Infection after primary total hip arthroplasty

Transfemoral Osseointegration in Association With Total Hip Replacement: Observational Cohort Study of Patients With Follow-Up Exceeding 2 Years

Background

Some amputees with transfemoral osseointegration (TFOI) have ipsilateral hip arthritis which can be addressed with total hip arthroplasty (THA). This study reported the medium-term outcomes of THA in association with TFOI (THA + TFOI).

Methods

Retrospective review was performed for eight patients with THA + TFOI performed at least 2 years prior. Primary outcomes include complications prompting surgical intervention. Secondary outcomes include changes in mobility (K-level, 6-minute walk test [6MWT], timed up and go) and patient-reported measures (hip pain, daily prosthesis wear hours, Questionnaire for Persons with a Transfemoral Amputation, and Short Form 36 [SF36]).

Results

One patient died after 11 months (cancer); he was included to maximally report complications but excluded from mobility and reported outcomes. Three patients required subsequent surgeries: Two had skin refashioning, and the other underwent hip debridement of the replaced joint with subsequent removal of the TFOI. No perioperative complications, fractures, or arthroplasty explantations occurred. All patients reported complete hip pain relief. Of 6 patients reporting prosthesis wear time, 2 (33%) wore their prosthetic leg at least 4 hours daily before, vs all (100%) who did afterward (P = .061). K-levels improved in all responding patients. All 5 wheelchair-bound patients achieved and maintained ambulation. The Questionnaire for Persons with a Transfemoral Amputation and Short Form 36 did not significantly change.

Conclusions

THA + TFOI does not appear to pose an inevitable risk for prosthetic hip infection and may improve mobility and enhance quality of life (QOL) for transfemoral amputees with concurrent arthritic hip pain who are dissatisfied with their outcome following traditional socket prosthesis rehabilitation.

Additional doses of prophylactic antibiotics post-arthroplasty: Are there any benefits?

Guidelines for prophylactic antibiotic administration in total joint replacement vary considerably in terms of drug, dosage, route of administration and duration of cover. Despite the range of treatment options available, infection remains the most common reason for arthroplasty failure in the decades following a procedure, simultaneously increasing health care costs and lowering patient satisfaction considerably. This work aims to evaluate whether there are benefits to administering further doses of antibiotic post-arthroplasty, in addition to the recommendations of current protocols. We present a review of evidence surrounding infection rates in a variety of prophylactic regimens, and weigh this against further considerations such as cost to the patient and risks of nephrotoxicity. In summary, the available evidence does not suggest a benefit to administering additional doses post-arthroplasty in most cases. However, further doses may benefit those deemed at high risk of infection, or those in areas of high methicillin-resistant Staphylococcus aureus prevalence.

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.

Incidence of periprosthetic joint infection after primary total hip arthroplasty is underestimated: a synthesis of meta-analysis and bibliometric analysis

The American Musculoskeletal Society updated the diagnostic criteria for periprosthetic joint infection (PJI) in 2011 and 2018. However, the overall incidence of PJI since the introduction of these new standards has not been assessed. In order to fill this knowledge gap, a single-group meta-analysis was conducted using articles obtained from several databases, focusing on the incidence of PJI after primary total hip arthroplasty (THA). Our study revealed a significant difference in the incidence of PJI reported by different national or regional databases. Moreover, most cases of PJI were found to be underestimated. This highlights the crucial need for standardized diagnostic criteria and monitoring methods to accurately identify and track cases of PJI. Furthermore, a bibliometric analysis was conducted to provide a comprehensive overview of the current state of research on PJI after THA. This analysis explored the most productive countries, organizations, journals, and individuals in this research area. Additionally, it identified the research trends and hotspots of the last decade, highlighting the advancements and areas of focus in this field. By conducting these analyses, the study aims to contribute to the understanding of PJI after THA and provide valuable insights for clinicians, researchers, and policymakers involved in the management of this condition.

Partial Two-Stage Exchange for Infected Total Hip Arthroplasty: A Treatment to Take into Account

INTRODUCTION

Two-stage revision is the gold standard for chronic periprosthetic joint infection (PJI). The removal of well-fixed implants, especially the femoral component, can be extremely difficult and additional osteotomies may be needed, which is time-consuming and results in bone stock loss. When the femoral stem is osseointegrated, there is no clear indication for the use of partial two-stage revision. The primary objective was to assess infection eradication after surgery.

METHODS

Retrospective study of specific case series. A total of eight patients with a chronic uncemented PJI, in the setting of complex revision surgeries, were treated with partial two-stage revision, which included selective retention of the well-fixed femoral component and complete acetabular removal. Stem retention was carried out regardless of the bacteria or associated comorbidities.

RESULTS

All patients were re-revision cases with at least two previous surgeries (range, 2-4). Complex revisions were performed in five cases (non-articulated spacer) and simple revisions in three cases (articulated spacer). The minimum follow-up time was 24 months (range, 24-132 months). The infection eradication rate at final follow-up was 100%.

CONCLUSION

Partial two-stage reconstruction is a promising technique for the treatment of chronic PJI in patients with a well-fixed stem and complex re-revision acetabular procedures. Further prospective studies and prolonged follow-ups are required to confirm our results.

The Use of Proximal Femur Replacement for the Management of Oncologic Lesions in the Proximal Femur: A Review

With improved chemotherapeutic treatment, patients with primary or metastatic bone tumor have improved prognoses and longer life expectancies; therefore, durable limb-salvage constructs are critical. For tumors of the proximal femur, endoprosthetic replacement is an option for treatment in primary and metastatic disease, with the goals being tumor and pain control, earlier mobilization, shorter recovery period, and, in primary tumors, cure. This study provides a summary of current concepts in the treatment of oncologic lesions in the proximal femur with endoprostheses. Discussion of the inherent complications of these constructs is presented as well as the risks and treatment of reconstruction failure.

Management of Intraoperative Contamination of the Custom Total Temporomandibular Joint Prosthesis

Management of intraoperative contamination of a custom total temporomandibular joint prosthesis has not been reported in the literature. As this complication is rare, it can be unsettling for the surgeon. Improper management may lead to a complicated treatment course and financial consequences. Prevention is the primary strategy for avoidance and appropriate management is dependent on many variables. The purpose of this report is to identify a unique complication associated with placement of a custom temporomandibular joint prosthesis and offer an algorithm for management.

Topical vancomycin powder does not affect patella cartilage degeneration in primary total knee arthroplasty and conversion rate for secondary patella resurfacing

INTRODUCTION

Vancomycin powder (VP) is an antibiotic first introduced in pediatric spinal surgery to prevent surgical site infections (SSI). Recently its topical application was expanded to total hip and knee arthroplasty (THA, TKA) and anterior cruciate ligament reconstruction (ACLR). Toxicity to cartilage is the subject of current research. The aim of this study was to prove the hypothesis that topical application of VP in TKA does not result in a degeneration of patella cartilage. We propagate that the conversion rate for secondary patella resurfacing is not influenced by its use.

MATERIALS AND METHODS

Between 2014 and 2021, 4292 joints were included in this monocentric retrospective cohort study. All patients underwent TKA without primary patella resurfacing. After a change of the procedure in the hospital, one group (VPG) was administered VP intraoperatively. The other group (nVPG) received no VP during surgery (nVPG). The remaining perioperative procedure was constant over the investigation period. Conversion rates for secondary patella resurfacing for both groups were determined without making distinctions in the indication. A second cohort was composed of patients presenting for follow-up examination 12 months after TKA and included 210 joints. Retrospective radiographic evaluations were performed preoperatively, before discharge and at follow-up examination. Patella axial radiographs were analyzed for patella tracking (lateral patellar tilt, patellar displacement) and patella degeneration (Sperner classification, patellofemoral joint space).

RESULTS

There was no significant difference in the conversion rate for secondary patella resurfacing (4.24% VPG, 4.97% nVPG). Patella tracking and patella degeneration did not differ significantly between both groups.

