Paradoxical Behavior of Plasma d-Dimer From Explantation to Reimplantation in a Two-Stage Revision for Periprosthetic Joint Infection.

BACKGROUND: The variation of plasma d-dimer, an inflammatory marker, from pre-explantation to pre-reimplantation in two-stage revision remains unclear. Our objective was to evaluate delta-changes (Δ) in d-dimer, erythrocyte sedimentation rate (ESR), and C-reactive-protein (CRP), to ascertain whether these delta-changes are associated with the outcome of reimplantation. We hypothesized a decrease in d-dimer before reimplantation. METHODS: A retrospective review was performed on a consecutive series of 95 two-stage revisions indicated for periprosthetic joint infection. Surgeries were performed by 3 surgeons at a single institution (2018-2020). The minimum follow-up was 1 year. The inclusion criteria comprised availability of d-dimer results at pre-explantation and pre-reimplantation. As a result, only 30 reimplantations were included. Success of reimplantation was defined by Musculoskeletal Infection Society outcome reporting tool: Tier 1/Tier 2 vs Tier 3/Tier 4. Nonparametric tests and Mann-Whitney U-tests were conducted to compare Δd-dimer% (pre-explantation value - pre-reimplantation value/pre-explantation value × 100). The bootstrapped receiver operating characteristic curve analyses with 2,000 replicates of 30 cases were conducted. RESULTS: The median time between explantation and reimplantation was 86 days (interquartile range [IQR] = 77.7-138.5 days). Overall, a paradoxical median percent increase (Δd-Dimer% [INCREMENT] = 12.6%) in d-dimer was found from pre-explantation to pre-reimplantation (IQR = -28.06% to 77.3%). However, there was a percentage decrease in ESR (ΔESR% [DECREMENT] = -40%; IQR = -70.52% to 3.85%) and CRP (ΔCRP% [DECREMENT] = -75%; IQR = -87.43% to -61.34%). The changes in all these markers were not different between Musculoskeletal Infection Society Tier 1/2 and 3/4 outcomes (Δd-Dimer%, P = .146; ΔESR%, P = .946; ΔCRP%, P = .463). With area under curve of 0.676, Δd-dimer% (INCREMENT) appeared to be performing best in diagnosing infection control, which was nonexplanatory. CONCLUSION: Plasma d-dimer paradoxically increases before reimplantation while other inflammatory markers (ESR/CRP) decrease, emphasizing that surgeons shall adopt caution using d-dimer to make clinical decisions.

Total Hip Arthroplasty After Prior Acetabular Fracture: Infection Is a Real Concern.

BACKGROUND: Acetabular fractures often require surgical intervention for fracture fixation and can result in premature osteoarthritis of the hip joint. This study hypothesized that total hip arthroplasty (THA) in patients with a prior acetabular fracture who had undergone open reduction and internal fixation (ORIF) is associated with a higher rate of subsequent periprosthetic joint infection (PJI). METHODS: About 72 patients with a history of acetabular fracture that required ORIF, undergoing conversion THA between 2000 and 2017 at our institution, were matched based on age, gender, body mass index, Charlson comorbidity index, and date of surgery in a 1:3 ratio with 215 patients receiving primary THA. The mean follow-up for the conversion THA cohort was 2.9 years (range, 1-12.15) and 3.06 years (range, 1-12.96) for the primary THA. RESULTS: Patients with a previous acetabular fracture, compared with the primary THA patients, had longer operative times, greater operative blood loss, and an increased need for allogeneic blood transfusion (26.4% vs 4.7%). Most notably, PJI rate was significantly higher in acetabular fracture group at 6.9% compared with 0.5% in the control group. Complications, such as aseptic revision, venous thromboembolism, and mortality, were similar between both groups. CONCLUSION: The present study demonstrates that conversion THA in patients with prior ORIF of acetabular fractures is associated with higher complication rate, in particular PJI, and less optimal outcome compared with patients undergoing primary THA. The latter findings compel us to seek and implement specific strategies that aim to reduce the risk of subsequent PJI in these patients.

