Tibial spurs (pes anserinus bony spurs) in children and adolescents: a case series of 21 patients

Abstract Background: Icicle-like bony spurs that originate from the proximal medial surface of the tibia in young persons have been referred to by various names in the literature. This tibial spur, called pes anserinus bony spurs (PABSs), can present as exostoses, but lacks a cartilage cap which is characteristic feature of osteochondroma. To date, there are only two small case series about the tibial spur, and little information is available. The aim of this study was to describe the characteristics of PABSs in children and adolescents. Methods: This retrospective study analysed patients diagnosed with PABSs on an orthopaedic oncology service from 2013 to 2020. Additionally, in order to estimate the prevalence of PABSs in children and adolescents, we retrospectively reviewed knee X-rays of patients who visited our hospital for other reasons from 2008 to 2020. Results: Thirteen male and 8 female patients with PABSs, with a mean age of 11.7 years, were evaluated. Bilateral spurs were observed in 7 of the 21 patients. Among 28 PABSs in 21 patients, 6 were incidentally identified. Radiological evaluation showed that the average PABS length was 10.6 mm. There was a statistically significant difference in the spur length between incidentally detected PABSs and symptomatic PABSs at the first visit. The prevalence rate of PABSs among children and adolescents was 0.94%. Computed tomography examinations showed that no PABSs occurred at the site of the tendinous insertion of the pes anserinus. Surgical resection was performed in only 2 patients, both of whom were high-performing athletes. Conclusions: This is the first study to describe the clinical and radiological features of PABSs in detail and to report their prevalence in children and adolescents. Although longer PABSs are symptomatic, most PABSs are non-problematic and surgical resection of PABSs should be considered only if pain persists despite conservative treatment.