Prevalence of accessory ossicles and sesamoid bones in hallux valgus

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.

Relationship between medial partite hallux sesamoid and hallux valgus in the general population

BACKGROUND

An association between the medial partite hallux sesamoid (MPHS) and hallux valgus (HV) has been suggested; however, a causal relationship has not been confirmed. This study aimed to determine their causal relationship using a cross-sectional radiographic survey of a large-scale population cohort covering a wide age group.

PATIENTS AND METHODS

The fifth survey of the Research on Osteoarthritis/Osteoporosis against Disability study involved 1997 participants aged 21-95 years who had undergone anteroposterior radiography of bilateral feet. The presence of MPHS, its morphology, and radiographic parameters related to the HV were assessed using radiographs. Changes in the prevalence of MPHS with age were assessed using trend tests. The relationship between the MPHS and HV was assessed based on sex and age.

RESULTS

MPHS was found in 508 out of 3994 feet (12.7 %), with a significant difference in prevalence between men and women (10.0 % vs. 13.7 %, p < 0.001). Trend analysis demonstrated a significant decrease in MPHS occurrence with age in both sexes. HV angle was significantly higher in feet with MPHS than in those without (Men: 17.8 ± 7.0° vs. 14.0 ± 5.9°, p < 0.0001; Women: 19.6 ± 7.7° vs. 17.7 ± 7.9°, p < 0.0001). The prevalence of HV angle ≥ 20° was also significantly higher in feet with MPHS than in those without (Men: 33.3 % vs. 14.6 %, p < 0.0001; Women: 46.5 % vs. 34.6 %, p < 0.0001). This association between MPHS and HV was noticeable in younger adults and became less prominent with age.

CONCLUSIONS

MPHS is associated with HV. The weakening of this relationship and the decreased prevalence of MPHS with age suggest that MPHS is not caused by HV, but is one of the causes of HV, especially in younger adults.

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.

Heel pain caused by os subcalcis: A case report

BACKGROUND

The accessory bones are common bone variations around the feet and ankles, which usually originate from nonunion of the secondary ossification center adjacent to the main bone mass, and most of them remain asymptomatic. Os subcalcis is an accessory bone at the plantar aspect of the calcaneus, which is located just posterior to the insertion of the plantar fascia. Focal bone formation at the calcaneal plantar pole with heel pain has rarely been reported.

CASE SUMMARY

A 55-year-old man presented to our clinic with left plantar heel pain and a progressive swelling for 8 years. X-ray, computer tomography and magnetic resonance imaging showed a large os subcalcison the plantar side of the calcaneus, located at the insertion of the plantar fascia. He underwent surgical excision of the lesion. Microscopically the bony trabeculae were intermingled with fat and covered with cartilage.

CONCLUSION

This is a rare case with accessory os subcalcis leading to heel pain. It highlights the awareness of os subcalcis and helps avoid future misdiagnosis of heel pain.

Accessory Lesser Metatarsal Sesamoids in All of the Metatarsophalangeal JointsA Case Report

Lesser metatarsal sesamoids are one of the most common accessory bones of the foot and are most commonly seen at the fifth metatarsophalangeal joint. They are rarely seen in other metatarsophalangeal joints. In the literature, there are reports of solitary accessory sesamoid bones seen at lesser metatarsophalangeal joints. We report the case of a 68-year-old woman with lesser metatarsal sesamoids accompanying all of the metatarsophalangeal joints.

The sesamoids of the feet in humans: a systematic review and meta-analysis

The prevalence and distribution of the sesamoid bones in the feet has been reported in the literature with a high degree of variability. This systematic review aims to provide a better estimate of the frequency of the sesamoids of the foot and their association with variables such as ancestry, gender, and side. Thirty-seven studies met the inclusion criteria and were submitted for meta-analyses, sensitivity analyses and proportion difference tests, whenever possible. At the metatarsophalangeal (MTP) joint of the hallux, sesamoids were nearly always present. At the interphalangeal (IP) joint, the pooled true estimates of large-sampled studies were: (1) an overall prevalence of 22.4 %, (2) a cadaveric rate at 71.6 %, and (3) a radiological rate (based on X-ray images) of 21.1 %. The pooled partition frequencies of the hallucal medial and lateral sesamoids were 10.7 and 1.3 %, respectively. Bipartism was the most frequent partition type (92 %), followed by tripartism (7.5 %) and quadripartism (0.5 %). Middle Eastern ancestry was associated with significantly lower hallucal partition rate (P < 0.0001) and African ancestry with significantly lower prevalence of the IP sesamoid than all other ethnicities (P < 0.001). Feet with a hallux valgus deformity seemed to be associated with significantly higher rate of partition of the medial sesamoid (odds ratio = 3) than that of the normal feet. The respective values of the pooled true prevalence in adults at the MTP joint for the 2nd, 3rd, 4th and 5th toes were 1.9, 0.32, 0.9 and 13 %, respectively. There was a significantly higher prevalence of tibial sesamoids vs lateral sesamoids, with pooled odds ratio of 34.7, 8, 4.8, and 2.27, respectively. Partition was found in around 10 % of the sesamoids of the 5th MTP joint; no partition was noted in the other toes. For most 2nd-5th MTP joints, European ancestry showed the highest frequency whereas African ancestry showed the lowest; Middle Eastern ancestry was in between. No sesamoids were found at the 4th proximal IP joint and at the 4th and 5th distal IP joints. No sesamoids were found at any IP joint in the feet of Middle Eastern and African populations. The pooled rates of the IP sesamoids of the second and third toes in European populations were 1.2 % for the 2nd proximal, 0.33 % for the second distal and 0.6 % for both IP joints of the third toe. This anatomical meta-analysis yielded results that are likely to be more accurate regarding the rates of the sesamoids in the foot, their laterality and partition. It also provided solid evidence for the genetic basis of the frequency distribution among the different populations.