Intra-operative bacterial contamination : control and consequences

Een combinatie van gedragsmaatregelen en een beter luchtinblaassysteem in de operatiekamer leidt tot een afname van het aantal bacteriën bij plaatsing van een knie- of heupprothese. Hierdoor neemt de kans af op infectie van de prothese en op problemen met wondgenezing na de operatie. Dit blijkt uit onderzoek van Bas Knobben, uitgevoerd bij de afdeling Orthopedie en de vakgroep Biomedical Engineering van het Universitair Medisch Centrum Groningen. Deze bevindingen kunnen ertoe bijdragen dat gewrichtsprothesen minder vaak infecteren en vervangen moeten worden. Hij promoveert op 26 april 2006 op zijn onderzoek aan de Rijksuniversiteit Groningen. In elke operatiekamer kunnen ondanks strenge hygiënische maatregelen bacteriën voorkomen die een mogelijk risico vormen voor infectie van prothesen en problemen met wondgenezing na de operatie. Tot nu toe was de omvang hiervan onduidelijk. Uit het onderzoek van Knobben blijkt dat bij 36 procent van de plaatsingen van heupprothesen bacteriën aanwezig waren op het instrumentarium en op verwijderde botsnippers bij het inbrengen van de prothesen. Ook bleek er een verband te zijn tussen het vóórkomen van deze bacteriën en het optreden van verstoorde wondgenezing en infectie van de prothesen. Gedragsmaatregelen Knobben onderzocht of gedrags- en technische maatregelen, aanvullend op de gebruikelijke hygiënerichtlijnen, de kans op bacteriële besmetting tijdens de operatie verkleinen. Uit zijn onderzoek blijkt dat de combinatie van deze maatregelen in een operatiekamer de kans op aanwezigheid van bacteriën deed afnemen van 34 procent naar 8 procent. Tegelijk nam de kans op infectie van prothesen, verstoorde wondgenezing en wondinfectie beduidend af. De gedragsmaatregelen die onder andere werden genomen, zijn het beperken van het spreken en het in- en uitlopen van de operatiekamer door het operatiekamerpersoneel, het gecontroleerd bewegen, het juiste gebruik van het neus-/mondkapje en een beter gebruik van het gebied onder de luchtstroom. Een van de technische maatregelen betrof het gebruik van een beter luchtinblaassysteem (laminaire airflow). Hierbij vindt een constante aanvoer van schone lucht plaats boven het operatiegebied en worden bacteriën via verticale luchtstromen afgevoerd. Kosteneffectief Met dit onderzoek toont Knobben aan dat gedragsmaatregelen en een beter luchtinblaassysteem in de operatiekamer infecties van prothesen en problemen met wondgenezing kunnen voorkomen. De maatregelen zijn bovendien kosteneffectief: de gemiddelde totale kosten per patiënt met een eerste (primaire) prothese zonder infectie zijn ongeveer € 15.000, zo’n 3,5 keer lager dan die van een patiënt met een geïnfecteerde prothese (ongeveer € 52.000). De resultaten van dit proefschrift hebben ertoe geleid dat het Universitair Medisch Centrum Groningen de aanvullende gedrags- en technische maatregelen toepast bij het plaatsen van prothesen. Verdubbeling In Nederland zijn in 2004 ongeveer 25.000 heup- en 20.000 knieprothesen geplaatst. De belangrijkste indicatie voor het plaatsen hiervan is gewrichtsslijtage. De verwachting is dat door vergrijzing het aantal mensen dat in aanmerking komt voor deze operaties de komende twintig jaar zal verdubbelen. Bij ongeveer één tot vier procent van de patiënten treedt na plaatsing een bacteriële infectie op.

The development of a comprehensive multidisciplinary care pathway for patients with a hip fracture:design and results of a clinical trial

Background: Hip fractures frequently occur in older persons and severely decrease life expectancy and independence. Several care pathways have been developed to lower the risk of negative outcomes but most pathways are limited to only one aspect of care. The aim of this study was therefore to develop a comprehensive care pathway for older persons with a hip fracture and to conduct a preliminary analysis of its effect. Methods: A comprehensive multidisciplinary care pathway for patients aged 60 years or older with a hip fracture was developed by a multidisciplinary team. The new care pathway was evaluated in a clinical trial with historical controls. The data of the intervention group were collected prospectively. The intervention group included all patients with a hip fracture who were admitted to University Medical Center Groningen between 1 July 2009 and 1 July 2011. The data of the control group were collected retrospectively. The control group comprised all patients with a hip fracture who were admitted between 1 January 2006 and 1 January 2008. The groups were compared with the independent sample t-test, the Mann-Whitney U-test or the Chi-squared test (Phi test). The effect of the intervention on fasting time and length of stay was adjusted by linear regression analysis for differences between the intervention and control group. Results: The intervention group included 256 persons (women, 68%; mean age (SD), 78 (9) years) and the control group 145 persons (women, 72%; mean age (SD), 80 (10) years). Median preoperative fasting time and median length of hospital stay were significantly lower in the intervention group: 9 vs. 17 hours (p <0.001), and 7 vs. 11 days (p <0.001), respectively. A similar result was found after adjustment for age, gender, living condition and American Society of Anesthesiologists (ASA) classification. In-hospital mortality was also lower in the intervention group: 2% vs. 6% (p <0.05). There were no statistically significant differences in other outcome measures. Conclusions: The new comprehensive care pathway was associated with a significant decrease in preoperative fasting time and length of hospital stay

