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

Accessory navicular in children

Accessory navicular (AN) is a developmental variation of the secondary ossification center of the navicular tuberosity. Ten percent of patients with AN will have pain symptoms that affect walking and life. As the AN changes the position of the posterior tibial tendon insertion, children with AN often have posterior tibial tendon function insufficiency and flexible flat foot. Surgical treatment is often required after failure of conservative treatment. This article reviewed the etiology, clinical manifestations, complications, and treatment methods of AN.

A modified method for reconstruction of posterior tibial tendon after resection of juvenile painful type II accessory navicular

BACKGROUND

The surgical treatment of accessory navicular (AN) is divided into simple resection of AN and Kidner surgery used to reconstruct posterior tibial tendon (PTT) after AN resection. However, both of these procedures have certain disadvantages. Herein, we proposed a modified method to reconstruct PTT and compared the short-term clinical effect of our method with the modified Kidner procedure.

METHODS

We collected data from 23 adolescent children with painful type II AN treated in our department between January 2015 and June 2020. The American Orthopedic Foot and Ankle Society Ankle-Hind foot (AOFAS-AH) Scores, the Meary Angle, and Pitch Angle of the lateral weight-bearing plain radiographs status were recorded before and after the operation to evaluate the treatment outcomes.

RESULTS

In the modified Kidner surgery (MK) group, the median AOFAS-AH increased from 61 (59-68) to 87 (83-91) (P < 0.05); the Pitch angle of the lateral weight-bearing plain radiographs increased from 13.0 (8-18) to 17.4 (14-22), and the Meary angle decreased from 18.3 (14-24) to 14.2 (8-20) (P < 0.05). In the PTT preservation folded suture (FS) group, the median AOFAS-AH increased from 61 (59-68) to 87 (85-91) (P < 0.05); the Pitch angle of the lateral weight-bearing plain radiographs increased from 12.3 (7-18) to 18.4 (15-26), and the Meary angle decreased from 17.8 (13-23) to 5.7 (3-8) (P < 0.05). There was no significant difference in AOFAS-AH postoperative scores between the FS group and MK group; however, the improvement on Pitch and Meary angle of the lateral weight-bearing plain radiographs was significantly better in the FS group than in MK group (P < 0.05).

CONCLUSIONS

For painful type II AN in juvenile patients, the insertion-preserving folding suture procedure had similar short-term results on AOFAS-AH scores but greater improvement in the Meary angle and the Pitch Angle than the modified Kidner method.

LEVEL OF EVIDENCE

III.

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.

Prevalence and classification of accessory navicular bone: a medical record review

BACKGROUND

The accessory navicular bone (ANB) is one of the most common accessory bones in the foot. Certain pathologies, such as posterior tibial tendon insufficiency are associated with ANB, and should be differentiated from midfoot and hindfoot fractures such as navicular tuberosity avulsion fractures. There are few studies addressing the prevalence and types of ANB in Saudi Arabia.

OBJECTIVES

Determine the prevalence and morphological variations of ANB and its relation with age and sex in patients visiting foot and ankle clinics.

DESIGN

Medical record review SETTING: Orthopedic foot and ankle clinic at a university hospital.

PATIENTS AND METHODS

The presence of ANB was retrospectively analyzed in radiographs from patients who presented to the orthopedic foot and ankle at our university hospital from February 2010 to December 2020. The patients were stratified according to sex, age, and diagnosis. For each ANB, recorded information included site, size, classification, subtypes, and symptomatology. Purposive sampling was used to select the patients for the study (non-probability sampling).

MAIN OUTCOME MEASURES

Prevalence of ANB in patients attending a foot and ankle clinic.

SAMPLE SIZE

117 patients and 194 feet.

RESULTS

ANB was analyzed in 1006 radiographs from 503 patients. ANB was detected in 117 (23.3%) patients and 194 (19.3%) feet Prevalence was significantly higher in females (67.5%) than in males (32.5%) (Z=5.359, P<.001). The ages ranged from 19 to 86 years, with a mean age of 48.26 (14.5) years. The most common site was bilateral (77 patients, 65.8 %). Type I was the most common type, with a prevalence of 42.1%. There were no significant differences in types in relation to sex, but all types and subtypes differed significantly from each other.

CONCLUSION

ANB was common among patients presenting to the foot and ankle clinic, with an overall prevalence of 23.3%. It should be considered among the differential diagnosis in chronic foot pain, and should be differentiated from midfoot and hindfoot fractures. Further studies with a larger, randomized sample are needed, for more accuracy and to confirm the reported results.

LIMITATIONS

Retrospective chart review, non-probability sampling, and use of plain radiographs.

CONFLICT OF INTEREST

None.

