Severe Obesity Increases Risk of Infection After Revision Total Hip Arthroplasty

[Strategies for stem revision : Surgery planning, implant removal and reimplantation]

BACKGROUND AND PLANNING

Femoral revision represents a challenging procedure in its surgical planning and technical execution. The results are mainly dependent on the bone loss present, the quality of the implant removal and the choice of revision system. Patient-specific factors such as age, comorbidities, bone quality or even the localization of the cement have a decisive influence on the surgical strategy. Appropriate preoperative preparation, including the presence of the necessary special instruments, which are essential for gentle implant removal, is indispensable to achieve the best possible result.

THERAPY

A bone-sparing implant removal can be particularly challenging, especially in the case of well-fixed stems and cement residues, which may extend far beyond the isthmus. In such situations, a transfemoral approach should be considered. Cementless reimplantation using modular or non-modular titanium stems is currently the preferred treatment of choice for most revisions. In elderly, low-demand patients or with poor bone quality, cemented revision remains a good alternative treatment option.

Debridement, antibiotics and implant retention for prosthetic joint infection: comparison of outcomes between total hip arthroplasty and hip resurfacing

INTRODUCTION

The management of prosthetic joint infection (PJI) has been widely studied in the context of total hip arthroplasty (THA). However, the outcomes of debridement, antibiotics and implant retention (DAIR) for PJI have never been compared between hip resurfacing arthroplasty (HRA) and THA. This led us to carry out a retrospective case-control study comparing the surgical treatment of post-operative infections between HRA and THA to determine the infection remission rate and the medium-term functional outcomes.

METHODS

This single-centre case-control study analysed 3056 HRA cases of which 13 patients had a PJI treated by DAIR. These patients were age-matched with 15 infected THA hips treated by DAIR and modular component exchange (controls). Their survival (no recurrence of the infection) was compared and factors that could affect the success of the DAIR were explored: sex, body mass index, age at surgery, presence of haematoma, type of bacteria present and antibiotic therapy.

RESULTS

At a mean follow-up of five years (2-7), the infection control rate was significantly higher in the HRA group (100% [13/13]) than in the THA group (67% [10/15]) (p = 0.044). More patients in the THA group had undergone early DAIR (< 30 days) (73% [11/15]) than in the HRA group (54% [7/13]). There was no significant difference between the two groups in the ASA score, presence of comorbidities, body mass index and duration of the initial arthroplasty procedure. At the review, the Oxford-12 score of 17/60 (12-28) was better in the HRA group than the score of 25/60 (12-40) in the THA group (p = 0.004).

CONCLUSION

DAIR, no matter the time frame, is a viable therapeutic option for infection control after HRA.

The Impact of Morbid Obesity on In-hospital Outcomes after Revision Total Hip Arthroplasty: An Analysis of the National Inpatient Sample

Introduction:

There remain limited data on the effect of obesity on in-hospital outcomes after revision total hip arthroplasty (rTHA).

Methods:

Discharge data from the National Inpatient Sample were used to identify patients undergoing rTHA from 2006 to 2015. Propensity score analysis was done to analyze the effects of obesity and morbid obesity on in-hospital economic and complication outcomes after rTHA.

Results:

The estimated 460,297 rTHAs were done during the study period. Obese patients were more likely to suffer from any complication than not obese patients (41.44% versus 39.41%, P = 0.0085), and morbidly obese patients were more likely to suffer from any complication than obese patients (47.22% versus 41.44%, P < 0.0001). Obesity was associated with increased risk of postoperative anemia compared with not obese patients, while morbid obesity was associated with increased risk of postoperative anemia, hematoma/seroma, wound dehiscence, and postoperative infection (P < 0.05). Morbidly obese patients also had a significantly greater average length of stay (6.40 days) than obese (5.23 days) and not obese (5.37 days) patients (P < 0.0001).

Discussion:

Although both obesity and morbid obesity are associated with higher risk of in-hospital postoperative complications after rTHA, morbid obesity is a larger risk factor and is associated with a longer length of stay.

