Evaluation and Management of Common Accessory Ossicles of the Foot and Ankle in Children and Adolescents

Four-Year Treatment Effect of Custom-Made Foot Orthosis on Pediatric Symptomatic Accessory Navicular Bone Combined with Flexible Flatfoot

Purpose

Congenital accessory navicular bone (ANB) is a common variant in the foot and is prone to cause several clinical symptoms. Wearing custom-made foot orthosis is considered a desirable option; however, there is limited evidence of its effectiveness. This study aims to report the mid-term effect of foot orthosis for symptomatic pediatric ANBs.

Methods

School-age children with symptomatic ANBs combined with flexible flatfoot in the authors' institute were recruited and got custom-made foot orthosis treatment. They were followed up over 4 years. The general characteristics of these children were collected before treatment, including age, gender, and body mass index (BMI). The indicators of foot symptoms, including frequency and location of pain, visual analogue scale (VAS), arch index (AI), and hind foot valgus angle (HVA), were measured during pretreatment and at the last follow-up.

Results

Twenty-seven children were recruited for this study. After 4 years of custom-made foot orthosis treatment, significant improvements showed in pain frequency, VAS, AI, and HVA (P < 0.001). Type II ANBs showed a higher pain index pretreatment (P < 0.001) and reduced after treatment (P < 0.001).

Conclusion

Mid-term effect of custom-made foot orthosis is inspiring in clinical symptoms of pediatric congenital ANBs combined with flexible flatfoot and may be an optional nonoperative treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-024-01210-7.

Pediatric Foot: Development, Variants, and Related Pathology

Pediatric foot development throughout childhood and adolescence can present a diagnostic dilemma for radiologists because imaging appearances may be confused with pathology. Understanding pediatric foot development and anatomical variants, such as accessory ossification centers, is essential to interpret musculoskeletal imaging in children correctly, particularly because many of these variants are incidental but others can be symptomatic. We first briefly review foot embryology. After describing common accessory ossification centers of the foot, we explain the different patterns of foot maturation with attention to irregular ossification and bone marrow development. Common pediatric foot variants and pathology are described, such as tarsal coalitions and fifth metatarsal base fractures. We also discuss pediatric foot alignment and various childhood foot alignment deformities.

Imaging of sports injuries in adolescents

Musculoskeletal injuries in adolescents tend to occur in particular locations and have distinct characteristics, as they affect an immature skeleton. Increased engagement in sports, extended training and competition periods, and early specialization in specific sports, among other factors, have contributed significantly to the rise in musculoskeletal sports injuries in adolescents. Furthermore, females show a particularly pronounced increase in sports participation, where anatomical and hormonal factors play crucial roles in the development and increased frequency of sports-related injuries. Consequently, there is a growing demand for diagnostic imaging techniques. Musculoskeletal and pediatric radiologists require a comprehensive understanding of intrinsic and extrinsic risk factors and the successive stages of skeletal development that can influence the specific characteristics of sports injuries in adolescents. These aspects are crucial for the diagnostic, prognostic, and therapeutic management of these injuries and for mitigating chronic conditions that could compromise future sports participation. This review analyzes the primary musculoskeletal injuries in adolescent athletes and highlights the pivotal role of different imaging methods in their diagnosis and management.

Surgical treatment of ankle instability in children with os subfibulare

INTRODUCTION

Ankle instability in children due to soft tissue injury usually resolves after non-operative treatment. However, some children and adolescents with chronic instability require surgical treatment. A rarer cause of developing ankle instability is injury to the ligament complex in the presence of os subfibulare, an accessory bone inferior to the lateral malleolus. The aim of this study was to assess the results of operative management of chronic ankle instability in children with os subfibulare.

MATERIALS AND METHODS

16 children with os subfibulare and chronic ankle instability who failed non-operative treatment were enrolled prospectively into the study. One child was lost to follow-up and excluded from analysis. The mean age at the time of the surgery was 14 years and 2 months (range 9.5-17 years). The mean follow-up time was 43.2 months (range 28-48 months). Surgical treatment in all cases involved removal of os subfibulare and a modified Broström-Gould lateral complex reconstruction with anchors. Ankle status was assessed before and after surgery with The 100 mm Visual Analogue Scale and Foot and Ankle Outcome Score questionnaire.