The Incidence and Anatomic Variation of Os Naviculare in a Multiethinic Asian Population

The incidence of asymptomatic os naviculare ranges from 4% to 21%, varying between different ethnicities, with majority of studies performed in Caucasians. The aim of this study was to document the incidence of asymptomatic os naviculare in an Asian population stratified by ethnicity, and to characterize the features of each type. The records of all patients who underwent dorsoplantar and oblique foot radiographs between July and December 2017 were reviewed. We excluded patients with medial-sided foot pain. The radiographs of the remaining patients were reviewed and the incidence and type of os naviculare according to Coughlin's classification were recorded. About 439 patients were included. The overall incidence of asymptomatic os naviculare was 46.0%, of which 76.7% were bilateral. The prevalence of type Ia, Ib, and Ic os was 7.5%, 6.2%, and 5.9%, respectively. The prevalence of type IIAa, IIAb, IIAc, IIBa, IIBb, and IIBc was 2.7%, 0.7%, 0.2%, 16.6%, 5.9%, and 2.1%, respectively. The prevalence of type IIIa, IIIb, and IIIc was 1.1%, 8.4%, and 0.2%. Type IIBa had the highest prevalence of 16.6% out of 439 patients. The highest incidence of os naviculare was in the Chinese population (n = 145, p = .034) at 50.2%. There was no significant gender difference in the incidence of asymptomatic os naviculare. The incidence of asymptomatic os naviculare in a multiethnic Asian population is higher than that reported in other populations, and particularly in the Chinese. Type IIBa was the most prevalent type, which differs from previous reports. When treating patients of Chinse ethnicity who present with pain over the medial aspect of the foot, the diagnosis of a symptomatic os naviculare should be considered.

Risk Factors for Persistent Pain Requiring Surgical Treatment in Adult Symptomatic Accessory Navicular

OBJECTIVE

Identifying the risk factors for persistent pain despite proper conservative treatment in adult symptomatic accessory navicular may reduce the need for surgical treatment. The aim of this study was to identify any such risk factors.

DESIGN

Cohort study.

SETTING

University hospital foot and ankle clinic.

PATIENTS

A retrospective review of 313 patients who presented with adult symptomatic accessory navicular was performed.

ASSESSMENT OF RISK FACTORS

Potential risk factors were identified via medical records and foot radiographs. The possible risk factors included age, gender, body mass index, smoking status, occurrence/cause of symptoms, occupation, type of accessory navicular, and radiographic foot parameters.

MAIN OUTCOME MEASURES

Predictors that relate to persistent pain requiring surgical treatment in adult accessory navicular were analyzed using logistic regression analysis.

RESULTS

Of the 313 patients included, 30 (9.6%) underwent surgical treatment due to failure of conservative treatment. The odds of needing surgical treatment decreased by 0.96 per year of age at symptom onset (P = 0.030), but those odds were 8.52 times higher in patients who had a type IIB accessory navicular (P = 0.001). Other variables did not reach statistical significance.

CONCLUSIONS

Younger age at symptom onset and type IIB were the risk factors for persistent pain requiring surgical treatment in adult symptomatic accessory navicular.

Accessory Ossicles in the Region of the Foot and Ankle: An Epidemiologic Survey in a Jordanian Population

Background and Objectives: The incidence of accessory bones in the region of foot and ankle is quite variable between studies and are often confused with avulsion fractures in trauma patients with musculoskeletal injuries. The aim of this study was to assess the incidence of accessory ossicles of the foot and ankle according to gender, side and coexistence, and to determine how frequently accessory ossicles were misdiagnosed as avulsion fractures. Materials and Methods: Oblique and/or lateral foot radiographs of 1000 adult patients referred from emergency departments to foot and ankle clinic were retrospectively reviewed for the presence of accessory ossicles. The Kappa statistic was used in order to assess the validity of radiographic interpretation for the presence of these bones. Results: Accessory ossicles were detected in 40.2% of the radiographs. The incidence rates for the accessory ossicles in order of frequency were: Os trigonum (15.4%), accessory navicular (13.7%), os peroneum (11.5%), os vesalianum (1.1%), os supranaviculare (0.7%), os subfibulare (0.6%), os talotibiale (0.4%), os calcaneus secundarius (0.3%), os supratalare (0.3%), os infranaviculare (0.3%), os intermetatarseum (0.2%), and os subtibiale (0.1%). Coexistence of two or three ossicles in the same foot was observed in 4.4% of the cases, mostly coexistence with os peroneum (2.9%), followed by accessory navicular (1.6%). 2.7% of accessory ossicles were initially misdiagnosed as avulsion fractures at emergency departments. Interrater agreement over identification of different accessory ossicles was found to be reasonably reliable, with a Kappa greater than 0.80 for all assessed bones. Conclusions: In clinical practice, a thorough knowledge of normal anatomical variants is essential to facilitate appropriate diagnosis and treatment and can help to prevent diagnostic errors.