Outcomes of Superficial and Deep Irrigation and Debridement in Total Hip and Knee Arthroplasty.

BACKGROUND: Following total knee arthroplasty and total hip arthroplasty, wound-related problems and deep periprosthetic joint infection may present in a similar fashion. Irrigation and debridement (I&D) has a great role in management of patients with early infection. The question that often arises is how to tell the difference between superficial and deep infection. This study evaluated the role and outcomes of both superficial and deep I&D in patients with wound-related issues and/or suspected periprosthetic joint infection. METHODS: A retrospective study was conducted evaluating patients who underwent I&D within 28 days of total joint arthroplasty. A total of 176 cases with a minimum of 1-year follow-up were identified, and clinical records were reviewed in detail. Reoperations included superficial (fascia not opened) or deep (fascia opened) I&D. Failure was defined as the need for further surgical intervention within 1 year of initial I&D. RESULTS: The overall success for superficial I&D was 84.28% vs 68.86% for deep I&D. The success of both deep and superficial I&D was higher if the I&D was performed closer to the index surgery. Superficial I&D in patients with a positive joint aspiration or evidence of intraoperative purulence or those in whom had no subcutaneous fluid had higher failure rates. CONCLUSION: Superficial I&D is a viable option in patients with wound-related issues as long as joint aspiration is performed to rule out infection involving the prosthesis. If there are findings of no fluid or purulence, fascia may need to be opened and the deeper tissues explored.

Direct Anterior Approach Total Hip Arthroplasty Using a Morphometrically Optimized Femoral Stem, a Conventional Operating Table, Without Fluoroscopy.

BACKGROUND: Our experience with direct anterior approach total hip arthroplasty (THA) suggests that it can be performed successfully with a morphometrically optimized metaphyseal-diaphyseal engaging femoral stem (NOT a short stem), a regular operating room table (NOT a special custom table), and WITHOUT intraoperative fluoroscopy. We report our minimum 2-year results. METHODS: A retrospective review of a single-surgeon series of primary direct anterior approach THAs was performed. All procedures were performed on a regular table, without fluoroscopy, using a cementless tapered femoral stem. Clinical, functional, and radiographic outcomes were evaluated at a minimum of 2 years. RESULTS: In total, 1017 primary THAs were performed. The preoperative Harris Hip Score was 40.7 ± 5.1 and improved to 95.3 ± 4.2 at minimum 2-year follow-up. There were 3 dislocations (0.3%) and 15 revisions (1.5%): 7 for infection (0.7%), 4 for periprosthetic fractures (0.4%), 2 for instability (0.2%), 1 for loosening (0.1%), and 1 for pain (0.1%). Five patients (0.5%) required blood transfusion. One patient developed deep vein thrombosis and pulmonary embolism. No intraoperative fractures, perforation, or THA-related mortality occurred. Neutral stem alignment was confirmed in 98.3%. Mean cup inclination was 38.8° ± 5.1° and anteversion was 16.2° ± 3.5°. The mean leg-length discrepancy was corrected from 1.2 ± 0.2 cm preoperatively to 0.2 ± 0.1 cm postoperatively. CONCLUSION: Using a morphometrically optimized metaphyseal-diaphyseal engaging tapered femoral stem instead of a short stem reduces component malposition and minimizes risk of loosening. Combining the use of this implant design and the technique and elements described in our cohort demonstrated to have excellent results at 2 years. The patients will need continued follow-up to demonstrate further durability of this device and technique compared to others performing direct anterior THA.

Longer Operative Time Results in a Higher Rate of Subsequent Periprosthetic Joint Infection in Patients Undergoing Primary Joint Arthroplasty.

