausal and controversial. So far, no literature reports the relationship between the sagittal morphology of subtalar joint and the alignment of foot. The purpose of this study was to explore whether the subtalar alignment would influence the configuration of foot. METHODS: From January 2017 to January 2020, we included 109 feet in the flatfoot group, 95 feet in the cavus group, and 104 feet in the control group in this retrospective comparative study. The Gissane angle and calcaneal posterior articular surface inclination angle represented the sagittal morphology of the subtalar joint. Meary's angle, calcaneal pitch angle, and talar pitch angle reflected the alignment of foot. They were measured in the weightbearing foot X-rays. The angles in different groups were compared via Mann-Whitney U test. We calculated the correlation between the sagittal alignment of subtalar joint and the alignment of foot using Spearman's correlation analysis. Interobserver and intraobserver reliability were calculated. RESULTS: The Gissane angle, calcaneal posterior articular surface inclination angle, Meary's angle, talar pitch angle, and calcaneal pitch angle were significantly different in the three groups. The Gissane angle had an excellent correlation with the Meary's angle (r = 0.850, p < 0.0001), and the talar pitch angle (r = -0.825, p < 0.0001), and a good correlation with the calcaneal pitch angle (r = 0.638, p < 0.0001). The calcaneal posterior articular surface inclination angle had an excellent correlation with the Meary's angle (r = -0.902, p < 0.001), and the talar pitch angle (r = 0.887, p < 0.0001), and a good correlation with the calcaneal pitch angle (r = -0.702, p < 0.0001). The interobserver and intraobserver reliability for all radiographic measurements was good to excellent. CONCLUSION: A subtalar joint with a larger Gissane angle and a more horizontal calcaneal posterior articular surface angle tended to have a higher foot arch and vice versa. The inspiration from this study was that the deformities of flatfoot and cavus foot may relate to the subtalar deformity.

3D Analysis of Joint-Sparing Charcot-Marie-Tooth Surgery Effect on Initial Standing Foot Alignment.

BACKGROUND: The complex deformities in cavovarus feet of Charcot-Marie-Tooth (CMT) disease are difficult to evaluate. The aim of this study was to quantify the initial standing alignment correction achieved after joint-sparing CMT cavovarus reconstruction using pre- and postoperative weightbearing computed tomography (WBCT). METHODS: Twenty-nine CMT cavovarus reconstructions were retrospectively analyzed. Three-dimensional measurements were performed using semiautomated software (Bonelogic 2.1) to investigate changes in sagittal, axial, and coronal parameters. Pre- and postoperative data were compared, along with normative data. Correlation among the preoperative measurements and the amount of correction in sagittal, axial, and coronal parameters were analyzed. RESULTS: The sagittal, axial, and coronal malalignment of the hindfoot, and the sagittal and axial malalignment of the forefoot, was significantly improved after corrective surgery (P < .05). Sagittal Meary angle (from 14.8 to 0.1 degrees), axial talonavicular angle (TNA, from 3.6 to 19.2 degrees), and coronal hindfoot alignment (from 11.0 to -11.1 degrees) showed significant changes postoperatively (P < .001). Hindfoot, forefoot sagittal, and forefoot axial parameters reached comparable outcomes compared with normative value (P > .05). Regarding amount of correction, Spearman correlation demonstrated that axial Meary angle and TNA were most strongly related to improvement in sagittal Meary angle and coronal hindfoot alignment. CONCLUSION: Preoperative and postoperative WBCT measurements demonstrated that joint sparing CMT cavovarus reconstruction significantly improved sagittal, axial, and coronal deformities of CMT, and sagittal Meary angle was restored toward normative values. Apparent axial plane correction, the majority of which occurred at the talonavicular joint, had the strongest correlation with deformity correction in multiple planes. This suggests that soft tissue releases and correction of the talonavicular joint may be a key component of a cavovarus foot correction.

Cavovarus Deformity: Why Weight-Bearing Computed Tomography Should Be a First-Line Imaging Modality.

Cavovarus foot is a complex three-dimensional deformity, which includes a wide range of clinical conditions from subtle deformities to disabling feet. In this article, the authors discuss the role of weight-bearing computed tomography, which might enable to avoid double imaging (radiographs + tomography) in patients for which a detailed osteoarticular assessment is required, with the advantage to obtain tomographic images in standing position and a reduction of radiation exposure.

Supramalleolar Osteotomies in Cavovarus Foot Deformity: Why Patient-Specific Instruments Make a Difference.

