Risk of Prosthetic Joint Infection Increases Following Early Aseptic Revision Surgery of Total Hip and Knee Arthroplasty

Low Risk of Periprosthetic Joint Infection After Aseptic Revision Total Knee Arthroplasty With Intraosseous Vancomycin

BACKGROUND

Aseptic revisions are the most common reason for revision total knee arthroplasty (rTKA). Previous literature reports early periprosthetic joint infection (PJI) rates after aseptic rTKA to range from 3 to 9.4%. Intraosseous (IO) regional administration of vancomycin has previously been shown to produce high local tissue concentrations in primary and rTKA. However, no data exist on the effect of prophylactic IO vancomycin on early PJI rates in the setting of aseptic rTKA. The aim of this study was to determine the following: (1) what is the rate of early PJI during the first year after surgery in aseptic rTKA performed with IO vancomycin; and (2) how does this compare to previously published PJI rates after rTKA.

METHODS

A consecutive series of 117 cases were included in this study who underwent rTKA between January 2016 and March 2022 by 1 of 2 fellowship-trained adult reconstruction surgeons and received IO vancomycin at the time of surgery in addition to standard intravenous antibiotic prophylaxis. Rates of PJI at 3 months, 1 year, and the final follow-up were evaluated and compared to prior literature.

RESULTS

Follow-up at 3 months was available for 116 of the 117 rTKAs, with 1 lost to follow-up. The rate of PJI was 0% at 3 months postoperatively. Follow-up at 1 year was obtained for 113 of the 117 rTKAs, and the PJI rate remained 0%. The rate of PJI at the final follow-up of ≥ 1 year was 0.88% (95% confidence interval: -0.84 to 2.61). Previous literature reports PJI rates in aseptic rTKA to range from 3 to 9.4%.

CONCLUSIONS

Dual prophylactic antibiotics with IO vancomycin in conjunction with intravenous cephalosporins or clindamycin were associated with a substantial reduction in early PJI compared to prior published literature. These data supplement the early evidence about the potential clinical benefits of IO vancomycin for infection prevention in high-risk cases.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Cement loaded with high-dose gentamicin and clindamycin does not reduce the risk of subsequent infection after aseptic total hip or knee revision arthroplasty: a preliminary study

PURPOSE

The aim of this study was to quantify the prophylactic effect of high-dose gentamicin and clindamycin antibiotic-loaded bone cement (ALBC) during revision total hip (rTHA) or knee (rTKA) arthroplasty for aseptic reasons. The hypothesis was that the raw surgical site infection (SSI) rate is lower when this particular cement is used in comparison with cement loaded with standard-dose gentamicin during rTHA or rTKA for aseptic reasons.

METHODS

This retrospective study included 290 consecutive patients undergoing aseptic rTHA or rTKA. Two consecutive cohorts were defined: the first (control group) involved 145 patients where ALBC with gentamicin only was used; the second (study group) involved 145 patients where ALBC with high-dose gentamicin and clindamycin was used. The primary endpoint was the raw SSI rate after 24 months.

RESULTS

The raw SSI rate was 8/145 (6%) in the control group and 13/145 (9%) in the study group (odds ratio 0.62, p = 0.26). There was a significant impact of the presence of any risk factor on the SSI rate (15/100 versus 6/169, odds ratio = 4.25, p = 0.002), but no significant impact of any individual risk factor. No complication or side effect related to ALBC was observed in either group.

CONCLUSION

These results do not support the routine use of gentamicin and clindamycin ALBC for fixation of revision implants after rTHA and rTKA for aseptic reasons.

Strikingly High Rates of Periprosthetic Joint Infection Following Revision Surgery for Periprosthetic Fractures Regardless of Surgery Timing

BACKGROUND

Periprosthetic fractures following total hip arthroplasty (THA) often occur in the early postoperative period. Recent data has indicated that early revisions are associated with higher complication rates, particularly periprosthetic joint infection (PJI). The purpose of this study was to assess the effect of timing of periprosthetic fracture surgery on complication rates. We hypothesized that complication rates would be significantly higher in revision surgeries performed within 3 months of the index THA.

METHODS

The Medicare Part A claims database was queried from 2010 to 2017 to identify patients who underwent surgery for a periprosthetic fracture following primary THA. Patients were divided based on time between index and revision surgeries: <1, 1 to 2, 2 to 3, 3 to 6, 6 to 9, 9 to 12, and >12 months. Complication rates were compared between groups using multivariate analyses to adjust for demographics, comorbidities, and types of revision surgery.

RESULTS

Of 492,340 THAs identified, 4,368 (0.9%) had a subsequent periprosthetic fracture requiring surgery: 1,725 (39.4%) at <1 month, 693 (15.9%) at 1 to 2 months, 202 (4.6%) at 2 to 3 months, 250 (5.7%) at 3 to 6 months, 134 (3.1%) at 6 to 9 months, 85 (19.4%) at 9 to12 months, and 1,279 (29.3%) at >12 months. The risk of PJI was 11.0% in the <1 month group, 11.1% at 1 to 2 months, 7.9% at 2 to 3 months, 6.8% at 3 to 6 months, 8.2% at 6 to 9 months, 9.4% at 9 to 12 months, and 8.5% at >12 months (P = .12). Adjusting for confounding factors, risk of PJI following periprosthetic fracture surgery was similar regardless of timing (P > .05). Rates of subsequent dislocation and aseptic loosening were also similar regardless of timing.

CONCLUSIONS

The risk of PJI following repeat surgery for a periprosthetic fracture was strikingly high regardless of timing (6.8 to 11.1%), underscoring the high-risk of complications.

Infection Rates After Aseptic Revision Total Hip Arthroplasty With Extended Oral Antibiotic Prophylaxis

INTRODUCTION

Few US studies have investigated the efficacy of extended oral antibiotic prophylaxis (EOAP) in the prevention of periprosthetic joint infection (PJI) after aseptic revision total hip arthroplasty (R-THA). This study compared PJI rates in aseptic R-THA performed with EOAP with PJI rates in published studies of aseptic R-THA patients not receiving EOAP.