Risk Factors for Delayed Discharge and Adverse Outcomes Following Outpatient Billed Total Knee Arthroplasty

BACKGROUND

The volume of outpatient total knee arthroplasty (TKA) has increased with advances in perioperative protocols, patient selection, and recent policy changes regarding insurance authorization. This study analyzed 30-day outcomes from a national database to better understand risk factors for delayed discharge (length of stay [LOS] ≥1), readmission, and reoperation after outpatient TKA.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was utilized to collect TKA (CPT 27447) billed as outpatient surgery performed from 2013 to 2018. Patient demographics, comorbidities, and short-term outcomes were collected and compared in LOS 0 versus LOS ≥1 cohorts. Subgroup analysis was completed for TKA performed in 2018, after the Center for Medicare Services removal of TKA from the inpatient-only list.

RESULTS

A total of 13,669 patients had outpatient TKA performed from 2013 to 2018. Most patients had LOS ≥1 day (77.1%). The LOS 0 cohort demonstrated a lower 30-day readmission rate (1.8%) compared to LOS ≥1 (2.8%), P > .01. Both groups demonstrated a low 30-day reoperation rate, LOS 0 (0.7%) and LOS ≥1 (1.1%), P = .05. Regression analysis demonstrated risk factors for LOS ≥1 day included COPD, ASA ≥3, age >75, and BMI >35 kg/m². Regression analysis demonstrated male gender, age >75, ASA ≥3, and albumin <3.5 g/dL were risk factors for readmission. Hypertension was a risk factor for 30-day reoperation.

CONCLUSION

Risk factors for LOS ≥1 day include age >75, ASA ≥3, BMI >35 kg/m². In addition, BMI >35 kg/m² was a risk factor for readmission and reoperation. These findings reinforce appropriate patient selection when considering outpatient TKA.

Increasing Reoperations and Failures With Increasing BMI in Patients Undergoing 2-Stage Exchange for Infected Total Hip Arthroplasty

BACKGROUND

While morbid obesity is associated with increased infection after total hip arthroplasty, little is known on the outcomes after 2-stage reimplantation for prosthetic joint infection (PJI) in this population. The purpose of this study is to evaluate the impact of morbid obesity (body mass index>40 kg/m2) on reinfection, postoperative complications, readmissions, and reoperations.

METHODS

We conducted a retrospective review of 107 patients undergoing first time 2-stage reimplantation for PJI from 2013 to 2019. 18 patients (50% women) with body mass index>40 kg/m2 were identified. To minimize confounders, three propensity score matched cohorts were created, yielding 16 nonobese (<30 kg/m2), 16 obese (30-39.9 kg/m2), and 18 morbidly obese (>40 kg/m2) patients. Outcomes were compared using chi-square or Fisher's exact tests. All patients had minimum 12-month follow-up, with mean follow-up of 36.3, 30.1, and 40.0 months in the nonobese, obese, and morbidly obese cohorts, respectively.

RESULTS

Compared with nonobese patients, morbidly obese patients had a higher rate of reinfection (0% vs 33%, P = .020 and higher likelihood of length of stay>4 days (19% vs 61%, P = .012). In addition, compared with nonobese and obese patients, morbidly obese patients had higher rate of return to the operating room for any reason (13% vs 19% vs 50%, respectively, P = .020). No differences between cohorts were found regarding complications, death, or revision surgery.

CONCLUSION

Morbidly obese patients have significantly increased risk of reinfection and reoperation after 2-stage reimplantation for PJI when compared with obese and nonobese patients. These data can be used to counsel morbidly obese patients contemplating total hip arthroplasty and supports the notion of deferring arthroplasty in this population pending optimization.

Wound complications and bleeding with new oral anticoagulants in patients undergoing total joint arthroplasty: A systematic review and meta-analysis of randomized controlled trials

AIMS

The results of associations between new oral anticoagulants (NOACs) and wound complications after total joint arthroplasty remain inconsistent. We conducted a systematic review and meta-analysis of randomized controlled trials to make comparisons with low molecular weight heparins (LMWH) on the clinical outcomes of total wound complications, together with other efficacy and safety endpoints to further evaluate the safety and efficacy of NOACs.