BACKGROUND: Whether prolonged operative time is an independent risk factor for subsequent surgical site infection (SSI) and periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant and underexplored issue. The aim of this study is to investigate the association between operative time and the risk of subsequent SSI and PJI in patients undergoing primary TJA. METHODS: We retrospectively reviewed 17,342 primary unilateral total knee arthroplasty and total hip arthroplasty performed at a single institution between 2005 and 2016, with a minimum follow-up of 1 year. A multivariate logistic regression model was conducted to identify the association between operative time and the development of SSI within 90 days and PJI within 1 year. RESULTS: Overall, the incidence of 90-day SSI and 1-year PJI was 1.2% and 0.8%, respectively. Patients with an operative time of >90 minutes had a significantly higher incidence of SSI and PJI (2.1% and 1.4%, respectively) compared to cases lasting between 60 and 90 minutes (1.1% and 0.7%), and those lasting ≤60 minutes (0.9% and 0.7%, P < .01). In the multivariate model, the risk for infection increased by an odds ratio of 1.346 (95% confidential interval 1.114-1.627) for 90-day SSI and 1.253 (95% confidential interval 1.060-1.481) for 1-year PJI for each 20-minute increase in operative time. CONCLUSION: In patients undergoing primary TJA, each 20-minute increase in operative time was associated with nearly a 25% increased risk of subsequent PJI. We advocate that surgeons pay close attention to this underappreciated risk factor while maintaining safe operative practices, which minimize unnecessary steps and wasted time in the operating room.

Total Hip Arthroplasty Through the Direct Anterior Approach Using a Bikini Incision Can Be Safely Performed in Obese Patients.

BACKGROUND: Direct anterior approach (DAA) total hip arthroplasty can be performed through a traditional vertical incision or a horizontal (bikini) incision. The purpose of this study is to compare the 2 approaches, performed by a single surgeon past the learning curve, in terms of (1) overall wound complications and (2) patient-reported esthetics at the 6-month follow-up. METHODS: A case-control retrospective study was conducted. Eighty-six bikini DAA patients were matched 3:1 to 230 conventional DAA patients for gender, age, body mass index (BMI), and American Society of Anesthesiologists score. Outcomes evaluated included wound complications, acute periprosthetic joint infection, transfusion, length of surgery, and dysesthesia. A subgroup analysis was also performed on obese patients, BMI greater than 30 kg/m2. Furthermore, the patients rated cosmesis of the incision at 6 months using a Patient Scar Assessment Scale and the Vancouver Scar Assessment Scale. RESULTS: Bikini patients had lower rates of delayed wound healing compared to conventional incision (2.3% vs 6.1%, P = .087). This difference was statistically significant (0% vs 16.6%, P < .05) in obese patients. There was no difference in terms of incision cosmesis between the 2 incision types. CONCLUSION: Our study demonstrates that the DAA total hip arthroplasty can be performed safely through an alternative horizontal bikini incision with complication rates equivalent to conventional incision DAA and to those in other approaches when performed by surgeons in a high volume, efficient hip replacement institution. In patients whose BMI is >30, a potential benefit of the horizontal incision may be lower wound complications. This study design should be performed at other institutions and ideally at a multi-institution level to evaluate if results can be corroborated. Our opinion is that the horizontal bikini incision should be utilized but only after mastery of the DAA approach using the conventional vertical incision.

Identifying Reasons for Failed Same-Day Discharge Following Primary Total Hip Arthroplasty.

