How to prevent dislocation after revision total hip arthroplasty: a systematic review of the risk factors and a focus on treatment options.

BACKGROUND: Dislocation represents the most common complication after revision total hip arthroplasty (rTHA). Understanding risk factors for dislocation has a great clinical relevance for every hip surgeon in order to consider all surgical options for effective planning. The aim of this systematic review was to answer two main questions-(1) what are the risk factors for instability after rTHA? and (2) what are the best preoperative assessments and surgical options to avoid dislocation after rTHA?

MATERIALS AND METHODS: Scientific databases were accessed to identify papers dealing with prevention and treatment of dislocation after rTHA. We performed a search using the keywords 'revision hip arthroplasty' and 'dislocation', 'instability', 'outcome', 'failure', 'treatment'. After removal of duplicates and exclusion of works published in different languages, 33 articles were reviewed completely.

RESULTS: Risk factors were analysed in order to establish the most relevant and evidence-based treatments available in the current literature.

CONCLUSIONS: The risk of dislocation after rTHA can be reduced using some precautions inferred from the literature. The use of a larger femoral and acetabular component, elevated rim liner and dual mobility implants can significantly reduce the risk of dislocation after rTHA. However, care must be taken regarding patient-related risk factors since these cannot be addressed and modified. Hence, a complete evaluation of risk factors should be performed for each patient and procedure before starting rTHA.