METHODS

Prospectively documented data on 127 consecutive aseptic R-THAs were retrospectively reviewed. Evidence-based perioperative infection prevention protocols were used, and all patients were discharged on 7-day EOAP. Superficial and deep infections at 30 and 90 days postoperatively and at mean latest follow-up of 27.8 months were statistically compared with all US studies reporting the prevalence of PJI after aseptic R-THA. Complications related to EOAP within 120 days of the index procedure also are reported.

RESULTS

No superficial or deep infections were observed at 30 and 90 days postoperatively when 7-day postdischarge EOAP was used. Superficial and deep infection rates were 1.57% (two patients) and 3.15% (four patients) at mean latest follow-up, respectively. Comparisons with published 30-day PJI rates of 1.37% ( P = 0.423) and 1.85% ( P = 0.257) were not statistically significant. Two of four comparisons with published 90-day PJI rates of 3.43% ( P = 0.027) and 5.74% ( P = 0.001) were statistically different. The deep PJI rate of 3.15% at mean latest follow-up was significantly lower than two of three published rates at equivalent follow-up including 10.10% ( P = 0.009) and 9.12% ( P = 0.041). No antibiotic-related complications were observed within 120 days of the index procedure.

DISCUSSION

Study findings possibly support the use of EOAP after aseptic R-THA to prevent catastrophic PJI with revision implants, indicating that the efficacy of EOAP cannot be definitively ruled-in or ruled-out based on available evidence.

Personalized digital simulation‑assisted acetabular component implantation in revision hip arthroplasty

The number of artificial total hip revision arthroplasties is increasing yearly in China, and >50% of these cases have acetabular defects. Accurately locating and quantifying the bone defect is one of the current challenges of this surgery. Thus, the objective of the present study was to simulate acetabular implantation with the aid of Mimics 17.0 software (Materialise NV) in patients with loosened acetabular prosthesis, to evaluate the 'ideal acetabular center' and the 'actual acetabular center' to guide the choice of prosthesis and surgical method. From January 2017 to June 2021, the present study included 10 hips from 10 patients [seven men (seven hips) and three women (three hips)]. In all patients, the Mimics software was applied to simulate the dislocation of the femoral prosthesis and acetabular prosthesis implantation before surgery; calculate the height difference between the 'ideal acetabular center' and the 'actual acetabular center' to assess the bone defect; confirm the size of the acetabular prosthesis, abduction angle, anteversion angle and bone coverage of the acetabular cup; and measure the intraoperative bleeding and postoperative follow-up Harris score of the hip joint. After statistical analysis, the present study revealed that digital simulation assistance could improve the accuracy of hip revision acetabular prosthesis implantation, reduce postoperative shortening of the affected limb, especially for surgeons with relatively little experience in hip revision surgery, and greatly reduce the occurrence of complications such as hip dislocation because of poor postoperative prosthesis position.

Early Periprosthetic Femur Fractures After Primary Cementless Total Hip Arthroplasty: High Risk of Periprosthetic Joint Infection and Subsequent Reoperation

BACKGROUND

Periprosthetic femur fracture (PFF) following total hip arthroplasty (THA) is a leading cause of early reoperation. The objective of this study was to compare rates of periprosthetic joint infection (PJI) and reoperation following PFFs occurring early postoperatively to those that occurred late.

METHODS

We retrospectively identified 173 consecutive surgically managed PFFs following primary THA. Cases were categorized as "early" if they occurred within 90 days of THA (n = 117) or "late" if they occurred following the initial 90 days (n = 56). Mean age at time of PFF was 68 years (range, 26 to 96) and 60% were women. Mean body mass index was 29 (range, 16 to 52). Mean follow-up was 2 years (range, 0 to 13). Kaplan-Meier survival analysis estimated cumulative incidences of PJI and reoperation.

RESULTS

Early PFFs had higher 2-year cumulative incidence of PJI (11% versus 0%, P < .001) and reoperation (24% versus 13%, P = .110). Following early PFF, 27 patients required reoperation (ie, 13 for PJI, 5 for instability, 2 for re-fracture, 2 for painful hardware, 2 for non-union, 1 for adverse local tissue reaction, 1 for aseptic loosening, and 1 for leg-length discrepancy). Following late PFF, 5 patients required reoperation (ie, 3 for instability, 1 for re-fracture, and 1 for non-union).

CONCLUSIONS

There are greater incidences of PJIs and overall reoperations following early PFFs compared to late PFFs after THA. In addition to focusing efforts on prevention of early PFFs, surgeons should consider antiseptic interventions to mitigate the increased risk of PJI after treatment of early PFF.

How are Oral Antibiotics Being Used in Total Joint Arthroplasty? A Review of the Literature

While the role and benefit of perioperative intravenous (IV) antibiotics in patients undergoing total joint arthroplasty (TJA) is well-established, oral antibiotic use in TJA remains a controversial topic with wide variations in practice patterns. With this review, we aimed to better educate the orthopedic surgeon on when and how oral antibiotics may be used most effectively in TJA patients, and to identify gaps in the literature that could be clarified with targeted research. Extended oral antibiotic prophylaxis (EOAP) use in high-risk primary, aseptic revision, and exchange TJA for infection may be useful in decreasing periprosthetic joint infection (PJI) rates. When prescribing oral antibiotics either as EOAP or for draining wounds, patient factors, type of surgery, and type of infectious organisms should be considered in order to optimally prevent and treat PJI. It is important to maintain antibiotic stewardship by administering the proper duration, dose, and type of antibiotics and by consulting infectious disease when necessary.