CONCLUSIONS

The topical application of VP does not influence the conversion rate for secondary patella resurfacing. Moreover, it does not result in a degeneration of patella cartilage in TK.

LEVEL OF EVIDENCE

Retrospective case series, Level III.

Assessment of Predictors of Infection in Primary Knee and Hip Arthroplasty: A Case-control Study

Objective This study assesses risk factors for periprosthetic joint infection after elective primary total knee or hip arthroplasty. Methods  The study included 706 medical records of patients undergoing elective primary total hip or knee arthroplasty from January to December 2018. We used a multivariate analysis of infection predictors through a logistic regression model. The R software performed all statistical analysis. Results  The prevalence of infection in the sample was 2.0% (14 cases). Most patients were women (79.6%), with an afflicted right side (50.6%), and underwent a total knee arthroplasty (61.3%). Significant risk factors ( p  < 0.05) for infection included surgical time greater than 120 minutes ( p  = 0.009) and a history of diabetes ( p  = 0.025). Conclusion  The risk of infection after elective primary total knee or hip arthroplasty is higher when the surgical procedure is lengthy (over 120 minutes), or the patient has a history of diabetes mellitus. Level of Evidence  IIIB, retrospective, case-control study.

Novel molded antibiotic cement spacer: is it better than handmade cement spacer for treatment of chronically infected total hip arthroplasty?

PURPOSE

A handmade antibiotic cement spacer is the easiest method for producing a spacer for treating chronic periprosthetic joint infection after total hip arthroplasty (THA). However, a molded spacer offers more head and stem sizes to match the patient's anatomy. The purpose of this study was to evaluate the functional outcomes and complications between handmade and molded spacers.

METHODS

This retrospective case note study compared the functional results, re-infection rate, and spacer related complications after the first stage and second stage exchange arthroplasty between a handmade spacer and a novel molded cement spacer with three sizes of femoral head (45, 50, and 55 mm) and two stem sizes (small, large).

RESULTS

Fifteen chronically infected THA patients were identified: nine handmade and 6 molded spacers. The modified Harris Hip Score showed no inter-group differences pre-operatively and after first stage and second stage exchange arthroplasty. The erythrocyte sedimentary rates and C-reactive protein concentrations were similar at all time points, and there were no re-infections. The molded spacer group showed lower post-operative complications with no spacer fractures, spacer dislocations, and periprosthetic fractures, but two had spacer subsidence. The handmade spacer had two spacer fractures, one spacer dislocation with a periprosthetic femoral fracture, and four cases of spacer subsidence.

CONCLUSION

Our small study showed no differences in functional outcomes and no re-infections in either group, but higher spacer-related complications occurred in the handmade spacer group. These data suggest molded spacers are better than handmade spacers.

Evaluation of Incise Drape Lift Using 2% Chlorhexidine Gluconate/70% Isopropyl Alcohol Preoperative Skin Preparations in a Human Volunteer Knee Model

Background

Before surgery, skin is prepped with antiseptics to reduce risk of surgical site infections. An incise drape can be used as an additional modality to immobilize any remaining bacteria. Good adhesion of this drape is critical for infection prevention.

Methods

This is a randomized controlled study using a human volunteer knee model (n = 30) to evaluate the adhesion performance of an incise drape comparing 2 skin preparations. A new investigational 2% chlorhexidine gluconate/70% isopropyl alcohol skin prep (prep A) was compared with an existing skin prep containing the same active agents (prep B). Two samples of an iodine-impregnated incise drape were placed on each knee after prepping. Knees were flexed in dry conditions, under a saline-soaked gauze, and after saline lavage. The frequency of drape lift was recorded after each challenge.

Results

After dry flex, 4 of 60 samples (6.7%) had lifted on prep A and 0 on prep B (P = .125). After wet flex, 20 of 60 samples (33%) had lifted on prep A, whereas 42 of 60 samples (70%) had lifted on prep B (P < .0001). After lavage, 23 of 60 samples (38%) had lifted on prep A, whereas 48 of 60 samples (80%) had lifted on prep B (P < .0001). Both preps were well tolerated with minimal erythema and no edema, rash, dryness, or denudation observed. No adverse events were reported.

Conclusions

Prep A resulted in reduced frequency of incise drape lift from skin under wet conditions in this model compared with prep B.

Rural Hospital Designation Is Associated With Increased Complications and Resource Utilization After Primary Total Hip Arthroplasty: A Matched Case-Control Study

BACKGROUND

As the prevalence of hip osteoarthritis increases, the demand for total hip arthroplasty (THA) has grown. It is known that patients in rural and urban geographic locations undergo THA at similar rates. This study explores the relationship between geographic location and postoperative outcomes.

METHODS

In this retrospective cohort study, the Truven MarketScan database was used to identify patients who underwent primary THA between January 2010 and December 2018. Patients with prior hip fracture, infection, and/or avascular necrosis were excluded. Two cohorts were created based on geographic locations: urban vs rural (rural denotes any incorporated place with fewer than 2500 inhabitants). Age, gender, and obesity were used for one-to-one matching between cohorts. Patient demographics, medical comorbidities, postoperative complications, and resource utilization were statistically compared between the cohorts using multivariate conditional logistic regression.

RESULTS

In total, 18,712 patients were included for analysis (9356 per cohort). After matching, there were no significant differences in comorbidities between cohorts. The following were more common in rural patients: dislocation within 1 year (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.08-1.41, P < .001), revision within 1 year (OR 1.17, 95% CI 1.05-1.32, P = .027), and prosthetic joint infection (OR 1.14, 95% CI 1.04-1.34, P = .033). Similarly, rural patients had higher odds of 30-day readmission (OR 1.31, 95% CI 1.09-1.56, P = .041), 90-day readmission (OR 1.41, 95% CI 1.26-1.71, P = .023), and extended length of stay (≥3 days; OR 1.52, 95% CI 1.22-1.81, P < .001).

CONCLUSION

THA in rural patients is associated with increased cost, healthcare utilization, and complications compared to urban patients. Standardization between geographic areas could reduce this discrepancy.

Modification of the Polymer of a Bone Cement with Biodegradable Microspheres of PLGA and Loading with Daptomycin and Vancomycin Improve the Response to Bone Tissue Infection

Chronic infections are one of the most serious adverse outcomes of prosthetic surgery. Prosthetic revision surgery using a bone cement loaded with antibiotics between the two stages of the surgery is commonly performed. However, this method often fails to reach the minimum inhibitory concentration and promotes antibiotic resistance, thus emphasizing the need for improving the current available therapies.

MATERIALS AND METHODS

In this study, we performed a study of the in vivo response of a polymer-based construct of poly (lactic-co-glycolic acid) (PLGA) in the solid phase of Palacos R^® in combination with vancomycin, daptomycin, and/or linezolid. To test its effectiveness, we applied an in vivo model, using both histological and immunohistochemical analyses to study the bone tissue.

RESULTS

The presence of PLGA in the combination of vancomycin with daptomycin showed the most promising results regarding the preservation of bone cytoarchitecture and S. aureus elimination. Conversely, the combination of vancomycin plus linezolid was associated with a loss of bone cytoarchitecture, probably related to an increased macrophage response and inefficient antimicrobial activity.

CONCLUSIONS

The modification of Palacos R^® bone cement with PLGA microspheres and its doping with the antibiotic daptomycin in combination with vancomycin improve the tissue response to bone infection.

Depression Is Transiently Increased in Patients Undergoing Two-Stage Revision Arthroplasty

BACKGROUND

The implications of two-stage revision on mental health are poorly understood. The purpose of this study is to determine (1) whether patients undergoing two-stage revision total hip and knee arthroplasty for prosthetic joint infection were more likely to get Patient-Reported Outcomes Measurement Information System (PROMIS) Depression scores consistent with major depressive disorder (MDD) than those undergoing aseptic revision and (2) whether these symptoms resolved after the procedure.

