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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. [ABSTRACT FROM AUTHOR]

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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. [ABSTRACT FROM AUTHOR]

The horse's navicular bone is located inside the hoof between the deep flexor tendon (DDFT) and the middle and end phalanges. The aim of this study was to calculate the stress distribution across the articular surface of the navicular bone and to investigate how morphological variations of the navicular bone affect the joint forces and stress distribution. Joint forces normalised to the DDFT force were calculated from force and moment equilibria from morphological parameters determined on mediolateral radiographs. The stress distribution on the articular surface was determined from the moment equilibrium of the stress vectors around the centre of pressure. The ratio of the proximal to the distal moment arms of the DDFT, as well as the proximo-distal position and extent of the navicular bone, individually or in combination, have a decisive influence on the position and magnitude of the joint force and the stress distribution. If the moment arms are equal and the bone is more proximal, the joint force vector originates from the centre of the joint surface and the joint load is evenly distributed. However, in a more distal position with a longer distal moment arm, the joint force is close to the distal edge, where the joint stress reaches its peak. Degenerative navicular disease, which causes lameness and pathological changes in the distal portion of the bone in sport horses, is likely to be more severe in horses with wedge-shaped navicular bones than in horses with square bones. [ABSTRACT FROM AUTHOR]

Les fractures de contrainte surviennent lorsque, en l'absence de véritable traumatisme, les contraintes mécaniques dépassent la résistance osseuse. On distingue les fractures de stress ou de fatigue qui se produisent par excès de sollicitation mécanique sur un os normal, comme cela arrive dans tout matériau, et les fractures par insuffisance osseuse qui surviennent pour des efforts banals sur un os lui-même fragile du fait d'une ostéopathie sous-jacente. Le pied et la cheville sont une des localisations les plus fréquentes des fractures de fatigue, moins courante que d'autres sites pour ce qui est des fractures par insuffisance osseuse. Elles peuvent survenir sur n'importe quel os de la cheville ou du pied, les plus fréquentes étant celles des métatarsiens. Le diagnostic est fortement suspecté devant une douleur assez localisée de rythme mécanique et d'installation rapidement progressive dans un contexte favorisant : milieu sportif ou militaire pour les fractures de fatigue, facteurs de risque d'ostéopathie fragilisante pour les fractures par insuffisance osseuse. La radiographie est peu sensible et le diagnostic pourra reposer sur la scintigraphie osseuse, l'échographie ou surtout l'IRM. La prévention a un rôle important en milieu sportif ou militaire en adaptant l'entraînement, le matériel, en dépistant des symptômes évocateurs de la triade de l'athlète. Le traitement de la fracture elle-même repose dans tous les cas sur la restriction d'appui. Elle sera plus importante avec parfois même un traitement chirurgical d'emblée dans les localisations à haut risque de retard de consolidation ou de pseudarthrose, qui sont la base du 5e métatarsien, le naviculaire, la malléole médiale, les sésamoïdes. Stress and insufficiency fractures occur in the absence of significant trauma when mechanical loads overcome bone resistance. Stress fractures occur on normal bone upon excessive solicitations, mainly in athletes or military recruits, whereas insufficiency fractures occur during normal occupations on a bone fragilized by an underlying condition such as osteoporosis. Foot and ankle are very common sites for stress factures and to a lesser extent for insufficiency fractures. Any foot or ankle bone may be affected, the most common location being metatarsal bones. Diagnosis should be addressed in presence of rapidly progressive and localized pain at weight-bearing in predisposed patients: high sports practice or military training for stress fractures, risk factors of fragilizing bone disease for insufficiency fractures. Plain radiographs are poorly sensitive, and diagnosis often will require bone scintigraphy, ultrasound or mainly MRI. There is a large place for prevention of stress fractures, by training or devices adaptation and screening of signs of the athlete's triad. Fracture treatment always necessitates weight-bearing restriction for several weeks. This will be even more strict and prolonged, with sometimes desirable preventive surgery in the case of high-risk fractures for delayed or non-union, namely the fifth metacarpal proximal part, navicular bone, medial malleola and sesamoids. [ABSTRACT FROM AUTHOR]

