Current concepts in the diagnosis and management of Os Acetabuli

The aim of this review is to appraise the current evidence on the epidemiology, pathophysiology, diagnosis and management of os acetabuli.

A scoping review was conducted according to the Joanna Briggs Institute guidelines. A systematic search was performed on Medline (PubMed), Embase and Cochrane Library. Inclusion criteria comprised observational and interventional studies and review articles published in the English language that focused on patients with os acetabuli according to the PRISMA extension of scoping reviews checklist using the terms 'Os Acetabuli' or 'os acetabula' or 'acetabular ossicles'. A narrative synthesis of results was undertaken, and the included articles were divided into (i) definition, (ii) aetiology, (iii) diagnosis and imaging and (iv) management of os acetabuli.

107 articles were screened, with 22 meeting the eligibility criteria. A total of 8836 patients were considered, of which 604 had os acetabuli. The mean age was 32.8 years. The prevalence of os acetabuli ranged from 3.4 to 7.7%, with a higher prevalence in males compared to females. True os acetabuli was defined as an unfused secondary ossification centre along the acetabular rim. The aetiology of os acetabuli is thought to be secondary to acetabular dysplasia and/or femoroacetabular impingement. Standard of care for management of symptomatic os acetabuli is considered to be arthroscopic excision unless the excision results in acetabular undercoverage and/or instability, in which case, fixation is recommended.

Successful management of os acetabuli depends on understanding the pathology and treating the underlying cause rather than treating the os acetabuli in isolation. Future work needs to focus on establishing clear diagnostic criteria, consensus on definition and an evidence-based treatment algorithm.