METHODS

Records of all 366 patients that underwent revision total hip or knee arthroplasty from January 1, 2015, - June 20, 2019, were reviewed. Forty-two patients were excluded for missing PROMIS Depression scores or incomplete treatment. Preoperative (<3 months), early postoperative (2-8 weeks), and final postoperative (6-18 months) Depression scores were collected. Patients crossing the PROMIS Depression threshold equivalent to a Patient Health Questionnaire-9 score ≥10, indicative of MDD, were evaluated.

RESULTS

More two-stage revision patients developed Depression scores indicative of MDD perioperatively than the aseptic cohort (20.0% vs 6.5%, P = .01). Two-stage revision patients had higher (worse) median Depression scores preoperatively (54.8 vs 51.3, P = .04) and at early follow-up (54.3 vs 49.9, P = .01), but not at final follow-up (50.4 vs 49.1, P = .39). Across all patients, Depression scores improved by 2.4 points at early follow-up (95% confidence interval:1.1-3.7; P < .001) and 3 points at final follow-up (95% confidence interval:1.5-4.5; P < .001; minimal clinically important difference 3.0).

CONCLUSIONS

Twenty percent of two-stage revision arthroplasty patients, compared to <7% of aseptic revision patients, developed PROMIS Depression scores consistent with MDD during treatment. At final follow-up, a clinically significant improvement in Depression scores from baseline was evident in both cohorts.

Intraoperative damage to surgical gloves during various operations on the musculoskeletal system: a multicenter study

INTRODUCTION

Various orthopedic surgical procedures cause mechanical stress for gloves. In some cases, sharp-edged objects impact on the glove surfaces. The systematic description of lesions is still missing.

METHODS

2289 gloves from 409 surgeries [primary hip and knee arthroplasties (PA), revisions arthroplasties (RA) and arthroscopic shoulder, hip and knee surgery (AY)] from 3 clinics were examined for lesions using water tightening test according to the European norm EN 455-1.

RESULTS

Arthroscopies showed the lowest rate of operations with damaged gloves (6.9%). Depending on clinic, 32.7% and 59.2% of PA surgeries generated damaged gloves, while in RA, these numbers rose to 76.0% and 72.8%, respectively. In PA and RA, the most affected finger was the index finger, whereas in arthroscopies, more damage occurred on the middle finger and the thumb. The size of the lesions was rather small with the vast majority being 1 mm or 2 mm in size.

CONCLUSION

All investigated interventions led to glove lesions. With increasing mechanical stress, the number of glove defects increased. EN 455 does not account for the intraoperative tear risk. Stricter requirements for gloves should be introduced. Glove change intervals should be defined and implemented, and new materials should be developed.

Population pharmacokinetic model of cefazolin in total hip arthroplasty

Cefazolin is an antibiotic recommended for infection prevention in total hip arthroplasty (THA). However, the dosing regimen necessary to achieve therapeutic concentrations in obese patients remains unclear. The aim of this study was to conduct a population analysis of cefazolin pharmacokinetics (PK) and assess whether cefazolin administration should be weight adapted in THA. Adult patients undergoing THA surgery received an injection of 2000 mg of cefazolin, doubled in the case of BMI > 35 kg/m² and total body weight > 100 kg. A population PK study was conducted to quantify cefazolin exposure over time compared to the therapeutic concentration threshold. A total of 484 cefazolin measurements were acquired in 100 patients, of whom 29% were obese. A 2-compartment model best fitted the data, and creatinine clearance determined interpatient variability in elimination clearance. Our PK simulations using a 2000 mg cefazolin bolus showed that cefazolin concentrations remained above the threshold throughout surgery, regardless of weight or renal function. A 2000 mg cefazolin single injection without adaptation to weight or renal function and without intraoperative reinjection was efficient in maintaining therapeutic concentrations throughout surgery. The optimal target concentration and necessary duration of its maintenance remain unclear.

Risk of 30-day Readmission after Knee or Hip Replacement in Rheumatoid Arthritis and Osteoarthritis by non-Medicare and Medicare Payer Status

OBJECTIVE

To determine the indication and risk of 30-day rehospitalization after hip or knee replacement among rheumatoid arthritis (RA) and osteoarthritis (OA) by Medicare and non-Medicare status.

METHODS

Using the Nationwide Readmission Database (2010-2014), we defined an Index hospitalization as an elective hospitalization with a principal procedure of total hip or knee replacement among adults aged ≥18 years. Primary payer was categorized as Medicare or non- Medicare. Survey logistic regression provided the odds of 30-day rehospitalization in RA relative to OA. We calculated the rates for principal diagnoses leading to rehospitalization.

RESULTS

Overall, 3.53% of 2,190,745 index hospitalization had a 30-day rehospitalization. Patients with RA had a higher adjusted risk of rehospitalization after TKR (Odds Ratio [OR], 1.11; 95% Confidence Interval [CI], 1.02 to 1.21) and THR (OR, 1.39; 95% CI, 1.19 to 1.62). Persons with RA and OA did not differ with respect to rates of infections, cardiac events, or postoperative complications leading to the rehospitalization. After TKR, RA patients with Medicare had a lower VTE risk (OR, 0.58;95% CI, 0.58 to 0.88) while post-THR those with RA had a greater VTE risk (OR, 2.41;95% CI, 1.04 to 5.57).

CONCLUSION

RA patients had a higher 30-day rehospitalization than OA after TKR and THR regardless of payer type. While infections, postoperative complications, cardiac did not differ, there was a significant difference in venous thromboembolism as the rehospitalization's principal diagnosis.

Preoperative Corticosteroid Injections Demonstrate a Temporal and Dose-Dependent Relationship with the Rate of Postoperative Infection Following Total Hip Arthroplasty

BACKGROUND

Corticosteroid injections (CSI) are commonly used for the treatment of osteoarthritis of the hip. There is concern, however, that these injections may increase the risk of postoperative infection if a subsequent total hip arthroplasty (THA) is performed. The purpose of the present investigation is to determine the relationship between CSI and the risk of periprosthetic joint infection (PJI) and surgical site infections (SSIs) following THA.

METHODS

The PearlDiver database was reviewed for patients undergoing THA from 2011 to 2018. Patients with unilateral hip osteoarthritis who received an intra-articular hip CSI prior to ipsilateral THA were matched in a sequential 1:1 fashion based on age, gender, and Charlson Comorbidity Index with THA patients who did not receive an injection in the preoperative period. PJI and SSI within 6 months of the surgical procedure were recorded. Statistical analysis included chi-squared test and multivariate logistic regression. Results were considered significant at P < .05.

RESULTS

In total, 29,058 patients underwent a hip CSI within 6 months prior to THA. CSI within 4 months of surgery was associated with a higher incidence of PJI at 6-month follow up (1.6% vs 1.1%, P = .040). An injection within 1 month of surgery corresponded to a higher odds of PJI (odds ratio [OR] 1.97) than an injection 4 months prior to surgery (OR 1.24). Furthermore, the quantity of CSI administered within the 3 months prior to THA demonstrated a dose-dependent relationship, with each subsequent injection increasing odds of PJI (OR 1.45-3.59). A similar relationship was observed for SSI.

CONCLUSION

There appears to be both a time and dose-dependent association of hip CSI and PJI following THA. Surgeons should consider delaying elective THA if a CSI has been administered within the 4 months prior to the planned procedure.

Safety of shoulder arthroplasty in lung transplant recipients

PURPOSE

Although shoulder arthroplasty is relatively safe in general population, it remains unclear in transplant recipient. Aim of this study was to determine outcomes and morbidity after shoulder arthroplasty in lung transplant recipients.

METHODS

A retrospective analysis was performed at our university hospital center from 2001 to 2015. Main inclusion criterion was all lung transplant recipient who underwent shoulder arthroplasty. Clinical outcomes including Constant score, visual analogue scale (VAS), American Shoulder and Elbow Surgeons score (ASES) were determined in pre-operative period and a minimum follow-up of 36 months. Special attention was taken about complications.

