Likelihood of hip infection with image-guided hip aspiration dry tap: a 10-year retrospective study

• Published in: Skeletal radiology Vol. 51; no. 10; pp. 1947 - 1958
• Main Authors: Serfaty, Aline, Jacobs, Adam, Gyftopoulos, Soterios, Samim, Mohammad
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2022; Springer; Springer Nature B.V
• Subjects: Arthritis; Biomedical materials; Cell culture; Dehiscence; Effusion; Hip; Imaging; Infection; Infections; Joint diseases; Joints (anatomy); Leukocytes; Magnetic resonance imaging; Medical imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Orthopedics; Pathology; Radiology; Scientific Article; Serology; Subgroups; Total hip arthroplasty; Dry tap; Hip infection; Image-guided hip aspiration; Total hip arthroplasty; MRI
• ISSN: 0364-2348; 1432-2161
• DOI: 10.1007/s00256-022-04046-0

Objective
To determine the rate of infection in patients with suspected hip septic arthritis who underwent image-guided aspiration (IHA) resulting in dry-tap, diagnostic value of subsequent lavage and re-aspiration, and if pre-aspiration MRI can help prevent a dry tap.
Materials and methods
Retrospective review between 2010 to 2020 identified native hip (NH) and total hip arthroplasty (THA) patients who had a dry-tap following aspiration for suspected infection or periprosthetic joint infection (PJI). Serology tests, lavage/re-aspiration volumes, and aspirate cell-count/culture were assessed. On pre-aspiration MRI, presence/grade of joint effusion (JE), pseudocapsule dehiscence (PD), extraarticular fluid and sinus-tract were recorded.
Results
Out of 215 included dry-taps, 185 (86.0%) were non-infected and 30 (13.9%) infected. In subgroup analysis, 64/71(90.1%) NH and 121/144(84.0%) THA dry-taps were non-infected. Pre-aspiration MRI of THA group with dry-tap showed significant findings; PD with extraarticular fluid (8/12, 66.7%) and sinus tract (7/12, 58.3%) were higher in the infected compared to non-infected group (5/42, 11.9% and 0/42, 0.0%) (both
p
 < 0.001). Among THA group, polymorphonuclear-leukocytes > 80% was present in 8/9 (88.9%) of infected versus 4/28 (14.3%) non-infected group (
p
 < 0.001). Multivariable regression showed PD (
p
 = 0.005) and JE (
p
 = 0.042) being significant independent predictors of PJI, similarly the elevated CRP (
p
 = 0.044) and JE (
p
 = 0.017).
Conclusion
Majority of patients suspected of hip joint infection with dry-tap were non-infected. Synovial PMN% following lavage maintains high sensitivity for detection of PJI. In patients with THA, PD and subsequent extraarticular collection can be associated with dry-tap therefore, pre-aspiration MRI can help determine their presence and plan the aspiration.