The Use of Artificial Intelligence for the Prediction of Periprosthetic Joint Infection Following Aseptic Revision Total Knee Arthroplasty

Periprosthetic joint infection (PJI) following revision total knee arthroplasty (TKA) for aseptic failure is associated with poor outcomes, patient morbidity, and high health care expenditures. The aim of this study was to develop novel machine learning algorithms for the prediction of PJI following revision TKA for patients with aseptic indications for revision surgery. A single-institution database consisting of 1,432 consecutive revision TKA patients with aseptic etiologies was retrospectively identified. The patient cohort included 208 patients (14.5%) who underwent re-revision surgery for PJI. Three machine learning algorithms (artificial neural networks, support vector machines, k-nearest neighbors) were developed to predict this outcome and these models were assessed by discrimination, calibration, and decision curve analysis. This is a retrospective study. Among the three machine learning models, the neural network model achieved the best performance across discrimination (area under the receiver operating characteristic curve = 0.78), calibration, and decision curve analysis. The strongest predictors for PJI following revision TKA for aseptic reasons were prior open procedure prior to revision surgery, drug abuse, obesity, and diabetes. This study utilized machine learning as a tool for the prediction of PJI following revision TKA for aseptic failure with excellent performance. The validated machine learning models can aid surgeons in patient-specific risk stratifying to assist in preoperative counseling and clinical decision making for patients undergoing aseptic revision TKA.

Graphic type differentiation of cell count data for diagnosis of early and late periprosthetic joint infection: A new method

BACKGROUND

Graphic type differentiation of cell count data of synovial aspirates is a new method for the diagnosis of early and late periprosthetic joint infection.

OBJECTIVE

The aim of the study was to analyse if the same 6 LMNE-types can be differentiated in the new Yumizen H500 cell counter as it was the case for the old cell counter ABX Pentra XL 80 of previous publications, to verify if the erythrocyte and thrombocyte curves of the new device give additional information and to calculate the difference of cell count in LMNE-type I and III (with abrasion) in the cell counter and in the manual counting chamber (Neubauer improved).

METHODS

450 aspirates of 152 total hip arthroplasties and 298 knee arthroplasties obtained for the diagnosis of periprosthetic joint infection were analysed with the Yumizen H500.

RESULTS

All LMNE-matrices of the 450 aspirates could assigned to one of the six LMNE-types. There were 76 LMNE-type I, 72 LMNE-type II, 14 LMNE-type III, 241 LMNE-type IV, 36 LMNE-type V and 12 LMNE-type VI. The erythrocyte and thrombocyte distribution curves were very helpful for differentiation of hematoma and infection. The cell count in the manual counting procedure was lower than in the cell counter: for the LMNE-type I (abrasion type) the median of the difference was 925/μL (median) and for the LMNE-type III (combined type of infection and abrasion) 3570/μL (median).

CONCLUSION

The described graphic type differentiation is a new and helpful method for differentiation of hematoma and early PJI as well as abrasion and late PJI.

Rate and factors associated with surgical site infection following aseptic revision fixation of orthopaedic trauma injuries

PURPOSE

The primary aim of this study was to define the rate of infection following revision of fixation for aseptic failure. The secondary aims were to identify factors associated with an infection following revision and patient morbidity following deep infection.

METHODS

A retrospective study was undertaken to identify patients who underwent aseptic revision surgery during a 3-year period (2017-2019). Regression analysis was used to identify independent factors associated with SSI.

RESULTS

Eighty-six patients were identified that met the inclusion criteria, with a mean age of 53 (range 14-95) years and 48 (55.8%) were female. There were 15 (17%) patients with an SSI post revision surgery (n = 15/86). Ten percent (n = 9) of all revisions acquired a 'deep infection', which carried a high morbidity with a total of 23 operations, including initial revision, being undertaken for these patients as salvage procedures and three progressed to an amputation. Alcohol excess (odds ratio (OR) 1.61, 95% CI 1.01-6.36, p = 0.046) and chronic obstructive pulmonary disease (OR 11.1, 95% CI 1.00-133.3, p = 0.050) were independently associated with an increased risk of SSI.

CONCLUSION

Aseptic revision surgery had a high rate of SSI (17%) and deep infection (10%). All deep infections occurred in the lower limb with the majority of these seen in ankle fractures. Alcohol excess and COPD were independent risk factors associated with an SSI and patients with a history of these should be counselled accordingly.

LEVEL OF EVIDENCE

Retrospective Case Series, Level IV.

Diagnosing periprosthetic joint infection

Aims

The diagnosis of periprosthetic joint infection (PJI) can be challenging as the symptoms are similar to other conditions, and the markers used for diagnosis have limited sensitivity and specificity. Recent research has suggested using blood cell ratios, such as platelet-to-volume ratio (PVR) and platelet-to-lymphocyte ratio (PLR), to improve diagnostic accuracy. The aim of the study was to further validate the effectiveness of PVR and PLR in diagnosing PJI.

Methods

A retrospective review was conducted to assess the accuracy of different marker combinations for diagnosing chronic PJI. A total of 573 patients were included in the study, of which 124 knees and 122 hips had a diagnosis of chronic PJI. Complete blood count and synovial fluid analysis were collected. Recently published blood cell ratio cut-off points were applied to receiver operating characteristic curves for all markers and combinations. The area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values were calculated.

Results

The results of the analysis showed that the combination of ESR, CRP, synovial white blood cell count (Syn. WBC), and polymorphonuclear neutrophil percentage (PMN%) with PVR had the highest AUC of 0.99 for knees, with sensitivity of 97.73% and specificity of 100%. Similarly, for hips, this combination had an AUC of 0.98, sensitivity of 96.15%, and specificity of 100.00%.

Conclusion

This study supports the use of PVR calculated from readily available complete blood counts, combined with established markers, to improve the accuracy in diagnosing chronic PJI in both total hip and knee arthroplasties.

