Comparison of Fluoroscopy Use Between Two Radiographic Overlay Techniques for Limb Length and Femoral Offset Assessment During Direct Anterior Approach Total Hip Arthroplasty.

BACKGROUND

Restoration of leg length and femoral offset is critical to optimizing outcomes following total hip arthroplasty (THA). Several intraoperative techniques are available to assess these parameters when utilizing the direct anterior approach (DAA), many of which rely on fluoroscopy. However, relative radiation exposure associated with these strategies has not been well characterized. This study aims to compare intraoperative radiation exposure between two techniques for limb length and offset assessment during DAA-THA.

METHODS

A retrospective chart review was conducted of 159 primary cementless DAA-THA procedures performed by a single fellowship-trained arthroplasty surgeon using either the contralateral or ipsilateral hip for length and offset reference. Medical records were reviewed to record fluoroscopy time, radiation dose, and operative time for each case.

RESULTS

No statistical difference in fluoroscopy time was noted between contralateral (60.4 ± 21.2 seconds) and ipsilateral (55.9 ± 19.6 seconds) techniques (P = 0.17). Similarly, no statistical difference was noted for radiation exposure between contralateral (15.4 ± 13.3 mGy) and ipsilateral (13.0 ± 9.0 mGy) techniques (P = 0.17). However, when adjusted for operative time and presented as arbitrary units (AU), the ipsilateral technique was associated with less fluoroscopy time (0.34 ± 0.1 AU, P = 0.0025) and radiation exposure (0.08 ± 0.05 AU, P = 0.045) when compared to contralateral fluoroscopy time (0.39 ± 0.1 AU) and radiation exposure (0.1 ± 0.07 AU). Stratified analysis by body mass index (BMI) demonstrated a significant main effect of BMI on radiation exposure (P < 0.001) and operative time (P < 0.001). Regardless of technique, increasing BMI was positively correlated with higher radiation dose (r= 0.52, P < 0.001) and longer operative time (r = 0.42, P < 0.001).

CONCLUSION

Both reference techniques had similar non-adjusted fluoroscopy time and exposure during DAA-THA; however, when normalized by operative time, the ipsilateral technique may require less fluoroscopy. BMI significantly influenced radiation dose and operative duration for both techniques. Ongoing critical evaluation of surgical techniques is essential to optimize safety, particularly when modifications may reduce radiation exposure to patients and operating room personnel.