Cruciate-Retaining vs Posterior-Stabilized Antibiotic Cement Articulating Spacers for Two-Stage Revision of Prosthetic Knee Infection: A Retrospective Cohort Study

Abstract

Cruciateretaining versus posterior-stabilized antibiotic cement articulating spacers for two-stage revision of prosthetic knee infection: a retrospective cohort study,

Effect of Surgeon Volume on Mechanical Complications after Resection Arthroplasty with Articulating Spacer

“…Lin et al also mentioned that to prevent post-cam failure of the PS spacer, an endoskeleton-reinforced femoral cam or additional hinged brace protection should be considered [8]. The finding that hinge knees were required in 47.2% of patients after mechanical spacer failure in our LV group is substantial, as this illustrates that the mechanical complications increased the level of constraint in final revision knee arthroplasty [12]. The above findings indicate that soft tissue compromise after an unstable joint event might be a predictor for highly constrained revision prostheses, which should be prepared and made available at the time of reimplantation.…”

“…Tan et al and George et al reported that the rates of spacer mechanical complications were approximately 17 to 18% [28,29], and our rate, 19.7%, was consistent with these data. Our mechanical complications were all atraumatic, with the majority (92.5%) of spacers failing at <6 weeks, which might be related to the unstable biomechanical environment in PKI after RA [12], in addition to the weaker strength of the cement due to high-dose antibiotics [8], and the spacers were fixed in the bone ends without tight interdigitation for ease of removal with minimal bone loss [17]. Lin et al found that a low surgical volume was a risk factor for spacer fractures with dislocation (odds ratio, 8.13) [8].…”

“…Demographic patient data, including medical comorbidities, microorganisms, spacer information, and spacer period, were extracted from medical charts. The following radiograph findings before reimplantation were recorded as mechanical complications using the INFINITT Picture Archiving and Communications System (INFINITT, Seoul, South Korea): spacer fracture, spacer migration, periprosthetic fracture, joint subluxation/dislocation, or extensor mechanism disruption [10,12,17]. Those with the progression of radiolucent lines around spacers without the above complications were excluded.…”

“…Lau et al found that 34.9% (22/63) of coronal subluxations of the articulating spacers required highly constrained knee systems during reimplantation [7]. Lin et al reported that 70% (14/20) of dislocated spacers needed rotating hinge knees during reimplantation and proposed the concept "added insult to injury" when knee dislocations occur after RA with articulating spacers, suggesting that surgeons must strive to prevent joint dislocation during the spacer period [12]. Lin et al also mentioned that to prevent post-cam failure of the PS spacer, an endoskeleton-reinforced femoral cam or additional hinged brace protection should be considered [8].…”

“…Posterior-stabilized (PS) cement articulating spacers were used (CADAS; EverYoung BioDimensions, Taichung, Taiwan) [12]. A PS spacer with a post-cam construct was fabricated intraoperatively using a silicone mold.…”