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.
METHODS: 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.
RESULTS: 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).
CONCLUSIONS: The classification of the navicular bone in this study may be helpful in making the treatment decision for navicular fracture.
METHODS: 4.

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.
CONCLUSIONS: 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.
UNASSIGNED: HINTERGRUND: Frakturen des Os naviculare sind selten, noch geringer ist die Anzahl derer, welche operativ versorgt werden. Wissenschaftliche Analysen hierzu sind zudem in der Literatur nur sporadisch präsent, weshalb diese retrospektive und monozentrische Studie initiiert wurde.
METHODS: Insgesamt 30 Patienten mit 30 Frakturen wurden eingeschlossen. Mit Ausnahme einer primären Arthrodese erhielten alle Patienten eine offene Reposition und interne Osteosynthese. Die klinisch-radiologische Nachuntersuchung erfolgte mindestens 2 Jahre postoperativ mittels AOFAS-Score, SF-12 sowie einer radiologischen Untersuchung. Primäres Ziel war das klinische und radiologische Ergebnis als mittel- bis langfristiges Outcome. Sekundäres Ziel war der Vergleich dieser Ergebnisse mit zwei bestehenden CT-Fraktur-Klassifikationen hinsichtlich ihres Zusammenhanges mit dem Outcome.
UNASSIGNED: Das mittlere Follow-up betrug 7,8 Jahre (Range 2 bis 16,2 Jahre) postoperativ. Ein Patient erlitt eine Infektion, 4 Patienten benötigten sekundär eine Arthrodese, und 8 Patienten mussten ihre berufliche Tätigkeit wechseln. Der mittlere AOFAS-Score betrug 80,8/100, der mittlere körperliche und psychische SF-12-Summen-Score betrug 47,1 resp. 55,7 Punkte. Männliches Geschlecht und Arthrodese gingen mit signifikant schlechteren klinischen Ergebnissen in beiden Scores einher, nicht aber Patientenalter oder ipsilaterale Begleitverletzungen. Beide CT-Fraktur-Klassifikationen zeigten einen geringen Zusammenhang mit beiden Scores.
UNASSIGNED: Das Verletzungsmuster im präoperativen CT zeigte keinen Zusammenhang mit dem klinischen Outcome im AOFAS-Score und im SF-12-Score. Posttraumatische Arthrosen und Arthrodesen gehen mit einem schlechten Outcome einher. Im Verlauf des Beobachtungszeitraumes konnten die Repositionsergebnisse verbessert werden; dies ging mit einem besseren klinischen Outcome einher.

Cubonavicular coalition is a rare congenital anomaly involving fibrous or osseous fusion between the cuboid and navicular bones. This case report presents a comprehensive analysis of a 10-year-old female patient with cubonavicular coalition, detailing the diagnostic challenges and tailored therapeutic interventions. The patient presented with persistent left foot pain and restricted range of motion. Clinical examination, radiographic studies, and magnetic resonance imaging confirmed cubonavicular coalition. Laboratory investigations ruled out systemic inflammatory processes. A multidisciplinary approach was adopted, initially employing nonsteroidal anti-inflammatory drugs and physical therapy. Surgical resection of the coalition was performed due to persistent symptoms, leading to successful outcomes. This case report contributes valuable insights into the clinical presentation, diagnosis, and management of cubonavicular coalition in pediatric patients. The successful outcome underscores the importance of a comprehensive and individualized approach, providing a basis for informed decision-making in similar cases. Continued research is essential to refine therapeutic algorithms and enhance understanding of rare musculoskeletal anomalies.

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.

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.
OBJECTIVE: To evaluate the morphometry and morphology of navicular bone.
METHODS: 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.
CONCLUSIONS: 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.

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.

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.

Tuberculosis of the bones and joints is a relatively rare entity, even in endemic countries. The disease is an outcome of a Mycobacterium tuberculosis infection. Tuberculosis of the small bones of the foot is extremely rare, requires a high index of suspicion for establishing the diagnosis, and is often associated with delayed diagnosis, ultimately affecting the treatment outcomes. Globally, tuberculosis of the navicular bone of the foot is an infrequently reported condition. We herein present a case of isolated tuberculosis of the navicular bone without pulmonary involvement. The patient reported complaints of pain and swelling in his left foot and underwent a detailed diagnostic workup. A final diagnosis was made with fine needle aspiration cytology, biopsy, culture, radiography, and magnetic resonance imaging (MRI). He was initiated on anti-tubercular chemotherapy for twelve months, with a substantial improvement in his symptoms. This case is very rare, as no such case with similar clinical features in this age group has ever been reported in the world.

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).
CONCLUSIONS: CBCT and FPI are reliable measurements of foot posture, with a high correlation between the two measurements.

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.