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.

Lateral Heel Pain Caused by Impingement of Hypertrophic Peroneal Tubercle and Os Peroneum

Hypertrophic peroneal tubercle (HPT) is an overgrowth of the peroneal tubercle located on the lateral aspect of the hindfoot, which could cause tenosynovitis of the peroneus longus tendon. Os peroneum (OP) is an accessory ossicle that exists in the peroneus longus tendon at the lateral aspect of the calcaneocuboid joint. Both HPT and OP can cause lateral foot pain and occasionally require surgical treatment. We encountered a case of lateral foot pain of HPT coexisting with OP. Careful preoperative magnetic resonance imaging, dynamic ultrasonographic image, and block injection suggested an impingement of HPT and OP as a cause of lateral foot pain. Surgical resection of HPT, while retaining OP, successfully achieved pain relief in the patient. To the best of our knowledge, this is the first report presenting a case of HPT coexisting with OP successfully treated without OP resection.

Pathologies of the Peroneals: A Review

Peroneal tendon disorders remain an often overlooked source of lateral hindfoot pain and tenderness. Medical professionals who specialize in foot and ankle care are still far more likely to diagnose a peroneal tendon disorder as an ankle injury. In fact, acute peroneal dislocations are misdiagnosed in up to 40% of cases. The major subsets of peroneal disorders include peroneal tendonitis and tenosynovitis, painful os peroneum syndrome, subluxation, and tearing of the peroneal tendons. Proper history and physical exam maneuvers must be performed to help identify the source of the injury and differentiate these categories. Detailed imaging through X-ray and magnetic resonance imaging must also be used to diagnose the etiology of the patient’s condition in order to direct management. Currently, there is very limited knowledge on peroneal pathologies, and treatment protocol is highly variable and limited to expert opinion. Despite the individual preferences and nuances held by each surgeon when it comes to operating, the overarching principles that guide appropriate management of tendonitis, subluxation, and tendon tear should maintain a higher level of consistency. Therefore, the authors of this review aim to elucidate the most current methods to diagnose these disorders as well as evidence-based practices for optimal management. Levels of Evidence: Level V