Clinical Effects of Tibial Posterior Tendon Reconstruction in the Treatment of Young Athletes With Accessory Navicular Bone Syndrome.

OBJECTIVE: To compare the effects of anchor reconstruction of posterior tibial tendon with the traditional Kidner's procedure for accessory navicular bone syndrome. METHODS: A retrospective analysis was conducted on 40 young athletes diagnosed with accessory navicular bone syndrome who were admitted to our hospital from 2018 to 2021. Among them, 20 patients underwent the modified Kidner procedure for the anchor reconstruction of the posterior tibial tendon (Experimental group), while the remaining 20 patients were treated with the traditional Kidner's procedure (Control group). Regular follow-ups were conducted to evaluate the degree of relief of foot symptoms and functional recovery. RESULTS: All patients were followed up for 12 to 24 months (mean duration: 18.6±3.7) after the operation. At the last follow-up, significant differences were observed in the function and symptom relief of the affected foot compared to the preoperative state. The experimental group had a mean operation time of 52.10 ± 3.41 minutes, significantly shorter than the control group's 61.25 ± 2.75 minutes. The mean time to return to normal activity was 12.65 ± 1.23 weeks for the experimental group, compared to 15.25 ± 1.16 weeks for the control group. CONCLUSION: The modified Kidner procedure demonstrates a higher patient satisfaction rate compared to the traditional Kidner procedure. This is attributed to its shorter duration, reduced trauma, and quicker recovery of normal activity.

Human navicular bone: a morphometric and morphological evaluation.

BACKGROUND: The composition of navicular joint complex is crucial to perform surgical interventions for multiple pathological foot aetiologies. The data on human navicular bone and its facets from Indian population remain scarce in literature. AIMS AND OBJECTIVES: To evaluate the morphometry and morphology of navicular bone. METHODOLOGY: A total of 77 (right: 40; left: 37) dried human navicular bones were used. The collected data were entered and analysed in SPSS software. RESULTS: The anteroposterior diameter of navicular bone on right side was 15.19 mm (13.92, 16.77) and on left side was 15.87 mm (13.83, 17.27). The transverse diameter on right and left sides were 34.21 mm (31.74, 36.6) and 33.59 mm (30.23, 35.43), respectively. The vertical diameter measured on the right was 22.31 mm (21.19, 23.94) and on left 22.53 mm (20.8, 24.24). Morphometric evaluation showed no significant difference between right and left navicular bones. The commonest shape for posterior facet was quadrilateral, on the right (62.5%) and left (40.5%). The most common shape of anterior facet for medial cuneiform is quadrilateral, on the right (85%) and left (89.1%). For intermediate cuneiform, triangular facet was common on the right side (72.5%) and on the left (59.5%). The lateral cuneiform facet was bean shaped on right side (72.5%) and quadrilateral on the left side (32.5%). There was a significant difference in shape distribution between right and left (P < 0.05). The median length of the groove for tibialis posterior tendon was 18.01 mm and 16.19 mm on right and left side, respectively. Cuboid facet was observed in 28 (70%) and 26 (65.9%) navicular bones on right and left sides, respectively. CONCLUSION: There is no significant difference between right and left bones with regards to morphometric parameters. Morphological evaluation revealed significant difference in the distribution of shape between right and left bones.

Morphological measurements and classification of the navicular bone: a study based on computed tomography imaging.

OBJECTIVE: The purpose of this study was to present the classification of navicular bones and the anatomical basis for the diagnosis and treatment of navicular fractures of the foot. METHOD: 351 computed tomographic (CT) images of the navicular bone were analyzed and classified. The navicular bone's anatomical morphology was measured by three independent researchers in each type. Analysis and recording of the measurement results followed. RESULT: Navicular bones were assorted into three types: I shape(37.04%), II shape(54.41%), and III shape(8.55%). The left and right sides did not differ in any appreciable ways, except ab, bc, and ∠abc (P < 0.05); And all data were statistically different between men and women except for ∠abc (p > 0.05). CONCLUSION: The classification of the navicular bone in this study may be helpful in making the treatment decision for navicular fracture. LEVEL OF CLINICAL EVIDENCE: 4.

