Pierre Hoffmeyer

Reduction of Urinary Tract Infection and Antibiotic Use after Surgery: A Controlled, Prospective, Before-After Intervention Study

BACKGROUND Urinary tract infection is the most frequent health care-associated complication. We hypothesized that the implementation of a multifaceted prevention strategy could decrease its incidence after surgery. METHODS In a controlled, prospective, before-after intervention trial with 1328 adult patients scheduled for orthopedic or abdominal surgery, nosocomial infection surveillance was conducted until hospital discharge. A multifaceted intervention including specifically tailored, locally developed guidelines for the prevention of urinary tract infection was implemented for orthopedic surgery patients, and abdominal surgery patients served as control subjects. Infectious and noninfectious complications, adherence to guidelines, and antibiotic use were monitored before and after the intervention and again 2 years later. RESULTS The incidence of urinary tract infection decreased from 10.4 to 3.9 episodes per 100 patients in the intervention group (incidence-density ratio, 0.41; 95% CI, 0.20-0.79; P=.004). Adherence to guidelines was 82.2%. Both the frequency and the duration of urinary catheterization decreased following the intervention. Recourse to antibiotic therapy after surgery dropped in the intervention group from 17.9 to 15.6 defined daily doses per 100 patient-days (P<.005) because of a reduced need for the treatment of urinary tract infection (P<.001). Follow-up after 2 years revealed a sustained impact of the strategy and a subsequent low use of antibiotics, consistent with stable adherence to guidelines (80.8%). CONCLUSIONS A multifaceted prevention strategy can dramatically decrease postoperative urinary tract infection and contribute to the reduction of the overall use of antibiotics after surgery.

Prevention of deep-vein thrombosis after total knee replacement. Randomised comparison between a low-molecular-weight heparin (nadroparin) and mechanical prophylaxis with a foot-pump system.

The optimal regime of antithrombotic prophylaxis for patients undergoing total knee arthroplasty (TKA) has not been established. Many surgeons employ intermittent pneumatic compression while others use low-molecular-weight heparins (LMWH) which were primarily developed for total hip arthroplasty. We compared the efficacy and safety of these two techniques in a randomised study with blinded assessment of the endpoint by phlebography. We randomised 130 patients, scheduled for elective TKA, to receive one daily subcutaneous injection of nadroparin calcium (dosage adapted to body-weight) or continuous intermittent pneumatic compression of the foot by means of the arteriovenous impulse system. A total of 108 patients (60 in the LMWH group and 48 in the mechanical prophylaxis group) had phlebography eight to 12 days after surgery. Of the 47 with deep-vein thrombosis, 16 had received LMWH (26.7%, 95% CI 16.1 to 39.7) and 31, mechanical prophylaxis (64.6%, 95% CI 49.5 to 77.8). The difference between the two groups was highly significant (p < 0.001). Only one patient in the LMWH group had severe bleeding. We conclude that one daily subcutaneous injection of calcium nadroparin in a fixed, weight-adjusted dosage scheme is superior to intermittent pneumatic compression of the foot for thromboprophylaxis after TKA. The LMWH scheme was also safe.

Prevention of deep-vein thrombosis after total knee replacement

The optimal regime of antithrombotic prophylaxis for patients undergoing total knee arthroplasty (TKA) has not been established. Many surgeons employ intermittent pneumatic compression while others use low-molecular-weight heparins (LMWH) which were primarily developed for total hip arthroplasty. We compared the efficacy and safety of these two techniques in a randomised study with blinded assessment of the endpoint by phlebography. We randomised 130 patients, scheduled for elective TKA, to receive one daily subcutaneous injection of nadroparin calcium (dosage adapted to body-weight) or continuous intermittent pneumatic compression of the foot by means of the arteriovenous impulse system. A total of 108 patients (60 in the LMWH group and 48 in the mechanical prophylaxis group) had phlebography eight to 12 days after surgery. Of the 47 with deep-vein thrombosis, 16 had received LMWH (26.7%, 95% CI 16.1 to 39.7) and 31, mechanical prophylaxis (64.6%, 95% CI 49.5 to 77.8). The difference between the two groups was highly significant (p < 0.001). Only one patient in the LMWH group had severe bleeding. We conclude that one daily subcutaneous injection of calcium nadroparin in a fixed, weight-adjusted dosage scheme is superior to intermittent pneumatic compression of the foot for thromboprophylaxis after TKA. The LMWH scheme was also safe.