MRI Assessment of Muscle Damage After the Posterolateral Versus Direct Anterior Approach for THA (Polada Trial). A Randomized Controlled Trial

BACKGROUND: There is controversy in literature whether the direct anterior approach (DAA) results in less muscle damage compared with the posterolateral approach (PLA) for total hip arthroplasty. The aim of this randomized controlled trial was to assess muscle damage between these two approaches. METHODS: Forty-six patients were included. Muscle atrophy, determined with the Goutallier classification, and muscle surface of twelve muscles were analyzed on magnetic resonance imaging images made preoperatively and one year postoperatively. Differences in component placement after DAA or PLA were assessed on radiographs. Harris hip scores and Hip disability and Osteoarthritis and Outcome Score were used as functional outcomes. RESULTS: External rotator musculature was damaged in both approaches. After PLA, the obturator muscles showed significantly more atrophy and a decrease in muscle surface. After DAA, the tensor fascia latae showed an increased muscle atrophy and the psoas muscle showed a decreased muscle surface. An increase in muscle surface was seen for the rectus femoris, sartorius, and quadratus femoris after both approaches. The muscle surface of the gluteus medius and iliacus was also increased after PLA. No difference in muscle atrophy was found between the approaches for these muscles. The inclination angle of the cup in PLA was significantly higher. No differences were found in functional outcomes. CONCLUSION: Different muscle groups were affected in the two approaches. After PLA, the external rotators were more affected, whereas the tensor fascia latae and psoas muscles were more affected after DAA

Flow cytometric assessment of leukocyte kinetics for the monitoring of tissue damage

Leukocyte populations quickly respond to tissue damage, but most leukocyte kinetic studies are not based on multiparameter flow cytometry. We systematically investigated several blood leukocyte populations after controlled tissue damage. 48 patients were assigned to either an anterior or posterolateral total hip arthroplasty. Peripheral blood was collected pre-operatively and at 2 h, 24 h, 48 h, 2 and 6 weeks postoperatively and assessed by flow cytometry for absolute counts of multiple leukocyte populations using standardized EuroFlow protocols. Absolute counts of leukocyte subsets differed significantly between consecutive time points. Neutrophils increased instantly after surgery, while most leukocyte subsets initially decreased, followed by increasing cell counts until 48 h. At two weeks all leukocyte counts were restored to pre-operative counts. Immune cell kinetics upon acute tissue damage exhibit reproducible patterns, which differ between the leukocyte subsets and with “opposite kinetics” among monocyte subsets. Flow cytometric leukocyte monitoring can be used to minimally invasively monitor tissue damage.This was supported by Stichting Anna Fonds/NOREF (Dutch Orthopedic Research and Education Fund) and the Erasmus MC Medical research grant (grant no. DRP337224)

A Second Surgical Debridement for Acute Periprosthetic Joint Infections Should Not Be Discarded

Background: In acute periprosthetic joint infections (PJIs), a second surgical debridement (debridement, antibiotics, and implant retention [DAIR]) is generally not recommended after a failed first one. We identified the failure rate of a second DAIR and aimed to identify patients in whom an additional debridement might still be beneficial. Methods: Patients with acute PJI of the hip or knee and treated with DAIR between 2006 and 2016 were retrospectively evaluated. A second DAIR was routinely performed provided that the soft tissue was intact. Failure of a second DAIR was described as (1) the need for additional surgical intervention to achieve infection control, (2) the need for antibiotic suppressive therapy due to persistent clinical and/or biochemical signs of infection, or (3) PJI related death. Results: From the 455 cases treated with DAIR, 144 cases underwent a second debridement (34.6%). Thirty-seven cases failed (37/144, 25.7%). The implant needed to be removed in 23 cases (23/144, 16%). Positive cultures during the second DAIR (odds ratio 3.16, 95% confidence interval 1.29-7.74) and chronic renal insufficiency (odds ratio 13.6, 95% confidence interval 2.03-91.33) were independent predictors for failure in the multivariate analysis. No difference in failure was observed between persistent infection with the same microorganism and reinfection with a new microorganism (failure rate 31.6% vs 34.6%, P =.83). Conclusion: A second DAIR had a low failure rate in our cohort of patients and the implant could be retained in the majority of them. Therefore, a second DAIR should not be discarded in acute PJIs