RESULTS

Among 700 lung transplant recipients, we identified 12 patients who underwent 14 shoulder arthroplasties. Arthroplasties were performed after proximal humeral avascular necrosis (n = 10), degenerative osteoarthritis (n = 1) and non-union of proximal humeral fracture (n = 1). 8 anatomical total shoulder arthroplasties and 6 reversed shoulder arthroplasties were performed. Mean follow-up was 61.4 months (± 22.1). Mean age was 47.1 (± 9.3) years. All patients had immunosuppression therapy at the time of surgery. Mean Constant score was improved at last follow-up [43(± 9.7) vs 94(± 4), p < 0.001]. VAS decreased from 6.4 (± 1.2) to 0.4 (± 0.8), p < 0.001. Mean ASES was improved from 33 (± 6) to 91 (± 5) at last follow-up (p < 0.001). Range of motion were improved between early post-operative evaluation and last follow-up: forward flexion: 85° (± 8°) vs 119°(± 13°); abduction: 83° (± 14°) vs 106°(± 23°); external rotation (RE1): 26° (± 7°) vs 36°(± 10°). At last follow-up, one revision was required for humeral prothesis loosening at 2 years post-surgery. One patient died due to acute pulmonary decompensation on chronic rejection 66 months after shoulder arthroplasty.

CONCLUSION

Shoulder arthroplasty is a safe procedure in this vulnerable population of lung transplant recipients. Such results encourage us to continue arthroplasty surgery when required.

LEVEL OF EVIDENCE

IV.

Low Reinfection Rates But a High Rate of Complications in THA for Infection Sequelae in Childhood: A Systematic Review

BACKGROUND

Childhood hip infections can result in serious sequelae during adulthood, including persistent pain, functional limitations, and premature THA. When THA is performed in patients who had hip joint infections during childhood, surgeons surmise these arthroplasties are at an increased risk of complications and incomplete recovery. However, the degree to which this is true is not well characterized and has varied across a large number of small, retrospective studies.

QUESTIONS/PURPOSES

(1) What proportion of THAs performed in patients who had pediatric septic arthritis result in periprosthetic joint infection? (2) What are the Harris hip scores associated with these reconstructions? (3) What proportion of these patients develop complications after THA? (4) What proportion of patients undergo revision after these THAs?

METHODS

For this systematic review, we searched the MEDLINE (PubMed), Scopus, and CINAHL (EbscoHost) electronic databases. We evaluated studies published in English between 1980 and 2020 that had a minimum of 10 patients (with a minimum of 2 years of follow-up) in whom sequelae of septic arthritis of the hip were treated with single-stage THA. We also evaluated studies reporting clinical outcomes by means of the Harris hip score, along with a radiographic assessment of the prosthesis. Updates of previous studies using the same database, case reports, surgical technique reports, systematic reviews, and expert opinions were excluded. No restrictions were applied regarding study design and loss to follow-up. A total of 430 studies were identified through the initial search, and 11 studies were included after applying the inclusion and exclusion criteria. All but two studies, which included a historical control group, were retrospective case series. A total of 691 patients with a mean age of 45 years were involved. A total of 599 patients underwent cementless THAs, 84 patients underwent hybrid THA (cemented stems), and the remaining eight patients received a cemented THA. A total of 287 additional procedures were performed on the acetabulum, including autografting, allografting, and medial wall osteotomies; in three hips, tantalum augments were used. Three hundred thirty-five additional procedures were performed on the femora, including 223 shortening osteotomies and 112 greater trochanter osteotomies. The mean follow-up duration ranged from 5.5 to 15.2 years (minimum follow-up range 2-13 years). To assess the quality of the studies, we used the Methodological Index for Non-randomized Studies and the Assessment of Quality in Lower-limb Arthroplasty, for which a higher score represents a better study quality. The mean Methodological Index for Non-randomized Studies score for case series was 9 of 16 (range 6-12), and 19 and 18 of 24 for the two comparative studies. The mean reporting quality of the Assessment of Quality in Lower Limb Arthroplasty score was 6 of 8 (range 3-8).

RESULTS

Because of loss to follow-up, which was not consistently reported in the source studies, we caution the reader that the estimates provided here likely underestimate the risks of adverse events and overestimate the mean hip scores. The pooled proportion of patients in whom infections developed was 1% (seven of 691 THAs). Considering only studies published in the past 10 years, the proportion was 0.7% (two of 276 THAs). The Harris hip score increased from a mean of 52 ± 6 points before THA to a mean of 88 ± 2 points after THA. The pooled proportion of complications, including sciatic nerve palsy, femoral nerve palsy, intraoperative periprosthetic fracture, deep venous thrombosis, and dislocation, was 11% (76 complications among 691 THAs). The pooled proportion of patients who underwent revision was 8% (53 revisions of any components for any reason among 691 THAs) at a mean follow-up interval of 9.1 ± 3 years.

CONCLUSION

In THAs for sequelae of childhood septic arthritis, reinfections were uncommon, whereas generally, infection rates were slightly higher than those reported for conventional primary THAs. However, the duration of follow-up might have been insufficient to identify all patients in whom infections later developed, and the available data were not adequate to precisely detect the minimum quiescent period to avoid reinfections. Moreover, the studies in this systematic review were retrospective, and selection bias, transfer bias, and assessment bias likely influenced our findings. The general effect of these biases is to cause an underestimation of the harms of the intervention. Complications, especially intraoperative fracture and nerve palsy, were common in patients with the most-severe infections. Further data on this topic are needed, ideally from multicenter or registry studies with even longer follow-up durations.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Vancomycin is toxic to human chondrocytes in vitro

INTRODUCTION

Vancomycin powder (VP) is a well-established topical antibiotic used in spinal surgery to prevent surgical site infections. More recently its extension to hip and knee arthroplasty was introduced. The aim of this study was to examine toxic effects of VP on the viability of human chondrocytes. Our hypothesis was that VP damages human chondrocytes in vitro with increasing concentration and length of exposure.

MATERIAL AND METHODS

Primary human chondrocytes were isolated and cultured from donated human knee joints. VP was added to these cultures with increasing concentrations (0-50 mg/ml) and length of exposure (0-336 h). Toxicity and viability were analyzed using LDH und XTT Elisa assays. Cell structure and determination of vital versus dead cells were visualized using light microscopy and fluorescence microscopy.

RESULTS

Light microscopy and fluorescence microscopy visualized defect cell structures and cell death proportional to increasing dose and length of exposure to VP. The analysis of LDH activity data showed toxic effects on chondrocytes as early as 2,5 min after exposure to VP. XTT activity data revealed a significant toxic threshold of a VP concentration above 12.5 mg/ml.

CONCLUSIONS

These results show that exposure to high VP concentrations yields to a damage of human chondrocytes in vitro. Chondrotoxicity is an immediate effect that is proportional to VP concentration. Therefore, the intraarticular use of high concentrations of vancomycin powder in the presence of native cartilage tissue must be considered critically.

Biofilm-coated microbeads and the mouse ear skin: An innovative model for analysing anti-biofilm immune response in vivo

Owing to its ability to form biofilms, Staphylococcus aureus is responsible for an increasing number of infections on implantable medical devices. The aim of this study was to develop a mouse model using microbeads coated with S. aureus biofilm to simulate such infections and to analyse the dynamics of anti-biofilm inflammatory responses by intravital imaging. Scanning electron microscopy and flow cytometry were used in vitro to study the ability of an mCherry fluorescent strain of S. aureus to coat silica microbeads. Biofilm-coated microbeads were then inoculated intradermally into the ear tissue of LysM-EGFP transgenic mice (EGFP fluorescent immune cells). General and specific real-time inflammatory responses were studied in ear tissue by confocal microscopy at early (4-6h) and late time points (after 24h) after injection. The displacement properties of immune cells were analysed. The responses were compared with those obtained in control mice injected with only microbeads. In vitro, our protocol was capable of generating reproducible inocula of biofilm-coated microbeads verified by labelling matrix components, observing biofilm ultrastructure and confirmed in vivo and in situ with a matrix specific fluorescent probe. In vivo, a major inflammatory response was observed in the mouse ear pinna at both time points. Real-time observations of cell recruitment at injection sites showed that immune cells had difficulty in accessing biofilm bacteria and highlighted areas of direct interaction. The average speed of cells was lower in infected mice compared to control mice and in tissue areas where direct contact between immune cells and bacteria was observed, the average cell velocity and linearity were decreased in comparison to cells in areas where no bacteria were visible. This model provides an innovative way to analyse specific immune responses against biofilm infections on medical devices. It paves the way for live evaluation of the effectiveness of immunomodulatory therapies combined with antibiotics.

