The Value of Serological Screening Prior to Conversion Total Hip Arthroplasty.

BACKGROUND: This study sought (1) to assess the value of serological testing prior to conversion total hip arthroplasty (THA) in predicting infection and (2) to identify optimal serological values for routine diagnostic workup prior to conversion THA. METHODS: All patients at our tertiary referral center undergoing conversion THA after hip/acetabular fracture procedure from 2013 to 2018 were retrospectively reviewed. Inclusion criteria were patients previously undergoing hemiarthroplasty or open reduction and internal fixation of acetabular, intertrochanteric, and subtrochanteric fractures that progressed to conversion THA due to post-traumatic arthritis having erythrocyte sedimentation rate/C-reactive protein (CRP) prior to conversion. Infection was defined as positive intraoperative cultures not deemed contaminant in collaboration with infectious disease consult and/or development of PJI within 1 year postoperatively. RESULTS: Twelve of 87 (14%) patients undergoing conversion THA developed infection. The mean erythrocyte sedimentation rate (37.2 vs 24.4 mm/h, P = .2062) and CRP (22.4 vs 9.0 mg/L, P = .0026) in the infected cohort were elevated compared to the noninfected group. An optimal cutoff value for CRP of 12 mg/L (area under the curve = 0.77, 95% confidence interval 0.58-0.97) revealed 75% sensitivity, 84% specificity, 43% positive predictive value, and 95% negative predictive value (P < .0001) in the entire cohort. CONCLUSIONS: Even without clinical signs and symptoms, patients undergoing conversion THA from internal fixation of hip/acetabular fractures are still at high risk for developing periprosthetic joint infection. All patients undergoing conversion THA should have CRP measured preoperatively as a part of the diagnostic workup for underlying infection. Further research should be devoted to creating a preoperative diagnostic algorithm incorporating CRP, similar to Musculoskeletal Infection Society criteria, dedicated to patients undergoing conversion THA. LEVEL OF EVIDENCE: Level III, Diagnostic retrospective cohort study.

The fate of positive intraoperative cultures following conversion total hip arthroplasty.

INTRODUCTION: The objectives of this study are to report the rates of positive intraoperative cultures obtained during conversion total hip arthroplasty (THA) according to index surgery, and to describe the natural history of treatment for a consecutive series of patients with unexpected positive intraoperative cultures during conversion THA. METHODS: We reviewed all patients at 2 institutions undergoing conversion THA from prior open reduction and internal fixation (ORIF) of acetabular and hip fractures or hemiarthroplasty for displaced femoral neck fractures from 2011 to 2018. Intraoperative cultures were taken in 105 patients. Positive intraoperative cultures during conversion were recorded and managed with an infectious diseases consult. The outcomes including PJI at 90 days and 1 year follow-up were documented. RESULTS: Overall, 19 of 105 patients (18%) undergoing conversion THA had positive intraoperative cultures, with the highest rates in the hemiarthroplasty 7/16 (44%) and acetabular ORIF 9/48 (19%) groups. All 19 patients were initially treated conservatively: 8 received IV antibiotics, 10 received no additional therapy, and 1 received oral antibiotics. 4/9 acetabular fracture conversions developed PJI at 1 year, with 3 requiring multiple irrigation and debridement/polyethylene exchanges to control the infection while the 4th patient required 2-stage exchange. There were no 1-year PJI from any of the other index procedures after conversion. All 7 hemiarthroplasty patients with positive cultures were treated to resolution with 4-8 weeks IV antibiotics alone. CONCLUSIONS: Patients undergoing conversion THA from prior hip or acetabular fracture have a high rate of positive intraoperative cultures. As such, all patients undergoing conversion THA from prior hip or acetabular fracture fixation should undergo thorough diagnostic workup prior to surgery, and have intraoperative cultures obtained during surgery if infection remains suspicious. Further work should be performed to develop MSIS criteria for preoperative management of patients undergoing conversion THA.

Civilian Ballistic Femoral Shaft Fractures Compared With Blunt Femur Shaft Fractures.

OBJECTIVE: To assess ballistic femoral shaft fracture outcomes in comparison with closed and open femoral shaft fractures sustained by blunt mechanisms. We hypothesized that ballistic femoral shaft fractures would have similar outcomes to blunt open fractures. DESIGN: Retrospective cohort study. SETTING: Academic Level I trauma center. PARTICIPANTS: Patients 16 years and older presenting with ballistic (140), blunt closed (317), or blunt open (71) femoral shaft fractures. MAIN OUTCOMES: Unplanned return to operating room, fracture-related infection, soft tissue reconstruction, nonunion, implant failure, length of stay, Injury Severity Scores, hospital charges, and compartment syndrome. RESULTS: A total of 528 femoral shaft fractures were identified. A group of 140 ballistic fractures and comparison groups of all femoral shaft fractures sustained by blunt mechanisms and treated with intramedullary nailing were included in the analysis. Among the 2 subgroups of nonballistic injuries, 317 were blunt closed fractures and 71 were blunt open fractures. The ballistic group was associated with a 3-fold increase in overall complications (30%) compared with the blunt closed group (10%, P < 0.001), had a higher occurrence of thigh compartment syndrome (P < 0.001), and required more soft tissue reconstruction (P < 0.001) than either of the blunt fracture groups. CONCLUSIONS: Ballistic femoral shaft fractures do not perfectly fit with blunt closed or open femoral fractures. A high index of suspicion for the development of thigh compartment syndrome should be maintained in ballistic femoral shaft fractures. The overall rates of nonunion and infection were comparable between all groups, but the all-cause complication rate was significantly higher in the ballistic group compared with the blunt closed group. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.