Copyright of Foot Medicine & Surgery / Medecine et Chirurgie du Pied is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Simple Summary: Lameness originating from the distal thoracic limb is common in horses and is often due to damage to the soft tissue structures in the heel region. The hoof capsule limits access to this region with ultrasound, and the scan approach can be technically challenging. However, because ultrasound is more readily available and less expensive than MRI, it is often used to assess injuries in this area. We compared ultrasound and high-field MRI findings of the palmar digit of 45 horses. MRI was considered the gold standard for the lesions. We found that ultrasound was a useful screening tool for assessing damage to the deep digital flexor tendon but risked overdiagnosing injuries. It also risks underdiagnosing injuries to other soft tissues in the palmar digit region. Damage to the soft tissue structures of the digit is a common source of equine lameness. While magnetic resonance imaging (MRI) allows for the most complete diagnostic imaging of the equine digit, ultrasound is more readily available and less expensive. This prospective diagnostic accuracy study compares ultrasound to MRI for the diagnosis of injuries visible with ultrasound within the digit, including the deep digital flexor tendon (DDFT), collateral sesamoidean ligament (CSL), and navicular bursa. Clinical patients underwent an MRI of the digit and a blinded ultrasound of the digit between the heel bulbs, and results of the two modalities were compared. A total of 70 ultrasound and MRI exams of 45 horses were included. Ultrasound had good sensitivity (85%), moderate specificity (60%), and accuracy of 70% for evaluating the dorsal tearing of the DDFT. Accuracy was lower for navicular bursa effusion (67%), navicular bursa proliferation (61%), and CSL enlargement (61%). Tearing of the DDFT distal to the navicular bone was identified with MRI in 27 limbs, 20 of which also had dorsal damage proximal to the navicular bone identified with ultrasound. Ultrasound evaluation remains a useful screening tool, particularly for the assessment of DDFT tearing proximal to the navicular bone but risks under-diagnosing pathology to the navicular bursa and CSL. Clinically significant concurrent damage to the distal DDFT and other osseous and soft tissues in the hoof capsule is unlikely to be identified without MRI. [ABSTRACT FROM AUTHOR]

Osseous cyst-like lesions belong to the recurrent findings in the locomotor system of the horse. Their cause is still not clearly understood. Their significance in the diagnosis of lameness is also difficult to determine. The objectives of the present study were to investigate the frequency of occurrence of osseous cyst-like lesions in the equine hoof and to compare radiographic and magnetic resonance imaging findings. In addition, the characteristics of the different osseous cyst-like lesions should be presented in relation to the clinical symptoms. In this study, 195 limbs of 176 horses were analyzed. Horses with radiographic suspicion of an osseous cyst-like lesion in the coffin joint or navicular bone were included and those horses in which this was confirmed or refuted. For the control group, all horses in the period that did not show any deviating findings in radiographic and MRI examinations were also recorded. Actual osseous cyst-like lesions were present in 109 limbs of 103 horses. Group 1 included 71 limbs of 68 lame horses with osseous cyst-like lesions in the coffin bone, middle phalanx or navicular bone that had positive anesthesia. Group 2 included 27 limbs of 26 horses with osseous cyst-like lesions that did not receive anesthesia. Group 3, which included 11 limbs from 11 horses, included sound horses with osseous cyst-like lesions in the coffin bone, middle phalanx or navicular bone. Of these 11 horses, 2 horses were already included in group 1 with a lame limb. Group 4, which included horses that had a suspected osseous cyst-like lesion on radiography that was not confirmed on MRI, included 19 limbs from 18 horses. In group 5, the control group without osseous cyst-like lesions and other findings in radiographic and MRI examination, 67 limbs of 55 horses were included. The age of the horses with osseous cyst-like lesions ranged from 1 to 22 years and was normally distributed (p=0.175). The majority of the patients were Warmbloods with 86 horses (82%). 12 patients (12%) belonged to Western horses, under which Paint Horses and Quarter Horses were grouped. For sport, 38 horses (37%) of the patient stock were used. For recreational use, there were 54 horses (52%). Of 109 osseous cyst-like lesions, 104 (95%) occurred on the forelimbs. The left forelimb was affected in 46% (49 horses) and the right forelimb in 49% (52 horses) of the patients. 28% of the osseous cyst-like lesions were found in the coffin bone and most commonly midsagittally, 21% in the middle phalanx and most commonly midsagittally, and 51% in the navicular bone, most commonly at the distal border. By MRI, these could be assigned predominantly to the flexor cortex (93%). The most common form appeared circular (65%) with a sclerotic rim (94%). Among these, the osseous cyst-like lesions in the coffin joint had more frequent communications with the joint (77%) than those of the navicular bone (14%). The size of osseous cyst-like lesions in the coffin bone was often somewhat overestimated radiographically and those in the navicular bone underestimated. Osseous cyst-like lesions in the navicular bone were significantly more common in older horses (p=0.029) and in pleasure horses (p=0.02). The agreement of radiographic and MRI findings of osseous cyst-like lesions in the coffin bone could be classified as moderate (Ƙ=0.515). Thus, a sensitivity of 74.1% and a specificity of 77.9% can be determined for radiographic detection of osseous cyst-like lesions in the distal toe. 10% of horses with osseous cyst-like lesions were sound. 24% of the limbs with panesthesia had findings other than the osseous cyst-like lesion in the distal limb, so these were also omitted from the assessment of lameness severity because it could not be ruled out that the lameness was due to other findings. Lameness caused by the osseous cyst-like lesion was found in 52 limbs. The degree of lameness varied from grade 1 to grade 4. The size of osseous cyst-like lesion did not show any relation to the degree of lameness. 69% of the limbs with osseous cyst-like lesions showed bursitis in lame horses. The presence of bursitis, coffin joint filling, and deep digital flexor tendon lesion resulted in more severe lameness. Whereas the degree of sclerosis did not seem to have an effect on the degree of lameness. Overall, it can be concluded that osseous cyst-like lesions occur more frequently in the navicular bone than in other bones of the hoof. The horses are significantly older when these osseous cyst-like lesions occur. There were no correlations between lameness and characteristics of the osseous cyst-like lesions, while age and use showed correlations. [ABSTRACT FROM AUTHOR]