Fe Analysis of the Symptomatic Navicular - A Case Report

The accessory navicular (AN) is a bony formation located on the medial side of the foot, proximal to the navicular and continuous with the posterior tibialis tendon. It emerges as a developmental variant due to the presence of the secondary ossification center adjacent to the primary center of the navicular. It is regarded as a physiological and anatomical variant. In most instances, this is an incidental finding. Radiographic values are used to define three types of AN based on its relationship with the navicular. The symptomatic AN causes pain in the medial portion of the bone, a decreased range of motion and discomfort with shoe wearing. In case of recurrent symptoms, following an inadequate diagnosis and treatment, it can result in acquired flatfoot. Our case study examined the condition of asymptomatic AN in a young man with both flatfeet, who was initially treated conservatively, and then, after the failed response to the therapy, surgically. Following the Kidner procedure (excision with the reattachment of the insertion in the posterior tibialis tendon) and rehabilitation, the patient reports no subjective symptoms in the period of 12- month monitoring. An objective examination was conducted with the use of FE analysis during weight-bearing. We determined a reduction in total weight-bearing and the pressure distribution to the lateral side of the foot, metatarsal, and the heel region.

Literature Review of Anatomical Variations: Clinical Significance, Identification Approach, and Teaching Strategies

This article is a comprehensive literature review on anatomical variations, shedding some light on their clinical significance, identification approaches, and teaching strategies. Anatomical variation is a normal presentation of body structure with morphological features different from those that have been classically described in several anatomy textbooks. Under normal circumstances, it has no impact on the function of the structure. However, it may influence different aspects of clinical practice. As a result, accurate knowledge of common anatomical variations in the treated area may improve clinical practice outcomes. On the other hand, anatomical variations are usually identified during routine dissection and clinical practice, including preoperative imaging and surgical procedures. Additionally, scientific research, such as observational studies using cadaveric dissection, medical images, and evidence-based anatomy, are effective approaches to identify anatomical variations. With regard to the teaching of anatomical variations, cadaveric dissection is the most commonly used and recommended learning tool for teaching anatomy and relevant variations in medical schools. However, the literature emphasizes introducing anatomical variations in the clinical phase of medical curricula and postgraduate training of surgical and radiological programs. The current study suggests creating a registry of anatomical variations encountered during practice that may enhance best care and prevent any confusion about those variations. In addition, there is a need to conduct more educational studies to research the best learning strategies for teaching and assessing anatomical variations in the medical curricula.

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.

Adult Flat Foot With Multiple Accessory Navicular Bones Treated Surgically: A Case Report and Review of the Literature

Multiple accessory navicular bones is an extremely rare condition. To the best of our knowledge, only 8 cases in 2 imaging studies have been published. We report a case of a patient with flat foot with 2 accessory navicular bones. This patient needed to be treated surgically, and the surgery was successful, with short-term follow-up. We believe this is the first case of multiple accessory navicular bones to be treated surgically in English literature. The incidence of multiple accessory navicular bones might be higher. There is a risk to remaining ossicles without resection or fixation during surgery; therefore, we strongly recommend using not only radiographs, but also 3-dimensional computed tomography scans or magnetic resonance imaging scans to confirm the type of accessory navicular bone, at least before surgery, for both painful accessory navicular bone and flat foot with accessory navicular bone.

Anatomical variation in the ankle and foot: from incidental finding to inductor of pathology. Part II: midfooot and forefoot

Accessory anatomical structures in the ankle and foot usually represent incidental imaging findings; however, they may also eventually represent a source of pathology, such as painful syndromes, degenerative changes, be the subject of overuse and trauma, or appear as masses and cause compression syndromes or impingement. This review aims to describe and illustrate the imaging findings related to the presence of accessory ossicles and muscles in the midfoot and forefoot through different techniques, with special attention on those variants that associate factors of clinical relevance or that would trigger challenges in the differential diagnosis.

Accessory navicular syndrome as a cause of foot pain during stroke rehabilitation

Although usually asymptomatic, an accessory navicular bone can lead to medial foot pain, especially in younger people engaged in high impact sports. In many such cases, the tendon of posterior tibialis (which inverts and plantarflexes the foot) inserts onto the accessory bone resulting in greater strain on the tendon. In the present case, pain due to an accessory navicular bone first developed during stroke rehabilitation in a 69-year-old man. The relative overactivity of posterior tibialis in strokes involving the leg and overuse due to active rehabilitation were likely contributors. An accessory navicular syndrome should be considered as a cause of medial foot pain in patients following a stroke. As in our case, conservative management with rest, ice and elevation is usually successful.