Chung, Andrew

Background: Low back injuries are common in collegiate football players and can frequently lead to persistent pain, reinjuries, and time lost from participation. Purpose: To describe the epidemiology of back injuries in National Collegiate Athletic Association (NCAA) football players during the 2009/2010 through 2013/2014 academic years utilizing the NCAA Injury Surveillance Program (ISP) database. Study Design: Descriptive epidemiology study. Methods: A convenience sample of NCAA varsity football teams was utilized to determine the rates and patterns of back injuries as well as to generate national injury estimates. The rates and distribution of back injuries were identified within the context of mechanism of injury, injury chronicity, and time lost from sport. Injury rates were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). Incidence rate ratios were calculated to compare the rates of injury between season, event type, mechanism of injury, injury chronicity, and time lost from sport. Results: Nationally, there were 267 low back injuries reported in the database. These were used to estimate 7076 back injuries over the 5-year period, approximately 82% of which were new injuries. The injuries occurred at a rate of 2.70 per 10,000 AEs. Overall, injuries were 3.12 times more likely to occur in competitions than in practices. Athletes were 4.67 times more likely to sustain a back injury during the preseason compared with the postseason but were 1.41 times more likely to sustain a low back injury during the preseason compared with the regular season. Both contact and noncontact were reported equally as the mechanism of injury (37.8% and 38.3%, respectively), and unspecified low back pain was the most common injury (64.2%). Only 1.6% of patients required surgery for their injury, and the majority of athletes (59.6%) returned to play within 24 hours. Conclusion: There was a relatively high rate of lumbar back injuries at the collegiate level (2.70/10,000 AEs), the majority of which were new injuries. About 18% of reported injuries were reinjuries. Although very few required surgery, a careful examination and work-up should be conducted to evaluate each injury. Regimented physical therapy and reconditioning programs are recommended to avert reinjuries.

Study Design. Descriptive epidemiology study. Objective. The purpose of this study was to describe the epidemiology of cervical spine injuries in collegiate football players. Summary of Background Data. The incidence and etiology of cervical spine injuries in National Collegiate Athletic Association (NCAA) football players has not been well defined in recent years. Methods. The incidence and characteristics of cervical spine injuries were identified utilizing the NCAA-ISP database. Rates of injury were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). AEs were defined as any student participation in one NCAA-sanctioned practice or competition. Results. An estimated 7496 cervical spine injuries were identified. Of these, 85.6% were categorized as new injuries. These occurred at a rate of 2.91 per 10000 AEs. Stingers were most common (1.87 per 10000 AEs) followed by cervical strains (0.80 per 10000 AEs). Injuries were nine times more likely to occur during competition when compared with practice settings. When compared with the regular season, the relative risks of sustaining a cervical spine injury during the preseason and postseason were 0.69 (95% CI 0.52–0.90) and 0.39 (95% CI 0.16–0.94), respectively. The rate of cervical spine injuries was highest in Division I athletes. Direct contact-related injuries were most common, representing 90.8% of all injuries sustained. Injuries were most common in linebackers (20.3%) followed secondarily by defensive linemen (18.2%). Most players returned to play within 24 hours of the initial injury (64.4%), while only 2.8% remained out of play for > 21 days. Conclusion. Fortunately, the rate of significant and disabling cervical spine injuries appears to be low in the NCAA football athlete. The promotion of safer tackling techniques, appropriate modification of protective gear, and preventive rehabilitation in these aforementioned settings is of continued value. Level of Evidence: 4

Study Design. Secondary analysis of a large administrative database. Objective. The objectives of this study are to: 1) identify the incidence and cause of 90-day readmissions following primary elective lumbar spine surgery, 2) offer insight into potential risk factors that contribute to these readmissions, and 3) quantify the cost associated with these readmissions. Summary of Background Data. As bundled-payment models for the reimbursement of surgical services become more popular in spine, the focus is shifting toward long-term patient outcomes in the context of 90-day episodes of care. With limited data available on national 90-day readmission statistics available, we hope to provide evidence that will aid in the development of more cost-effective perioperative care models. Methods. Using ICD-9 coding, we identified all patients 18 years of age and older in the 2014 Nationwide Readmissions Database (NRD) who underwent an elective, inpatient, primary lumbar spine surgery. Using multivariate logistic regression, we identified independent predictors of 90-day readmission while controlling for a multitude of confounding variables and completed a comparative cost analysis. Results. We identified 169,788 patients who underwent a primary lumbar spine procedure. In total 4268 (2.5%) were readmitted within 90 days. There was no difference in comorbidity burden between cohorts (readmitted vs. not readmitted) as quantified by the Elixhauser Comorbidity index. Independent predictors of increased odds of 90-day readmission were: anemia, uncomplicated diabetes and diabetes with chronic complications, surgical wound disruption and acute myocardial infarction at the time of the index admission, self-pay status, and an anterior surgical approach. Implant complications were identified as the primary related cause of readmission. These readmissions were associated with a significant cost increase. Conclusion. There are clearly identifiable risk factors that increase the odds of hospital readmission within 90 days of primary lumbar spine surgery. An overall 90-day readmission rate of 2.5%, while relatively low, carries significantly increased cost to both the patient and hospital. Level of Evidence: 3