Supramalleolar osteotomy enables correction of the ankle varus deformity and is associated with improvement of pain and function in the short term and long term. Despite these beneficial results, the amount of surgical correction is challenging to titrate and the procedure remains technically demanding. Most supramalleolar osteotomies are currently planned preoperatively on 2-dimensional weight-bearing radiographs and executed peroperatively using free-hand techniques. This article encompasses 3-dimensional planning and printing techniques based on weight-bearing computed tomography images and patient-specific instruments to correct ankle varus deformities.

Joint preserving procedures for painful plantar callosities in patients with flexible cavovarus foot.

BACKGROUND: The outcome of a constant joint preserving procedure for painful plantar callosities with cavovarus foot remains unclear. METHODS: Eleven patients (11 feet) who underwent lateral displacement calcaneal osteotomy (LDCO), dorsiflexion first metatarsal osteotomy (DFMO), and plantar fasciotomy (PF), simultaneously were included. The presence of painful callosities, heel alignment of standing (HA), and the Japanese Society for Surgery of the Foot ankle/hindfoot (JSSF) score were evaluated. Radiographically, the talonavicular coverage angle (TNCA), lateral talo-first metatarsal angle (LTMA), calcaneal pitch angle (CPA), and heel alignment angle (HAA) were measured. RESULTS: Postoperatively, painful plantar callosities disappeared in 10 patients and remained in one patient. The postoperative HA and JSSF score significantly improved. The postoperative TNCA, LTMA, CPA, and HAA significantly improved. CONCLUSIONS: In patients with flexible cavovarus foot, LDCO, DFMO, and PF yielded good outcomes at mid-term follow-up with preservation of the foot and ankle joints.

2D Manual vs 3D Automated Assessment of Alignment in Normal and Charcot-Marie-Tooth Cavovarus Feet Using Weightbearing CT.

BACKGROUND: The complex deformities in cavovarus feet may be difficult to assess and understand. Weightbearing computed tomography (WBCT) is increasingly used in evaluating complex deformities. However, the bone axes may be difficult to calculate in the setting of severe deformity. Computer-assisted 3D axis calculation is a novel approach that may allow for more accurate assessment of foot alignment or deformity. This study aimed to assess differences in measurements done manually on 2D slices of WBCT vs 3D computer models in normal and cavus feet. METHODS: We retrospectively analyzed WBCT scans from 16 normal and 16 cavus feet in patients with Charcot-Marie-Tooth disease. Six measurements were assessed: talar-first metatarsal angle (axial plane), forefoot arch angle (coronal plane), and Meary angle, calcaneal pitch, and cuneiform and navicular to floor distances (sagittal plane). 2D measurements were performed manually and 3D measurements were performed using specialized software (Bonelogic, DISIOR). Bland-Altman plots and linear regression were used to analyze differences. RESULTS: There were no significant biases in measured variables in normal feet. In the cavovarus group, automated assessment calculated increased sagittal plane deformity (fixed bias 7.31 degrees for Meary angle, 2.39 degrees for calcaneal pitch) and less axial plane deformity (fixed bias 10.61 degrees for axial talar-first metatarsal angle). The latter also demonstrated proportional bias indicating greater discrepancy with increasing adduction. CONCLUSION: Measurements were comparable in normal feet suggesting automated techniques can reliably assess the alignment of bony axes. However, automated calculations show greater sagittal and less axial deformity in cavovarus feet than measured by manual techniques. This discrepancy may relate to rotational deformity seen in cavovarus feet, which may not be easily assessed manually. 3D automated measurements may therefore play a role in better assessing and classifying the cavovarus foot, which may ultimately inform treatment algorithms. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Imaging of the Pes Cavus Deformity.

Direct-type cavus foot deformities are most commonly encountered and are primarily sagittal plane deformities. Direct deformities should be delineated from rarer triplane pes cavovarus deformities. The lateral weight-bearing radiograph is the cornerstone of imaging evaluation of direct pes cavus foot deformity. The apex of Meary talo-first metatarsal angle on the lateral radiograph represents the pinnacle of the cavus deformity and assists in subclassification of the deformity. With routine application, ancillary radiographic imaging techniques, such as the modified Saltzman view or the modified Coleman block test, can give valuable insight into deformity assessment and surgical planning.

Ankle and Pantalar Arthrodesis: End-Stage Salvage in Cavus Foot.