BACKGROUND: As total hip arthroplasty (THA) gains popularity in ambulatory surgery centers, it is important to understand the causes of failed same-day discharge (SDD). The purpose of this study is to (1) identify reasons for an overnight stay among patients selected as candidates for SDD following THA and (2) determine what pre-operative factors are more common among patients who fail SDD. METHODS: This is a prospective cohort study of patients undergoing THA who were identified as candidates for SDD (<75 years, ambulate without walker, American Society of Anesthesiologists score 1-3, body mass index <40 kg/m2, and agreed to SDD pre-operatively). The primary outcome was the reason for not discharging home on the same day of surgery. Secondary outcomes included the proportion of patients who failed SDD and any pre-operative patient characteristics that could be linked to failed SDD. RESULTS: Seventy-eight of 106 (74%) patients pre-selected for SDD were successfully discharged per protocol. Of the 28 (26%) patients who failed SDD, the most common reasons for failure were patient preference (12), dizziness or hypotension (8), failure to clear physical therapy (5), urinary retention (2), and pain management (1). There was a higher percentage of patients in the failed SDD group who reported multiple allergies (P = .02), anxiety/depression (P = .24), obstructive sleep apnea (P = .38), and rheumatoid arthritis (P = .02). CONCLUSION: SDD is a viable option for surgeons interested in rapid recovery THA. In a pool of patients selected for SDD, the main cause of SDD failure was a change in patient preference post-operatively, despite having agreed to SDD pre-operatively and meeting all discharge criteria.

Intraoperative Dexamethasone Reduces Readmission Rates Without Affecting Risk of Thromboembolic Events or Infection After Total Joint Arthroplasty.

BACKGROUND: The use of perioperative dexamethasone has been proven to reduce pain and shorten recovery for patients undergoing total hip and knee arthroplasty. However, the effect of these medications on 90-day readmissions and the rates of clinically significant venous thromboembolic events (VTE) after total joint arthroplasty (TJA) remains unknown. METHODS: Patients undergoing unilateral, primary total joint arthroplasty between 2009 and 2016 in a single institution were identified. There were 6617 patients who did not receive dexamethasone intraoperatively compared to 1293 patients who received a single, intraoperative, intravenous dose of dexamethasone (8-10 mg). The primary outcomes were the rate of clinically significant VTE and 90-day readmission. Secondary outcomes included wound complications, periprosthetic joint infection, and 90-day mortality. RESULTS: While the overall rate of clinically symptomatic VTE was lower in the dexamethasone group, this did not reach significance in a univariate analysis (0.1% vs 0.2%, P = .353). Only body mass index (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.03-1.24; P = .006) and longer length of stay (OR, 1.16; 95% CI, 1.06-1.28; P = .001) were associated with VTE in the multivariate analysis (OR, 0.31; 95% CI, 0.04-2.36; P = .319). However, the use of intravenous dexamethasone was independently associated with a reduction in 90-day readmission rate (1.6% vs 2.5%; OR, 0.57; 95% CI, 0.36-0.90; P = .016). There was no difference in the rate of periprosthetic joint infection or mortality. CONCLUSION: A single, intraoperative, low dose of dexamethasone is not associated with a reduction in clinically significant VTE but may be a safe and effective adjunct medication to lower 90-day readmission rates. LEVEL OF EVIDENCE: Level III.

Recurrent Periprosthetic Joint Infection After Irrigation and Debridement With Component Retention Is Most Often Due to Identical Organisms.

BACKGROUND: Irrigation and debridement with prosthetic retention (I&D) is an oft-utilized treatment option for PJI, despite its known limited success. While it is known that nearly half of all patients treated with I&D have recurrent infection, the organism persistence between infection events remains unreported. In addition, identifying those cases in which I&D routinely failed to eradicate the infection (not simply prevent recurrent infection) may allow improved patient selection for this less morbid procedure-a difficult task to date. METHODS: Using an institutional database, 146 patients (153 joints) undergoing I&D between April 2000 and July 2013 were identified. There were 60 hips (40%). The overall success rate of I&D in this group was 52% (80/153). The failure group was limited to those patients with growth on culture at both initial failure and recurrent failure (46 cases). Analyses were performed to identify potential predictors of failed I&D and organism persistence in those cases. RESULTS: In the study group, 83.7% (36/43) of cases failed with the same organism. Knees with failed I&D had an organism persistence of 92.3% (24/26) compared with 70.5% (12/17; P = .09) for the hip. Patients initially infected with Staphylococcus aureus (specifically methicillin-resistant [13/13]) had a higher risk of persistent PJI (96%; 24/25) compared to other organisms (66.7%; 12/18; P = .01). CONCLUSION: I&D had a success rate of approximately 50% and typically failed due to organism persistence rather than a new infection. Given that persistent infection was most common in knees and S aureus, I&D should have a limited role in treating PJI, especially in these cases.

