This study sought to quantify the total patient radiation exposure during fluoro-assisted direct anterior approach (DAA) total hip arthroplasty (THA). We hypothesized that the patient radiation exposure would fall within acceptable published limits for a 1-time patient exposure.
After institutional review board approval, we performed a retrospective chart review of consecutive unilateral primary DAA THAs at 2 institutions (N = 157) between 2012 and 2014 by a single fellowship-trained arthroplasty surgeon assisted by residents and fellows. Incomplete dose reporting information was the sole exclusion criterion. Patient electronic medical records were queried regarding exposure time (seconds), radiation emittance (mGy), and peak kilovoltage (kVp). Descriptive statistics were calculated. Pearson correlation coefficients were used to determine the correlation between variables.
Mean radiation dose for patient exposure measured 2.97 ± 1.63 mGy (range: 0.29-9.83). Positive but weak linear relationship with radiation dose and body mass index (BMI; r = 0.34; P < .0002). Average exposure time per procedure was 23.74 s (range: 11.3-61.7). Average kVp per procedure was 75.38 (range: 65-86). Average BMI was 28.32 (range: 16.6-39.8). There was a significantly strong correlation between kVp and BMI (r = 0.75; P< .0001).
Total patient radiation exposure was nearly identical with previously published values for a screening mammogram (3 mGy) and 4 times less than that of a standard chest computed tomography (13 mGy). Although it is difficult to ascertain the exact patient-absorbed radiation, our data suggest that a 1-time exposure during DAA THA is likely negligible and provides the surgeon with additional data for counseling patients preoperatively.