Bony alignment is the primary goal in foot and ankle reconstruction of the cavovarus foot. This condition presents as a malalignment causing a medial overload of the ankle articular surface and lateral overload of the hindfoot, midfoot, and forefoot. A painful gait associated with articular degeneration of the numerous joints can lead to a chronic and rigid arthrosis of joints, warranting arthrodesis of the affected joints accordingly.

Association of HSS score and mechanical alignment after primary TKA of patients suffering from constitutional varus knee that caused by combined deformities: a retrospective study.

For pre-operative osteoarthritis (OA) patients with varus knee, previous studies showed inconsistent results. Therefore, we conducted this study to better identify the association of Hospital for Special Surgery (HSS) score and mechanical alignment. 44 patients (51 knees) with constitutional varus knee caused by combined deformities (LDFA (lateral distal femoral angle) > 90°and MPTA (medial proximal tibial angle) < 85°)) were selected and analyzed with a mean follow-up period of 14 months after total knee arthroplasty (TKA). From January 2015 to December 2016, patients were collected consecutively after primary TKA. After filtering, fifty-one knees (44patients) were analyzed with a mean follow-up period of 14 months. All patients were divided into two groups based on post-operative hip-knee-ankle (HKA) acute angle: varus mechanical alignment (VMA) group (HKA < - 3°) and neutral mechanical axis (NMA) group (- 3° ≤ HKA ≤ 3°). 30 knees were included in the NMA group, and 21 knees in the VMA group. Comparisons of HSS between NMA group and VMA group were performed. After adjusting for age and Body Mass Index (BMI) confounders, Compared with NMA group, the HSS score in VMA group decreased by 0.81 units (95% CI, - 3.37 to 1.75) p = 0.5370). For pre-operative constitutional varus knee caused by combined deformities in chinese populations, no significant association between post-operative lower limb mechanical alignment and HSS score was found.

[Cavovarus foot]. / Ballenhohlfuß.

The cavovarus foot (CF) is a complex three-dimensional foot deformity. In addition to primary forms, secondary forms can be distinguished. The diagnosis of CF is made clinically; however, anamnestic information, a targeted examination including neurological status and at least radiological imaging using the hindfoot-centered imaging technique are required to determine the treatment. Conservative treatment for CF consists of the provision of insoles up to the adaptation of an orthopedic custom-made shoe, depending on the severity of the deformity. The indications for a surgical procedure are present in the case of increasing complaints, although the timing should be extensively discussed with the patient in order to be able to achieve the best functional results. Surgical treatment is generally complex but a combination of soft tissue interventions and osteotomy/arthrodesis can usually be used to achieve a plantigrade foot position and thereby enable the patient to walk with a functionally improved gait.

Distance mapping of the foot and ankle joints using weightbearing CT: The cavovarus configuration.

INTRODUCTION: The goal of this study was to characterize the abnormal joint surface interaction at the ankle, hindfoot and midfoot joints of the cavovarus foot using distance mapping on weightbearing computed tomography (WBCT) images by comparing a series of cavovarus feet to a series of normally-aligned feet. METHODS: In this case-control study, ten feet (10 patients) with asymptomatic cavovarus shape (cases; N = 10) were compared to 10 matched-paired (by age, gender and body mass index) normally-aligned feet (10 patients) (controls; N = 10). Three-dimensional models were produced from the images and distance maps representing joint surface configuration were generated for the ankle, hindfoot and midfoot joints. The distance maps for each joint were then compared between the two groups and between regions in the same group. RESULTS: In the cavovarus group there was a significant increase in surface-to-surface distance at the posterior tibiotalar joint and a reduced distance at the anterior part, together with a greater distance at the posterior half of the medial gutter. Also, a decrease in surface-to-surface distance on the anterior half of the anterior facet and an increased distance on the posterior quadrants of the posterior facet of the subtalar joint were found. At the sinus tarsi, the lateral aspect of the talonavicular joint, the naviculocuneiform and the tarsometatarsal joints there was a statistically significant increase in surface-to-surface distance in cavovarus patients as compared to controls. CONCLUSION: Distance mapping analysis on WBCT images identified significant differences in surface-to-surface interaction at the foot and ankle joints between cavovarus and normally-aligned feet. LEVEL OF EVIDENCE: Level III, case-control study.

Pes cavovarus in Charcot-Marie-Tooth compared to the idiopathic cavovarus foot: A preliminary weightbearing CT analysis.

