Posterior approach for THA may have higher dislocation risk
DALLAS — Use of the posterior approach in total hip arthroplasty had the highest risk of dislocation and use of the lateral approach had highest rate of all-cause revision surgery, according to results of a comparison of three different THA approaches presented at the American Association of Hip and Knee Surgeons Annual Meeting.
Michael J. Taunton, MD, and colleagues identified 7,000 THAs performed using the direct anterior (22%), lateral (25%) or posterior (53%) approaches.
“In order to find the cumulative incidence, we estimated using death as a competing risk for time to event outcomes of dislocation, revision and reoperation,” Taunton said in his presentation.
Taunton noted an overall incidence of dislocation of 1.3% for primary THA, with a risk of dislocation at 1 year of 2.1%, 0.7% and 0.4% for the posterior, lateral and direct anterior approaches, respectively. He added a dislocation risk of 3% with the posterior approach at 5 years.
“When adjusting the risk of dislocation for patient risk factors, the hazard ratios were significantly lower for the lateral at 0.28 and 0.10 for the direct anterior approach compared to the posterior approach,” Taunton said.
Patients who underwent the posterior approach had an incidence of revision for dislocation of 1% at 5 years compared with 0.6% in the lateral group and 0% in the direct anterior group, according to Taunton. He noted a significantly increased incidence of all-cause revision associated with the lateral approach, with a hazard ratio of 2.45.
“The most prevalent cause for revision in the posterior approach was instability. For the lateral approach, fracture was the most common cause, as was for the direct anterior approach,” Taunton said.
When adjusted for risk of dislocation, Taunton noted patient risk factors included female gender and diagnosis of osteoarthritis.
“There was a statistically significant delta change in Harris Hip Score in the direct anterior approach at 37, with a decrease in the posterior at 33 and lateral at 29,” Taunton said. – by Casey Tingle
Wyles CC, et al. Paper 11. Presented at: American Association of Hip and Knee Surgeons Annual Meeting; Nov. 7-10, 2019; Dallas.
Disclosure: Taunton reports he receives IP royalties from and is a consultant for DJO and receives research support from DePuy Synthes and Stryker.