Prevention of surgical site infections in orthopaedic surgery and bone trauma: state-of-the-art update

Prevention of surgical site infection in orthopaedic surgery and bone trauma has some hallmarks not shared with other surgical disciplines: low inoculum for implant infections; pathogenicity of coagulase-negative staphylococci and other skin commensals; possible haematogenous origin; and long post-discharge surveillance periods. Only some of the many measures to prevent orthopaedic surgical site infection are based on strong evidence and there is insufficient evidence to show which element is superior over any other. This highlights the need for multimodal approaches involving active post-discharge surveillance, as well as preventive measures at every step of the care process. These range from preoperative care to surgery and postoperative care at the individual patient level, including department-wide interventions targeting all healthcare-associated infections and improving antibiotic stewardship. Although theoretically reducible to zero, the maximum realistic extent to decrease surgical site infection in elective orthopaedic surgery remains unknown.

Low incidence of haematogenous seeding to total hip and knee prostheses in patients with remote infections

OBJECTIVES The exposure of joint prostheses to remote infections is unknown. We wanted to estimate (a) the exposure of arthroplasty patients to severe remote infections, and (b) the incidence of arthroplasty infections associated with remote infections. METHODS Prospective cohort study of all elective hip and knee arthroplasties performed between March 1996 and September 2008, with retrospective documentation of remote infections in hospitalized patients. RESULTS A total of 6101 elective total joint arthroplasties, consisting of 4002 hip replacements (66%) and 2099 knee replacements (34%), were included. The mean follow-up was 70 months. During the study period, the cohort patients experienced 553 remote infections after a median delay of 33 months post-arthroplasty. There were 71 prosthetic infections detected, 7 (total incidence 7/6101, 0.1%) of which were secondary to a remote infection. The ratio of infections associated with remote infections to potential exposure was 1:79. Among hip arthroplasty patients the incidence rate was 1.4 infections associated with remote infections per 10,000 patient-years of follow-up. Infections associated with remote infections occurred later than surgical site infections, (46 months vs. 19 months post-surgery, respectively; mean difference 27 months, 95% CI 8-45 months). CONCLUSIONS Arthroplasty infections associated with remote infections were rare, and occurred like their potential exposure mostly more than 24 months post-arthroplasty.

Acromioclavicular joint reconstruction: a comparative biomechanical study of three techniques

BACKGROUND Acute acromioclavicular joint dislocations indicated for surgery can be treated with several stabilization techniques. This in vitro study evaluated the acromioclavicular joint stability after 3 types of validated repair techniques compared with the native situation. MATERIALS AND METHODS Nine pairs (right-left) of intact cadaveric shoulder specimens were assigned to 3 study groups with randomly distributed samples according to the coracoclavicular distance. The groups were instrumented with acromioclavicular and coracoclavicular cerclages (CE), a Twin Tail TightRope (TR), or a locking compression superior and anterior clavicle plate (CP). Native and instrumented specimens were tested quasi-static nondestructively (superior: 70 N; anteroposterior: ± 35 N, 10 mm/min) and cyclically until failure (superior, valley load: 20 N; initial peak load: 70 N; increment: 0.02 N/cycle). RESULTS The TR study group showed the highest (in N/mm) superoinferior (73.77 ± 14.04) and anteroposterior (29.58 ± 1.52) stiffness, followed by CE (superoinferior: 59.73 ± 10.33; anteroposterior: 24.31 ± 4.14) and CP (superoinferior: 24.08 ± 5.29). Instrumentation generally led to increased superoinferior and anteroposterior stiffness in each study group but to a significant superoinferior stiffness reduction for CP (P = .029). Significantly lower coracoclavicular displacement at valley load after 1 and 500 cycles was observed for TR (P = .018) and CE (P = .041) compared with CP. Cycles to failure were significantly higher in CE (7298 ± 1244 cycles, P = .011) and TR (4434 ± 727 cycles, P = .031) compared with CP (1683 ± 509 cycles). CONCLUSIONS The CE and TR techniques led to similar biomechanical performances. The CE repair might mimic the native acromioclavicular joint stiffness better than the other 2 setups, leading to more physiological stabilization.

Short duration of antibiotic prophylaxis in open fractures does not enhance risk of subsequent infection

We undertook a retrospective case-control study to assess the clinical variables associated with infections in open fractures. A total of 1492 open fractures were retrieved; these were Gustilo and Anderson grade I in 663 (44.4%), grade II in 370 (24.8%), grade III in 310 (20.8%) and unclassifiable in 149 (10.0%). The median duration of prophylaxis was three days (interquartile range (IQR) 1 to 3), and the median number of surgical interventions was two (1 to 9). We identified 54 infections (3.6%) occurring at a median of ten days (IQR 5 to 20) after trauma. Pathogens intrinsically resistant to the empirical antibiotic regimen used (enterococci, Enterobacter spp, Pseudomonas spp) were documented in 35 of 49 cases (71%). In multivariable regression analyses, grade III fractures and vascular injury or compartment syndrome were significantly associated with infection. Overall, compared with one day of antibiotic treatment, two to three days (odds ratio (OR) 0.6 (95% confidence interval (CI) 0.2 to 2.0)), four to five days (OR 1.2 (95% CI 0.3 to 4.9)), or > five days (OR 1.4 (95% CI 0.4 to 4.4)) did not show any significant differences in the infection risk. These results were similar when multivariable analysis was performed for grade III fractures only (OR 0.3 (95% CI 0.1 to 3.4); OR 0.6 (95% CI 0.2 to 2.1); and OR 1.7 (95% CI 0.5 to 6.2), respectively). Infection in open fractures is related to the extent of tissue damage but not to the duration of prophylactic antibiotic therapy. Even for grade III fractures, a one-day course of prophylactic antibiotics might be as effective as prolonged prophylaxis.