METHODS

This meta-analysis was conducted based on a published protocol (PROSPERO: CRD42019140841). We searched for available articles in PubMed, Embase and Cochrane Library through Jun 62 021. Random-effects meta-analyses, including subgroup analyses, were conducted to estimate the pooled relative risk (RR) and 95% confidence interval (CI) for specific doses of NOACs.

RESULTS

We retrieved 1683 studies, of which 20 were eligible for inclusion. We found that apixaban was associated with a lower incidence of total wound complications compared with LMWH (RR = 0.81; 95% CI: 0.65-1.00), while dabigatran and rivaroxaban did not increase the risk of total wound complications. In addition, apixaban was associated with a reduction in the risk of major/clinically relevant nonmajor bleeding events compared to LMWH (RR = 0.80, 95% CI: 0.65-0.99), while rivaroxaban increased the risk for major/clinically relevant nonmajor bleeding events (RR = 1.23, 95% CI: 1.02-1.50). Moreover, all 4 NOACs were associated with lower incidences of major venous thromboembolism compared with LMWH.

CONCLUSION

A lower risk of wound complications was detected for apixaban, while dabigatran and rivaroxaban did not increase the risk when compared with LMWH. The efficacy of 4 NOACs was broadly similar.

Aspirin Use for Venous Thromboembolism Prevention Is Safe and Effective in Overweight and Obese Patients Undergoing Revision Total Hip and Knee Arthroplasty

BACKGROUND

Venous thromboembolism (VTE), defined as pulmonary embolism or deep venous thrombosis, is a rare but serious complication following revision total hip arthroplasty (RTHA) and revision total knee arthroplasty (RTKA). Previous studies show that obesity may be associated with an increased risk for pulmonary embolism, wound complications, and infection. With no current universal standard of care for VTE prophylaxis, we sought to determine whether aspirin prescribed (ASA) is safe and effective in obese patients undergoing RTHA/RTKA.

METHODS

A retrospective review of 1578 consecutive RTHA/RTKA cases (751 RTHAs and 827 RTKAs) was conducted identifying patients prescribed 325 or 81 mg ASA. Ninety-day postoperative VTE rates, bleeding, wound complications, deep infections, and mortality were collected. Cohorts were stratified according to body mass index (BMI): normal (18-24.9 kg/m²), overweight (25-29.9 kg/m²), obese (30-34.9 kg/m²), severely obese (35-39.9 kg/m²), and morbidly obese (≥40 kg/m²).

RESULTS

The cohort comprised of 335 patients with a normal BMI, 511 were overweight, 408 obese, 232 severely obese, and 92 morbidly obese. Total VTE rates were statistically similar between BMI groups (0.90% vs 0.78% vs 0.74% vs 0.43% vs 0%, P = .89). There were no differences in bleeding rates (0.90% vs 0% vs 0% vs 0.43% vs 0%, P = .08), wound complications (0.30% vs 0.20% vs 0.25% vs 0% vs 0%, P = .93), infection (1.49% vs 1.57% vs 0.98% vs 1.29% vs 1.09%, P = .66), or mortality (0% vs 0.20% vs 0% vs 0% vs 0%, P = .72).

CONCLUSION

ASA is safe and effective for VTE prevention in obese patients with similar complication rates to nonobese patients undergoing RTHA/RTKA.

Antibacterial and anti-inflammatory ultrahigh molecular weight polyethylene/tea polyphenol blends for artificial joint applications

Periprosthetic joint infection (PJI) is one of the main causes for the failure of joint arthroplasty. In view of the limited clinical effect of oral/injectable antibiotics and the drug resistance problem, there is a pressing need to develop antibacterial implants with therapeutic antimicrobial properties. In this work, we prepared a highly antibacterial ultrahigh molecular weight polyethylene (UHMWPE) implant by incorporating tea polyphenols. The presence of tea polyphenols not only improved the oxidation stability of irradiated UHMWPE, but also gave it the desirable antibacterial property. The potent antibacterial activity was attributed to the tea polyphenols that produced excess intracellular reactive oxygen species and destroyed the bacterial membrane structure. The tea polyphenol-blended UHMWPE had no biological toxicity to human adipose-derived stem cells and effectively reduced bacteria-induced inflammation in vivo. These results indicate that tea polyphenol-blended UHMWPE is promising for joint replacement prostheses with multifunctionality to meet patient satisfaction.