The prevalence and anatomy of accessory navicular bone: a meta-analysis.

PURPOSE: There have been over 40 descriptions of the common developmental variants of the accessory ossicles of the feet. Although predominantly asymptomatic, they sometimes may be linked to painful conditions. One of the most common accessory ossicles in the foot is the accessory navicular bone (AN), located on the medial side of the foot. Our research provides a first meta-analysis on this topic that establishes its frequency by contrasting 39 studies from across the globe. METHODS: Up to February 2024, PubMed and Embase databases were thoroughly searched for research on the AN. Eligible data regarding AN prevalence was extracted. This study strictly adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: A total of 39 studies, 11,015 patients, and 36,837 feet were analyzed in our study. The pooled prevalence estimate (PPE) of AN was found to be 17.5% (95%CI: 11.5-25.7) and 12.6% (95%CI: 10.1-15.5) in patients and feet analyses, respectively. Accessory navicular occurred bilaterally in 50.0% of patients, with similar distribution in gender-based groups (21.1% of males and 22.0% of females were confirmed with AN). Accessory navicular was most prevalent in the East Asian population (38.4%) and least prevalent in North Americans (8.0%). No significant differences in AN prevalence were found when comparing different imaging modalities (X-ray and cadaver dissection). CONCLUSION: Accessory navicular is a common finding in imaging studies. Its prevalence depends on the population covered by the study but is not affected by the patient's gender or the imaging modality utilized for AN assessment.

Simultaneous subtalar arthroeresis, midfoot soft tissue release, and talo-navicular arthrodesis in children with planovalgus neurologic foot.

PURPOSE: Planovalgus foot deformity (PVFD) is common in children with neuromuscular conditions and severe deformity may require surgical correction. This study aims to assess clinical and radiological outcomes of PVFD secondary to neuromuscular disease managed by subtalar arthroeresis (SuAE), midfoot soft tissue release and talo-navicular arthrodesis (TNA). METHODS: A retrospective analysis of children with neuromuscular disease and nonreducible PVFD who underwent SuAE, midfoot soft tissue release, and TNA and with a minimum follow-up of 5 years was performed. A total of 60 patients with neuromuscular disease (108 feet) including cerebral palsy were reviewed. Mean age at surgery was 12.7 ± 4.6 years (6-17). Mean follow-up was 7 ± 2.9 years (5-10). Clinical outcomes and radiologic correction at final follow-up were compared with preoperative values. Statistical analysis was performed and significance was set at P < 0.01. RESULTS: Statistically significant radiological improvements between pre- and postoperative values were found for all angle values. At final follow-up, there was a significant improvement in VAS score (4.8 vs. 2; P < 0.01). There was also a positive trend in the improvement of walking ability. No cases of pseudoarthrosis were reported at final follow-up. Screw removal was required in 5 out of 108 feet (4.6%) and 2 feet (3.3%) had delayed medial wound healing. CONCLUSIONS: SuAE combined with TNA and midfoot soft tissue is a safe and feasible procedure that can provide good clinical and radiologic results in patients with neuromuscular disease and nonreducible PVFD; the procedure can improve foot stability, and has a limited number of complications. LEVEL OF EVIDENCE: IV.

Early euprimates already had a diverse locomotor repertoire: Evidence from ankle bone morphology.

The morphological adaptations of euprimates have been linked to their origin and early evolution in an arboreal environment. However, the ancestral and early locomotor repertoire of this group remains contentious. Although some tarsal bones like the astragalus and the calcaneus have been thoroughly studied, the navicular remains poorly studied despite its potential implications for foot mobility. Here, we evaluate early euprimate locomotion by assessing the shape of the navicular-an important component of the midtarsal region of the foot-using three-dimensional geometric morphometrics in relation to quantified locomotor repertoire in a wide data set of extant primates. We also reconstruct the locomotor repertoire of representatives of the major early primate lineages with a novel phylogenetically informed discriminant analysis and characterize the changes that occurred in the navicular during the archaic primate-euprimate transition. To do so, we included in our study an extensive sample of naviculars (36 specimens) belonging to different species of adapiforms, omomyiforms, and plesiadapiforms. Our results indicate that navicular shape embeds a strong functional signal, allowing us to infer the type of locomotion of extinct primates. We demonstrate that early euprimates displayed a diverse locomotor behavior, although they did not reach the level of specialization of some living forms. Finally, we show that the navicular bone experienced substantial reorganization throughout the archaic primate-euprimate transition, supporting the major functional role of the tarsus during early primate evolution. This study demonstrates that navicular shape can be used as a reliable proxy for primate locomotor behavior. In addition, it sheds light on the diverse locomotor behavior of early primates as well as on the archaic primate-euprimate transition, which involved profound morphological changes within the tarsus, including the navicular bone.

