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.

Prevalence of Sesamoids and Accessory ossicles of the Foot: A Radiographic study of the Indian population and a literature review

The prevalence of accessory ossicles and sesamoids is widely variable.[1,4,5] These bones are normal variants and remain asymptomatic, usually overlooked or misdiagnosed.[1,6] These ossicles and sesamoids are involved in various diseases, including fractures, dislocations, degenerative changes. Others include osteonecrosis, osteoarthritis, osteochondral lesion, avascular necrosis, and impingement syndromes.

The Incidence of Accessory Ossicles of the Wrist: A Radiographic Study

Objective Accessory ossicles of the wrist are generally asymptomatic and detected incidentally as radiological findings. These bones are rarely symptomatic but can produce pain in cases of impingement or direct trauma. More frequently, these bones are misinterpreted as avulsion fractures in trauma patients, which may lead to unnecessary immobilization and overtreatment. The aim of this study is to determine the incidence of accessory ossicles of the wrist and also determine if the incidence is related to age, gender, or ongoing wrist pain. Materials and Methods A total of 1146 wrist radiographs were included in the study. All radiographs were analyzed for the presence of 20 different accessory ossicles of the wrist. Patients were also divided into two groups, as with and without accessory ossicle. Two groups were compared in terms of age, gender, and side. Results About 113 accessory ossicles were detected in 111 (9.7%) radiographs. The most common accessory ossicles were os triangulare and os ulnostyloideum, and the least common accessory ossicles were os gruberi and os praetrapezium. Patients who had accessory ossicle had a significantly higher age than those who did not have accessory ossicle. There was no significant difference between the patients with and without accessory ossicle in terms of gender and side. Conclusions The results of this study showed that the most common accessory ossicles in the wrist were os triangulare and os ulnostyloideum, and the incidence of accessory bones increased with age. Clinical Relevance Since accessory ossicles of the wrist can be confused with fractures in trauma patients and are frequently ignored in patients presenting with pain, it is very important to know the incidence and distribution of these ossicles. Therefore, this study is important, in that it provides potentially guiding anatomical data for clinicians in terms of diagnosis and management.

Painful Os Intermetatarseum: Abnormal MRI imaging findings

Accessory ossicles are a common incidental finding on imaging of the feet. Os intermetatarseum is one such ossicle. These mostly remain asymptomatic; however, pain syndromes associated with accessory ossicles are a known entity and the diagnosis of painful os syndrome should be considered in undifferentiated foot pain. Whilst use of imaging in the diagnosis of painful os syndromes of the foot is well substantiated, there is little available literature on the use of magnetic resonance imaging (MRI) in the diagnosis of painful os intermetatarseum. We report a case of painful os intermetatarseum with MRI findings that have not previously been described

Bone scan with SPECT/CT in children with complex foot and ankle pain: Initial experience of a paediatric tertiary referral centre

Purpose This study was designed to review the diagnostic yield of single photon emission computed tomography-computed tomography (SPECT/CT) in children with complex foot/ankle pain. Methods We reviewed the records of 33 patients with complex foot and ankle pain referred for SPECT/CT (36 scans) performed between 1st September 2009 to 30th September 2019. All patients had foot and ankle radiographs and 18 out of 33 patients had undergone magnetic resonance imaging (MRI) prior to SPECT/CT. The diagnostic contribution of SPECT/CT was established at the time of the scan during a multi-disciplinary team meeting. Results The patients’ mean age was 13.4 years (range six to 16.5 years) and 58% were female. In total, 18 patients had undergone previous surgical treatment. SPECT/CT was found to have decisive clinical value compared with radiographs and CT/MRI in 28 out of 36 cases. In ten patients it prompted surgical management (coalition excision, arthrodesis), in seven patients it redirected conservative management, in six patients it excluded other pathology and in five patients it showed additional/unexpected focal areas of mechanical stress, thus avoiding surgery. When compared with MRI, SPECT/CT added further clinical information in 13 out of 18 cases. SPECT/CT added decisive clinical value in five out of five patients with accessory ossicles, eight out of nine patients with tarsal coalition, five out of seven patients with surgically treated Congenital Talipes Equinovarus (CTEV) and four out of five patients with neuromuscular feet. In eight out of 36 cases SPECT/CT confirmed the diagnosis without adding significant information. Conclusions SPECT/CT can identify foci of active mechanical stress at cortical bone level in children with unexplained complex foot and ankle pain, particularly in the multiply operated foot, accessory ossicles and tarsal coalitions. Level of Evidence IV