Morbid Obesity Is a Risk Factor for Infection Recurrence Following Debridement, Antibiotics, and Implant Retention for Periprosthetic Joint Infection

BACKGROUND

Although morbid obesity is an established risk factor for periprosthetic joint infection following total hip arthroplasty and total knee arthroplasty, little is known regarding the infection control rate of this cohort following debridement, antibiotics, and implant retention (DAIR). The purpose of this study is to investigate the infection control rate following DAIR in a morbidly obese patient cohort compared to a nonobese patient cohort and discern the relationship between time from diagnosis to treatment and risk of DAIR failure.

METHODS

Results of all DAIR procedures were retrospectively reviewed across 4 institutions. Those with a body mass index of at least 40 kg/m² were matched 2:1 on the basis of patient age, sex, date of surgery, and presence of staphylococcal species in culture to a cohort of patients with body mass index of <30 kg/m². Demographic variables were collected for each patient. Kaplan-Meier survivorship curves were constructed and multivariable Cox regression was performed for analysis.

RESULTS

The morbidly obese group experienced a higher treatment failure rate (57.9%) compared to the nonobese group (36.8%; P = .035). Morbid obesity and major depressive disorder/generalized anxiety disorder diagnosis significantly increased the risk of failure, with hazard ratios of 1.82 and 2.09, respectively. Morbidly obese patients who received DAIR within 48 hours of symptom presentation did not face an increased risk of reinfection compared to nonobese patients.

CONCLUSION

Our findings suggest morbidly obese patients face an increased risk of DAIR failure; however, this risk can be mitigated if DAIR is received within 48 hours of symptom onset.

Explantation, Followed by Serial Debridement Without Antibiotic Spacers and Subsequent Revision With Cementless Components, Is Associated With High Remission Rates and Low Mortality in Periprosthetic Hip Joint Infections

BACKGROUND

In difficult-to-treat cases, it is necessary to add debridement steps in prosthesis-free interval of 2-stage exchange. We aimed to analyze the functional and clinical outcome of patients treated with a multistage exchange of total hip arthroplasty without the use of spacers, rather only cementless implants.

METHODS

Between 2009 and 2018, 84 patients (mean age: 67.3 [39-90] years) suffering chronic late-onset periprosthetic joint infection (PJI) were treated using a multistage prosthesis exchange without spacers. The mean follow-up was 70 ± 45.3 [14-210] months. The treatment included prosthesis exchange and at least 1 additional revision step before a reimplantation, owing to ongoing acute infection in the prosthesis-free interval. High-efficiency antimicrobial therapy was administered in between, which was discontinued after cementless revision implantation.

RESULTS

The mean number of revisions between explantation and implantation was 2.6 (1-9). The most common microorganism was Staphylococcus epidermidis (53.6%) followed by Staphylococcus aureus (16.7%) and Cutibacterium acnes (11.9%). The bacterial load was more than one bacterium per patient in 38% of cases. All patients could be treated using a cementless implant. PJI remission was achieved in 92% of cases. Overall, 9 prostheses (11%) were replaced because of an ongoing PJI or fracture. The mean modified Harrison Hip Score was 63.4 (22-88) points. No patient died.

CONCLUSION

Multistage total hip arthroplasty exchange showed high remission rates and low mortality in difficult-to-treat cases. Spacer-free and multistage treatment had no negative effect on the success rate or functional outcome, consistent with the results of published 2-stage exchange studies. Implantation of an uncemented press-fit prosthesis was possible in all patients with no elevated periprosthetic fracture rate.