Plantar Pressure Characteristics and Prevention of Painful Accessory Navicular in Military Recruits.

OBJECTIVE: The objective of this study was to provide practical guidance for the prevention of painful accessory navicular among recruits by comparing and analyzing the plantar pressure parameters of individuals with normal foot, flat foot, and accessory navicular. METHODS: After training, a total of 90 military recruits were included in this study, comprising 30 with normal foot, 30 with flat foot, and 30 with painful accessory navicular. The plantar pressure distribution was measured for all participants. RESULTS: In individuals with flat feet, there was an increase in plantar pressure on the medial side of the forefoot, as well as a significant increase in pressure on the medial side of the heel and arch (P<0.05). Conversely, there was a significant decrease in pressure on the lateral side of the heel and arch (P<0.05). In patients with painful accessory navicular, the medial pressure on the foot arch showed a further increase (P<0.001), while the lateral pressure on the foot arch exhibited a further decrease (P<0.001), indicating highly significant differences. CONCLUSION: Compared to participants with flat feet, participants with accessory navicular demonstrated faster and more impulsive impact on the ground within the same stress area, resulting in more noticeable pain caused by the injury to the accessory navicular.

Reliability and correlation of weight-bearing cone beam CT and Foot Posture Index (FPI) for measurements of foot posture: a test-retest study.

OBJECTIVE: To assess test-retest reliability and correlation of weight-bearing (WB) and non-weight-bearing (NWB) cone beam CT (CBCT) foot measurements and Foot Posture Index (FPI) MATERIALS AND METHODS: Twenty healthy participants (age 43.11±11.36, 15 males, 5 females) were CBCT-scanned in February 2019 on two separate days on one foot in both WB and NWB positions. Three radiology observers measured the navicular bone position. Plantar (ΔNAVplantar) and medial navicular displacements (ΔNAVmedial) were calculated as a measure of foot posture changes under loading. FPI was assessed by two rheumatologists on the same two days. FPI is a clinical measurement of foot posture with 3 rearfoot and 3 midfoot/forefoot scores. Test-retest reproducibility was determined for all measurements. CBCT was correlated to FPI total and subscores. RESULTS: Intra- and interobserver reliabilities for navicular position and FPI were excellent (intraclass correlation coefficient (ICC) .875-.997). In particular, intraobserver (ICC .0.967-1.000) and interobserver reliabilities (ICC .946-.997) were found for CBCT navicular height and medial position. Interobserver reliability of ΔNAVplantar was excellent (ICC .926 (.812; .971); MDC 2.22), whereas the ΔNAVmedial was fair-good (ICC .452 (.385; .783); MDC 2.42 mm). Using all observers' measurements, we could calculate mean ΔNAVplantar (4.25±2.08 mm) and ΔNAVmedial (1.55±0.83 mm). We demonstrated a small day-day difference in ΔNAVplantar (0.64 ±1.13mm; p<.05), but not for ΔNAVmedial (0.04 ±1.13mm; p=n.s.). Correlation of WBCT (WB navicular height - ΔNAVmedial) with total clinical FPI scores and FPI subscores, respectively, showed high correlation (ρ: -.706; ρ: -.721). CONCLUSION: CBCT and FPI are reliable measurements of foot posture, with a high correlation between the two measurements.

Navicular Bone Fracture after Radiofrequency Ablation in a Patient with Osteoid Osteoma.