RESULTS

The mean Foot and Ankle Outcome Score improved from 66.8 to 92.3 (p < 0.001). Pain level improved from 67.1 preoperatively to 12.7 (p < 0.001). All children reported improvement in their ankle stability. There was one case of scar hypersensitivity that improved during observation and one superficial wound infection that resolved with oral antibiotics. One child reported intermittent pain without symptoms of instability following another injury.

CONCLUSIONS

Ankle joint sprain with associated injury to os subfibulare complex can lead to chronic instability in children. If conservative management fails, then surgical treatment with modified Broström-Gould technique and excision of accessory bone is a safe and reliable method.

Surgical outcome of avulsion fractures of the distal fibula: a systematic literature review

PURPOSE

To provide a systematic overview of clinical and radiographic outcomes in patients who underwent surgical treatment of a painful avulsion fragment of the distal fibula also known as posttraumatic os subfibulare.

METHODS

A systematic literature search across two major sources (PubMed and Scopus) was performed. Twenty-seven studies were included and analyzed using the modified Coleman score to assess the methodologic quality.

RESULTS

The surgical treatment of symptomatic os subfibulare, with or without concomitant ankle instability, generally results in substantial improvement in clinical and radiographic outcomes with relative low complication rates. Clinical outcome measures may not be affected by the presence of ankle instability or by the fragment size. The methodological quality of analyzed studies was satisfactory.

CONCLUSION

Posttraumatic os subfibulare may result in chronic pain and ankle instability. If surgery is indicated, ankle instability should be concomitantly addressed when present. Based on available literature, satisfactory postoperative outcomes can be reliably expected following surgical treatment.

LEVEL OF EVIDENCE

Systematic Review of Level III and Level IV Studies, Level IV.

Treatment of Symptomatic Subfibular Ossicle by Excision and Modified Broström Procedure for Skeletally Immature Patients

BACKGROUND

Ossicle resection combined with ligament repair using the modified Broström procedure (MBP) is generally associated with favorable results in adults with symptomatic subfibular ossicles; however, the surgical results of this approach in skeletally immature patients remain unclear. The purpose of this study was to investigate the midterm clinical outcomes and radiographic outcomes including leg length and physeal growth of skeletally immature patients after this procedure.

METHODS

Twenty-six consecutive skeletally immature patients who underwent ossicle resection combined with the MBP were retrospectively evaluated. Clinical scores were evaluated using the visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Karlsson-Peterson score, and Tegner score. The talocrural angle, fibular length on radiographs, and tape-measured leg length between the 2 ankles were also measured at the final follow-up. Time of return to sports and postoperative complications were also evaluated.

RESULTS

Fourteen girls (53.8%) and 12 boys (46.2%) had surgery at a mean age of 12.7±2.4 years. Mean postoperative follow-up time was 40.0±10.8 months. Mean VAS pain score improved from 4.1 preoperatively to 0.5 at final follow-up (P < .05). Mean AOFAS score, Karlsson score, and Tegner score all improved from 62.0, 54.0, and 2.8 preoperatively to 95.5, 94.0, and 5.4 (P < .05), respectively, at final follow-up. Median time of return to sports was 17.0 weeks. Mean talocrural angle, fibular length, and tape-measured leg length of the injured ankle were not significantly different from those of the contra-side at the final follow-up. All patients were satisfied with the results; repeat ligamentous injury occurred in 2 patients (7.7%). We had no cases of wound infection, nerve injury, compartment syndrome, or any other complications.

CONCLUSION

Ossicle resection combined with the MBP performed in skeletally immature patients with symptomatic subfibular ossicles resulted in improved clinical outcomes without disruption of fibular physeal growth by an average of 3.3-year follow-up.

LEVEL OF EVIDENCE

Level IV, case series.