A Surgeon’s Transition from Posterior to Direct Anterior Approach
This single-surgeon study suggests that when adopting the direct anterior approach, the use of this intraoperative imaging may help diminish errors that can occur during the learning curve.
John M. Dundon, MD, and William J. Long, MD, FRCSC
Hamilton WG, Parks NL, Huynh C. Comparison of cup alignment, jump distance, and complications in consecutive series of anterior approach and posterior approach total hip arthroplasty. J Arthroplasty 2015; Nov (30):1959-62.
This study is a retrospective review from a single surgeon comparing his results with a switch from the posterior approach (PA) to the direct anterior approach (DAA) for total hip arthroplasty using a fracture table and intraoperative fluoroscopy.
The surgeon compared complication rate, acetabular component position including both cup anteversion and inclination, and femoral head jump distance for his last 100 posterior approach procedures to his first 100 direct anterior approach procedures.
The authors found a significantly increased cup anteversion in the posterior group (22.6⁰ PA vs. 17.6⁰ DAA), although no significant difference in cup inclination.
There was significantly more variance in acetabular component position in both anteversion (41.3⁰ PA vs. 20.2⁰ DAA; P<0.001) and component inclination (44.4⁰ PA vs. 24.9⁰ DAA; P=0.02).
No significant difference was found between approaches with regard to jump distance (13.4 mm PA vs. 13.9 mm DAA), although the surgeon was able to use more large femoral heads with the posterior approach.
No difference was noted in terms of complication rate or dislocation rate (4% PA vs. 2% DAA), although this study was underpowered to determine this.
In the literature, the transition from the posterior approach to the direct anterior approach for total hip arthroplasty has been associated with a steep learning curve and increased complication rate. This study reports the transition of a single surgeon who utilized intraoperative fluoroscopy to facilitate reliable acetabular component position without an increase in the complication rate. When adopting the direct anterior approach, the use of this intraoperative imaging may help diminish errors that can occur during the learning curve.
The study contributes to the accumulating literature on the advantages and disadvantages of the posterior and the direct anterior approaches. Although improved component position and precision in component placement under fluoroscopy can be achieved, larger studies need to be performed to determine if this has any effect on clinical outcomes or complication rates.
This study is underpowered and represents Level IV evidence, but it provides some insight to the surgeon on radiographic advantages to the direct anterior approach. Further data and larger studies are necessary in a more heterogeneous patient and surgeon population.
John M. Dundon, MD, is an Adult Reconstruction Fellow with the ISK Institute and NYU Langone Medical Center – Hospital for Joint Diseases, New York, New York. William J. Long MD, FRCSC, is an Attending Orthopedic Surgeon with the ISK Institute and Clinical Associate Professor of Orthopedic Surgery, Division of Adult Reconstruction, Department of Orthopedic Surgery, at NYU Langone Medical Center – Hospital for Joint Diseases, New York, New York.