Does intraoperative contamination during primary knee arthroplasty affect patient-reported outcomes for patients who are uninfected 1 year after surgery? A prospective cohort study of 714 patients

Background and purpose - It is well recognized that some knee arthroplasty (KA) patients present with prolonged postoperative inflammation and some develop persistent pain. It can reasonably be speculated that some of these problems develop because of low-grade infections with low virulence bacteria caused by intraoperative contamination. This prospective study was performed to investigate whether intraoperative contamination results in lower patient-reported outcomes (PRO) for patients who were clinically uninfected in the first year after surgery. Patients and methods - We combined data from 2 major prospective studies on patients undergoing primary KA at 2 Danish hospitals between September 2016 and January 2018. Pre- and postoperative (1.5, 3, 6, and 12 months) PROs and intraoperative microbiological cultures were obtained on a total of 714 patients who were included in the study. Based on the microbiological cultures, the patients were divided into 2 groups, contaminated and non-contaminated, and differences in PROs between the 2 groups were analyzed. Results - 84 of 714 (12%) patients were intraoperatively contaminated; none of the 714 patients developed clinical infection. The preoperative Oxford Knee Score was 24 and 23 for contaminated and non-contaminated patients, respectively, improving to 40 and 39 at 1 year (p = 0.8). 1-year AUC for Oxford Knee Score and absolute improvement at each postoperative time point for Forgotten Joint Score and EQ-5D-5L also were similar between contaminated and non-contaminated patients. Interpretation - Patient-reported outcomes from 714 patients do not indicate that intraoperative contamination affects the knee-specific or general health-related quality of life in primary KA patients who are clinically uninfected 1 year after surgery.

Complications to 6 months following total hip or knee arthroplasty: observations from an Australian clinical outcomes registry

Background

Total hip and total knee arthroplasty (THA/TKA) are increasing in incidence annually. While these procedures are effective in improving pain and function, there is a risk of complications.

Methods

Using data from an arthroplasty registry, we described complication rates including reasons for reoperation and readmission from the acute period to six months following THA and TKA in an Australian context. Data collection at 6 months was conducted via telephone interview, and included patient-reported complications such as joint stiffness, swelling and paraesthesia. We used logistic regression to identify risk factors for complications.

Results

In the 8444 procedures included for analysis, major complications were reported by 9.5 and 14.4% of THA and TKA patients, respectively, whilst minor complications were reported by 34.0 and 46.6% of THA and TKA patients, respectively. Overall complications rates were 39.7 and 53.6% for THA and TKA patients, respectively. In THA patients, factors associated with increased risk for complications included increased BMI, previous THA and bilateral surgery, whereas in TKA patient factors were heart disease, neurological disease, and pre-operative back pain and arthritis in a separate joint. Female gender and previous TKA were identified as protective factors for minor complications in TKA patients.

Conclusion

We found moderate rates of major and high rates of minor postoperative complications following THA and TKA in Australia and have identified several patient factors associated with these complications. Efforts should be focused on identifying patients with higher risk and optimising pre- and post-operative care to reduce the rates of these complications.

Metabolic factors and post-traumatic arthritis may influence the increased rate of surgical site infection in patients with human immunodeficiency virus following total hip arthroplasty

BACKGROUND

The impact of CD4+ T-cell count and highly active antiretroviral therapy (HAART) on the rate of surgical site infection (SSI) in patients with human immunodeficiency virus (HIV) undergoing total hip arthroplasty is still unclear. The goals of this study were to assess the rate of perioperative infection at a large tertiary care referral center and to identify risk factors in HIV+ patients undergoing total hip arthroplasty (THA).

METHODS

This study was a prospective, observational study at a single medical center from 2000-2017. Patients who were HIV+ and underwent THA were followed from the preoperative assessment period, through surgery and for a 2-year follow-up period.

RESULTS

Sixteen of 144 HIV+ patients (11%) undergoing THA developed perioperative surgical site infections. Fourteen patients (10%) required revision THA within a range of 12 to 97 days after the initial surgery. The patients' mean age was 49.6 ± 4.5 years, and the most common diagnosis prompting THA was osteonecrosis (96%). Patients who developed SSI had a lower waist-hip ratio (0.86 vs. 0.93, p = 0.047), lower high density lipoprotein cholesterol (45.8 vs. 52.5, p = 0.015) and were more likely to have post-traumatic arthritis (12.5% vs. 0%, p = 0.008). Logistic regression analysis demonstrated that current alcohol use and higher waist-hip ratio were significant protectors against infection (p < 0.05). No other demographic, medical, immunologic parameters, or specific HAART regimens were associated with perioperative infection.

CONCLUSIONS

Immunologic status as measured by CD4+ cell count, HIV viral load, and medical therapy do not appear to influence the development of SSI in HIV+ patients undergoing THA. Metabolic factors and post-traumatic arthritis may influence the increased rate of infection in HIV+ patients following THA.

Intraarticular vancomycin powder is effective in preventing infections following total hip and knee arthroplasty

Locally applied vancomycin is increasingly being used in primary hip and knee arthroplasty to reduce the risk of infection. Despite encouraging initial results, considerable debate remains on the basis of the data currently available. In particular, it has been unclear up to now whether local vancomycin is suitable to further reduce the risk of infection even if the rate of infection is already low (< 1%). In this monocentric retrospective cohort study, all primary total hip and knee arthroplasties performed between 2013 and 2018 were included. After a change in procedure at the hospital, 1 g vancomycin powder was applied intraarticularly before wound closure. The remaining perioperative procedure was constant over the investigation period. The follow-up was one year. The presence of an infection according to the currently valid MSIS criteria was defined as the endpoint. In patients with TKA two infections (0.3%) were observed under vancomycin prophylaxis in contrast to 44 infections (1.3%) in the control group (p = 0.033). In patients with THA two infections (0.5%) were observed under vancomycin prophylaxis and 48 infections (1.1%) in the control group without local vancomycin but this difference was statistically not significant. No wound complications requiring revision were observed as a result of the vancomycin. On the basis of the results of this study, intraarticular application of vancomycin powder in total hip and knee arthroplasty may be considered. Prospective randomized studies have to confirm this promising results prior a common recommendation.Level of Evidence III Retrospective cohort study.

Prospective Short-Term and Return-to-Sports Results of a Novel Uncemented Short-Stem Hip Prosthesis with Metaphyseal Anchorage

Short-stem hip prostheses were developed to treat active patients requiring total hip arthroplasty (THA). This study provides short-term data about a short-stem total hip arthroplasty system. Functional and radiological outcomes as well as return to sports and activity level were assessed. A series of 55 patients was primarily included. Data were available for 47 patients at an average follow-up of 38 ± 4.6 months. The back-to-sports analysis showed a 98% return-to-sports rate (46/47 patients). The average time for return to sports was 13 weeks (± 8) postoperatively. Five patients (10.6%) were more active postoperatively. The Harris Hip Score (HHS) improved from 34.8 (±9.4) preoperatively to 94.7 (±8.4, p ≤ 0.001) and the University of California, Los Angeles (UCLA) score improved from 4.5 (±1.8) to 6.9 (±1.9) (p ≤ 0.001). The High Activity Arthroplasty Score (HAAS) was 12 (±3.6) at 3-year follow-up. Pre- and postoperative UCLA and postoperative HHS and HAAS scores had a positive influence on the return-to-sports rate (p ≤ 0.05). The collection of radiographic data during all postoperative follow-ups showed no signs of radiolucent lines or bone fissures. The complication rate was at 5%. Short-stem systems are equaling conventional prostheses and offer benefits regarding soft tissue and bone stock preservation. Fast recovery and return to sports can be achieved.

