Prognostic Implications of Unexpected Positive Intraoperative Cultures in Two-Stage Knee Arthroplasty Reimplantations: A Minimum Five-Year Retrospective Analysis.

BACKGROUND: The clinical challenge of unexpected positive intraoperative cultures (UPICs) persists in two-stage resection arthroplasty for managing periprosthetic joint infections (PJIs) following total knee arthroplasty (TKA). This study aimed to investigate the incidence of UPICs during the definitive reimplantation phase of two-stage resection arthroplasty of the knee and to assess both the infection- and revision-free survivorship of the implanted prosthesis. METHODS: This retrospective study included 450 two-stage resection arthroplasties of primary knee prostheses performed between January 2012 and April 2017. Patients were excluded if they: (1) underwent three or more staged resections; (2) had ambiguous clinical documentation or deviated from the two-stage protocol; or (3) underwent revision arthroplasty prior to the PJI. Additionally, patients presumed aseptic before the second-stage reimplantation were excluded if they lacked joint aspiration or met the 2011 Musculoskeletal Infection Society (MSIS) criteria for PJI before implantation. RESULTS: After exclusions, 300 patients were analyzed. Among them, 14% had UPIC during the second-stage reimplantation. The follow-up time was 2,316 (range, 1,888 to 3,737) days and 2,531 (range, 1,947 to 3,349) days for UPIC and negative intraoperative culture (NIC) groups, respectively. Re-revision due to subsequent PJI occurred in 26.2% of UPIC patients and 15.1% of NIC patients. The 2-year infection-free survival rates for the NIC, 1 UPIC, and ≥ 2 UPIC cohorts were 99.5, 98.2, and 94.3%, respectively, while the 5-year survival rates were 92.1, 91.1, and 54.3%, respectively. The unfavorable survivorship was significantly different in multiple UPIC cases (P < 0.001). Multiple UPICs with pathogens consistent with the first-stage findings were strongly associated with the risk of reinfection (P < 0.001). CONCLUSIONS: An UPIC was identified in 14% of second-stage reimplantations. Patients who had multiple UPICs demonstrated truncated survivorship and suboptimal outcomes relative to the NIC and single UPIC cohorts, especially with pathogen consistency to the first-stage surgery.

Critical distance of the sacroiliac joint for open reduction using screw fixation for traumatic sacroiliac joint diastasis: a retrospective study.

BACKGROUND: Osteosynthesis for sacroiliac joint (SIJ) diastasis using an iliosacral screw (ISS) and a trans-iliac-trans-sacral screw (TITSS) can be performed using a closed or an open method. However, no clear indication for open reduction has been established. METHODS: Data on patients with unilateral traumatic SIJ diastasis who underwent ISS and TITSS fixation were retrospectively collected and separated into groups according to the reduction method: closed reduction group (C group) and open reduction group (O group). Demographic data and perioperative image assessments were compared between the groups. The critical distance of the SIJ was identified to elucidate the indication for open reduction of the diastatic SIJ. RESULTS: Fifty-six patients met the inclusion criteria over a 3-year period. There was no significant difference in the reduction quality of pelvic ring injuries between the groups, according to Matta's and Lefaivre's criteria. The improvement in the SIJ distance was significantly greater in the O group than in the C group in the axial plane on multiplanar computed tomography (p = 0.021). This model predicted that a difference of > 3.71 mm between the injured and healthy SIJ was a recommended indication for open reduction, with an area under the curve of 0.791 (95% confidence interval 0.627-0.955, p = 0.004). CONCLUSIONS: Open reduction for SIJ diastasis might achieve better reduction quality than does closed reduction in the axial plane in selected cases. When the difference between the injured and healthy SIJ was wider than 3.71 mm, open reduction was recommended for satisfactory radiological outcomes.

Percutaneous iliosacral screw and trans-iliac trans-sacral screw with single C-arm fluoroscope intensifier is a safe treatment for pelvic ring injuries.

To elucidate the accuracy, efficacy, and safety of percutaneous iliosacral screw (ISS) and trans-iliac trans-sacral screw (TITS) insertion using a single C-arm fluoroscopy intensifier. Additionally, the potential risk factors that might cause mal-positioned screws were identified. Patients with pelvic ring injuries who underwent percutaneous screw fixation in a single medical institute were divided into an ISS group (n = 59) and a TITS group (n = 62) and assessed. The angles deviated from ideal orientation (ADIO) of the implanted screw were measured, and potential risk factors for mal-positioned screws were analyzed. Overall, the reduction quality of the pelvic ring was good or excellent in 70 patients (82.4%) by Matta's criteria and in 48 patients (56.5%) by Lefaivre's criteria. ADIO measurements of the ISS and TITS groups via multi-planar computed tomography were 9.16° ± 6.97° and 3.09° ± 2.8° in the axial view, respectively, and 5.92° ± 3.65° and 2.10° ± 2.01° in the coronal view, respectively. Univariate statistical analysis revealed body mass index as the single potential risk factor of mal-positioned screws. With careful preoperative planning and intraoperative preparations, placing ISS and TITS under the guidance of single C-arm fluoroscopy intensifier is a reliable and safe technique. Caution should be exercised when performing this procedure in patients with a high body mass index.

Two-stage exchange Arthroplasty for knee Periprosthetic joint infection exhibit high infection recurrence rate in patients with chronic viral hepatitis.

BACKGROUND: Currently, there is little evidence about the outcome of two-stage exchange arthroplasty for the treatment of knee periprosthetic joint infection (PJI) in patients with chronic viral hepatitis. To evaluate it, we set the primary outcome as infection recurrence, and the secondary outcome as the difference between patients diagnosed with hepatitis B virus or hepatitis C virus. PATIENTS AND METHODS: Between June, 2010 and December, 2016, 172 patients with knee PJIs were treated with two-stage exchange arthroplasty at our institute. Treatment success was defined using Delphi-based consensus. These patients were further divided into groups with or without chronic hepatitis. Variables were analyzed, including age, sex, comorbidities, microbiology, and operative methods. Minimum follow-up was 12 months (mean, 35 months; range, 12-85 months). RESULTS: Of the 172 knee PJI patients, 25 were identified with chronic hepatitis. The infection recurrence rate in the hepatitis group (28%, 7 in 25) was significantly higher than that in the non-hepatitis group (9.5%, 14 in 147), p = 0.017. However, there was no significant difference in the infection recurrence rates between patients with HBV (24%, 4 in 16) and HCV (33.3%, 3 in 9). Regarding the outcomes of patients with infection recurrence, 4 of the non-hepatitis patients were treated with the debridement, antibiotic treatment, irrigation, and retention of prosthesis (DAIR) procedure, with a success rate of 75%. The other 17 patients (7 with hepatitis and 10 without) were treated with repeated two-stage exchange arthroplasty with 100% infection elimination rate until the final follow-up. CONCLUSIONS: Knee PJI patients with chronic hepatitis have higher infection recurrence rate after two-stage exchange arthroplasty (28%).