Osteoid osteoma (OO) is a benign bone tumor that presents with nocturnal pain. Computed tomography (CT)- guided radiofrequency ablation (RFA) has been widely performed for OO, and major adverse events post-RFA are rare. We report a case of OO in the left navicular bone of a 15-year-old male. He underwent RFA for OO, and the pain improved temporarily. At the 1-month follow-up, the patient complained of left foot pain, and a CT examination revealed a fracture of the ablated navicular bone. Fractures are rare but must be taken into account after bone RFA.

Establishment of a sequential dual tracer 18 F-NaF/18 F-FDG PET protocol for imaging the equine foot.

The combination of 18 F-Sodium Fluoride (18 F-NaF) and 18 F-FluoroDeoxyGlucose (18 F-FDG) for positron emission tomography (PET) imaging of the equine foot is appealing for detection of both osseous and soft tissue lesions in a single scan. As the combination of tracers could lead to a loss of information, a sequential approach, consisting in imaging with one tracer prior to injecting the second tracer, might be valuable. The goals of this prospective, methods comparison, exploratory study were to establish the order of tracer injection and timing for imaging. Six research horses were imaged under general anesthesia with 18 F-NaF PET, 18 F-FDG PET, dual 18 F-NaF/18 F-FDG PET, and CT. Proper uptake could be identified in tendon lesions as early as 10 min after 18F-FDG injection. Bone uptake was limited when 18F-NaF was injected under general anesthesia, even at 1 h after injection, when compared with 18 F-NaF injection prior to anesthesia. The sensitivity and specificity of the dual tracer scans were 0.77 (0.63 to 0.86) and 0.98 (0.96 to 0.99) respectively, to assess 18 F-NaF uptake and 0.5 (0.28 to 0.72) and 0.98 (0.95 to 0.99), respectively, for 18F-FDG uptake. These results suggest that the sequential dual tracer approach is a pertinent technique to optimize the PET data gained from a single anesthetic episode. Based on dynamics of tracer uptake, the optimal protocol consists in injecting 18F-NaF prior to anesthesia, acquire 18F-NaF data then inject 18F-FDG and start acquisition of dual tracer PET data 10 min later. This protocol should be further validated in a larger clinical study.

Is the Small Ossicle of Type 1 Accessory Navicular a Cause of Foot Pain?-A Case Report.

Background and objectives: An accessory navicular (AN) bone is often classified into types 1-3 according to the Veitch classification, and symptomatic type 1 patients usually receive non-surgical treatment. However, there are cases in which AN cannot be classified into one of these three types using this classification system, and the small ossicle of type 1 AN may not be the cause of foot pain. This report aimed to present a case of symptomatic type 1 AN that required surgical treatment without the excision of the small ossicle after long-term conservative treatment had failed. Case presentation: A 15-year-old girl who was diagnosed with symptomatic type 1 AN was referred to our department. Medial-side foot pain had prevented her from playing soccer well. She had been treated conservatively for type 1 AN for more than 12 months at several orthopedic clinics. Tenderness of the prominent navicular tubercle was identified, and computed tomography and magnetic resonance imaging findings suggested that the cause of her foot pain was derived from the prominent navicular tubercle not the small ossicle itself. Osteotomy of the prominent navicular tubercle with the advancement of the tibialis posterior tendon, without excision of the ossicle, was performed. At the 12-month follow-up examination, she was completely free from foot pain, and the patient-reported outcome measures were excellent. She now plays soccer at the pre-injury level. Conclusions: We report the case of a patient with symptomatic type 1 AN who underwent osteotomy of the prominent navicular tubercle with advancement of the tibialis posterior tendon, without excision of the ossicle, and who showed favorable short-term clinical outcomes. The evaluation of symptomatic patients with AN based on the Veitch classification alone may lead to inappropriate management. The small ossicle of type 1 AN was not the cause of foot pain in the present case.

Is Kidner procedure necessary during subtalar arthroereisis for pediatric flexible flatfoot that combined with symptomatic type 2 accessory navicular? A retrospective comparative study.