The Use of Oral Antibiotics After Total Joint Arthroplasty: A Critical Analysis Review

» There is conflicting and insufficient evidence that extended oral antibiotic (EOA) therapy prevents infection in high-risk patients undergoing primary total joint arthroplasty (TJA), limiting recommendation for or against the practice.» In the case of aseptic revision TJA, the evidence is also conflicting and limited by underlying confounders, preventing recommendation for use of EOA.» There is fair evidence that use of EOA after debridement antibiotic therapy and implant retention of the prosthesis prolongs infection-free survival, but randomized controlled trials are needed. On the other hand, there is strong evidence that patients undergoing 2-stage revision should receive a period of suppressive oral antibiotics after the second stage.» The optimal duration of EOA in primary TJA, aseptic revision, and debridement antibiotic therapy and implant retention of the prosthesis is unknown. However, there is strong evidence that 3 months of EOA suppression may be appropriate after reimplantation as part of 2-stage exchange arthroplasty.» Complications secondary to EOA are reported to be between 0% and 13.7%, yet are inconsistently reported and poorly defined. The risks associated with antibiotic use, including development of antimicrobial resistance, must be weighed against a possible decrease in infection rate.

A Low Rate of Periprosthetic Infections after Aseptic Knee Prosthesis Revision Using Dual-Antibiotic-Impregnated Bone Cement

AIM

The incidence of periprosthetic joint infections (PJI) following aseptic knee revision arthroplasty lies between 3% and 7.5%. The aim of this study was to verify the hypothesis that the use of dual-antibiotic-impregnated cement in knee revision arthroplasty leads to a lower rate of periprosthetic joint infections.

METHODS

We retrospectively reviewed 403 aseptic revision knee arthroplasties performed between January 2013 and March 2021 (148 revisions of a unicompartmental prosthesis, 188 revisions of a bicondylar total knee arthroplasty (TKA), 41 revisions of an axis-guided prosthesis, and 26 revisions of only one component of a surface replacement prosthesis). The bone cement Copal G+C (Heraeus Medical, Wertheim, Germany) with two antibiotics-gentamycin and clindamycin-was used for the fixation of the new implant. The follow-up period was 53.4 ± 27.9 (4.0-115.0) months.

RESULTS

Five patients suffered from PJI within follow-up (1.2%). The revision rate for any reason was 8.7%. Survival for any reason was significantly different between the types of revision (p = 0.026, Log-Rank-test), with lower survival rates after more complex surgical procedures. The 5-year survival rate with regard to revision for any reason was 91.3% [88.2-94.4%] and with regard to revision for PJI 98.2% [98.7-99.9%], respectively.

CONCLUSION

The use of the dual-antibiotic-impregnated bone cement Copal G+C results in a lower rate of periprosthetic infections after aseptic knee prosthesis replacement than that reported in published prosthesis revisions using only one antibiotic in the bone cement.

Clinical Outcomes and Infection Rates Following Revision Total Knee Arthroplasty: Aseptic Failure versus Septic Failure

Background

It is controversial whether revision total knee arthroplasty (TKA) due to septic failure shows inferior clinical outcomes compared with TKA due to aseptic failure. Moreover, few studies have compared the infection rates after revision TKA between aseptic and septic failure. We aimed to compare the clinical outcomes and infection rates after aseptic and septic revision TKA.

Methods

Between April 2006 and May 2019, 68 and 26 patients underwent revision TKA due to aseptic failure (aseptic group) and septic failure (septic group), respectively. The postoperative range of motion (ROM), Western Ontario and McMaster Universities Osteoarthritis index, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), and infection rates were compared between the two groups.

Results

The mean follow-up durations in the aseptic and septic groups were 44.4 and 54.8 months, respectively. The septic group showed inferior postoperative ROM (124.1° and 109.4°, p = 0.004), KSKS (88.9 and 78.8, p = 0.001), and KSFS (72.8 and 59.0, p = 0.001). Three patients of aseptic group had infection. Three patients of septic group had recurred infection (same pathogen with the first infection) and 1 patient had a new infection (different pathogen). The septic group showed slightly higher but not significantly different infection rates (4.4% and 15.4%, p = 0.089).

Conclusions

Revision TKA with septic failure showed inferior postoperative clinical outcomes compared with aseptic revision surgery. A slightly higher infection rate was observed in the septic group but it was not significantly different.

Managing early complications in total hip arthroplasty: the safety of immediate revision

PURPOSE

Immediate revision refers to a reoperation that involves resetting, draping, and exchanging the implant, after wound closure in total hip arthroplasty. The purpose of this study is to investigate the impact of immediate revision after total hip arthroplasty on subsequent infection and complication rates.

METHODS

A total of 14,076 primary total hip arthroplasties performed between 2010 and 2020 were identified in our institutional database, of which 42 underwent immediate revision. Infection rates were determined 2 years after the index arthroplasty. The cause and type of revision, duration of primary and revision surgeries, National Nosocomial Infections Surveillance score, implant type, changes in implants, complications, and preoperative and intraoperative antibiotic prophylaxis were all determined.

RESULTS

No infections were observed within 2 years after the index arthroplasty. Leg length discrepancy (88%, n = 37) and dislocation (7.1%, n = 3) were the main causes of immediate revision. In most cases of discrepancy, the limb was clinically and radiologically longer before the immediate revision. The mean operative time was 48 ± 14 min for the primary procedure and 23.6 ± 9 min for the revision. The time between the first incision and last skin closure ranged from 1 to 3 h. None of the patients were extubated between the two procedures. Two patients had a National Nosocomial Infections Surveillance score of 2, 13 had a score of 1, and 27 had a score of 0.

CONCLUSION

Immediate revision is safe for correcting clinical and radiological abnormalities, and may not be associated with increased complication or infection rates.

STUDY DESIGN

Retrospective cohort study; level of evidence, 3.

Human Knee Has A Distinct Microbiome: Implications for Periprosthetic Joint Infection

INTRODUCTION

Pathogens causing prosthetic joint infection are thought to gain access to the knee during surgery or from a remote site in the body. Recent studies have shown that there is a distinct microbiome in various sites of the body. This prospective study, and first of its kind, was set up to investigate the presence of possible microbiome in human knee and compare the profile in different knee conditions.

