Factors predicting hip joint aspiration yield or "dry taps" in patients with total hip arthroplasty
Justin Ong1, Alex Tang2, Joshua C Rozell2
1NYU Langone Health, New York, USA. Justin.Ong@nyulangone.org.
Background:
Image-guided joint aspirations used to assist the diagnosis of periprosthetic joint infection (PJI) may commonly result in a dry tap-or insufficient fluid for culture and cell count analysis. Dry tap aspirations are painful and invasive for patients and often utilize a subsequent saline lavage to obtain a microbiology sample. Currently, there is a paucity of the literature addressing predictors that could suggest whether a dry tap will occur. The purpose of this study was to examine the effects of various factors on "dry tap" occurrence in patients with suspected PJI following total hip arthroplasty (THA).
Methods:
A retrospective review was performed among THA patients suspected for PJI who received image-guided joint aspiration procedures at our institution from May 2016 to February 2020. The procedural factors included the imaging modality used for aspiration, anatomic approach, needle gauge size used, and the presence of a trainee. The patient-specific factors included number of prior ipsilateral hip surgeries, femoral head size, ESR/CRP values, and BMI.
Results:
In total, 336 patients met our inclusion criteria. One hundred and twenty hip aspirations resulted in a dry tap (35.7%) where the patients underwent a saline lavage. Among the procedural and patient-specific factors, none of the factors were found to be statistically different between the two cohorts nor conferred any greater odds of a dry tap occurring.
Conclusion:
No associations with dry tap occurrence were found among the procedural and patient-specific factors studied. Further research is needed to identify additional factors that may be more predictive of dry taps.
Insights
Predicting dry taps during image-guided hip aspirations for periprosthetic joint infection (PJI) is challenging. This study found no significant patient or procedural factors predicting dry taps in total hip arthroplasty (THA) patients.
Area of Science:
- Orthopedic Surgery
- Infectious Disease Diagnostics
- Medical Imaging
Background:
- Image-guided joint aspirations are crucial for diagnosing periprosthetic joint infection (PJI).
- A significant number of these aspirations result in a 'dry tap,' yielding insufficient fluid for analysis.
- Dry taps necessitate painful saline lavage for microbial sampling, highlighting the need to predict their occurrence.
Purpose of the Study:
- To investigate patient-specific and procedural factors influencing "dry tap" rates in total hip arthroplasty (THA) patients with suspected PJI.
- To identify predictors that could help anticipate dry tap events before aspiration.
Main Methods:
- Retrospective review of 336 THA patients undergoing image-guided joint aspiration for suspected PJI (May 2016 - February 2020).
- Analysis of procedural factors: imaging modality, approach, needle gauge, trainee presence.
- Evaluation of patient factors: prior surgeries, femoral head size, inflammatory markers (ESR/CRP), BMI.
Main Results:
- 120 out of 336 aspirations (35.7%) resulted in a dry tap.
- No statistically significant differences were observed in procedural or patient-specific factors between dry tap and non-dry tap groups.
- None of the studied factors increased the odds of experiencing a dry tap.
Conclusions:
- The study did not identify any procedural or patient-specific factors that predict dry tap occurrence in THA PJI evaluations.
- Further research is required to discover additional predictive markers for dry taps in image-guided joint aspirations.