BACKGROUND: Kidner procedure is thought to be able to eliminate the medial foot pain and contribute to restoring the medial longitudinal foot arch, making it particularly suitable for surgical treatment of pes planus that combined with symptomatic type 2 accessory navicular (AN). However, controversy remains, and the clinical evidence is still lacking. The aim of the current study is to verify the necessity of Kidner procedure during subtalar arthroereisis (STA) for pediatric flexible flatfoot (PFF) that combined with symptomatic type 2 AN. METHODS: Forty pediatric patients (72 feet) who had undergone STA for flexible flatfoot and were also diagnosed with symptomatic type 2 AN concomitantly were reviewed retrospectively and divided into two groups (STA + Kidner vs STA alone). The visual analog scale (VAS), the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, the Oxford ankle foot questionnaire for children (OAFQC), and the radiographic parameters that quantifying pes planus were evaluated as primary outcomes. Secondary outcomes included the incidence of complications. RESULTS: There were 35 feet in the STA + Kidner group and 37 feet in the STA alone group, with mean follow-up periods of 2.7 years and 2.1 years, respectively. The VAS, AOFAS, OAFQC scores and radiographic parameters presented no significant difference between the two groups both preoperatively and at final follow-up (P > 0.05 for each). The complications of STA surgery occurred equally in both groups, and Kidner procedure could lead to more incision problems (22.9% vs. 2.7%) and a longer time to return to activity. CONCLUSION: Kidner procedure may be unnecessary during surgical treatment of PFF that combined with painful type 2 AN. Correcting the PFF while leaving the AN alone has a high possibility of relieving the pain in the AN region, and tibialis posterior tendon (TPT) rerouting hardly aids in reconstruction of the medial foot arch. LEVEL OF EVIDENCE: III.

Analysis of skeletal characteristics of flat feet using three-dimensional foot scanner and digital footprint.

BACKGROUND: Flat feet increase the risk of knee osteoarthritis and contribute to frailty, which may lead to worse life prognoses. The influence of the foot skeletal structure on flat feet is not yet entirely understood. Footprints are often used to evaluate feet. However, footprint-based measurements do not reflect the underlying structures of feet and are easily confounded by soft tissue. Three-dimensional evaluation of the foot shape can reveal the characteristics of flat feet. Therefore, foot shape evaluations have garnered increasing research interest. This study aimed to determine the correlation between the three-dimensional (3D) features of the foot and the measurement results of footprint and to predict the evaluation results of flat feet from the footprint based on the 3D features. Finally, the three-dimensional characteristics of flat feet, which cannot be revealed by footprint, were determined. METHODS: A total of 403 individuals (40-89 years) participated in this study. The proposed system was developed to identify seven skeletal features that were expected to be associated with flat feet. The loads on the soles of the feet were measured in a static standing position and with a digital footprint device. Specifically, two footprint indices were calculated: the Chippaux-Smirak index (CSI) and the Staheli index (SI). In the analysis, comparisons between male and female measurement variables were performed using the Student's t test. The relationships between the 3D foot features and footprint index parameters were determined by employing the Pearson correlation coefficient. Multiple linear regression was utilized to identify 3D foot features that were strongly associated with the CSI and SI. Foot features identified as significant in the multivariate regression analysis were compared based on a one-way analysis of variance (ANOVA) with Tukey's post hoc test. RESULTS: The CSI and SI were highly correlated with the instep height (IH) and navicular height (NH) of the 3D foot scanning system and were also derived from multiple regression analysis. In addition to the NH and IH, the indicators of the forefoot, transverse arch width, and transverse arch height were considered. In the flat foot group with CSI values above 62.7%, NH was 13.5% (p < 0.001) for males and 14.9% (p = 0.01) for females, and the axis of the bone distance was 5.3% (p = 0.05) for males and 4.9% (p = 0.10) for females. In particular, for CSI values above 62.7% and NH values below 13%, the axis of the bone distance was large and the foot skeleton was deformed. CONCLUSIONS: Decreased navicular bone height could be evaluated with the 3D foot scanning system even when flat feet were not detected from the footprint. The results indicate that the use of quantitative indices for 3D foot measurements is important when evaluating the flattening of the foot. Trial registration number UMIN000037694. Name of the registry: University Hospital Medical Information Network Registry. Date of registration: August 15, 2019.

Agreement between clinical measures to classify foot posture in asymptomatic adults.

