Comparing the Efficacy of Articulating Spacers in Two-Stage Revision for Periprosthetic Joint Infection Following Total Knee Arthroplasty: All-Cement Spacers vs Sterilized Replanted Metal-Polyethylene Spacers.

Purpose: Two-stage revision is the most common treatment for periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). Few studies have compared the clinical efficacy of different articulating spacers. This study compared the outcomes of all-cement articulating spacers and sterilized replanted metal-polyethylene articulating spacers for PJI following TKA. Patients and Methods: In this retrospective observational study, 47 patients who received two-stage revision for PJI following TKA between 2006 and 2020 in our hospital were included. Patients were categorized as receiving an all-cement articulating spacer or a sterilized replanted metal-polyethylene articulating spacer in exclusion. Data on demographics, surgical information, and outcomes were collected in 2021. Results: Forty-seven spacers were identified: all-cement spacer was noted in 23 patients and sterilized replanted spacer in 24. Patients in the all-cement spacer group had shorter operation time (155.87 ± 33.12 vs 189.79 ± 51.21 min; P = 0.0102) and less blood loss (845.22 ± 525.92 vs 1114.50 ± 547.81 mL; P = 0.0427) in exclusion. Patients in the sterilized replanted spacer group had superior interval range of motion (ROM; 61.00 ± 31.94° vs 31.75 ± 33.38°; P = 0.0072), postoperative ROM (85.00 ± 11.11° vs 77.37 ± 9.18°; P = 0.0329) as compared to all-cement spacers, but there was no difference in infection control between 2 groups. Conclusion: The two types of spacers had no difference in the reinfection rate, indicating that both articulating spacers are safe and effective for 2-stage revision. Considering ROM of knee joint, bone loss and cost, sterilized replanted metal-polyethylene spacers are preferred in the treatment of PJI.

Globulin and albumin to globulin ratio precisely diagnose periprosthetic joint infection and determine the timing of second-stage reimplantation.

BACKGROUND: Periprosthetic joint infection (PJI) is one of the most challenging complications of total joint arthroplasty (TJI). An early and accurate diagnosis of PJI is associated with better treatment outcomes. However, whether the platelet-related markers and globulin-related markers can be used to assist the diagnosis of PJI remains elusive. METHODS: A total of 206 patients who underwent revision hip or knee arthroplasty in our institution were divided into two groups: 79 patients in PJI group and 127 patients in aseptic failure group. The levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), platelet-related markers including platelet count (PLT), mean platelet volume (MPV), plateletcrit (PCT) and PLT to MPV ratio (PMR) and globulin-related markers such as globulin (GLB), albumin to globulin ratio (AGR) and PLT to AGR ratio were compared. The diagnostic value was measured using area under the curve (AUC) after constructing receiver operating characteristic (ROC) curves. The potential of each marker for determining the timing of second-staged reimplantation was also evaluated. RESULTS: Significantly increased levels of ESR, CRP, PLT, PCT, PMR, GLB and PLT to AGR ratio were identified in PJI group, while decreased levels of MPV and AGR were also found. The diagnostic values of all platelet-related markers and GLB were considered as fair, and good diagnostic values of AGR and PLT to AGR ratio were found, which were comparable to those of ESR and CRP. The levels of GLB and AGR can also be used to predict negative culture result and the timing of second-stage reimplantation. CONCLUSIONS: Globulin and albumin to globulin ratio were found to have good diagnostic values for PJI, and they can precisely predict the culture results and persistent infection.

A prospective comparative study of staged total knee arthroplasty: ninety-day versus seven-day interval.

PURPOSE: The optimal interval between staged bilateral total knee arthroplasty (STBTKA) is unclear. Studies have reported STBTKA being performed at the same admission, with a seven day interval. The safety and outcomes of patients submitted to same-admission STBTKA (SA-STBTKA) are questionable and need further investigation. METHODS: A prospective non-randomized study was performed to compare the early postoperative outcomes, systemic complications, and surgical-related complications between the first and second knees, as well as between SA-STBTKA and STBTKA groups. From July 2018 to November 2019, a total of 430 patients were recruited. Analyzed parameters included the Knee Society score (KSS), Knee Society functional score (KSFS), range of motion (ROM), Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score, WOMAC stiffness score, and WOMAC score for daily life difficulty. RESULTS: Pre-operatively, the demographic data and functional scores were not significantly different between the two groups. The KSS, WOMAC pain score, and WOMAC stiffness score of the second knee in the STBTKA group were significantly better than those of the first knee. A total of 426 patients completed the last follow-up one  year after surgery, and the post-operative functional scores were not significantly different between the two groups and between the two knees within the same group. Before the second operation, more systemic complications were identified in the SA-STBTKA group, while the rate of surgical complication was not significantly different when compared to STBTKA patients. CONCLUSIONS: With equivalent post-operative function and a higher frequency of minor complications, SA-STBTKA should be cautiously selected as a treatment option for bilateral osteoarthritis.