METHODS

This transversal study prospectively obtained synovial fluid from 65 knees (55 patients) with various conditions that included normal knee, osteoarthritis, aseptic revision, and those undergoing revision for periprosthetic joint infection (PJI). The contralateral knee of patients who had a PJI were also aspirated to compare the composition of the PJI knee with uninfected contralateral knee. A minimum of 3 milliliters (ml) of synovial fluid was collected per joint. Then, the samples were aliquoted for culture and next generation sequencing (NGS) analysis.

RESULTS

The highest number of species was found in native osteoarthritic knees (P≤0.035). Cutibacterium, Staphylococcus, and Paracoccus species were dominant in native non-osteoarthritic knees, and meanwhile a markedly high abundance of Proteobacteria was observed in the osteoarthritic joints. Moreover, the contralateral and aseptic revision knees showed a similar trend in bacterial composition (P=0.75). The NGS analysis of patients who had PJI diagnosis, confirmed the culture results.

DISCUSSION/CONCLUSION

Distinct knee microbiome profiles can be detected in patients who have osteoarthritis and other knee conditions. The distinct microbiome in the knee joint and the close host-microbe relationships within the knee joint may play a decisive role in the development of osteoarthritis and periprosthetic joint infection.

Which Patients with Chronic Periprosthetic Joint Infection Are Less Suitable to Successful Two Stage Exchange Arthroplasty Surgery? A Retrospective Clinical Trial

BACKGROUND

Two-stage exchange (TSE) arthroplasty is currently considered the gold standard for chronic periprosthetic joint infections (PJIs), despite a failure rate reported in up to 10% of patients. Little is known about the risk factors that may compromise successful TSE arthroplasty management in such patients. The main purpose of the current study was to highlight the potential risk factors of patients with chronic PJIs after THA managed by implant removal, outlining the differences between reimplanted patients and those that were never reimplanted because of a non-eradicated infection.

METHODS

We conducted a retrospective observational study of patient candidates for TSE arthroplasty surgery, managed at the authors' institution, over a four-year timeframe. The data were retrieved from the hospital's information database. The enrolled population was divided into two Groups: A, reimplanted; B, non-reimplanted because of a non-eradicated infection within one year. For each Group, demographic information, PJI-related risk factors, type of pathogen and presence of single or polymicrobial infection, were collected and analyzed.

RESULTS

In total, 21 patients were included in the study, 14 patients in Group A and 7 in Group B. Major Depression (p = 0.049) and polymicrobial infection (p = 0.04) were more commonly observed in patients that were not reimplanted in the study period. No differences between the two groups were observed when other characteristics were compared.

CONCLUSIONS

Patients with major depression, or those hosting polymicrobial periprosthetic hip infections, are more susceptible to failure of TSE arthroplasty procedures for chronic PJIs, hampering THA reimplantation. Current findings may drive further research and contribute to the understanding of the role of these risk factors in chronic PJI patients.

Preoperatively elevated HbA1c levels can meaningfully improve following total joint arthroplasty

BACKGROUND

Prior literature has demonstrated that diabetic (DM) patients undergoing total joint arthroplasty (TJA) with elevated preoperative HbA1c scores have poorer clinical outcomes. However, no literature has reported the effect of undergoing TJA on laboratory markers of glycemic control. This study sought to evaluate effect of undergoing TJA on postoperative glycemic control and outcomes.

METHODS

This retrospective study reviewed all patients with DM who underwent primary, elective TJA at our high volume orthopedic institution. Included patients had at least one HbA1c value 3 months to 2 weeks pre-surgery and 3-6 months after surgery. Changes in HbA1c from before to after surgery were calculated. Change in HbA1c greater than 1.0% was considered clinically meaningful. Change in HbA1c was analyzed and stratified into subgroups.

RESULTS

In total, 770 primary TJA patients were included. Patients with preoperative HbA1c > 7% vs. ≤ 7% were significantly more likely to have clinically meaningful post-TJA decrease in HbA1c (24.5 vs. 2.9%, p < 0.001). Patients with preoperative HbA1c > 8 were significantly more likely to have decrease of > 2.0 compared to those with HbA1c < 8 (p < 0.001). Multivariate regression revealed that preop HbA1c > 7.0, former and current smokers, males, and African-Americans were significantly more likely to achieve clinically meaningful decrease in HbA1c. Additionally, postoperative increase in HbA1c > 1% was associated with significantly higher 90-day ED visits.

DISCUSSION

Patients with higher preoperative HbA1c were more likely to have clinically meaningful decreases in HbA1c postoperatively. A combination of preoperative medical optimization and improvements in mobility after TJA may play a role in these changes. Those with elevated HbA1c can have meaningful improvement in HbA1c after TJA.

A retrospective study of risk factors, causative micro-organisms and healthcare resources consumption associated with prosthetic joint infections (PJI) using the Clinical Practice Research Datalink (CPRD) Aurum database

BACKGROUND

Prosthetic joint infection (PJI) is a serious complication after joint replacement surgery and it is associated with risk of mortality and morbidity along with high direct costs.

METHODS

The Clinical Practice Research Datalink (CPRD) data were utilized to quantify PJI incidence after hip or knee replacement up to 5 years after implant and a variety of risk factors related to patient characteristics, medical and treatment history along with characteristics of the original surgery were analyzed through Cox proportional hazard.

RESULTS

221,826 patients (individual joints 283,789) met all the inclusion and exclusion criteria of the study; during the study follow-up period (5 years), 707 and 695 PJIs were diagnosed in hip and knee, respectively. Patients undergoing joint replacement surgery during an unscheduled hospitalization had greater risk of PJI than patients whose surgery was elective; similarly, the risk of developing PJI after a secondary hip or knee replacement was about 4 times greater than after primary arthroplasty when adjusted for all other variables considered. A previous diagnosis of PJI, even in a different joint, increased the risk of a further PJI. Distribution of average LoS per each hospitalization caused by PJI exhibited a right skewed profile with median duration [IQR] duration of 16 days [8-32] and 13 days [7.25-32] for hip and knee, respectively. PJIs causative micro-organisms were dependent on the time between initial surgery and infection offset; early PJI were more likely to be multispecies than later (years after surgery); the identification of Gram- pathogens decreased with increasing post-surgery follow-up.

