New Primary Total Knee Arthroplasty Components Versus Other Contemporary Types of Spacers for the Treatment of Chronic Periprosthetic Knee Infection With a Two-Stage Protocol

Abstract

The optimal type of antibiotic spacer for the treatment of a knee periprosthetic joint infection (PJI) remains a topic of debate. Although the ultimate goal of an antibiotic spacer is infection control, contemporary spacer iterations, such as the use of a new femoral component (NFC), may offer unique advantages. The primary goal of this study was to compare rates of infection control and functional outcomes between contemporary spacer types. We retrospectively reviewed 96 patients who underwent removal of a total knee arthroplasty with insertion of an antibiotic spacer for knee PJI over a 14-year period at a single institution with a minimum 1-year follow-up. Three patient cohorts were defined based on spacer type: NFC (n=30), cement-on-cement (n=19), and static (n=47). There was no association between spacer type and the odds of infection clearance ( P =.60). The NFC spacers resulted in increased knee range of motion before replantation and improved ambulatory status at 8 weeks postre-plantation, although no difference was seen at final follow-up. The use of NFC spacers may provide functional advantages over their contemporary counterparts, and the potential of NFC spacers to be used in single-stage exchange arthroplasty remains an appealing area of investigation. Future high-powered, prospective, noninferiority studies between contemporary spacer types are needed. [ Orthopedics . 2022;45(2):109–115.]

Are Static Spacers Superior to Articulated Spacers in the Staged Treatment of Infected Primary Knee Arthroplasty? A Systematic Review and Meta-Analysis

“…A total of 3421 studies were found through the electronic search and 21 studies were added after the cross-referenced research on the bibliographies of the examined full-text articles. After a preliminary analysis, a total of 87 studies reporting series of knee spacers used for two-stage treatment of PJI were included in this systematic review (1 randomized controlled trial, 3 prospective comparative cohort studies, 26 retrospective comparative cohort studies, 9 prospective case series, 48 retrospective case series [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , ...…”

“…Studies comparing static vs. articulated spacers were 1 RCT [ 43 ], 1 PCCS [ 22 ], and 16 RCCS [ 18 , 20 , 21 , 26 , 27 , 28 , 31 , 35 , 36 , 41 , 43 , 44 , 45 , 47 , 49 , 51 ]. In total, 34 series on static spacers [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ] and 71 on articulated spacers [ 18 , 20 , 21 , 26 , 27 , 28 , 31 ,…”

“… Quality assessment of the included studies in meta-analysis according to RoB2 [ 43 ] ( a ) and ROBINS-I [ 21 , 23 , 25 , 29 , 30 , 31 , 34 , 38 , 39 , 44 , 46 , 47 , 48 , 50 , 52 , 54 , 106 ] ( b ) tools: “traffic light” plots of the domain-level judgments for each individual result ( a , b ); weighted bar plots of the distribution of risk-of-bias judgments within each bias domain ( c ). …”

“… Forest plot of overall meta-analysis evaluating comparative studies (static spacers vs. articulated spacers) with data about PJI recurrences [ 21 , 23 , 24 , 25 , 29 , 30 , 31 , 34 , 38 , 39 , 43 , 44 , 46 , 47 , 48 , 50 , 52 , 54 ] ( a ), active knee flexion at last follow-up ( b ), and non-infection-related peri-operative local complications ( c ). Abbreviations: ES, effect size; 95% CI, 95% confidence interval; W, weight; V, variance; SE, standard error; N, sample size; N1, static spacer series sample size; N2, articulated spacer series sample size.…”

What’s New in Musculoskeletal Infection

“…High-dose antibiotic cement spacers for the treatment of PJI were found to be independent risk factors for acute kidney injury, which had a rate of 22.7% following the first stage of a planned 2-stage exchange versus 6.6% following a 1-stage exchange 36 . A study comparing knee spacer types (new femoral component, cement-on-cement, and static) found no difference in the odds of infection clearance and showed increased range of motion and improved ambulatory status prior to reimplantation utilizing the new-femoral-component spacer design 37 .…”