Clinical outcomes of articulating spacers in treatment of chronic knee periprosthetic joint infection / 中华创伤骨科杂志

ABSTRACT

Objective:To explore the clinical outcomes of articulating spacers in the treatment of chronic knee periprosthetic joint infection (PJI).Methods:A retrospective study was conducted of the 38 patients who had undergone stage-two revision for chronic knee PJI from January 2014 to January 2020 at Department of Articular Surgery, The First Affiliated Hospital to Fujian Medical University. They were 8 men and 30 women, aged from 37 to 84 years (average, 66.2 years). The PJI was unilateral in all, affecting 19 left sides and 19 right sides. According to the kind of spacers used in the stage-one revision, they were divided into 3 groups metal-polyethylene one (10 cases), metal-cement one (15 cases) and cement one (13 cases). In the stage-two revision following infection control, the spacers were removed for sonication and microbial culture. Infection control, range of motion (ROM), Knee Society Score (KSS), and complications were followed up.Results:The 38 patients were followed up for an average of 30.8 months (from 13 to 75 months). All patients underwent spacer implantation at stage-one revision and infection was controlled in 37 of them (97.4%, 37/38). After stage-one revision, metal-polyethylene, metal-cement and cement groups achieved 95.0°±11.3°, 92.9°±8.3° and 75.5°±11.9° in ROM, 79.4±6.1, 77.3±4.0 and 73.0±7.2 in clinical KSS and 67.5±11.8, 69.0±10.4 and 60.8±11.0 in functional KSS, showing significant improvements in the above indexes between preoperation and postoperation ( P<0.05). The ROMs for the metal-polyethylene and metal-cement groups were significantly better than for the cement group ( P<0.05). A total of 32 patients completed stage-two revision, with 7 in the metal-polyethylene group, 12 in the metal-cement group and 13 in the cement group. Respectively, ROMs after stage-two revision were 104.6°±9.8°, 98.5°±8.7° and 86.1°±8.9°, clinical KSSs 85.3±4.6, 82.7±4.3 and 78.0±4.8 and functional KSSs 78.6±6.9, 77.3±8.2 and 69.5±8.3 for the metal-polyethylene, metal-cement and cement groups, showing significant improvements after stage-one revision ( P<0.05). The postoperative sonication fluid culture showed negative results in all. Conclusions:Articulating spacers can effectively control knee PJI and improve the knee function during revision interval and after revision. Metal spacers may lead to a better range of motion than traditional cement ones.