BACKGROUND: Pes cavovarus is a foot deformity that can be idiopathic (I-PC) or acquired secondary to other pathology. Charcot-Marie-Tooth disease (CMT) is the most common adult cause for acquired pes cavovarus deformity (CMT-PC). The foot morphology of these distinct patient groups has not been previously investigated. The aim of this study was to assess if morphological differences exist between CMT-PC, I-PC and normal feet (controls) using weightbearing computed tomography (WBCT). METHODS: A retrospective analysis of WBCT scans performed between May 2013 and June 2017 was undertaken. WBCT scans from 17 CMT-PC, 17 I-PC and 17 healthy normally-aligned control feet (age-, side-, sex- and body mass index-matched) identified from a prospectively collected database, were analysed. Eight 2-dimensional (2D) and three 3-dimensional (3D) measurements were undertaken for each foot and mean values in the three groups were compared using one-way ANOVA with the Bonferroni correction. RESULTS: Significant differences were observed between CMT-PC or I-PC and controls (p<0.05). Two-dimensional measurements were similar in CMT-PC and I-PC, except for forefoot arch angle (p=0.04). 3D measurements (foot and ankle offset, calcaneal offset and hindfoot alignment angle) demonstrated that CMT-PC exhibited more severe hindfoot varus malalignment than I-PC (p=0.03, 0.04 and 0.02 respectively). CONCLUSIONS: CMT-related cavovarus and idiopathic cavovarus feet are morphologically different from healthy feet, and CMT feet exhibit increased forefoot supination and hindfoot malalignment compared to idiopathic forms. The use of novel three-dimensional analysis may help highlight subtle structural differences in patients with similar foot morphology but aetiologically different pathology. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Diagnosis and Operation Results for Chronic Lateral Ankle Instability with Subtle Cavovarus Deformity and a Peek-A-Boo Heel Sign.

Cavovarus deformity is considered an anatomical risk factor for chronic lateral ankle instability (CLAI). However, subtle deformity can be difficult to detect, and its correction is controversial. The current study aimed to evaluate clinical and radiographic outcomes of a modified Broström procedure (MBP) with additional procedures for CLAI with subtle cavovarus deformity and a positive peek-a-boo heel sign. We reviewed the records of 15 patients who underwent MBP with additional procedures for CLAI with a positive peek-a-boo heel sign between August 2009 and April 2015. Consecutive physical and radiographic examinations were performed. The visual analog scale (VAS) for pain, the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, and the Karlsson-Peterson (KP) ankle score were applied to assess clinical outcomes. Weight bearing radiographs, hindfoot alignment view, and ankle stress radiographs were also examined. The mean follow-up period was 58.5 months. Calcaneal lateral closing wedge osteotomy was performed in seven patients to correct fixed hindfoot varus, and first metatarsal dorsiflexion osteotomy was performed in 11 patients to correct plantarflexion of the first ray. Three patients underwent both procedures. Mean VAS, AOFAS, and KP ankle scores improved significantly (p=0.001), and instability did not recur. Radiographically, all stress parameters improved significantly (p=0.007). Simultaneous correction of a positive peek-a-boo heel sign and cavovarus deformity with MBP for CLAI improves clinical outcomes and prevents recurrent instability. A comprehensive evaluation and cautious approach for subtle cavovarus deformity should be followed when treating patients with CLAI. This trial is registered on Clinical Research Information Service (CRiS, KCT0003287).

Is subtle cavus foot a risk factor for chronic ankle instability? Comparison of prevalence of subtle cavus foot between chronic ankle instability and control group on the standing lateral radiograph.

BACKGROUND: Subtle cavus foot (SCF) is an entity characterized by mild cavus. However, few studies have examined whether a SCF may be a risk factor for chronic ankle instability (CAI). METHODS: This study included 116 patients who underwent lateral ankle ligament repair (modified Broström operation) for CAI and 105 controls. We used the standing lateral radiograph, so compared calcaneal pitch angle, Meary's angle, heights of the first and fifth metatarsal bases, and fibular positions between groups. Additionally, two observers subjectively rated the standing lateral radiographs for the presence of SCF. RESULTS: There were no significant intergroup differences in any of the radiographic angles. The prevalence of SCF was 20.7% in the CAI group and 18.1% in the control group according to observer 1 versus 21.6% and 28.6% (CAI group and control group, respectively) according to observer 2. There were no significant intergroup differences in the proportion of SCF between the two observers (p=0.105 and 0.211, respectively). CONCLUSION: SCF was not a significant risk factor for CAI when judging by standing lateral radiograph, and the detection of SCF seems to require considerable experience. Thus, care should be taken when determining whether to perform corrective osteotomies when treating CAI patients with SCF. LEVEL OF EVIDENCE: III, case control.