BACKGROUND: Various clinical measures of static foot posture have been developed and used. However, consensus among clinical measures to classify foot posture remains to be established. Therefore, this study aimed to determine the level of agreement as a reliability component between two common clinical methods in asymptomatic adults: the normalised navicular height truncated (NNHt) and the Foot Posture Index-6 (FPI-6). METHODS: The NNHt and FPI-6 were conducted on 102 asymptomatic adults. The measurement sequence was randomly arranged for each participant. Weighted Kappa (Kw) was used to determine the agreement between the methods. RESULTS: Both the NNHt and FPI-6 achieved similar foot posture distributions: approximately 40-50% of the participants had a normal foot, approximately 40% had a pronated foot and approximately 10-20% had a supinated foot. The agreement between the methods to classify foot posture was excellent (Kw = 0.84). CONCLUSIONS: The present study found excellent agreement between two commonly used clinical measures. This finding highlights the NNHt and FPI-6 consensus for foot posture classification in asymptomatic adults.

Kinematic Effect on the Navicular Bone with the Use of Rearfoot Varus Wedge.

BACKGROUND: The rearfoot varus wedge (RVW) is a common treatment for foot pain and valgus deformity. There is research on its effects in the calcaneus, but there is little research on the navicular. More research is needed with the use of RVW due to the relationship that exists between the position of the navicular and the risk of suffering an injury. OBJECTIVES: this study sought to understand how RVW can influence the kinematics of the navicular bone, measuring their movement with the 6 SpaceFastrak system. METHODS: a total of 60 subjects participated in the study. Two sensors were used to measure the movement of the calcaneus and navicular using RVWs as compared in the barefoot position in a static way. RESULTS: there were statistically significant differences, the use of RVWs caused changes in the navicular bone, with subjects reaching the maximum varus movement with the use of RVW 7 mm of 1.35 ± 2.41° (p < 0.001), the maximum plantar movement flexion with the use of RVW 10 mm of 3.93 ± 4.44° (p < 0.001). CONCLUSIONS: when RVWs were placed under the calcaneus bone, the navicular bone response was in varus movement too; thus, the use of rearfoot varus wedge can influence the movement of the navicular bone.

Plantar Venous Pump Activity, Generalized Joint Hypermobility, and Foot Mobility in Ballerinas: A Case-Control Study.

CONTEXT: The plantar venous pump (PVP) is a vascular network located between the muscles of the foot arch. It has been suggested foot mobility is critical for PVP activation. OBJECTIVE: This study investigates the effect of generalized joint hypermobility (GJH) on foot mobility and PVP activity in ballerinas and to determine how a short-term warm-up exercise impacts these parameters in the presence of GJH. DESIGN: Prospective study. METHODS: Twelve ballerinas (age = 16.73 [1.8] y) and 15 non-dancer-matched controls (age = 16.31 [2.1] y) were included. When performing weight-bearing activities, venous return parameters (diameter, velocity, and flow volume) from the posterior tibial vein were measured using color and spectral Doppler ultrasonography. Foot mobility was determined using navicular drop test. The participants performed a 10-minute cycling exercise to reveal its effect on reducing tissue stiffness. All measurements were performed synchronously and twice-before and after the cycling exercise. RESULTS: The results showed the navicular height obtained before and after exercise in the ballerinas was significantly different compared with that obtained in the sitting position, and the values obtained in the 3 measurement positions in the nondancer group were significantly different from each other (P < .05). The difference between the venous diameter values measured before and after exercise and the reference value was significant in both groups (P < .001). There was a significant decrease in venous velocity following exercise in the nondancer group (P = .044). The venous volume values obtained after exercise were significantly different between the groups (P = .039). CONCLUSIONS: The GJH has no distinctive effect on foot mobility and PVP activity in ballerinas. The presence of GJH did not influence the effect of short-term warm-up exercise on foot mobility and PVP activity. We believe that measuring the navicular drop and venous return with a more precise synchronization may provide additional information regarding the link between arch tension and venous return.

Validity of a simple footprint assessment board for diagnosing the severity of flatfoot: a prospective cohort study.

