The symptomatic accessory navicular bone: a report and discussion of the clinical presentation

Relationship Between the of Type of Accessory Navicular Bone and Radiological Parameters of the Foot

BACKGROUND

In this study, we evaluated to the relationship between the type of accessory navicular bone (ANB) and radiological parameters of foot in patients with bilateral ANB of different types.

METHODS

Patients with bilateral ANB of different types participated in this study, from May 2019 to April 2020. Patient data, including age, sex, body mass index (BMI), and presence of symptoms were obtained. We aimed to compare the radiological parameters of both the feet for evaluate the differences from one another in patients with bilateral ANB of different types (one side type 1 and contralateral side type 2) because the foot angles may differ in each person. Seven radiographic parameters were measured, including calcaneal pitch angle, talocalcaneal angle, tibiocalcaneal angle, naviculocuboid overlap, talonavicular coverage angle, anteroposterior talo-first metatarsal angle, and the lateral talo-first metatarsal angle, which evaluated hindfoot, midfoot, and forefoot alignment.

RESULTS

Twenty patients (13 women and 7 men) with a mean age (and standard deviation) of 38.5 {plus minus} 12.3 years were included in the study. The patients had a mean height of 168.1 {plus minus} 7.1 cm, a mean weight of 77.2 {plus minus} 10.5 kg, and a mean BMI of 27.4 {plus minus} 4.3 kg/m2. There was no significant difference between type 1 and type 2 in all radiological parameters. There was no significant correlation between radiological parameters and age, BMI, or the presence of symptoms.

CONCLUSIONS

We found that the type of ANB had no effect on the radiological measurements of the foot in which we evaluate the parameters patients with bilateral ANB of different types. Additionally, age, BMI, and the presence of symptoms, also demonstrated no correlation with the radiological parameters of the foot.

How to increase the accuracy of the diagnosis of the accessory bone of the foot?

PURPOSE

The study was conducted to search for confident radiological signs in symptomatic cases of accessory bones. A normal accessory bone appearance on X-ray does not exclude that the accessory bone is the source of the discomfort; because of this, MRI examination can later be applied as part of the diagnosis.

METHODS

We retrospectively analysed cases of 64 patients with recognized 70 symptomatic accessory bones of the foot. The average age was 29.2 (range 8-42) years. We included only patients with X-ray and MRI examinations. We investigated the following radiological features of the bone (structural and signal) in relation to soft tissue.

RESULTS

The most constant symptoms identified in our study were bone marrow oedema (93%) and soft tissue oedema (77%). Changes in structures in which accessory bones were located or in adjacent structures to accessory bone were identified: tendon changes 51%, fluid adjacent to bone 51% and tenosynovitis 46%. MRI revealed changes in bone structure that are not seen on X-ray, including changes in contour (28%), sclerosis (3%) or osteonecrosis (3%).

CONCLUSIONS

MRI plays an important role in determining whether accessory bones cause symptoms because it shows specific and accurate changes in accessory bone and/or in adjacent soft tissue.

Accessory Navicular is Associated With Wider and More Prominent Navicular Bone in Pediatric Patients by Radiographic Measurement

BACKGROUND

Accessory navicular (AN) is a common anatomic variant that is known to cause medial foot pain. Surgery may be required for excision if conservative measures fail. Often, the medial border of the navicular is excised in addition to the AN during surgery. The purpose of this radiographic study is to determine if the presence of an AN is associated with a wider or more prominent navicular in pediatric patients compared with normal controls.

METHODS

This study included pediatric patients who received an initial plain anteroposterior foot radiograph between January 1, 2004 and December 31, 2012 and were between the ages of 10 and 20 years. Feet with an AN were compared with those without, while controlling for age. Male and female patients were analyzed independently. Feet with fractures, deformities, or previous surgeries were excluded. Radiographic measurements included the navicular width and the protrusion of the navicular bone medially.

RESULTS

A total of 592 feet were included. An AN was identified in 73 feet. Male patients were analyzed separately from females. Cases with 1 AN bone had similar-sized native navicular bones in the contralateral normal foot compared with controls with 2 normal feet (P>0.05). The presence of an AN was associated with a larger navicular width (male: P=0.02, female: P=0.02) and a larger medial protrusion percent (male: P<0.01, female: P<0.01). Age was controlled for.

CONCLUSION

On radiographic examination, feet with an AN had wider native navicular bones that protruded more medially than feet without an AN.

LEVEL OF EVIDENCE

Level IV-diagnostic.

Incidence and anatomical variations of accessory navicular bone in patients with foot pain: A retrospective radiographic analysis

The accessory navicular (AN) is an accessory ossicle anatomically located on the medial side of the foot, proximal to the navicular and continuous with the tibialis posterior tendon. It is occasionally a source of pain and local tenderness. Knowledge of the AN and its morphological variations can help identify the source of a patient's symptoms and prevent misinterpreting them as fractures. Foot radiographs from 1,240 patients who presented in two centers with chronic foot pain, or persistent pain developed after trauma, were retrospectively reviewed to determine the incidence and variations of the AN in relation to gender. The AN was found in 20.9% (259/1240). Among 259 feet with AN, Type 1 was identified in 25.4% (66/259), Type 2 in 42.4% (110/259) (20.0% (52/259) Type 2 A and 22.4% (58/259) Type 2B), and Type 3 in 32.0% (83/259). After 13 patients with incomplete medical records had been excluded, the remaining records showed that foot pain was associated with an AN in 10.6% of patients (26/246). In 1.2% of cases, two additional ossicles were found proximal to the navicular, possibly the result of multiple ossification centers that did not unite at the time of development. Patient symptomatology was related to the presence of an AN in 2% of patients with chronic foot pain. The AN could vary morphologically. Our data can enhance our diagnostic skills in detecting these ossicles. Clin. Anat. 30:436-444, 2017. © 2017 Wiley Periodicals, Inc.

