Risk of surgical site infections following hip and knee arthroplasty: results of the ISChIA-GISIO study

Plasma and tissue concentrations of 2 g prophylactic cefazolin prior to lower extremity surgery

Surgical site infections (SSIs) are among the most clinically relevant complications and the use of prophylactic cefazolin is common practice. However, the knowledge about the pharmacological aspects of prophylactic cefazolin in the lower extremities remains limited. In this prospective cohort, a sub-study of the WIFI-2 randomized controlled trial, adults between 18 and 75 years of age who were scheduled for implant removal below the level of the knee and randomized for cefazolin, was included. A maximum of two venous plasma, target-site plasma, and target-site tissue samples were taken during surgery. The primary outcomes were the cefazolin concentrations in venous plasma, target-site plasma, and target-site tissue. A total of 27 patients [median (interquartile range) age, 42 (29-59) years; 17 (63%) male] with 138 samples were included in the study. A minimum of 6 weeks follow-up was available for all patients. The mean (SD) venous plasma, target-site plasma, and target-site tissue concentrations were 36 (13) µg/mL, 29 (13) µg/mL, and 28 (13) µg/g, respectively, and the cefazolin concentrations between the different locations of surgery did not differ significantly in both target-site plasma and target-site tissue (P = 0.822 and P = 0.840). In conclusion, 2 g of prophylactic cefazolin demonstrates adequacy in maintaining coverage for a duration of at least 80 minutes of surgery below the level of the knee, significantly surpassing the MIC90 required to combat the most prevalent microorganisms. This study represents the first of its kind to assess cefazolin concentrations in the lower extremities by examining both plasma and tissue samples in this magnitude.

"Single-use peripheral" vs "conventional" reaming in total hip arthroplasty: how to respect native centre of rotation and acetabular offset? A CT study

PURPOSE

The respect of native hip offset represents a mainstay for satisfying results in total hip arthroplasty (THA). Historically, a great interest has been focused on restoration of femoral offset, while only in recent years, acetabular offset (AO) has been considered. The purpose of the current study was to compare the "single-use peripheral" reaming technique with the "conventional" one for the maintenance of the native COR of the hip and AO in patients undergoing to primary THA.

METHODS

Eighty patients affected from primary hip osteoarthritis were prospectively enrolled in the study and were divided in two groups (Group A "single-use peripheral" and Group B "conventional" reaming technique). Pre- and post-operatively, AO, acetabular floor distance (AFd) and acetabular version (AV) were assessed through a CT scan. A comparison between groups for the radiological parameters, surgical time and complications was performed.

RESULTS

The demographic data were similar in both groups. The complications rate and the AV did not differ statistically between groups. Group A presented a statistically significant shorter surgical time and lower variation between pre- and post-operative AO and AFd. Statistical significance was defined as p < 0.05.

CONCLUSIONS

The "single-use peripheral" reaming technique demonstrated to be more reliable in reproducing the native COR and AO of patients undergoing to primary THA than the "conventional" one. The operative time was significantly reduced, and it may lead to a reduction in the infection risk even though it was not observed in the current study. Further research could be useful to validate such findings and to assess clinical impact and long-term survival of the implant.

Locking plates for distal fibula fractures in young and elderly patients: A retrospective study

BACKGROUND

Ankle fractures are common injuries in the young and elderly populations. To prevent post-traumatic arthritis, an anatomic reconstruction of the ankle structure is mandatory. Open reduction and internal fixation is the treatment of choice among orthopaedics. Conventional plates allow stability of the fracture if bone quality is present. Locking plates might offer an advantage for the treatment of lateral malleolar fracture in patients with comminution, severe instability, distal fractures, or osteoporotic bone. Our hospital introduced a new locking plate for fracture of the distal fibula.

AIM

To evaluate locking plates in terms of outcomes and complications in young and elderly patients.

METHODS

We retrospectively reviewed a total of 67 patients treated for displaced distal fibula fractures. Demographic data, number of comorbidities, use of inter fragmentary screw, complication, time of fracture healing, partial or full weight bearing, and reoperation were recorded for all patients. Clinical outcome was assessed by the American Orthopedic Foot and Ankle Society clinical scoring system. Radiographs were obtained at 4, 8, 12, 16, 20, and 24 wk until radiographic union was obtained.