Sexual activity after total hip arthroplasty: a motion capture study.

Relative risk of impingement and joint instability during sexual activities after total hip arthroplasty (THA) has never been objectively investigated. Hip range of motion necessary to perform sexual positions is unknown. A motion capture study with two volunteers was performed. 12 common sexual positions were captured and relevant hip joint kinematics calculated. The recorded data were applied to prosthetic hip 3D models to evaluate impingement and joint instability during motion. To explore the effect of acetabular component positioning, nine acetabular cup positions were tested. Four sexual positions for women requiring intensive flexion (> 95°) caused prosthetic impingements (associated with posterior instability) at 6 cup positions. Bony impingements (associated with anterior instability) occurred during one sexual position for men requiring high degree of external rotation (> 40°) combined with extension and adduction at all cup positions. This study hence indicates that some sexual positions could be potentially at risk after THA, particularly for women.

Measurement of plasma D-dimer is not useful in the prediction or diagnosis of postoperative deep vein thrombosis in patients undergoing total knee arthroplasty

Plasma D-dimer, a highly sensitive marker of venous thromboembolism, was measured using an enzyme-linked immunosorbent assay pre-operatively, on the third postoperative day, and at the time of phlebography in 118 patients undergoing elective total knee arthroplasty. Deep venous thrombosis (DVT) was detected using systematic bilateral phlebography between the eighth and 12th postoperative day in 47 (39.8%) patients. D-dimer plasma concentrations did not differ between patients who had DVT and those who had no DVT, either pre-operatively (n = 118, P = 0.63) or at the time of phlebography (n = 111, P = 0.70). On the third postoperative day, D-dimer concentration was significantly higher (P < 0.01) in the patients who had DVT (median 3270 μg/l, range 1156–9996, n = 47) than in those who did not (2287 μg/l, 685–7062, n = 64). However, receiver operating characteristics curve analysis did not provide any useful cutoff values that would allow individual diagnoses to be made. In conclusion, the results of the present study suggest that plasma measurement of D-dimer concentration is of no value for predicting, diagnosing or ruling out DVT in patients undergoing total knee arthroplasty.

Infectious olecranon and patellar bursitis: short-course adjuvant antibiotic therapy is not a risk factor for recurrence in adult hospitalized patients

OBJECTIVES No evidence-based recommendations exist for the management of infectious bursitis. We examined epidemiology and risk factors for recurrence of septic bursitis. Specifically, we compared outcome in patients receiving bursectomy plus short-course adjuvant antibiotic therapy (<or=7 days) with that of patients receiving bursectomy plus longer-course antibiotic therapy (>7 days). PATIENTS AND METHODS Retrospective study of adult patients with infectious olecranon and patellar bursitis requiring hospitalization at Geneva University Hospital from January 1996 to March 2009. RESULTS We identified 343 episodes of infectious bursitis (237 olecranon and 106 patellar). Staphylococcus aureus predominated among the 256 cases with an identifiable pathogen (85%). Three hundred and twelve cases (91%) were treated surgically; 142 (41%) with one-stage bursectomy and closure and 146 with two-stage bursectomy. All received antibiotics for a median duration of 13 days with a median intravenous component of 3 days. Cure was achieved in 293 (85%) episodes. Total duration of antibiotic therapy [odds ratio (OR) 0.9; 95% confidence interval (95% CI) 0.8-1.1] showed no association with cure. In multivariate analysis, only immunosuppression was linked to recurrence (OR 5.6; 95% CI 1.9-18.4). Compared with <or=7 days, 8-14 days of antibiotic treatment (OR 0.6; 95% CI 0.1-2.9) or >14 days of antibiotic treatment (OR 0.9; 95% CI 0.1-10.7) was equivalent, as was the intravenous component (OR 1.1; 95% CI 1.0-1.3). CONCLUSIONS In severe infectious bursitis requiring hospitalization, adjuvant antibiotic therapy might be limited to 7 days in non-immunosuppressed patients.