To the Editor:
The recent article “Fluoroscopic Imaging of Acetabular Cup Position During THA Through a Direct Anterior Approach,” by Alvarez et al,1 was well written, and the content should be beneficial to surgeons performing total hip arthroplasty (THA) using this approach. However, the article contains an error that could potentially mislead surgeons using a direct anterior approach toward achieving the desired cup anteversion.
According to Figure 3’s caption, when the fluoroscopic beam is moved in the cephalic direction, the cup position appears more anteverted, and when it is moved in the caudal direction, the cup position appears less anteverted. This should actually be the other way around—when the beam is moved in the cephalic direction, the cup should look less anteverted, and when the beam is moved in the caudal direction, the cup should look more anteverted. This is evident when looking at Figures 3A (showing less anteversion) and 3B (showing more anteversion).
Reference
- Alvarez AM, Suarez JC, Patel P, Benton EG. Fluoroscopic imaging of acetabular cup position during THA through a direct anterior approach. Orthopedics. 2013; 36(10):776–777. doi:10.3928/01477447-20130920-06 [CrossRef]
Reply:
We thank Drs Deshmukh, Rathod, and Rodriguez and Dr D’Ambrosia for pointing out this oversight. Figure 3’s caption mentioned that when the fluoroscopic beam is moved in the cephalic direction, the cup position appears more anteverted, and when it is moved in the caudal direction, the cup position appears less anteverted. However, this should have read that when the beam is moved in the cephalic direction, the cup should appear less anteverted, and when the beam is moved in the caudal position, the cup should appear more anteverted. The Figure and corrected caption are printed here.
Andres M. Alvarez, MD, MSc
Weston, Florida