RESULTS

All patients displayed complete bony union on radiographic assessment, and no patients developed any serious complications. We observed two superficial infections, one delayed wound healing, and two plate intolerances. Significant differences were observed between the two age groups in terms of radiographic healing (11.9 wk in younger patients vs 13.7 wk in older patients; P = 0.011) and in the American Orthopedic Foot and Ankle Society score at 6 mo after surgery (88.2 in younger patients vs 86.0 in older patients; P = 0.001) and at 12 mo after surgery (92.6 in younger patients vs 90.0 in older patients; P = 0.000).

CONCLUSION

Locking plates provide a stable and rigid fixation in multifragmentary and comminuted fractures or in the presence of poor bone quality.

Longitudinal Rates, Patient Risk Factors, and Economic Impact of Superficial and Deep Incisional Surgical Site Infection After Primary and Revision Total Hip Arthroplasty: A U.S. Retrospective Commercial Claims Database Analysis

Background: Longitudinal rates, risk factors, and costs of superficial and deep incisional surgical site infection (SSI) were evaluated six months after primary total hip arthroplasty (pTHA) and revision total hip replacement (rTHA). Patients and Methods: Patients who had pTHA or rTHA between January 1, 2016 and March 31, 2018 were identified using the IBM^® MarketScan^® administrative claims databases. Kaplan-Meier survival curves evaluated time to SSI over six months. Cox proportional hazard models evaluated SSI risk factors. Generalized linear models estimated SSI costs up to 12 months. Results: The total cohort included 17,514 pTHA patients (mean [standard deviation] age 59.6 [10.1] years, 50.2% female; 66.4% commercial insurance), and 2,954 rTHA patients (61.2 [12.0] years, 52.0% female; 48.6% commercial insurance). Deep and superficial post-operative SSI at six months affected 0.30% (95% confidence interval [CI], 0.22%-0.39%) and 0.67% (95% CI, 0.55%-0.79% of patients in the pTHA, and 8.9% (95%CI: 7.8%-10.0%) and 4.8% (95% CI, 4.0%-5.6%) of patients in the rTHA cohorts. Hazards for SSI were related to patient comorbidities that included diabetes mellitus, obesity, renal failure, pulmonary or circulatory disorders, and depression. The adjusted average all-cause incremental commercial costs associated with post-operative infection ranged from $21,434 to $42,879 for superficial incisional SSI and $53,884 to $76,472 for deep incisional SSI, over a 12-month post-operative assessment period. Conclusions: The SSI rate after revision total hip arthroplasty (rTHA) was nearly 9% compared with 1.0% after pTHA. The risk of infection was influenced by several comorbid risk factors. The incremental cost associated with SSIs was substantial.

Operative Time and Risk of Surgical Site Infection and Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of this study was to perform a systematic review and meta-analysis on the association between operative time and peri-prosthetic joint infection (PJI) after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

PubMed, Embase, and Cochrane CENTRAL databases were searched for relevant articles dating 2000-2020. Relationship of operative time and PJI rate in primary total joint arthroplasty (TJA) was evaluated by pooled odds ratios (OR) and 95% confidence intervals.

RESULTS

Six studies were identified for meta-analysis. TJA lasting greater than 120 minutes had greater odds of PJI (OR, 1.63 [1.00-2.66], p=0.048). Similarly, there were greater odds of PJI for TJA procedures lasting greater than 90 minutes (OR, 1.65 [1.27-2.14]; p<0.001). Separate analyses of TKA (OR, 2.01 [0.76-5.30]) and THA (OR, 1.06 [0.80-1.39]) demonstrated no difference in rates of PJI in cases of operative time ≥ 120 minutes versus cases < 120 minutes (p>0.05 for all). Using any surgical site infection (SSI) as an endpoint, both TJA (OR, 1.47 [1.181.83], p<0.001) and TKA (OR, 1.50 [1.08-2.08]; p=0.016) procedures lasting more versus less than 120 minutes demonstrated significantly higher odds of SSI.