[Hindfoot-centred X-ray technique for the evaluation of cavovarus deformity : A proposal for the optimization of radiologic delineation]. / Die "rückfußzentrierte Röntgentechnik" zur Erfassung von Cavovarusdeformitäten : Vorschlag zur Optimierung der radiologischen Darstellung.

In surgical correction of cavovarus deformity bony hindfoot procedures are required in most cases. For treatment planning X­rays in two or more planes are usually used. In conventional X­ray-techniques the hindfoot and ankle joint are presented in a more or less outward rotated position. Moreover, the peritalar complex is not delineated in the most corrected position. Therefore, the frequently used talus-metatarsal-I-angle (Meary angle) cannot be measured correctly. By application of the Coleman block test and additional adjustment of the malrotation in the lateral view, the peritalar complex and ankle joint can be evaluated in the corrected and "hindfoot-centred" position. Also, the frequently seen anterior ankle impingement can be observed precisely. Planning of osteotomies or corrective peritalar fusions is supported thereby. Some treatment examples are presented.

Immediate and short-term radiological changes after combining static stretching and transcutaneous electrical stimulation in adults with cavus foot: A randomized controlled trial.

BACKGROUND: Cavus foot is a deformity represented by an increased and rigid medial longitudinal arch, and it is often associated with persistent pain and gait disturbances. None of the conservative conventional treatments for cavus foot have shown conclusive evidence of effectiveness, and so further is research needed to understand how to manage this condition better. This study aimed to assess the immediate and short-term radiological changes after combining static stretching and transcutaneous electrical stimulation of the plantar fascia in adults with idiopathic cavus foot. METHODS: A randomized, single-blinded clinical trial was conducted. Sixty-eight participants with idiopathic cavus foot, as determined by an internal Moreau-Costa-Bertani angle (MCBA) less than 125° in a lateral weight-bearing foot radiograph, were equally distributed into a neuromuscular stretching group (NSG) or a control group (no intervention). The NSG underwent a single session, combining transcutaneous electrical nerve stimulation with static stretching of the plantar fascia. Primary measurements of 3 angles were taken using a lateral weight-bearing foot radiograph: the internal MCBA; the calcaneal pitch angle (CPA); and the first metatarsal declination angle (FMDA). Outcomes were collected at baseline, immediately postintervention, and 1 week after intervention. RESULTS: Analysis of variance revealed a significant group effect for all angles (all, P < .05). NSG participants showed a significant increase in the internal MCBA (P = .03), and a significant decrease in the CPA (P = .01) and FMDA (P = .04) from baseline to immediately postintervention. These changes remained statistically significant 1 week after the intervention (all, P < .05). CONCLUSION: The combination of static stretching and transcutaneous electrical stimulation of the plantar fascia, compared with no treatment, achieved immediate and short-term changes in the internal MCBA, the CPA, and the FMDA, which resulted in flattening the medial longitudinal plantar arch in adults with idiopathic cavus foot.

The Cole Midfoot Osteotomy: Clinical and Radiographic Retrospective Review of Five Patients (Six Feet) with Different Etiologies.

BACKGROUND: Cole osteotomy is performed in patients having a cavus deformity with the apex of the deformity in the midfoot. Correction of the deformity at this midfoot level improves foot and ankle stability by creating a plantigrade foot. We retrospectively reviewed the clinical and radiographic results of six feet (five patients) that underwent Cole midfoot osteotomy (2011-2015). METHODS: The patients had different etiologies (spastic cerebral palsy, burn sequelae, spina bifida, and Charcot-Marie-Tooth disease). Dorsal and slightly laterally based transverse wedge osteotomy through the navicular bone medially and the cuboid bone laterally was performed. Patients were under routine clinical follow-up. We evaluated clinical and radiographic results. RESULTS: Mean clinical follow-up was 15.7 months (range, 6-36 months). The mean preoperative and postoperative talo-first metatarsal angles on lateral radiographs were 29.9° and 8.7°, respectively (P < .05) and on anteroposterior radiographs were 30.3° and 8.6° (P < .05). The mean preoperative talocalcaneal angle on anteroposterior radiographs increased from 19.2° to 29.8° postoperatively (P < .05). The mean postoperative calcaneal pitch angle change was 10.8° on the lateral radiograph (P < .05). At final follow-up, all five patients were independently active, had plantigrade feet, and were able to wear conventional shoes. The mean American Orthopaedic Foot and Ankle Society questionnaire score was 38.8 preoperatively and 79.5 postoperatively (P < .05). Only one patient did not have full bony union. Achilles tightness was seen in one patient. CONCLUSIONS: Cole midfoot osteotomy is a laboring procedure to correct adult pes cavus deformity with the apex in midfoot, although having some complication risks.

