Deep Surgical Site Infection after Fracture Has a Profound Effect on Functional Outcomes.

Background: Fracture-related infection is one of the most challenging complications in orthopaedic trauma surgery. However, the effect of infection on functional and pain-related outcomes has not been well established. The aims of this study were to evaluate functional recovery for patients with fracture and a deep surgical site infection compared with patients with fracture without infection and to evaluate whether pain severity, social support, and preinjury mental health have a moderating effect on the magnitude and direction of the relationship between deep surgical site infection and functional recovery. Methods: This is a secondary retrospective cohort study using prospectively collected data from the VANCO trial (Local Antibiotic Therapy to Reduce Infection After Operative Treatment of Fractures at High Risk of Infection) and the OXYGEN (Supplemental Perioperative Oxygen to Reduce Surgical Site Infection After High Energy Fracture Surgery) trial. In this study, 2,116 patients with tibial plateau, pilon, or calcaneal fractures at high risk for infection were included. Patients were divided into cohorts of patients who experienced a deep surgical site infection and those who did not. The primary outcome measure was the functional outcome using the Veterans RAND 12-Item Health Survey (VR-12). Results: After controlling for covariates, deep surgical site infection was independently associated with functional outcome, with a 3.3-point reduction in the VR-12 Physical Component Score, and pain severity was independently associated with functional outcome, with a 2.5-point reduction in the VR-12 Physical Component Score. Furthermore, the Brief Pain Inventory pain severity demonstrated an important moderating effect on the relationship between infection and functional outcome. In patients with lower pain scores, infection had a large negative impact on functional outcome, whereas, in patients with higher pain scores, infection had no significant impact on functional outcome. Furthermore, the functional outcome in the entire cohort remains at only 61% of baseline. Conclusions: This study documents the negative impact of postoperative infection on functional recovery after injury, as well as the novel finding of pain severity as an important moderating factor. This study emphasizes not only the importance of developing effective interventions designed to reduce postoperative infection, but also the role that factors that moderate pain severity plays in limiting recovery of physical function. Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

How many sites should an orthopedic trauma prospective multicenter trial have? A marginal analysis of the Major Extremity Trauma Research Consortium completed trials.

BACKGROUND: Multicenter trials in orthopedic trauma are costly, yet crucial to advance the science behind clinical care. The number of sites is a key cost determinant. Each site has a fixed overhead cost, so more sites cost more to the study. However, more sites can reduce total costs by shortening the study duration. We propose to determine the optimal number of sites based on known costs and predictable site enrollment. METHODS: This retrospective marginal analysis utilized administrative and financial data from 12 trials completed by the Major Extremity Trauma Research Consortium. The studies varied in size, design, and clinical focus. Enrollment across the studies ranged from 1054 to 33 patients. Design ranged from an observational study with light data collection to a placebo-controlled, double-blinded, randomized controlled trial. Initial modeling identified the optimal number of sites for each study and sensitivity analyses determined the sensitivity of the model to variation in fixed overhead costs. RESULTS: No study was optimized in terms of the number of participating sites. Excess sites ranged from 2 to 39. Excess costs associated with extra sites ranged from $17K to $330K with a median excess cost of $96K. Excess costs were, on average, 7% of the total study budget. Sensitivity analyses demonstrated that studies with higher overhead costs require more sites to complete the study as quickly as possible. CONCLUSIONS: Our data support that this model may be used by clinical researchers to achieve future study goals in a more cost-effective manner. TRIAL REGISTRATION: Please see Table 1 for individual trial registration numbers and dates of registration.

Does Topical Vancomycin Powder Use in Fracture Surgery Change Bacteriology and Antibiotic Susceptibilities? An Analysis of the VANCO Trial.