CONCLUSION

Following TJA, rates of SSI and PJI are significantly greater in procedures ≥120 minutes in duration relative to those < 120 minutes. When analyzing TKA separately, higher rates of SSI were observed in procedures ≥ 120 minutes in duration relative to those <120 minutes. Rates of PJI in TKA or THA procedures alone were not significantly impacted by operative time. Level of Evidence: V.

Similar infection rates in a new wound closure method following knee arthroplasty

Surgical site infections, defined as acute wound infections requiring surgical intervention within 90 days post-surgery, were retrospectively compared between a novel, zipper-like closure method (ZM) and staples in 682 patients (904 knees) and 772 patients (971 knees), respectively. The incidence of deep infections was 0.6% for staples and 0.2% for ZM (p = 0.169) and superficial infections was 0.1% for staples and 0.0% for ZM (p = 0.518). With no difference in wound complications, the ZM may be preferred since the two-week post-operative clinic visit required for wound check and staple removal was eliminated, thereby, decreasing clinic volume.

A retrospective analysis of factors affecting surgical site infection in orthopaedic patients

Objective

To investigate the factors affecting surgical site infections (SSI) in patients undergoing orthopaedic surgery.

Methods

The electronic medical records of patients undergoing orthopaedic surgery between September 2010 and July 2018 were retrospectively retrieved and reviewed. Logistic regression analyses were used to analyse the correlation between surgery-related variables and SSI. The odds ratio (OR) and 95% confidence interval (CI) were estimated for the risk factors.

Results

Clinical data from 25 954 patients were reviewed and 804 (3.1%) were found to have become infected at the surgical site. Older age (≥60 years) was a risk factor (OR 2.218) and younger age (<18 years) was a protective factor (OR 0.258). Diabetes mellitus (OR 6.560) and hypertension (OR 3.991) were independent risk factors. Compared with type II incisions, type I incisions had a lower risk for SSI (OR 0.031), while type III incisions had a greater risk of SSI (OR 2.599). Compared with upper limbs and hands, the feet had a lower risk of infection, while surgery performed at the spine and joints did not increase the risk as compared with foot surgery.

Conclusion

Older age, hypertension, diabetes mellitus and type III incisions were risk factors for SSI following orthopaedic surgery.

Wound infection following implant removal of foot, ankle, lower leg or patella; a protocol for a multicenter randomized controlled trial investigating the (cost-)effectiveness of 2 g of prophylactic cefazolin compared to placebo (WIFI-2 trial)

Background

Elective implant removal (IR) after fracture fixation is one of the most common procedures within (orthopedic) trauma surgery. The rate of surgical site infections (SSIs) in this procedure is quite high, especially below the level of the knee. Antibiotic prophylaxis is not routinely prescribed, even though it has proved to lower SSI rates in other (orthopedic) trauma surgical procedures. The primary objective is to study the effectiveness of a single intravenous dose of 2 g of cefazolin on SSIs after IR following fixation of foot, ankle and/or lower leg fractures.

Methods

This is a multicenter, double-blind placebo controlled trial with a superiority design, including adult patients undergoing elective implant removal after fixation of a fracture of foot, ankle, lower leg or patella. Exclusion criteria are: an active infection, current antibiotic treatment, or a medical condition contraindicating prophylaxis with cefazolin including allergy. Patients are randomized to receive a single preoperative intravenous dose of either 2 g of cefazolin or a placebo (NaCl). The primary analysis will be an intention-to-treat comparison of the proportion of patients with a SSI at 90 days after IR in both groups.

Discussion

If 2 g of prophylactic cefazolin proves to be both effective and cost-effective in preventing SSI, this would have implications for current guidelines. Combined with the high infection rate of IR which previous studies have shown, it would be sufficiently substantiated for guidelines to suggest protocolled use of prophylactic antibiotics in IR of foot, ankle, lower leg or patella.

Trial registration Nederlands Trial Register (NTR): NL8284, registered on 9th of January 2020, https://www.trialregister.nl/trial/8284

Polyester mesh dressings reduce delayed wound healing rates after total hip arthroplasty compared with silver-impregnated occlusive dressings

Background

New dressings purport to reduce surgical wound complications after total hip arthroplasty (THA). This study compared delayed wound healing rates and reoperations between 2 increasingly popular dressings: a silver-impregnated occlusive (standard) dressing and a 2-octyl cyanoacrylate adhesive with polyester mesh.

