Arthrocentesis in the Setting of Total Hip Arthroplasty - Provider Type and other Risk Factors for a Failed...

This study aims to identify risk factors for an unsuccessful aspiration of total hip arthroplasty (THA). Cases of painful THA requiring image-guided arthrocentesis between May 1, 2008 and May 1, 2018 were identified. Patient demographics, comorbidities, laboratory values and surgical histories were assessed. Aspirations performed by musculoskeletal radiologists (MR) and arthroplasty surgeons (AS) were compared. Pre-aspiration risk factors were placed in a univariate analysis to look for risk factors for a failed aspiration - defined as a procedure yielding less than one milliliter (ml) of synovial fluid without lavage. Three hundred and forty-seven patients required a total of 429 arthrocenteses, and 55 index cases were performed by an AS and 292 by a MR. MR performing the index aspiration was the only significant variable associated with a failed aspiration (OR: 2.23; 95% CI: 1.1 - 6.5; p = 0.021). Sixteen failed MR aspirations required subsequent AS aspiration (75% successful). The median volume of synovial fluid obtained in the AS cohort was 5 ml (interquartile range [IQR] 2.5, 15) versus 3 ml in MR cases (IQR 0.5, 7) (p = 0.002). Anterior placement of the needle and aspiration from the head-neck junction had a higher failure rate when compared to all other described needle positions (42% vs. 29%, p = 0.020; 51% vs. 29%, p = 0.002; respectively). Successful arthrocentesis of a THA was associated with provider type and needle location. All proceduralists performing image-based aspirations should be encouraged to avoid placing the needle tip anterior to the implant or at the head-neck junction. (Journal of Surgical Orthopaedic Advances 35(1):014 - 018, 2026).