What are the diagnoses attributed to persistent hip pain after hip arthroplasty? A systematic review.

Background: Persistent hip pain after total hip arthroplasty has been reported in up to 23 % of cases. Despite routine clinical tests, the source of pain often remains unclear, and diagnosis requires extensive investigation with imaging or surgical exploration. Aims: This systematic review aimed to identify the diagnoses attributable to the painful hip arthroplasty. The second aim was to identify diagnostic techniques used to identify them. Method: Three databases (Medline, Scopus and CINAHL) were searched from 2012 to 2024 using keywords and medical subject headings (MeSH) including 'persistent pain AND hip arthroplasty AND diagnoses'. Quality assessment was undertaken with the Joanna Briggs Institute checklist for case-series. Data extraction was performed by one author using Covidence software and crosschecked by another for accuracy. Data included age, sex, arthroplasty type, diagnostic method, and confirmed diagnosis. Data was synthesised to provide a quantitative overview of diagnoses and diagnostic methods. PROSPERO number CRD42022340158. Results: The search and reference screening returned 285 papers of which seven high quality and two unclear quality case-series met the inclusion criteria. There was a total of 388 painful hip arthroplasties included. Prostheses loosening or infection was present in 28.6 % of cases. Iliopsoas impingement was present in 21 % of cases. Causes outside the hip accounted for 16.4 % of cases with referred pain from the lumbar spine (14.6 %) most common. Greater trochanteric pain syndrome (GTPS) was present in 13 %. The painful etiology remained unknown in 9.2 % of participants. The most common diagnostic imaging technique was x-ray (100 %) followed by magnetic resonance imaging (22 %). Conclusion: Prosthesis loosening and infection remain a significant cause of pain despite preliminary screening to exclude them. Iliopsoas impingement and causes outside the hip require significant consideration due to high prevalence. Less common differential diagnoses have been identified. X-ray is an important front-line imaging tool while other advanced imaging is used selectively to identify a diagnosis.