Risk Factors for Periprosthetic Joint Infection Following Primary Total Hip Arthroplasty: A 15-Year, Population-Based Cohort Study

BACKGROUND

Periprosthetic joint infection (PJI) is one of the most devastating complications following total hip arthroplasty. The purposes of this study were to determine risk factors for PJI after primary total hip arthroplasty for osteoarthritis using a Canadian population-based database collected over 15 years and to determine the incidence of PJI, the time to PJI following primary total hip arthroplasty, and whether the PJI rate had changed over 15 years.

METHODS

We performed a population-based cohort study using linked administrative databases in Ontario. We included all primary total hip arthroplasties performed for osteoarthritis in patients who were ≥55 years of age. We used a Cox proportional hazards model to analyze the effect of surgical and patient factors on the risk of developing PJI. We calculated 1, 2, 5, and 10-year PJI rates. We used the Cochran-Armitage test to assess the evidence of trends in PJI rates over time.

RESULTS

A total of 100,674 patients who were ≥55 years of age underwent a primary total hip arthroplasty for osteoarthritis. The cumulative incidence for PJI at 15 years was 1.44% (95% confidence interval [CI], 1.38% to 1.50%). Risk factors associated with the development of PJI include male sex (hazard ratio [HR], 1.43 [95% CI, 1.30 to 1.51]), type-2 diabetes mellitus (HR, 1.51 [95% CI, 1.31 to 1.70]), and being discharged to convalescent care (HR, 1.36 [95% CI, 1.05 to 1.77]). Sixty-two percent of PJI cases occurred within 2 years after the surgical procedure and 98% occurred within 10 years. The rate of PJI following primary total hip arthroplasty did not change over the 15 years of our study period.

CONCLUSIONS

The risk of developing PJI following primary total hip arthroplasty did not change in 15 years, despite improvements in other arthroplasty outcomes. Male sex, type-2 diabetes mellitus, and discharge to convalescent care were associated with an increased risk of PJI. The surgical approach, income quintile, and use of bone-grafting or cement were not significantly associated with increased risk of infection in our cohort.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Silver-Containing Titanium Dioxide Nanocapsules for Combating Multidrug-Resistant Bacteria

BACKGROUND

Joint arthroplasty has improved the quality of life of patients worldwide, but infections of the prosthesis are frequent and cause significant morbidity. Antimicrobial coatings for implants promise to prevent these infections.

METHODS

We have synthesized nanocapsules of titanium dioxide in amorphous or anatase form containing silver as antibacterial agent and tested their impact on bacterial growth. Furthermore, we explored the possible effect of the nanocapsules on the immune system. First, we studied their uptake into macrophages using a combination of electron microscopy and energy-dispersive spectroscopy. Second, we exposed immune cells to the nanocapsules and checked their activation state by flow cytometry and enzyme-linked immunosorbent assay.

RESULTS

Silver-containing titanium dioxide nanocapsules show strong antimicrobial activity against both E. coli and S. aureus and even against a multidrug-resistant strain of S. aureus. We could demonstrate the presence of the nanocapsules in macrophages, but, importantly, the nanocapsules did not affect cell viability and did not activate proinflammatory responses at doses up to 20 μg/mL.

CONCLUSION

Our bactericidal silver-containing titanium dioxide nanocapsules fulfill important prerequisites for biomedical use and represent a promising material for the coating of artificial implants.

Partial 2-Stage Exchange for Infected Total Hip Arthroplasty: An Updated Report

BACKGROUND

Management of an infected total hip arthroplasty (THA) is challenging. The eradication of infection as well as complications of component removal must all be considered. This study is an update on previous reports of treating periprosthetic infection of the hip with a partial 2-stage exchange with retention of the femoral component.

METHODS

A retrospective review of our practice's arthroplasty registry from 2000 to 2018 revealed 41 hips with 2-year minimum follow-up that were treated with a 2-stage partial exchange for an infected THA. All first-stage procedures allowed an articulating construct with 1 of 3 variations: cemented constrained liner (13 hips), StageOne Hip Cement Spacer Mold (14 hips), or an antibiotic polymethylmethacrylate head molded from a bulb syringe (14 hips). Of 41 cases, 34 were culture positive, with 3 cases having methicillin-resistant Staphylococcus.

RESULTS

Mean follow-up was 5.5 years (range, 1.5-18.5 years). The second-stage reimplantation was accomplished in 39 of the 41 hips (95%) at a mean interval of 9.2 weeks (range, 5-9 weeks). Two patients underwent repeat radical debridement with removal of all components before reimplantation for persistent clinical evidence of infection. Thirty-three of the 41 hips (81%) were infection free at most recent follow-up. The mean postoperative Harris hip score at most recent evaluation was 63.6 (range, 24-100).

CONCLUSION

Eradication of periprosthetic joint infections, while minimizing patient morbidity, continues to be a challenge. Partial 2-stage exchange may be considered in cases where removal of a well-fixed femoral component may result in significant bony destruction.

Musculoskeletal Infection in Orthopaedic Oncology: Assessment of the 2018 International Consensus Meeting on Musculoskeletal Infection

BACKGROUND

The first International Consensus Meeting (ICM) on Musculoskeletal Infection convened in 2013 in order to provide agreement on the prevention, the diagnosis, and the treatment of surgical site infection (SSI) and periprosthetic joint infection (PJI). Recognizing the added susceptibility of orthopaedic oncology patients to SSI and PJI, the second ICM in 2018 included questions and corresponding recommendations from this subspecialty of orthopaedics.

METHODS

The 13 steps of the Delphi method were followed over the course of 26 months, starting in June 2016. From July 25 to 27, 2018, delegates from 93 countries convened at Thomas Jefferson University in Philadelphia, Pennsylvania. Delegates were divided into their subspecialty workgroups, where questions and recommendations were discussed, modified, and subsequently voted upon. The level of consensus measured the agreement among the delegates on the basis of the voting results. The level of evidence that accompanied each question and recommendation was dependent on the types of studies that were reviewed for each question and the number of flaws that were present in those studies.

RESULTS

There were 30 orthopaedic oncology questions and recommendations that were voted on by 14 delegates with expertise in either orthopaedic oncology or infectious disease. Twenty-six (87%) of the questions were unanimous among the delegates. The remaining 13% (n = 4) were agreed upon by 93% of the delegates, with 7% of the delegates abstaining from the vote.

CONCLUSIONS

The inclusion of orthopaedic oncology in the 2018 ICM on Musculoskeletal Infection was particularly important because of the high rate of SSI and PJI following these procedures. Despite there being strong consensus among voting delegates, these recommendations are based on limited levels of evidence and tend to reflect the recommendations from hip and knee arthroplasty. We hope that high-quality prospective studies in the field of orthopaedic oncology are available for the third ICM.

The Impact of Running, Monofilament Barbed Suture for Subcutaneous Tissue Closure on Infection Rates in Total Hip Arthroplasty: A Retrospective Cohort Analysis

BACKGROUND

Recently, running, monofilament barbed suture has become more popular as an efficient and economical alternative to traditional braided interrupted suture for wound closure following total joint arthroplasty. Its overall association with wound complications following surgery remains unknown at this time. Several studies have investigated its use in total knee arthroplasty (TKA), but there is limited literature surrounding use in total hip arthroplasty (THA). In this retrospective cohort study, our primary objective was to determine whether the use of monofilament barbed suture in THA was associated with reduced rates of postoperative infection when compared to traditional braided suture.