OBJECTIVE: To determine whether intrawound vancomycin changes the bacteriology of surgical site infection pathogens and investigate the emergence of antibiotic-resistant pathogens. DESIGN: Secondary analysis of phase III, prospective, randomized clinical trial. SETTING: Thirty-six US trauma centers. PATIENT SELECTION CRITERIA: Patients who became infected after fixation of tibial plateau or pilon fracture. OUTCOME MEASURES AND COMPARISONS: Pathogen types and bacterial susceptibilities as determined from routine clinical culture in the operating room. RESULTS: Seventy-four patients were studied who were 67.5% male with a mean age of 48.6 years. A lower proportion of gram-positive cocci was observed in the vancomycin powder compared with the standard-of-care group (3.7% vs. 8.0%, P = 0.01). Methicillin-resistant Staphylococcus aureus infection incidence was comparable in both the vancomycin powder and the standard-of-care groups, but rates of methicillin-susceptible S. aureus infections were lower in the treatment group (1.4% vs. 4.8%, P = 0.01). The incidence of coagulase-negative Staphylococci and gram-negative rod infections were similar in both groups. There was no significant difference in susceptibilities between groups in rates of vancomycin-resistant enterococcus. CONCLUSIONS: Topical vancomycin powder decreases the likelihood of gram-positive infections consistent with the biologic activity of vancomycin. Fewer methicillin-susceptible S. aureus and coagulase-negative Staphylococci infections were observed in the group treated with vancomycin powder. An effect of vancomycin powder on methicillin-resistant S. aureus infection risk was not detected given the low incidence in both the intrawound vancomycin and the standard-of-care groups. There was no emergence of gram-negative rod infections or increased resistance patterns observed. Use of topical vancomycin powder does not seem to produce infections in these patients with greater antibiotic resistance than would have occurred without its use. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

The VANCO Trial Findings Are Generalizable to a North American Trauma Registry.

OBJECTIVES: To estimate the generalizability of treatment effects observed in the VANCO trial to a broader population of patients with tibial plateau or pilon fractures. METHODS: Design and Setting: Clinical trial data from 36 United States trauma centers and Trauma Quality Programs registry data from more than 875 Level I-III trauma centers in the United States and Canada.Patient Selection Criteria: Patients enrolled in the VANCO trial treated with intrawound vancomycin powder from January 2015 to June 2017 and 31,924 VANCO-eligible TQP patients admitted in 2019 with tibial plateau and pilon fractures.Outcome Measure and Comparisons: Deep surgical site infection and gram-positive deep surgical site infection estimated in the TQP sample weighed by the inverse probability of trial participation. RESULTS: The 980 patients in the VANCO trial were highly representative of 31,924 TQP VANCO-eligible patients (Tipton generalizability index 0.96). It was estimated that intrawound vancomycin powder reduced the odds of deep surgical infection by odds ratio (OR) = 0.46 (95% confidence interval [CI] 0.25-0.86) and gram-positive deep surgical infection by OR = 0.39 (95% CI, 0.18-0.84) within the TQP sample of VANCO-eligible patients. For reference, the trial average treatment effects for deep surgical infection and gram-positive deep surgical infection were OR = 0.60 (95% CI, 0.37-0.98) and OR = 0.44 (95% CI, 0.23-0.80), respectively. CONCLUSIONS: This generalizability analysis found that the inferences of the VANCO trial generalize and might even underestimate the effects of intrawound vancomycin powder when observed in a wider population of patients with tibial plateau and pilon fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Minimal Clinically Important Difference (MCID) for the Short Musculoskeletal Function Assessment (SMFA) in Severe Lower Extremity Trauma: Pooled Data from 7 Multicenter, Prospective Clinical Trials.

BACKGROUND: The Short Musculoskeletal Function Assessment (SMFA) is a well validated, widely used patient-reported outcome (PRO) measure for orthopaedic patients. Despite its widespread use and acceptance, this measure does not have an agreed upon minimal clinically important difference (MCID). The purpose of the present study was to create distributional MCIDs with use of a large cohort of research participants with severe lower extremity fractures. METHODS: Three distributional approaches were used to calculate MCIDs for the Dysfunction and Bother Indices of the SMFA as well as all its domains: (1) half of the standard deviation (one-half SD), (2) twice the standard error of measurement (2SEM), and (3) minimal detectable change (MDC). In addition to evaluating by patient characteristics and the timing of assessment, we reviewed these calculations across several injury groups likely to affect functional outcomes. RESULTS: A total of 4,298 SMFA assessments were collected from 3,185 patients who had undergone surgical treatment of traumatic injuries of the lower extremity at 60 Level-I trauma centers across 7 multicenter, prospective clinical studies. Depending on the statistical approach used, the MCID associated with the overall sample ranged from 7.7 to 10.7 for the SMFA Dysfunction Index and from 11.0 to 16.8 for the SMFA Bother Index. For the Dysfunction Index, the variability across the scores was small (<5%) within the sex and age subgroups but was modest (12% to 18%) across subgroups related to assessment timing. CONCLUSIONS: A defensible MCID can be found between 7 and 11 points for the Dysfunction Index and between 11 and 17 points for the Bother Index. The precise choice of MCID may depend on the preferred statistical approach and the population under study. While differences exist between MCID values based on the calculation method, values were consistent across the categories of the various subgroups presented. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.