Background: Lumbar spine injuries in National Collegiate Athletic Association (NCAA) athletes have not been well studied. Purpose: To describe the epidemiology of lumbar spine injuries in NCAA athletes during the 2009/2010 through 2013/2014 academic years utilizing the NCAA Injury Surveillance Program (ISP). Study Design: Descriptive epidemiology study. Methods: A voluntary convenience sample of NCAA varsity teams from 25 sports was examined. Mechanism of injury, injury recurrence, and time lost from sport were recorded. Injury rates were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). AEs were defined as any student participation in 1 NCAA-sanctioned practice or competition. Injury rate ratios and injury proportion ratios were calculated to compare the rates within and between sports by event type, season, patient sex, mechanism, injury recurrence, and time lost from sport. Comparisons between sexes were made utilizing data that had both male and female samples. Results: An estimated 50,834 lumbar spine injuries were identified. The overall rate of injuries was 2.88 per 10,000 AEs. The rate of injuries was 2.60 per 10,000 AEs in men compared with 2.89 per 10,000 AEs in women for sex-comparable sports. Women were 1.11 times more likely than men to suffer a lumbar spine injury. Women's gymnastics (8.02 injuries per 10,000 AEs) and women's tennis (5.73 injuries per 10,000 AEs) had the highest rates of lumbar spine injuries. Athletes were 1.6 and 2.4 times more likely to sustain a lumbar spine injury during the preseason than the regular season or postseason, respectively. Noncontact was the most common mechanism of injury (45%). Injury recurrence was most common in men’s outdoor track (43%). Most injuries resulted in less than 24 hours of time loss from event participation (64%). Conclusion: The rate of lumbar spine injuries was high in NCAA athletes, and injuries commonly recurred (20.73%). In general, women were more likely to sustain a lumbar spine injury compared with men. Higher injury rates occurred during competition and via a noncontact mechanism of injury. In addition to prevention programs, reconditioning programs should be considered to prevent these injuries.

Background: The minimum clinically important difference (MCID) attempts to define the patient’s experience of treatment outcomes. Efforts at calculating the MCID have yielded multiple and inconsistent MCID values. The purposes of this review were to describe the usage of the MCID in the most recent orthopaedic literature, to explain the limitations of its current uses, and to clarify the underpinnings of the MCID calculation, so as to help practitioners to understand and utilize the MCID and to guide future efforts to calculate the MCID. In Part I of this review, we sampled the orthopaedic literature in relation to the upper extremity. In this part, Part II, of the review, we will focus on the lower-extremity literature. Methods: A review was conducted of the 2014 to 2016 MCID-related publications in The Journal of Arthroplasty, The Journal of Bone & Joint Surgery, The American Journal of Sports Medicine, Foot & Ankle International, Journal of Orthopaedic Trauma, Journal of Pediatric Orthopaedics, and Journal of Shoulder and Elbow Surgery. Only clinical science articles utilizing patient-reported outcome measures (PROMs) were included in the analysis. A keyword search was then performed to identify articles that used the MCID. Articles were then further categorized into upper-extremity and lower-extremity publications. The MCID utilization in the selected articles was characterized and was recorded. Results: The MCID was referenced in 129 (7.5%) of 1,709 clinical science articles that utilized PROMs: 79 (61.2%) of the 129 articles were related to the lower extremity; of these, 11 (13.9%) independently calculated the MCID values and 68 (86.1%) used previously published MCID values as a gauge of their own results. The MCID values were calculated or were considered for 31 PROMs, of which 24 were specific to the lower extremity. Eleven different methods were used to calculate the MCID. The MCID had a wide range of values for the same questionnaires, for instance, 5.8 to 31.3 points for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Conclusions: There are more than twice as many PROMs for the lower extremity (24) than for the upper extremity (11), confirming that the determination of useful MCID values is, in part, hampered by the proliferation of PROMs in the field of orthopaedics. The difference between significance and clinical importance needs to be further clarified. For instance, the common use of determining sample size with the MCID and comparing group means with the MCID implies that a significant result will also be clinically important. Further, the study of the MCID would benefit from consensus agreement on relevant terminology and the appropriate usage of the MCID determining equations. Clinical Relevance: MCID is increasingly used as a measure of patients’ improvement. However, MCID does not yet adequately capture the clinical importance of patients’ improvement.

