The Influence of Body Mass Index on Radiation Dose and Exposure Time in Fluoroscopic Guided Hip Injections - A Comparative Analysis of Two Approaches

Document Type : RESEARCH PAPER


Department of Trauma and Orthopaedics, Southend University Hospital, Mid and South Essex NHS Foundation Trust, Prittlewell Chase, Westcliff-on-Sea, Essex, SS0 0RY, United Kingdom


Objectives: Intra-articular hip injections (IHI) are routinely performed for both diagnostic and 
therapeutic purposes. The procedure can be performed via either an anterior or a lateral approach 
with fluoroscopic guidance being widely practised. There is a risk of radiation exposure associated 
with fluoroscopy assisted IHI. This may be influenced either by the surgical approach or the patient ’s 
body mass index (BMI) or both. This study was undertaken to compare the relationships of the 
respective approaches to BMI, fluoroscopic exposure time (FET) and radiation dose (RD). 
Methods: A retrospective study was conducted comprising 74 patients who underwent IHI with 37 
patients in each group (anterior and lateral). Patients were assessed pre -operatively and post 
operatively for any complications. The intra-operative radiation dose, fluoroscopic exposure time and 
BMI data were collected and analyzed. 
Results: The mean age of the patients in anterior and lateral groups was 61.18 ±14.08 and 
67.21±14.39 years respectively. No complications were noted in either group. However, there was a 
significant increase in FET (P=0.002) and RD (P<0.001) in patients with BMI ≥ 30. In the lateral 
group, this trend was markedly noted with increase in FET (P<0.001) and RD (P<0.001) in patients 
with BMI ≥ 30. On the other hand, in the anterior group there was no statistically significant increase 
in FET (P=0.155) and only a moderate increase in RD (P=0.020) in patients with BMI ≥ 30. 
Conclusion: Both anterior and lateral approaches to fluoroscopic guided IHI are equally safe in terms 
of complications involved. There is statistically significant increase in both radiation dose and 
fluoroscopic exposure time in patients with BMI ≥ 30. This is more pronounced in lateral approach. The 
anterior approach is most effective in reducing both radiation dose and fluoroscopic exposure time, 
more so in patients with BMI of 30 and above.
 Level of evidence: III


Main Subjects

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