Better outcomes after TKA with articulating vs static spacers
ORLANDO — Use of an articulating spacer in patients with chronic periprosthetic joint infection undergoing primary total knee arthroplasty yielded improved outcomes compared to use of a static spacer, according to results presented at the Current Concepts in Joint Replacement Winter Meeting.
Cindy R. Nahhas, BS, and colleagues randomly assigned 68 patients with chronic periprosthetic joint infection undergoing primary TKA with planned two-stage exchange to receive either a static spacer (n=32) or an articulating spacer (n=36).
“Our primary outcome variable was range of motion as measured with a goniometer, and secondary outcome measures included operating time, hospital length of stay, infection recurrence, reoperation rate and Knee Society Score,” Nahhas said in her presentation, which received the Orthopaedic Research and Education Foundation/Current Concepts in Joint Replacement Clinical Award.
At a mean follow-up of 3.5 years, Nahhas noted there were a total of 24 static spacers and 25 articulating spacers available for analysis.
“In terms of perioperative outcomes, there was no difference in operative time of stage one or stage two between the two cohorts,” Nahhas said. “Similarly, there was no difference in blood transfusion rates between the groups.”
Patients in the static spacer group had longer hospital length of stay after stage one and patients in the articulating spacer cohort had a higher Knee Society Score, according to Nahhas.
“In the articulating cohort, the mean motion arc was 113° compared to 100.2° in the static cohort,” Nahhas said.
She added 8% of the static spacer group had recurrent infection compared with 4% of the articulating spacer group. Although reoperation for any reason after the completed two-stage procedure occurred in 8% of the articulating spacer cohort vs. 25% of the static spacer cohort, Nahhas noted this finding did not reach statistical significance.
“Of note, at baseline there was no difference between the cohorts while we were looking at age, Charlson Comorbidity Index, laterality of the procedure, distribution of infecting organism, in which methicillin-sensitive Staphylococcus aureus was most common in both cohorts, no difference in the Knee Society Score or the Knee Society Function Score,” Nahhas said. – by Casey Tingle
Nahhas CR, et al. Paper 27. Presented at: Current Concepts in Joint Replacement Winter Meeting; Dec. 11-14, 2019; Orlando.
Disclosure: Nahhas reports no relevant financial disclosures.