If, When, and How to Use Rifampin in Acute Staphylococcal Periprosthetic Joint Infections, a Multicentre Observational Study

Background: Rifampin is generally advised in the treatment of acute staphylococcal periprosthetic joint infections (PJI). However, if, when, and how to use rifampin remains a matter of debate. We evaluated the outcome of patients treated with and without rifampin, and analyzed the influence of timing, dose and co-antibiotic. Methods: Acute staphylococcal PJIs treated with surgical debridement between 1999 and 2017, and a minimal follow-up of 1 year were evaluated. Treatment failure was defined as the need for any further surgical procedure related to infection, PJI-related death or the need for suppressive antimicrobial treatment. Results: A total of 669 patients were analyzed. Treatment failure was 32.2% (131/407) in patients treated with rifampin and 54.2% (142/262) in whom rifampin was withheld (P < .001). The most prominent effect of rifampin was observed in knees (treatment failure 28.6% versus 63.9%, respectively, P < .001). The use of rifampin was an independent predictor of treatment success in the multi-variate analysis (OR 0.30, 95% CI 0.20 - 0.45). In the rifampin group, the use of a co-antibiotic other than a fluoroquinolone or clindamycin (OR 10.1, 95% CI 5.65 - 18.2) and the start of rifampin within 5 days after surgical debridement (OR 1.96, 95% CI 1.08 - 3.65) were predictors of treatment failure. The dosing of rifampin had no effect on outcome. Conclusions: Our data supports the use of rifampin in acute staphylococcal PJIs treated with surgical debridement, particularly in knees. Immediate start of rifampin after surgical debridement should probably be discouraged, but requires further investigation

Debridement, antibiotics and implant retention is a viable treatment option for early periprosthetic joint infection presenting more than four weeks after index arthroplasty

Background. The success of debridement, antibiotics, and implant retention (DAIR) in early periprosthetic joint infection (PJI) largely depends on the presence of a mature biofilm. At what time point DAIR should be disrecommended is unknown. This multicenter study evaluated the outcome of DAIR in relation to the time after index arthroplasty. Methods. We retrospectively evaluated PJIs occurring within 90 days after surgery and treated with DAIR. Patients with bacteremia, arthroscopic debridements, and a follow-up <1 year were excluded. Treatment failure was defined as (1) any further surgical procedure related to infection; (2) PJI-related death; or (3) use of long-term suppressive antibiotics. Results. We included 769 patients. Treatment failure occurred in 294 patients (38%) and was similar between time intervals from index arthroplasty to DAIR: The failure rate for Week 1-2 was 42% (95/226), the rate for Week 3-4 was 38% (143/378), the rate for Week 5-6 was 29% (29/100), and the rate for Week 7-12 was 42% (27/65). An exchange of modular components was performed to a lesser extent in the early post-surgical course compared with the late course (41% vs 63%, respectively; P < .001). The causative microorganisms, comorbidities, and durations of symptoms were comparable between time intervals. Conclusions. DAIR is a viable option in patients with early PJI presenting more than 4 weeks after index surgery, as long as DAIR is performed within at least 1 week after the onset of symptoms and modular components can be exchanged

Mobile laminar air flow screen for additional operating room ventilation: reduction of intraoperative bacterial contamination during total knee arthroplasty

Background Surgical site infections are important complications in orthopedic surgery. A mobile laminar air flow (LAF) screen could represent a useful addition to an operating room (OR) with conventional turbulent air ventilation (12.5 air changes/h), as it could decrease the bacterial count near the operating field. The purpose of this study was to evaluate LAF efficacy at reducing bacterial contamination in the surgical area during 34 total knee arthroplasties (TKAs). Materials and methods The additional unit was used in 17 operations; the LAF was positioned beside the operating table between two of the surgeons, with the air flow directed towards the surgical area (wound). The whole team wore conventional OR clothing and the correct hygiene procedures and rituals were used. Bacterial air contamination (CFU/m3) was evaluated in the wound area in 17 operations with the LAF unit and 17 without the LAF unit. Results The LAF unit reduced the mean bacterial count in the wound area from 23.5 CFU/m3 without the LAF to 3.5 CFU/m3 with the LAF (P&lt;0.0001), which is below the suggested limit for anORwith ultraclean laminar ventilation. There were no significant differences in the mean bacterial count in the instrument table area: 28.6 CFU/m3 were recorded with the LAF (N = 6) unit and 30.8 CFU/m3 (N = 6) without the LAF unit (P = 0.631). During six operations with LAF and six without LAF, particle counts were performed and the number of 0.5 lm particles was analyzed. The particle counts decreased significantly when the LAF unit was used (P = 0.003). Conclusion When a mobile LAF unit was added to the standard OR ventilation, bacterial contamination of the wound area significantly decreased to below the accepted level for an ultraclean OR, preventing SSI infections