The combination of 18F‐Sodium Fluoride (18F‐NaF) and 18F‐FluoroDeoxyGlucose (18F‐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 18F‐NaF PET, 18F‐FDG PET, dual 18F‐NaF/18F‐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 18F‐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 18F‐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. [ABSTRACT FROM AUTHOR]

Osteoid osteoma is a benign bone tumour that causes significant nocturnal pain, cortical thickness and is relieved by salicylates. When it occurs, typical radiologic and clinical features are diagnostic. Radiography and computed tomography show a cortically based sclerotic lesion with a radiolucent nidus within it. The lesion usually involves long bones and most frequently presents in the diaphysis of the femur and tibia. Rare and unusually located lesions lead to misdiagnosis, even if the characteristic symptoms are present. We report an unusual case of osteoid osteoma in the tarsal navicular bone in which the diagnosis was delayed. This case, in which diagnosis was initially missed and treatment was delayed, resulted in a significant functional loss for the patient. A review of the literature revealed only two reported osteoid osteoma cases in the tarsal navicular bone. [ABSTRACT FROM AUTHOR]

The horse’s navicular bone is located inside the hoof between the deep flexor tendon (DDFT) and the middle and end phalanges. The aim of this study was to calculate the stress distribution across the articular surface of the navicular bone and to investigate how morphological variations of the navicular bone affect the joint forces and stress distribution. Joint forces normalised to the DDFT force were calculated from force and moment equilibria from morphological parameters determined on mediolateral radiographs. The stress distribution on the articular surface was determined from the moment equilibrium of the stress vectors around the centre of pressure. The ratio of the proximal to the distal moment arms of the DDFT, as well as the proximo-distal position and extent of the navicular bone, individually or in combination, have a decisive influence on the position and magnitude of the joint force and the stress distribution. If the moment arms are equal and the bone is more proximal, the joint force vector originates from the centre of the joint surface and the joint load is evenly distributed. However, in a more distal position with a longer distal moment arm, the joint force is close to the distal edge, where the joint stress reaches its peak. Degenerative navicular disease, which causes lameness and pathological changes in the distal portion of the bone in sport horses, is likely to be more severe in horses with wedge-shaped navicular bones than in horses with square bones.

Damage to the soft tissue structures of the digit is a common source of equine lameness. While magnetic resonance imaging (MRI) allows for the most complete diagnostic imaging of the equine digit, ultrasound is more readily available and less expensive. This prospective diagnostic accuracy study compares ultrasound to MRI for the diagnosis of injuries visible with ultrasound within the digit, including the deep digital flexor tendon (DDFT), collateral sesamoidean ligament (CSL), and navicular bursa. Clinical patients underwent an MRI of the digit and a blinded ultrasound of the digit between the heel bulbs, and results of the two modalities were compared. A total of 70 ultrasound and MRI exams of 45 horses were included. Ultrasound had good sensitivity (85%), moderate specificity (60%), and accuracy of 70% for evaluating the dorsal tearing of the DDFT. Accuracy was lower for navicular bursa effusion (67%), navicular bursa proliferation (61%), and CSL enlargement (61%). Tearing of the DDFT distal to the navicular bone was identified with MRI in 27 limbs, 20 of which also had dorsal damage proximal to the navicular bone identified with ultrasound. Ultrasound evaluation remains a useful screening tool, particularly for the assessment of DDFT tearing proximal to the navicular bone but risks under-diagnosing pathology to the navicular bursa and CSL. Clinically significant concurrent damage to the distal DDFT and other osseous and soft tissues in the hoof capsule is unlikely to be identified without MRI.

