Direct anterior, posterior approach yielded similar outcomes after THA

Researchers found no differences in the dislocation rate between the direct anterior vs. posterior approach.

Use of the direct anterior approach or posterior approach during total hip arthroplasty resulted in similar short-term outcomes and complications, according to results presented at the Current Concepts in Joint Replacement Spring Meeting.

“Short-term outcome and complication data from the state joint replacement registry demonstrate that total hip arthroplasty performed using either the direct anterior approach or posterior approach have no compelling advantage over each other, including no difference in the dislocation risk,” Joseph D. Maratt, MD, of the University of Michigan Health System, said in his presentation. The study won the Orthopaedic Research Society/Current Concepts in Joint Replacement Clinical Practice Award.

Direct anterior vs posterior

Utilizing the Michigan Arthroplasty Registry between February 2012 and September 2014, Maratt and his colleagues matched patients who underwent posterior approach total hip arthroplasty (THA) to patients who underwent direct anterior approach THA on the basis of age, gender, BMI and American Society of Anesthesia classification, which yielded 2,147 matched pairs.

Results showed dislocation rates of 0.84% with the direct anterior approach and 0.79% with the posterior approach. Maratt said there was an increase in procedure duration for patients who underwent the direct anterior approach (100 minutes vs. 76 minutes with the posterior approach). The two groups also showed no significant differences in fracture rate, blood loss, transfusion, hematoma, length of stay or readmission. However, Maratt noted trends toward a slightly longer length of stay in the posterior approach group and a greater risk of fracture, increased blood loss and hematoma in the director anterior group.

“Our results are different from the results recently reported from the Kaiser registry,” Maratt said. “This difference may be explained by the broader time period of that study and changes in technique and implant choices over the time period having a greater impact in the posterior approach group.”

Limitations

Although the Michigan Arthroplasty Registry had 98% data completeness and large representative cohorts, according to Maratt, it is limited to hospital-level data.

“[Surgeon-level data] is only available to the surgeon and the participating institution, so we cannot control for learning curves and volume,” Maratt said. “There is also implant variability and we do not have access to implant data at the time for analysis, so we cannot control for head size or stem design.”

He noted future research on this topic using the Michigan Arthroplasty Registry will be able to include functional outcomes which, although unavailable at the time of the study, is now being collected by the registry along with level 3 data. – by Casey Tingle

Disclosure: Maratt reports he is an employee of Alexion Pharmaceuticals, Biogen and Dimension Therapeutics; and receives stock or stock options from Alexion Pharmaceuticals, Biogen, Dimension Therapeutics, Merck and Sanofi-Aventis.

Use of the direct anterior approach or posterior approach during total hip arthroplasty resulted in similar short-term outcomes and complications, according to results presented at the Current Concepts in Joint Replacement Spring Meeting.

“Short-term outcome and complication data from the state joint replacement registry demonstrate that total hip arthroplasty performed using either the direct anterior approach or posterior approach have no compelling advantage over each other, including no difference in the dislocation risk,” Joseph D. Maratt, MD, of the University of Michigan Health System, said in his presentation. The study won the Orthopaedic Research Society/Current Concepts in Joint Replacement Clinical Practice Award.

Direct anterior vs posterior

Utilizing the Michigan Arthroplasty Registry between February 2012 and September 2014, Maratt and his colleagues matched patients who underwent posterior approach total hip arthroplasty (THA) to patients who underwent direct anterior approach THA on the basis of age, gender, BMI and American Society of Anesthesia classification, which yielded 2,147 matched pairs.

Results showed dislocation rates of 0.84% with the direct anterior approach and 0.79% with the posterior approach. Maratt said there was an increase in procedure duration for patients who underwent the direct anterior approach (100 minutes vs. 76 minutes with the posterior approach). The two groups also showed no significant differences in fracture rate, blood loss, transfusion, hematoma, length of stay or readmission. However, Maratt noted trends toward a slightly longer length of stay in the posterior approach group and a greater risk of fracture, increased blood loss and hematoma in the director anterior group.

“Our results are different from the results recently reported from the Kaiser registry,” Maratt said. “This difference may be explained by the broader time period of that study and changes in technique and implant choices over the time period having a greater impact in the posterior approach group.”

Limitations

Although the Michigan Arthroplasty Registry had 98% data completeness and large representative cohorts, according to Maratt, it is limited to hospital-level data.

“[Surgeon-level data] is only available to the surgeon and the participating institution, so we cannot control for learning curves and volume,” Maratt said. “There is also implant variability and we do not have access to implant data at the time for analysis, so we cannot control for head size or stem design.”

He noted future research on this topic using the Michigan Arthroplasty Registry will be able to include functional outcomes which, although unavailable at the time of the study, is now being collected by the registry along with level 3 data. – by Casey Tingle

Disclosure: Maratt reports he is an employee of Alexion Pharmaceuticals, Biogen and Dimension Therapeutics; and receives stock or stock options from Alexion Pharmaceuticals, Biogen, Dimension Therapeutics, Merck and Sanofi-Aventis.