BACKGROUND: A simple, non-quantitative, and cost-effective diagnostic tool would enable the diagnosis of flatfoot without need for specialized training. A simple footprint assessment board that investigates which toe the cord passes through from the centre point of the heel to the most lateral point of the medial contour of the footprint has been developed to assess flatfoot. The purpose of this study was to verify the validity of a simple footprint assessment board for flatfoot. METHODS: Thirty-five consecutive patients with foot pain, foot injury, or any associated symptoms who underwent computed tomography (CT) were analysed prospectively. At the time of the CT scan, a footprint analysis using a simple footprint assessment board was performed. The navicular index, tibiocalcaneal angle, and calcaneal inclination angle were evaluated by CT to assess flat feet. These three criteria were compared to those evaluated with the simple footprint assessment board by regression analysis. In addition, the same analysis was conducted separately for young, middle-aged, and older patients in order to investigate each age group. RESULTS: The navicular index and tibiocalcaneal angle generally decreased as the score of the simple footprint assessment board increased. Calcaneal inclination angle generally increased as the score of the simple footprint assessment board increased. As the scores of the simple footprint assessment board decreased by approaching the great toe, the navicular index and tibiocalcaneal angle were higher and calcaneal inclination angle was lower, which is indicative of a higher likelihood of flatfoot. The scores derived from the simple footprint assessment board was correlated with these three criteria measured by CT, not only when the result of simple footprint assessment board was set as a non-continuous variable but also when the result was set as a continuous variable. The results of the age-stratified survey were similar for all groups. CONCLUSIONS: The findings of this study suggest that a simple footprint assessment board can be potentially useful to detect flatfoot. TRIAL REGISTRATION: Retrospectively registered.

Increase in foot arch asymmetry after full marathon completion.

Long-distance running results in lowering of the foot medial longitudinal arch, but it is unknown whether the left and right arches decrease equally. This study aimed to determine whether foot arch asymmetry increases upon completion of a full marathon and to identify factors capable of explaining the degree of asymmetry of navicular height and navicular height displacement. The three-dimensional foot posture data of 74 collegiate runners were obtained using an optical foot scanner system before (PRE) and immediately after (POST) a full marathon. The navicular height and arch height ratio (normalised navicular height by foot length) of both feet significantly decreased from PRE to POST full marathon completion (44.3 ± 6.3 mm versus 40.8 ± 6.5 mm, 17.8 ± 2.5 versus 16.6 ± 2.7, respectively; p < 0.001, both). The asymmetry of the arch height ratio was significantly greater POST than PRE marathon. Multiple linear regression analysis indicated that the POST-race Asymmetry Index (AI) of navicular height was significantly predicted by the PRE-race AI of navicular height; navicular height displacement was predicted by PRE-race navicular height and the marathon time. Full marathon running induced increasing asymmetry and lowering of the medial longitudinal arch in runners.

Return to sport following navicular stress fracture: a systematic review and meta-analysis of three hundred and fifteen fractures.