CONCLUSIONS

This study offers a contemporary assessment of the budgetary and capacity (number and duration of hospitalizations along with the number of Accident and Emergency (A&E) visits) posed by PJIs in UK for the national healthcare system (NHS). The results to provide risk management and planning tools to health providers and policy makers in order to fully assess technologies aimed at controlling and preventing PJI. The findings add to the existing evidence-based knowledge surrounding the epidemiology and burden of PJI by quantifying patterns of PJI in patients with a relatively broad set of prevalent comorbidities.

Extended Oral Antibiotic Prophylaxis After Aseptic Total Hip or Knee Arthroplasty Revisions: A Preliminary Report

BACKGROUND

It is unknown whether extended oral antibiotic (EOA) prophylaxis reduces periprosthetic joint infection (PJI) rates after aseptic revision total hip (THA) and knee arthroplasty (TKA). The literature is scarce. Therefore, we sought to ascertain whether EOA prophylaxis decreases PJI rates after aseptic first-time revision THA and TKA when compared to standard prophylaxis.

METHODS

This is a retrospective review of 328 consecutive revisions (3 surgeons, single institution, from September 27, 2017 to December 31, 2019). Preoperative 2013 Musculoskeletal Infection Society (MSIS) criteria, radiographs, and medications were reviewed. Inclusion criteria included aseptic first-time revision THA and TKA. Exclusion criteria were positive intraoperative cultures and/or histology, PJI (2013 MSIS criteria), hemiarthroplasty/partial arthroplasty revision, revision using foreign material (ie, mesh), metastatic bone disease, and intravenous antibiotics >24 hours after surgery. A total of 178 revisions were included, and 2 groups were set apart based on antibiotic prophylactic regime. The following were the groups: (1) EOA prophylaxis (>24 hours, n = 93) and (2) standard prophylaxis (≤24 hours, n = 85). Demographics, joint types, lengths of stay, skin-to-skin operative times, revision types, transfusions, discharge dispositions, and PJIs (per 2013 MSIS criteria) after the first-time revision were compared between groups. There were no significant differences in demographics. However, skin-to-skin operative time was significantly higher in the EOA group (123 minutes versus 98 minutes, P = .01). Mean follow-up was 849 days (range, 15-1,671). Statistical significance was set at a P value lower than .05.

RESULTS

Postoperative PJI rates were not significantly different: 2.2% EOA prophylaxis versus 3.5% standard prophylaxis (P = .671).

CONCLUSION

No significant difference was found between PJI rates between both prophylactic regimens. A large multicenter study with a larger sample size is needed to support EOA after aseptic revisions.

LEVEL OF EVIDENCE

Level III.

Outcomes of novel 3D-printed fully porous titanium cup and a cemented highly cross-linked polyethylene liner in complex and revision total hip arthroplasty

INTRODUCTION

A novel fully porous acetabular titanium shell has been designed to reduce stiffness mismatch between bone and implant and promote osseointegration in complex (cTHA) and revision total hip arthroplasty (rTHA). A highly cross-linked polyethylene (XLPE) liner is cemented within the cup to reduce wear rates and increase survivorship. This study reported the outcomes of an XLPE liner cemented into a novel 3D-printed fully porous cup in cTHA and rTHA.

METHODS

Presented was a multicenter retrospective review of 40 patients (6 cTHA and 34 rTHA) who underwent THA with a fully porous titanium acetabular cup and cemented XLPE liner. Data were collected on demographics, surgical information, outcomes, including osseointegration and migration and implant survivorship.

RESULTS

On average, patients were 71.42 ± 9.97 years old and obese (BMI: 30.36 ± 6.88 kg/m²) and were followed up for a mean time of 2.21 ± 0.77 years. Six patients underwent cTHA and 34 patients underwent rTHA. The mean hospital length of stay was 5.34 ± 3.34 days. Three (7.5%) 90-day readmissions were noted. Harris Hip Scores improved, on average, from 53.87 ± 12.58 preoperatively to 83.53 ± 12.15 postoperatively (P<0.001). One case of acetabular shell aspetic loosening with migration was noted. Thirty-nine of the 40 acetabular components were fully osseointegrated without migration. Two patients underwent re-revision surgery for PJI and one patient received acetabular shell+liner re-revision due to aseptic loosening. Kaplan-Meier analysis showed an all-cause revision-free survival rate of 95.0% at 6 months and 1 year, and 92.0% at 4-years. Aseptic acetabular cup, liner dislocation/loosening, and fracture-free survival was 100% at 6 months and 1-year, and 97.1% at 2 years.

CONCLUSION

The combined use of a novel 3D-printed fully porous titanium acetabular shell and cemented XLPE acetabular liner yielded excellent rates of osseointegration, and all-cause and acetabular aseptic loosening survivorship at a minimum 1-year follow-up. Further long-term studies are needed to assess the longevity of this construct.

Underweight Body Mass Index Is Associated With Increased In-Hospital Complications and Length of Stay After Revision Total Joint Arthroplasty

INTRODUCTION

The purpose of this study was to assess the impact of underweight status on in-hospital postoperative outcomes and complications after revision total joint arthroplasty (rTJA) of the hip and knee.

METHODS

Data from the National Inpatient Sample were used to identify all patients undergoing rTJA in the United States between 2006 and 2015. Patients were divided into two groups based on a concomitant diagnosis of underweight body mass index and a control normal weight group. Propensity score analysis was performed to determine whether underweight body mass index was a risk factor for in-hospital postoperative complications and resource utilization.

