The Journal of Arthroplasty , Volume 33 , Issue 8 , 2530 - 2534

Evaluation of the Learning Curve When Transitioning From Posterolateral to Direct Anterior Hip Arthroplasty: A Consecutive Series of 1000 Cases

Stone, Andrea H. et al.


The direct anterior approach (DAA) for primary hip replacement has been gaining more attention and widespread use in recent years. There are a number of published studies evaluating the learning curve when a surgeon changes technique; these studies typically look at complications during the initial cases. This study examines procedure and total operating room (OR) time along with all complications for a surgeon transitioning from the posterolateral approach (PA) to DAA.


A retrospective review of a single surgeon series of 1000 initial DAA procedures. Total OR time, procedure time, and complications were collected and analyzed. One-way analysis of variance and post hoc least significant difference tests were used for statistical analysis.


There was an initial increase in both procedure and OR times compared with the mature PA, by 34% and 30%, respectively. The procedure time became statistically equivalent to the mature PA time after the 400th DAA case, and significantly shorter after the 850th case. The total OR time became statistically equivalent after the 900th DAA case. There were 18 early (<90 days) and 18 late reoperations performed in this series with a nonsignificant trend toward femoral complications occurring early in the series. Minimum follow-up time was 2 years.


There was an initial increase in both total OR time and procedure time when an experienced surgeon introduced the DAA. By the end of the series, procedure time was significantly shorter and total OR time was equivalent. Complications overall were low and femoral complications decreased with time.

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