Methods

This retrospective cohort study reviewed 431 consecutive THAs performed by 2 surgeons between January 2017 and May 2019. One hundred and eight were excluded for not using standard or mesh dressings. A final 323 cases were separated into 2 cohorts: mesh (n = 186) and standard dressings (n = 137). Standard dressings were removed at 1 week. Mesh persisted until nonadherent, approximately 3-4 weeks. The surgeon assessed delayed wound healing at the 2-week postoperative visit. Secondary outcomes include deep infection and return to the operating room for a wound-related diagnosis. Differences were determined using the chi-square test.

Results

There were no demographic, comorbidity, or surgical differences between groups. There were 22 total cases of delayed wound healing with 7 (3.8%) in the mesh group and 15 (10.9%) in the standard dressing group (P = .01). There were no significant differences in reoperations (2 [1.1%] vs 2 [1.5%], P = .76) or deep infections (2 [1.1%] vs 1 [0.7%], P = .75).

Conclusions

Mesh dressings are a safe and reliable dressing type for THA and were associated with a decrease in early wound healing complications when compared with standard, silver-impregnated occlusive dressings in this retrospective series. The mesh tension sharing properties and longer duration of occlusive protection may explain this difference.

Level of Evidence

Level III.

Economic burden of surgical site infections within the episode of care following joint replacement

Background

Recent policy initiatives, including Bundled Payments for Care Improvement (BPCI) Initiative by the Centers for Medicare and Medicaid Health Services (CMS), encourage healthcare providers to manage the total episode of care, rather than just the surgical episode. Surgical site infections (SSI) following total joint replacement result in preventable morbidity and suffering for patients and excess healthcare utilization for healthcare providers. This study sought to estimate the additional resources associated with SSIs within the 90-day episode of care following hip and knee joint replacement.

Methods

Using the 2013 Nationwide Readmissions Database (NRD), healthcare resource utilization was compared between propensity score matched patient groups with and without SSI-related readmissions within the 90-day episode of care following total joint replacement.

Results

Surgical site infections were associated with significantly longer hospital length of stay and increased costs following hip and knee joint replacement procedures. Generalized estimating equation regression results confirmed that additional costs associated with SSIs following both cohorts were significant, with additional hospital length of stay and costs following total hip and knee replacement procedures ranging from 4.9 to 5.2 days and $12,689 to $12,890, respectively.

Conclusion

Surgical site infections following total joint replacement account for significant additional healthcare resource use within the 90-day episode of care.

Target site antibiotic concentrations in orthopedic/trauma extremity surgery: is prophylactic cefazolin adequately dosed? A systematic review and meta-analysis

Background and purpose - The incidence of surgical site infections (SSIs) in trauma/orthopedic surgery varies between different body parts. Antibiotic prophylaxis (e.g., with cefazolin) lowers infection rates in closed fracture surgery and in primary arthroplasty. For prophylactic antibiotics to prevent infections, sufficient concentrations at the target site (location of surgery) are required. However, dosage recommendations and the corresponding efficacy are unclear. This review assesses target site cefazolin concentrations and the effect of variation in dose and location of target site during orthopedic extremity surgery. Methods - For this meta-analysis and systematic review, the literature was searched using the following keywords: "cephalosporins," "orthopedic," "extremity," "surgical procedures," and "pharmacokinetics". Trials measuring target site antibiotic concentrations (bone, soft tissue, synovia) during orthopedic surgery after a single dose of cefazolin were included. Results - The search identified 14 studies reporting on concentrations in the shoulder (n = 1), hip (n = 8), knee (n = 8), or foot (n = 1). A large variation was seen between studies, but the pooled results of 4 studies showed higher concentrations in hip than in knee (mean difference: 4 ug/g, 95% CI 0.8-7). Articles comparing different doses of cefazolin reported higher bone concentrations after 2 g than before, but pooling results did not lead to a statistically significant difference. Interpretation - Although not all results could be pooled, this study shows that cefazolin concentrations are higher in the hip than in the knee. These findings suggest that the dose of prophylactic cefazolin might not be sufficient in distal parts of the extremity. Further research should investigate whether a higher dose of cefazolin can lead to higher concentrations and fewer SSIs.