RESULTS

A total of 865,993 rTJAs were analyzed. Within the study cohort, 2,272 patients were classified as underweight, whereas 863,721 were classified as a normal weight control group. Underweight patients had significantly higher rates of several comorbidities compared with the control cohort. Underweight patients had significantly higher rates of any complication (49.98% versus 33.68%, P = 0.0004) than normal weight patients. Underweight patients also had significantly greater length of stay compared with normal weight patients (6.50 versus 4.87 days, P < 0.0001).

CONCLUSION

Underweight patients have notably higher rates of any complication and longer length of stay after rTJA than those who are not underweight. These results have important implications in preoperative patient discussions and perioperative management. Standardized preoperative protocols should be developed and instituted to improve outcomes in this patient cohort.

Characteristics and outcomes of culture-negative prosthetic joint infections from the Prosthetic Joint Infection in Australia and New Zealand Observational (PIANO) cohort study

Introduction: Culture-negative (CN) prosthetic joint infections (PJIs) account for approximately 10 % of all PJIs and present significant challenges for clinicians. We aimed to explore the significance of CN PJIs within a large prospective cohort study, comparing their characteristics and outcomes with culture-positive (CP) cases. Methods: The Prosthetic joint Infection in Australia and New Zealand Observational (PIANO) study is a prospective, multicentre observational cohort study that was conducted at 27 hospitals between 2014 and 2017. We compared baseline characteristics and outcomes of all patients with CN PJI from the PIANO cohort with those of CP cases. We report on PJI diagnostic criteria in the CN cohort and apply internationally recognized PJI diagnostic guidelines to determine optimal CN PJI detection methods. Results: Of the 650 patients with 24-month outcome data available, 55 (8.5 %) were CN and 595 were CP. Compared with the CP cohort, CN patients were more likely to be female (32 (58.2 %) vs. 245 (41.2 %); p   =  0.016), involve the shoulder joint (5 (9.1 %) vs. 16 (2.7 %); p   =  0.026), and have a lower mean C-reactive protein (142 mg L- 1 vs. 187 mg L- 1 ; p   =  0.016). Overall, outcomes were superior in CN patients, with culture negativity an independent predictor of treatment success at 24 months (adjusted odds ratio, aOR, of 3.78 and 95 %CI of 1.65-8.67). Suboptimal diagnostic sampling was common in both cohorts, with CN PJI case detection enhanced using the Infectious Diseases Society of America PJI diagnostic guidelines. Conclusions: Current PJI diagnostic guidelines vary substantially in their ability to detect CN PJI, with comprehensive diagnostic sampling necessary to achieve diagnostic certainty. Definitive surgical management strategies should be determined by careful assessment of infection type, rather than by culture status alone.

Patients at a high risk of PJI: Can we reduce the incidence of infection using dual antibiotic-loaded bone cement?

Prosthetic joint infection (PJI) is one of the most devastating complications of orthopedic surgery. However, not all patients are equally at the risk of severe infection. The incidences of PJI vary with the host and surgery-related risk factors. It is now generally accepted that some important medical comorbidities may predispose the patients to a high risk of PJI. Time-consuming and invasive surgical procedures, such as revision arthroplasties, are also associated with a high incidence of PJI, presumably due to the increased risk of surgical site contamination. Effective infection-preventing strategies should begin with identifying and optimizing the patients at a high risk of infection prior to surgery. Optimizing the operating room environment and antibiotic prophylaxis are also essential strategies that help minimize the overall incidence of infection in orthopedic surgery. The ideal antibiotic prophylaxis is still under debate, and discussions have emerged about whether variations or adjustments to the standard protocol are justified in patients at a high risk of infection. This also includes evaluating the possible benefits and risks of using high-dose dual antibiotic-loaded bone cement instead of low-dose single antibiotic-loaded bone cement in arthroplasty. This review summarizes the evidence showing that the combination of two local antibiotics in bone cement exerts a strong and longer-lasting antimicrobial effect against PJI-associated pathogens. This conclusion is consistent with the preliminary clinical studies showing a low incidence of PJI in high-risk patients undergoing cemented hemiarthroplasty, cemented revision, and primary arthroplasty if dual ALBC is used. These results may encourage clinicians to consolidate this hypothesis in a wider clinical range.

Reduced Infection Rate After Aseptic Revision Total Knee Arthroplasty With Extended Oral Antibiotic Protocol

BACKGROUND

The optimal postoperative antibiotic duration has not been determined for aseptic revision total knee arthroplasty (R-TKA) where the risk of periprosthetic joint infection (PJI) is 3%-7.5%. This study compared PJI rates in aseptic R-TKA performed with extended oral antibiotic prophylaxis (EOAP) to published rates.

METHODS

Aseptic R-TKAs consecutively performed between 2013 and 2017 at a tertiary care referral center in the American Midwest were retrospectively reviewed. All patients were administered intravenous antibiotics while hospitalized and discharged on 7-day oral antibiotic prophylaxis. Infection rates and antibiotic-related complications were assessed.

RESULTS

Sixty-seven percent of the 176 analysis patients were female, with an average age of 64 years and body mass index of 35 kg/m². Instability and aseptic loosening comprised 86% of revision diagnoses. Overall, 87.5% of intraoperative cultures were negative, and the remainder were single positive cultures considered contaminants. PJI rates were 0% at 90 days, 1.8% (95% confidence interval 0.4%-5.3%) at 1 year, and 2.2% (95% confidence interval 0.6%-5.7%) at mean follow-up of approximately 3 years (range, 7-65 months).

CONCLUSION

EOAP after aseptic R-TKA resulted in a PJI rate equivalent to primary TKA, representing a 2- to-4-fold decrease compared with published aseptic R-TKA infection rates. Further study on the benefits and costs of EOAP after aseptic R-TKA is encouraged.

Early, Mid-Term, and Late-Term Aseptic Femoral Revisions After THA: Comparing Causes, Complications, and Resource Utilization

BACKGROUND

Registry data suggest increasing rates of early revisions after total hip arthroplasty (THA). We sought to analyze modes of failure over time after index THA to identify risk factors for early revision.