Objective: Navicular bone is a very important bone for foot movements. Although the risk of osteonecrosis is high in navicular bone fractures, anatomical studies are very rare because fractures are rare. The aim of this study is to describe the morphological and morphometric features of navicular bone reconstruction in the Turkish population. Methods: 100 (50 right, 50 left) dry os naviculare were measured. The length and width of the bone, groove length of the tibialis posterior tendon, the number of foramen nutricium, and the location of these foramina in palmar, dorsal, medial and lateral areas were measured. Additionally, area measurements of the joint surfaces were also made. Results: The length and width of the navicular bone were 38.11±2.15 mm and 23.15±1.75 mm. The length of the groove tibialis posterior tendon was 15.35±2.11 mm. A total of 729 nutrient foramina (280 dorsal, 238 plantar, 55 medial, 156 lateral) were measured. Conclusion: Navicular bone is important for foot movements and its anatomy should be well known in terms of reconstruction. For this reason, morphological and morphometric properties of bone are clinically important. We think that the measurements made together with the joint surface area can be used for reconstruction. [ABSTRACT FROM AUTHOR]

Midfoot injuries, encompassing navicular dislocations and fractures of the navicular bone, present unique challenges in trauma care. We report the case of a 27-year-old male who suffered a fall down a flight of stairs, resulting in navicular dislocation and multifocal fractures of the midfoot. The patient underwent a comprehensive management plan, including admission, closed reduction, and internal fixation with parallel K-wires. Radiological evaluations confirmed the extent of the injuries. Postoperatively, the patient received tailored care, incorporating pain management, antibiotics, and thromboprophylaxis. The successful outcome underscores the importance of a structured approach in addressing midfoot injuries, contributing to the existing literature on optimal management strategies. This case report serves as a valuable addition to the growing body of knowledge guiding clinicians in the effective treatment of navicular dislocations and navicular fractures., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Khan et al.)

Background: Fractures of the navicular bone are rare and the number of those treated surgically is even smaller. Moreover, scientific analyses on this topic are only sporadically present in the literature, therefore this retrospective and monocentric study was initiated., Methods: A total of 30 patients with 30 fractures were included. With the exception of one primary fusion, all patients underwent open reduction with internal osteosynthesis. Clinical and radiological follow-up was performed at least 2 years postoperatively using AOFAS-Score, SF-12 and a radiological examination. The primary objectives were the clinical and radiologic outcomes as mid-term to long-term outcomes. The secondary objective was to compare these results with two existing computed tomography (CT) fracture classifications in terms of their association with the outcome., Results: The median follow-up was 7.8 years (range 2-16.2 years) postoperatively. One patient suffered an infection, four patients required secondary arthrodesis and eight patients had to change their occupation. The mean AOFAS-Score was 80.8/100 and the mean physical and mental SF-12 component summary scores were 47.1 and 55.7 points, respectively. Male sex and arthrodesis were associated with worse outcomes in both scores but not patient age or ipsilateral concomitant injuries. Both CT fracture classifications showed low predictive value., Conclusion: The severity of the injury in the preoperative CT showed no connection with the clinical outcome in the AOFAS-Score and SF-12 scores. Posttraumatic osteoarthritis and secondary arthrodesis are associated with a poor outcome. In the course of the observational period the reduction results improved, which was accompanied by a better clinical outcome., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

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.

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., (© 2023 American College of Veterinary Radiology.)

Kohler's disease (KD) is a rare disorder of the foot in children where there is avascular necrosis of the navicular bone (NB). It presents with pain and limping and is often misdiagnosed as an infection. However, by adding single-photon emission computed tomography-computed tomography (SPECT-CT) of the foot, the lesion is localized to the NB, leading to the diagnosis of KD. We report the case of a 6-year-old boy with limping and foot pain, who underwent a bone scan using Tc-99m hydroxydiphosphonate and SPECT-CT of the feet. SPECT-CT was necessary not only to localize the exact site of the pathology in an area with small bones but also to confidently reach the diagnosis of KD and proceed with the correct management plan., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Indian Journal of Nuclear Medicine.)

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. [ABSTRACT FROM AUTHOR]