Clinical Examination and Radiographic Assessment of the Cavus Foot.

The purpose of the clinical examination is to detect subtle cavus or cavovarus deformity, assess the severity and type of deformity, differentiate between idiopathic versus secondary etiologies of cavus foot deformity, and evaluate for other associated abnormalities. The clinical examination should begin with a gait analysis. The neurologic examination reveals peripheral neuropathy or central nervous system etiology for the foot deformity. On plain radiographs, forefoot-driven deformity can be assessed using the Meary angle, and hindfoot-driven deformity can be measured by the calcaneal pitch. Computed tomography and MRI scans can assess for tarsal coalitions and soft tissue pathologies, respectively.

The effect of foot type on the Achilles tendon moment arm and biomechanics.

BACKGROUND: The aim was to calculate the Achilles tendon moment arm in different degrees of plantarflexion for pes planus, pes cavus and normal arched feet. METHODS: 99 patients (99 radiographs; 40 males, 59 females; mean age 49 years, SD 15) with a healthy ankle joint and a preoperative weightbearing lateral radiograph of the foot were included. Three groups (pes planus, pes cavus and normal-arched feet) with equal sample sizes (n=33) were formed. On radiographs, the angle formed between a horizontal line and the line connecting the insertion of the Achilles tendon with the center of rotation of the ankle, was measured. The interrater reliabilities (ICC) of the angle alpha were compared on radiographs and on MRIs. Using the angle alpha, the Achilles tendon moment arm was calculated in different plantarflexion positions. RESULTS: The ICC of alpha was higher on radiographs (0.84, [0.73-0.91]) than on MRIs (0.61, [0.27-0.81]). The average alpha was statistically significantly different (normal arched foot 31 degrees (°), pes planus 24°, pes cavus 36°, p=0.021), resulting in a significant shorter Achilles tendon moment arm for pes cavus than for pes planus (p<0.0001) and normal arched feet (p=0.006) in neutral position. CONCLUSION: The data suggests that it is feasible to use radiographs to measure the Achilles tendon moment arm. The maximum Achilles tendon moment arm is reached at different angles of ankle flexion for pes cavus, pes planus and normal-arched feet. This has to be taken into consideration when planning surgeries.

Evaluation of Asymptomatic Contralateral Foot Deformities Using the Tripod Index.

Background: The primary aim of this study was to determine the prevalence of asymptomatic pes planus and cavovarus foot deformities using the tripod index (TI). Methods: A retrospective study was conducted on 122 adult subjects over the age of 18 from January 2010 to December 2016 with symptomatic pes planus (n=78) or cavovarus (n=44) foot deformities. We subdivided both groups into subjects who presented with unilateral symptomatic deformities (pes planus unilateral symptomatic; cavovarus unilateral symptomatic) and bilateral symptomatic foot deformities (pes planus bilateral symptomatic feet and cavovarus bilateral symptomatic feet). The severity of TI was compared between sides. Results: The prevalence of asymptomatic pes planus and cavovarus foot deformities was 52% and 67.6%, respectively. Subjects with unilateral symptomatic foot deformities had significantly more severe TI values for the symptomatic cavovarus foot -98.96% (-288.89 to 0%) compared to asymptomatic cavovarus -67.41% (-270.59 to 14.71%) (p=0.015). Subjects with unilateral symptomatic pes planus deformity also had more severe TI on the symptomatic foot 57.49 (-9.38 to 141.67%) compared to the asymptomatic foot 30.43 (-51.52 to 119.23%) (p<0.01). Subjects with bilateral symptomatic foot deformities had no significant difference in severity of Tripod Index between feet. Conclusion: Although half of subjects with unilateral symptomatic deformities had a foot deformity on the contralateral side, the severity of deformity between symptomatic and asymptomatic feet was significantly different for both pes planus and cavovarus feet. Further studies should prospectively follow postoperative radiographs to determine whether a correction in foot alignment directly improves symptoms.Level of evidence: III.