A History of Treated Periprosthetic Joint Infection Increases the Risk of Subsequent Different Site Infection.

BACKGROUND: After the successful treatment of periprosthetic joint infection (PJI), patients may present with degenerative joint disease in another joint with symptoms severe enough to warrant arthroplasty. However, it is not known whether patients with a history of treated PJI at one site will have an increased risk of PJI in the second arthroplasty site. QUESTIONS/PURPOSES: The primary objective of this study is to determine if there is a difference in the risk of developing a PJI after a second total hip arthroplasty (THA) or total knee arthroplasty (TKA) in patients who have had a previous PJI at another anatomic site compared with patients who have had no history of PJI. The secondary objective is to determine other potential risk factors that may predict PJI at the site of the second arthroplasty. METHODS: A retrospective matched cohort study was performed to identify all patients at four academic institutions successfully treated for PJI who subsequently underwent a second primary THA or TKA (n = 90), constituting our study group. Patients were matched (one-to-one) to control subjects who had no history of PJI after their first arthroplasty (n = 90); they were matched based on age, sex, diabetic status, BMI, American Society of Anesthesiologists, institution, joint of interest, and year of surgery (± 2 years). We compared the case and control groups to determine whether a prior infection increased the relative risk of a subsequent PJI at another anatomic site. To identify other potential risk factors for subsequent PJI, a subgroup univariate analysis of our study group (n = 90) was performed. To identify other potential risk factors for subsequent PJI, a subgroup univariate analysis of our study group (n = 90) was performed. RESULTS: Patients with a history of PJI had a greater risk of developing PJI in a subsequent THA or TKA (10 of 90 versus zero of 90 in the control group; relative risk, 21.00; 95% confidence interval [CI], 1.25-353.08; p = 0.035). Excluding PJI, we identified no other factors associated with a second joint infection. In patients with a history of PJI, a second PJI occurred more frequently in female patients (female: nine of 10 [90%] versus female: 40 of 80 [50%]; odds ratio [OR], 8.83; 95% CI, 1.13-403.33; p = 0.02) and in those whose initial infection was a staphylococcal species (subsequent PJI seven of 10 [70%] versus no subsequent PJI 28 of 80 [35%]; OR, 4.26; 95% CI, 0.89-27.50; p = 0.04). CONCLUSIONS: A history of PJI predisposes patients to subsequent PJI in primary THA or THA. Patients and surgeons must be aware of the higher risk of this devastating complication before proceeding with a second arthroplasty. LEVEL OF EVIDENCE: Level III, prognostic study.

Bacterial Contamination in Tips of Electrocautery Devices During Total Hip Arthroplasty.

Surgical equipment can become contaminated during surgery. It is unknown if electrocautery tips can become contaminated in clean orthopedic procedures despite the produced heat. Therefore, we conducted a prospective study to address this concern. The tips from 25 primary and 25 aseptic revision THAs were collected and an additional 5 sterile tips served as negative controls. Aerobic and anaerobic cultures were incubated for a minimum of 3 days. There were 3 positive cultures (6%); one in primary THA (4%) with Lactobacillus and Enterococcus faecalis; two among revisions (8%), one with E. faecalis and another one with alpha hemolytic streptococci and coagulase negative Staphylococcus. The mean exposure time of the contaminated tips was 132.3 minutes. Patients were followed for 90 days postoperatively and none of them developed surgical site infection. This is the first study to demonstrate that electrosurgical devices can become contaminated during THA in laminar flow equipped operating rooms.