Clinical Meaning of Hot Uptake on Bone Scan in Symptomatic Accessory Navicular Bones

INTRODUCTION

We analyzed clinical factors related to uptake on a Tc-99 m HDP bone scan of the accessory navicular (AN).

MATERIALS AND METHODS

We retrospectively reviewed patients who had been examined by an orthopedic surgeon and underwent bone scan due to suspected symptomatic AN. A three-point grading system was used to evaluate uptake on bone scan. Relationships between grade, symptoms, age, gender, symptom duration, and bone size were analyzed.

RESULTS

In total, 73 ANs (30 asymptomatic, 43 symptomatic) were enrolled. The majority of asymptomatic ANs had no uptake but some had grade 1 (n = 8) or 2 (n = 2) uptake. All asymptomatic ANs with uptake remained asymptomatic during follow-up. For the asymptomatic ANs, larger bones showed a higher grade. With a cut-off value of size ≤6.8 mm, there is no chance of uptake. All symptomatic ANs showed uptake on bone scan. For symptomatic ANs, larger size and shorter pain duration were related to a higher grade. Age, gender, and left-/right-sideness were not related to grade. Multiple regressions revealed that only uptake grade, not size or symptom duration, was the significant risk factor for a symptomatic AN. With a cut-off value of grade <1, a symptomatic AN could be ruled out with a negative predictive value of 100 %.

CONCLUSION

Bone scanning is useful for symptomatic ANs with a high negative predictive value. Higher grade is related to larger size and shorter pain duration. For asymptomatic ANs, grade was related to size but did not predict symptom development.

Incremental value of single photon emission tomography/computed tomography in 3-phase bone scintigraphy of an accessory navicular bone

Accessory navicular bone is one of the supernumerary ossicles in the foot. Radiography is non diagnostic in symptomatic cases. Accessory navicular has been reported as a cause of foot pain and is usually associated with flat foot. Increased radio tracer uptake on bone scan is found to be more sensitive. We report a case highlighting the significance of single photon emission tomography/computed tomography in methylene diphosphonate bone scan in the evaluation of symptomatic accessory navicular bone where three phase bone scan is equivocal.

Accessory navicular bone incidence in Chinese patients: a retrospective analysis of X-rays following trauma or progressive pain onset

BACKGROUND

Optimal treatment of symptomatic accessory navicular bones, generally asymptomatic 'extra' ossicles in the front interior ankle, remains debated.

OBJECTIVE

Incidence and type of accessory navicular bones in Chinese patients were examined as a basis for improving diagnostic and treatment standards.

METHODS

Accessory navicular bones were retrospectively examined in 1,625 (790 men and 835 women) patients with trauma-induced or progressive symptomatic ankle pain grouped by gender and age from August 2011 to May 2012. Anterior-posterior/oblique X-ray images; presence; type; affected side; modified Coughlin's classification types 1, 2A, 2B, and 3; and subgroups a-c were recorded.

RESULTS

Accessory navicular bones were found in 329 (20.2%) patients (143 men and 186 women; mean age, 47.24 ± 18.34, ranging 14-96 years). Patients aged 51-60 exhibited most accessory navicular bones (29.7%), with risk slightly higher in women and generally increasing from minimal 10.9% at ages 11-20 to age 51 and thereafter declining to 0.4% by age 90. The incidence was 41.6% for Type 1 (Type 1a: 9.1%, Type 1b: 15.5%, and Type 1c: 19.4%), 36.8% for Type 2 (Type 2Aa: 2.1%, Type 2Ab: 13.7%, Type 2Ac: 5.1%, Type 2Ba: 2.1%, 2Bb: 2.1%, and 2Bc: 11.6%), and 21.6% for Type 3 (Type 3a: 4.5%, Type 3b: 14%, and Type 3c: 3.0%).

CONCLUSIONS

Approximately one-fifth (20.3%) of ankle pain patients exhibited accessory navicular bones, with Type 2 most common and middle-aged patients most commonly affected. Thus, accessory navicular bones may be less rare than previously thought, underlying treatable symptomatic conditions of foot pain and deformity.

The incidence of accessory navicular bone types in Turkish subjects

Accessory ossicles are the skeletal variations of the ankle and foot that can cause painful syndromes. The accessory navicular bone is one of the most common accessory ossicle of the foot (4-21%) and is also known as os tibiale, os tibiale externum and os naviculare secundarium. This bone can be adjacent to the posteromedial tuberosity of the navicular bone or can be separated and may cause various diseases in the foot and mimic fractures of foot bones. The aim of this study was to document a detailed investigation of incidence and types of accessory navicular bones of Turkish subjects according to sex in both extremities. The accessory navicular bone was detected (11%) via the posterior-anterior radiographs of 650 subjects in the radiological examination. The incidences of accessory navicular bones were identified as 6.1-4.9% in female and male participants. Accessory navicular bones were classified into three groups as Type I, Type II and Type III and the incidences of these bones were determined as 3.3, 3.1, 4.6%, respectively. Each group was also divided into subgroups. The incidences of the subgroups are as Type Ia 0.6%, Type Ib 1.5%, Type Ic 1.2%, Type IIA/a 0.8%, Type IIA/b 0.4%, Type IIA/c 0%, Type IIB/a 1.1%, IIB/b 0.3%, IIB/c 0.5%, Type IIIa 1.5%, Type IIIb 1.4%, Type IIIc 1.7%. Finally, the types of accessory navicular bones were discussed and the imaging modalities for diagnosis were presented.