PURPOSE: This meta-analysis aims to provide updated evidence on the success rate, return to play (RTP) rate, time to RTP, and complications of operatively and conservatively managed navicular stress fractures (NSFs) as well as delays in diagnosis while avoiding limitations of previous similar studies. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, two independent team members electronically searched MEDLINE (PubMed), EMBASE, Google Scholar, SCOPUS, and Cochrane databases throughout February 2021 using the following keywords with their synonyms: "Navicular stress fracture," "return to play," and "athletes." The primary outcomes were (1) management success rate, (2) RTP rate, and (3) time to RTP. The secondary outcomes were (1) non-union, (2) time to diagnosis, (3) refracture, and (4) other complications. Inclusion criteria were clinical studies on NSFs reporting at least one of the desirable outcomes. Studies not reporting any of the outcomes of interest or the full text was not available in English, German, French, or Arabic were excluded. Case reports, case series with less than ten cases, and studies reporting exclusively on navicular non-union management were also excluded. The Newcastle-Ottawa scale was used for quality assessment while Review Manager (RevMan) Version 5.4 was used for the risk of bias assessment. Data were presented by type of treatment (surgical or conservative). If enough studies were present that were clinically and statistically homogeneous and data on them adequately reported, a meta-analysis was performed using a fixed-effects model. In case of statistical heterogeneity, a random-effects model was used. If meta-analysis was not possible, results were reported in a descriptive fashion. The need to explore for statistical heterogeneity was determined by an I2 greater than 40%. RESULTS: Eleven studies met the inclusion criteria with a total of 315 NSF. Out of those, 307 (97.46%) NSFs were in athletes. One hundred eight (34.29%) NSFs were managed operatively, while 207 (65.71%) NSFs were managed conservatively. Successful outcomes were reported in 104/108 (96.30%) NSF treated operatively with a mean success rate of 97.9% (CI: 95.4-100%, I2 = 0%). Successful outcomes were reported in 149/207 (71.98%) NSF treated conservatively, with a mean success rate of 78.1% (CI: 66.6-89.6%, I2 = 84.93%). Successful outcome differences were found to be significant in favor of operative management (OR = 5.52, CI: 1.74-17.48, p = 0.004, I2 = 4.6%). RTP was noted in 97/98 (98.98%) NSF treated operatively and in 152/207 (73.43%) NSF treated conservatively, with no significant difference between operative and conservative management (OR = 2.789, CI: 0.80-9.67, p = 0.142, I2 = 0%). The pooled mean time to RTP in NSF treated operatively was 4.17 months (CI: 3.06-5.28, I2 = 92.88%), while NSF treated conservatively returned to play at 4.67 months (CI: 0.97-8.37, I2 = 99.46%) postoperatively, with no significant difference between operative and conservative management (SMD = - 0.397, CI: - 1.869-1.075, p = 0.60, I2 = 92.24). The pooled mean duration of symptoms before diagnosis was 9.862 (3.3-123.6) months (CI: 6.45-13.28, I2 = 94.92%), reported in ten studies. Twenty (23.53%) refractures were reported after conservative management of 85 NSFs, while one (1.28%) refracture was reported after operative management of 78 NSFs, with a significant difference in favor of operative management (OR = 0.083, CI: 0.007-0.973, p = 0.047, I2 = 38.78%). CONCLUSION: Operative management of NSF provides a higher success rate, a lower refracture rate, and a lower non-union rate as compared to other non-operative management options. While not significant, there is a notable trend towards superior RTP rates and time to RTP following operative management. Therefore, we recommend operative fixation for all NSFs type I through III in athletes. Athletes continue to exhibit an alarmingly long duration of symptoms before diagnosis is made; a high index of suspicion must be maintained, therefore, and adjunct CT imaging is strongly recommended in the case of any work-up. Unfortunately, the published literature on NSFs remains of lower level of evidence and high-quality studies are needed.

Atypical Presentation of Navicular Aneurysmal Bone Cyst in a Symptomatic Pediatric Flatfoot Deformity: A Case Report.

Aneurysmal bone cysts (ABCs) are rare in the foot, accounting for 4% to 6.3% of all ABCs found in the body. Approximately 80% of patients diagnosed with an ABC are in the second decade of life. While benign, pain and deformity are often the presenting symptoms. This report's objective is to describe, to our knowledge, the first reported case of a pediatric navicular ABC in association with pediatric flatfoot deformity that was successfully treated with curettage and bone grafting. An additional goal of the report is to highlight how the diagnosis of these osseous tumors can easily be missed given the overlap in symptoms with pediatric flatfoot deformity. An 11-year-old female presented to clinic with a chief complaint of painful, flatfoot deformity and discomfort to the medial midfoot after walking for more than 2 city blocks. The patient was conservatively treated for pediatric flatfoot deformity at an outside institution and advised that a surgical flatfoot reconstruction would be necessary to relieve her symptomology. On examination, the patient exhibited focal pain to the medial aspect of the navicular. Radiographs revealed an ill-defined, expansile, sclerotic lesion of the navicular, and MRI demonstrated a multicystic lesion filling the navicular, consistent with an ABC. Treatment included curettage and packing with allograft. At 1-year follow-up, the patient is well, with minimal pain and return to full activity without functional limitations. Local recurrence of an aneurysmal bone cyst following curettage and bone grafting is as high as 22% with patient age and lesion size comprising the main risk factors. This report demonstrates successful curettage of an ABC within the navicular and preservation of osseous articulations in a pediatric patient. At 1-year follow-up, the patient had minimal pain with no evidence of recurrence.