METHODS

Patients who underwent primary unilateral THA between November 2011 and December 2017 by a single senior surgeon with closure using either monofilament barbed suture (162 patients) or braided interrupted suture (429 patients) were retrospectively reviewed for postoperative wound complications during the first 90 days after surgery. Demographics, comorbidities, and perioperative data were also included to assess for risk factors for infection.

RESULTS

There was no difference between braided and barbed suture in overall rates of major complication, including periprosthetic joint infection (PJI) (0.47% vs 0.62%, P = .82) or revisions (1.86% vs 1.23%, P = .60). The overall rate of minor, superficial wound complications was also similar between both groups (6.1% vs 3.1%, P = .15). However, when superficial complications were categorized by type (dehiscence vs infection), the use of barbed suture was associated with a decreased rate of superficial wound infection (0% vs 5.4%, P = .003) and an increased rate of wound dehiscence (3.1% vs 0.7%, P = .04).

CONCLUSION

The use of monofilament barbed suture for superficial skin closure in THA leads to similar overall rates of both major and minor wound complications when compared to traditional interrupted braided suture. However, while barbed suture was associated with fewer superficial infections, there was an increased incidence of wound dehiscence. Overall, barbed suture demonstrated a cumulatively equivalent rate of superficial wound complications compared to braided suture. Based on this investigation, barbed suture appears safe to use in THA and may represent an efficient and effective alternative to braided suture for wound closure.

LEVEL OF EVIDENCE

Level IV; retrospective cohort study.

Clinical Characteristics and Long-term Outcomes After Septic Arthritis of the Native Glenohumeral Joint: A 20-Year Retrospective Review

Septic arthritis of the native glenohumeral joint is rare, and there is little information available regarding the natural progression and long-term joint outcomes of this pathology. The authors performed a retrospective analysis of 97 patients with culture-positive glenohumeral septic arthritis between 1995 and 2015 at their institution with a mean clinical follow-up of 83.1 months. Patient records were reviewed to document demographic and laboratory data, clinical presentation, postoperative complications, recurrences, and subsequent shoulder arthroplasty. Common comorbidities uncovered included 20 immunocompromised patients (20.6%), intravenous drug use among 27 patients (27.8%), diabetes mellitus among 40 patients (41.2%), and 18 patients (18.5%) receiving hemodialysis. Staphylococcus aureus was the most common pathogen identified (61 patients; 62.8%), followed by streptococcal species (17 patients; 17.2%). Hematogenous spread of infection was the most common etiology of shoulder sepsis (40.2%). Seven patients (7.2%) developed shoulder sepsis of undetermined etiology in the absence of established risk factors, and 16 patients (16.4%) developed recurrent glenohumeral septic arthritis at a mean of 40 months following initial eradication of infection. Three patients (3.0%) eventually underwent same-side shoulder arthroplasty at a mean of 18 months following septic arthritis, with none experiencing a periprosthetic joint infection. Glenohumeral septic arthritis is highly unlikely in the absence of medical risk factors. Long-term recurrence after clinically successful treatment is low (16.5%), and few patients undergo elective arthroplasty following shoulder septic arthritis. However, orthopedic surgeons can expect 30% to 40% of patients to require multiple trips to the operating room to successfully treat the initial joint infection, regardless of treatment method. [Orthopedics. 2019; 42(1):e118-e123.].

Preoperative hematocrit on early prosthetic joint infection and deep venous thrombosis rates in primary total hip arthroplasty: A database study

BACKGROUND

Total hip arthroplasty (THA) is a very successful surgery in restoring a patient's quality of life. Infection is a devastating complication of THA. Many risks factors for infection in THA have been identified but little is known of the effect by preoperative hematocrit.

PURPOSE

We aimed to evaluate the effect of preoperative hematocrit on early superficial site infections, deep infections, and deep organ space infections.

METHODS

Our study cohort included patients undergoing a THA in the ACS National Surgical Quality Improvement Program database from 2006 to 2015. We conducted a multivariate logistic regression analysis to evaluate an association between preoperative hematocrit and infection controlling for patients demographics and known risk factors.

RESULTS

A total of 98,869 patients were identified in this study. Of these, 702 (0.71%) developed a superficial site infection, 314 (0.32%) a deep infection, and 226 (0.23%) an organ space infection. Our results suggested a significant increased risk of deep infection (OR = 2.38, p = 0.0120) and organ space infection (OR = 3.05, p = 0.0234) in patients with lower preoperative hematocrit (<41). In addition, patients with lower preoperative hematocrit had higher chance to receive postoperative transfusion (OR = 2.93, p < 0.0001). However, no significant associations between preoperative hematocrit and superficial site infections (p = 0.8554), wound dehiscence (p = 0.0660) and DVT (p = 0.9236) were detected.

CONCLUSION

Low preoperative hematocrit is associated with increased risk of deep, organ space infections, and postoperative transfusion in THA, but not with superficial site infections, wound dehiscence and DVT.

Control Strategies for Infection Prevention in Total Joint Arthroplasty

Despite the development of newer preventative measures, the rate of infection continues to be approximately 1% for patients undergoing total joint arthroplasty (TJA). The extent of the infection can range from a mild superficial infection to a more serious periprosthetic joint infection (PJI). PJIs not only play a significant role in the clinical well-being of the TJA patient population, but also have substantial economic implications on the health care system. Several approaches are currently being used to mitigate the risk of PJI after TJA. The variety of prophylactic measures to prevent infection after TJA must be thoroughly discussed and evaluated.

In vitro and in vivo accumulation of magnetic nanoporous silica nanoparticles on implant materials with different magnetic properties

Background

In orthopedic surgery, implant-associated infections are still a major problem. For the improvement of the selective therapy in the infection area, magnetic nanoparticles as drug carriers are promising when used in combination with magnetizable implants and an externally applied magnetic field. These implants principally increase the strength of the magnetic field resulting in an enhanced accumulation of the drug loaded particles in the target area and therewith a reduction of the needed amount and the risk of undesirable side effects. In the present study magnetic nanoporous silica core–shell nanoparticles, modified with fluorophores (fluorescein isothiocyanate/FITC or rhodamine B isothiocyanate/RITC) and poly(ethylene glycol) (PEG), were used in combination with metallic plates of different magnetic properties and with a magnetic field. In vitro and in vivo experiments were performed to investigate particle accumulation and retention and their biocompatibility.

Results

Spherical magnetic silica core–shell nanoparticles with reproducible superparamagnetic behavior and high porosity were synthesized. Based on in vitro proliferation and viability tests the modification with organic fluorophores and PEG led to highly biocompatible fluorescent particles, and good dispersibility. In a circular tube system martensitic steel 1.4112 showed superior accumulation and retention of the magnetic particles in comparison to ferritic steel 1.4521 and a Ti90Al6V4 control. In vivo tests in a mouse model where the nanoparticles were injected subcutaneously showed the good biocompatibility of the magnetic silica nanoparticles and their accumulation on the surface of a metallic plate, which had been implanted before, and in the surrounding tissue.

Conclusion

With their superparamagnetic properties and their high porosity, multifunctional magnetic nanoporous silica nanoparticles are ideal candidates as drug carriers. In combination with their good biocompatibility in vitro, they have ideal properties for an implant directed magnetic drug targeting. Missing adverse clinical and histological effects proved the good biocompatibility in vivo. Accumulation and retention of the nanoparticles could be influenced by the magnetic properties of the implanted plates; a remanent martensitic steel plate significantly improved both values in vitro. Therefore, the use of magnetizable implant materials in combination with the magnetic nanoparticles has promising potential for the selective treatment of implant-associated infections.

Electronic supplementary material

The online version of this article (10.1186/s12951-018-0422-6) contains supplementary material, which is available to authorized users.

Damages with High Consequences: Analysis of Perforations in Surgical Latex Operation Gloves from Orthopedic Surgeries

Introduction

To prevent surgical site infections (SSIs) during operation, the use of sterile surgical latex gloves is common. The aim of this study was to examine the damage of the gloves in surgeries with different mechanical stress and the influence on the kind of damages. Gloves were collected during primary arthroplasty, revision arthroplasty (hip and knee), and arthroscopy (shoulder, hip, and knee).