METHODS

We identified 208 aseptic femoral revision THAs performed between February 2011 and July 2019 using an institutional database. We compared demographics, diagnoses, complications, and resource utilization between aseptic femoral revision THA occurring within 90 days (early), 91 days to 2 years (mid), and greater than 2 years (late) after index arthroplasty.

RESULTS

Early revisions were 33% of revisions at our institution in the time period analyzed. Periprosthetic fractures were 81% of early, 27% of mid, and 21% of late femoral revisions (P < .01). Women were more likely to have early revisions than men (75% vs 53% of mid and 48% of late revisions; P < .01). Patients who had early revisions were older (67.97 ± 10.06) at the time of primary surgery than those who had mid and late revisions (64.41 ± 12.10 and 57.63 ± 12.52, respectively, P < .01). Index implants were uncemented in 99% of early, 96% of mid, and 64% of late revisions (P < .01). Early revisions had longer postoperative length of stay (4.4 ± 3.3) than mid and late revisions (3.0 ± 2.2 and 3.7 ± 2.1, respectively, P = .02). In addition, 58% of early revisions were discharged to an inpatient facility compared with 36% of mid and 41% of late revisions (P = .03).

CONCLUSION

Early aseptic femoral revisions largely occur in older women with uncemented primary implants and primarily due to periprosthetic fractures. Reducing the incidence of periprosthetic fractures is critical to decreasing the large health care utilization of early revisions.

Revision Surgery for Instability After Total Hip Arthroplasty: Does Timing Matter?

BACKGROUND

Instability is a common reason for revision surgery after total hip arthroplasty (THA). Recent studies suggest that revisions performed in the early postoperative period are associated with higher complication rates. The purpose of this study is to assess the effect of timing of revision for instability on subsequent complication rates.

METHODS

The Medicare Part A claims database was queried from 2010 to 2017 to identify revision THAs for instability. Patients were divided based on time between index and revision surgeries: <1, 1-2, 2-3, 3-6, 6-9, 9-12, and >12 months. Complication rates were compared between groups using multivariate analyses to adjust for demographics and comorbidities.

RESULTS

Of 445,499 THAs identified, 9298 (2.1%) underwent revision for instability. Revision THA within 3 months had the highest rate of periprosthetic joint infection (PJI): 14.7% at <1 month, 12.7% at 1-2 months, and 10.6% at 2-3 months vs 6.9% at >12 months (P < .001). Adjusting for confounding factors, PJI risk remained elevated at earlier periods: <1 month (adjusted odds ratio [aOR]: 1.84, 95% confidence interval [CI]: 1.51-2.23, P < .001), 1-2 months (aOR: 1.45, 95% CI: 1.16-1.82, P = .001), 2-3 months (aOR: 1.35, 95% CI: 1.02-1.78, P = .036). However, revisions performed within 9 months of index surgery had lower rates of subsequent instability than revisions performed >12 months (aOR: 0.67-0.85, P < .050), which may be due to lower rates of acetabular revision and higher rates of head-liner exchange in this later group.

CONCLUSION

When dislocation occurs in the early postoperative period, delaying revision surgery beyond 3 months from the index procedure may be warranted to reduce risk of PJI.

Dual antibiotic loaded bone cement in patients at high infection risks in arthroplasty: Rationale of use for prophylaxis and scientific evidence

In view of the demographic changes and projected increase of arthroplasty procedures worldwide, the number of prosthetic joint infection cases will naturally grow. Therefore, in order to counteract this trend more rigid rules and a stricter implementation of effective preventive strategies is of highest importance. In the absence of a “miracle weapon” priorities should lie in evidence-based measures including preoperative optimization of patients at higher infection risks, the fulfilment of strict hygiene rules in the operating theatre and an effective antibiotic prophylaxis regimen. Instead of a “one size fits all” philosophy, it has been proposed to adjust the antibiotic prophylaxis protocol to major infection risks taking into account important patient- and procedure-related risk factors. A stronger focus on the local application mode via use of high dose dual antibiotic-loaded bone cement in such risk situations may have its advantages and is easy to apply in the theatre. The more potent antimicrobial growth inhibition in vitro and the strong reduction of the prosthetic joint infection rate in risk for infection patients with aid of dual antibiotic-loaded bone cement in clinical studies align with this hypothesis.

Calcium sulfate antibiotic-impregnated bead implantation for deep surgical site infection associated with orthopedic surgery in small animals

OBJECTIVE

To report the outcomes and complications associated with antibiotic-impregnated calcium sulfate beads for prevention and treatment of orthopedic-related surgical site infection (SSI) in companion animals.

STUDY DESIGN

Retrospective case series.

ANIMALS

Client-owned cats (n = 2) and dogs (n = 14).

METHODS

Medical records of 16 cases in which implantation of antibiotic-impregnated calcium sulfate beads was performed for the prevention or treatment of SSI were reviewed. Information collected included signalment, prior surgery, reason for bead placement, antibiotics used, bacterial culture results, and clinical outcomes.

RESULTS

Surgical site infection resolved in six of 10 animals treated therapeutically and did not occur in six of six animals treated prophylactically. Susceptibility of the causative bacteria to the antibiotic implanted was confirmed in five of six cases with resolved SSI treated therapeutically but in only one of four cases with unresolved SSI treated therapeutically. Complications directly related to bead placement were evident in only one case in which beads extruded from external skeletal fixator pin tracts 7 days after implantation. At final follow-up, 11 of 12 animals without SSI had satisfactory limb use and no clinical, cytologic, or radiographic evidence of infection.

CONCLUSION

Implantation was well tolerated. Resolution of SSI was inconsistent; however, when bacteria were susceptible to the antibiotic implanted, SSI resolved in all but one case.

CLINICAL SIGNIFICANCE

Antibiotic-impregnated calcium sulfate beads could be considered for prevention or treatment of orthopedic SSI in small animals. A prospective clinical study is required to obtain additional information, including the value of preoperative bacterial culture.