Materials and methods

Surgical latex operation gloves were collected from surgeons after the operation and were tested with watertightness test (ISO EN 455-1:2000).

Results

A total of 1460 surgical gloves were retrieved from 305 elective operations. On average, 15.9% of the gloves showed postoperative lesions, with the highest incidence occurring in revision arthroplasty with 25%. In primary and revision arthroplasty, the index finger of the dominant hand was most frequently affected (62.7% and 58.6%); in contrast, gloves from arthroscopies had most lesions on thumb and middle finger (42.9% each). Tear and perforation size differed from ≤1 mm to >5 mm, and primary and revision arthroplasty showed bigger damages.

Conclusions

Surgical gloves have a high malfunction, which increases with growing mechanical stress. A high rate of perforation occurred mostly in revision arthroplasty. Breaching the integrity of the gloves, especially by high mechanical loads, could lead to an increased rate of infection.

Total Hip Arthroplasty in Hemophilia Patients: A Mid-term to Long-term Follow-up

OBJECTIVE

To report the results of mid-term to long-term follow-up after primary total hip arthroplasty (THA) in hemophiliacs and to hypothesize that THA can provide satisfactory outcomes in these patients.

METHODS

Twenty-four primary THA performed in 21 hemophilia patients between 2002 and 2012 were reviewed retrospectively, including 20 cases of hemophilia A and 1 case of hemophilia B. The standard lateral approach was used for all implantations. Substitution therapy for factor VIII and activated prothrombin complex concentrates were administered to patients with hemophilia A and B, respectively. Total and hidden blood loss were calculated. Outcomes were assessed using the Harris hip score before surgery and at the final follow-up visit. Complications were recorded by clinical and radiographic assessment and then compared to those in previous reports.

RESULTS

The mean follow-up period was 113 months (range, 5-15 years). The average total blood loss was 3559 mL (range, 1494-7506 mL). The mean amount of red blood cell (RBC) transfusion was 4.4 U (range, 0-14 U). The mean amount of clotting factor used in the perioperative period for management of hemophilia was 14 031.3 U (range, 8100-25 200 U). Harris hip scores improved from 37 points (range, 15-81) before surgery to 90 points (range, 70-96) at the last follow-up. No signs of loosening, infection or other complications of the implant components occurred after discharge. The overall survivorship of the implants was 100% for all patients, and no revision surgery was performed.

CONCLUSIONS

With modern techniques and hematological management, THA in patients with hemophilia leads to significant improvement in joint function with a relatively low incidence of complications. Increased blood loss and substitution therapy have no obvious negative influences on the mid-term to long-term results of THA.

Cost and determinants of acute kidney injury after elective primary total joint arthroplasty

Background

Acute kidney injury (AKI) is a serious complication after major surgery, which may lead to increased morbidity and mortality. The aim of this study was to identify cost and determinants of AKI after total joint arthroplasty.

Methods

A retrospective case-controlled study was conducted with 1719 primary elective total hip or knee replacements performed from January 2004 through September 2015 at an urban teaching hospital. Patients who developed AKI were matched in a 1:3 ratio with those in a control group who did not develop AKI based on age, sex, race, operated joint, and comorbidities including hypertension and diabetes. Increased postoperative serum creatinine was considered indicative of AKI.

Results

Fifty-four patients (3.1%) had AKI that was significantly associated with increased length of hospital stay (8.07 days) compared with that of the control group (4.50 days, P < .0001) and incurred significantly higher hospital charges ($224,533) than those of the control group ($142,753, P < .0001). We identified high body mass index, undergoing bilateral surgery in one session, high estimated blood loss, and longer duration of surgery as significant risk factors for AKI in univariate analysis. Elevated preoperative creatinine, large postoperative drop in hemoglobin, and high American Society of Anesthesiologists physical status scores were significant independent predictors of AKI in multivariate analysis.

Conclusions

Health-care providers and patients should work together to manage risk factors and to lower the risk of morbidity and mortality, longer in-hospital stay, and high associated costs of AKI.

Impact of operative time on early joint infection and deep vein thrombosis in primary total hip arthroplasty

PURPOSE

Infections and deep vein thrombosis (DVT) after total hip arthroplasty (THA) are challenging problems for both the patient and surgeon. Previous studies have identified numerous risk factors for infections and DVT after THA but have often been limited by sample size. We aimed to evaluate the effect of operative time on early postoperative infection as well as DVT rates following THA. We hypothesized that an increase in operative time would result in increased odds of acquiring an infection as well as a DVT.

METHODS

We conducted a retrospective analysis of prospectively collected data using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2006 to 2015 for all patients undergoing primary THA. Associations between operative time and infection or DVT were evaluated with multivariable logistic regressions controlling for demographics and several known risks factors for infection. Three different types of infections were evaluated: (1) superficial surgical site infection (SSI), an infection involving the skin or subcutaneous tissue, (2) deep SSI, an infection involving the muscle or fascial layers beneath the subcutaneous tissue, and (3) organ/space infection, an infection involving any part of the anatomy manipulated during surgery other than the incisional components.

RESULTS

In total, 103,044 patients who underwent THA were included in our study. Our results suggested a significant association between superficial SSIs and operative time. Specifically, the adjusted odds of suffering a superficial SSI increased by 6% (CI=1.04-1.08, p<0.0001) for every 10-minute increase of operative time. When using dichotomized operative time (<90minutes or >90minutes), the adjusted odds of suffering a superficial SSI was 56% higher for patients with prolonged operative time (CI=1.05-2.32, p=0.0277). The adjusted odds of suffering a deep SSI increased by 7% for every 10-minute increase in operative time (CI=1.01-1.14, p=0.0335). No significant associations were detected between organ/space infection, wound dehiscence, or DVT and operative time either as continuous or as dichotomized.

CONCLUSION

Prolonged operative times (>90min) are associated with increased rates of superficial SSIs, but not deep SSIs, organ/space infections, wound dehiscence, or DVT.

LEVEL OF EVIDENCE

III.

The effect of wound dressings on infection following total joint arthroplasty

Background

The use of perioperative surgical wound dressings is an important factor in the mitigation of infection following total joint arthroplasty (TJA). Few studies have been published comparing wound dressings and infection rates after TJA.

Methods

MEDLINE, PubMed, and EMBASE were searched for studies published between 2006 and 2016 reporting infection rates in patients using various wound dressings after undergoing TJA. All studies comparing Hydrofibre dressings to Standard dressings or Absorbent dressings were included in this meta-analysis. Studies looking at TJA secondary to trauma were excluded. Two individuals independently extracted data, and study results were divided based on type of treatment. The primary outcome was to compare the infection rate of Hydrofibre dressings to that of both Standard Dressings and Absorbent dressings.

Results

Of a total of 3721 participants, 1483 were treated with Standard dressings (non-impregnated gauze), 1911 with Hydrofibre dressings, and 327 with Absorbent dressings. The risk ratio for infection comparing Standard with Hydrofibre was 4.16 (95% confidence interval, 1.71-10.16) as compared to 2.60 (95% confidence interval, 0.66-10.27) when comparing Absorbent with Hydrofibre dressings.

Conclusions

Our analysis suggests that Hydrofibre dressings may be significantly better than Standard and Absorbent dressings with respect to reducing infection. However, given the observed heterogeneity and small number of studies included, more comparative studies are needed to definitively recommend superiority among dressings following TJA.

Level of Evidence

Level 1.

Surgical Site Infections Following Birmingham Hip Resurfacing

The Birmingham Hip Resurfacing procedure (BHR) is metal-on-metal resurfacing procedure for hip arthritis. BHR was associated with low risk of surgical site infection (SSI; 0.6%). In addition to antimicrobials, superficial SSIs were treated with incision and drainage, whereas deep incisional or organ-space SSIs required removal of prosthesis. Infect Control Hosp Epidemiol 2016;1-4.