Background: The minimum clinically important difference (MCID) attempts to define the patient’s experience of treatment outcomes. Efforts at calculating the MCID have yielded multiple and inconsistent MCID values. The purposes of this review were to describe the usage of the MCID in the most recent orthopaedic literature, to explain the limitations of its current uses, and to clarify the underpinnings of MCID calculation. Subsequently, we hope that the information presented here will help practitioners to better understand the MCID and to serve as a guide for future efforts to calculate the MCID. The first part of this review focuses on the upper-extremity orthopaedic literature. Part II will focus on the lower-extremity orthopaedic literature. Methods: A review was conducted of the 2014 to 2016 publications in The Journal of Arthroplasty, The Journal of Bone & Joint Surgery, The American Journal of Sports Medicine, Foot & Ankle International, Journal of Orthopaedic Trauma, Journal of Pediatric Orthopaedics, and Journal of Shoulder and Elbow Surgery . Only clinical science articles utilizing patient-reported outcome measure (PROM) scores were included in the analysis. A keyword search was then performed to identify articles that calculated or referenced the MCID. Articles were then further categorized into upper-extremity and lower-extremity publications. MCID utilization in the selected articles was subsequently characterized and recorded. Results: The MCID was referenced in 129 (7.5%) of 1,709 clinical science articles that utilized PROMs: 52 (40.3%) of 129 were related to the upper extremity, 5 (9.6%) of 52 independently calculated MCID values, and 47 (90.4%) of 52 used previously published MCID values as a gauge of their own results. MCID values were considered or calculated for 16 PROMs; 12 of these were specific to the upper extremity. Six different methods were used to calculate the MCID. Calculated MCIDs had a wide range of values for the same PROM (e.g., 8 to 36 points for Constant-Murley scores and 6.4 to 17 points for American Shoulder and Elbow Surgeons [ASES] scores). Conclusions: Determining useful MCID values remains elusive and is compounded by the proliferation of PROMs in the field of orthopaedics. The fundamentals of MCID calculation methods should be critically evaluated. If necessary, these methods should be corrected or abandoned. Furthermore, the type of change intended to be measured should be clarified: beneficial, detrimental, or small or large changes. There should also be assurance that the calculation method actually measures the intended change. Finally, the measurement error should consistently be reported. Clinical Relevance: The MCID is increasingly used as a measure of patients’ improvement. However, the MCID does not yet adequately capture the clinical importance of patients’ improvement.

Objectives: Low serum albumin levels (hypoalbuminemia) have classically been used to identify malnutrition. The effect of increasing severity of malnutrition on postoperative outcomes in patients undergoing hip fracture surgery has not been well delineated on a large scale. Design: Retrospective. Setting: Multicenter. Patient/Participants: A total of 12,373 patients undergoing hip fracture surgery from 2006 to 2013 National Surgery Quality Improvement Project data were identified. Intervention: Patient demographic, comorbidity, and preoperative laboratory data and complication, reoperation, and readmission data were collected. Main Outcome Measurements: Multivariate logistic regression was used to determine the effect of increasing severity of malnutrition on rates of 30-day postoperative complications, readmissions, and reoperations. Results: A total of 12,373 hip fractures met inclusion criteria. A total of 6506 (52.6%) patients had normal albumin levels (albumin ≥3.5 g/dL), 3205 (25.9%) patients were mildly malnourished (albumin 3.1–3.49 g/dL), 2265 (18.3%) were moderately malnourished (albumin 2.4–3.1 g/dL), and 397 (3.2%) patients were severely malnourished (albumin <2.4 g/dL). Mean age was similar between the 4 cohorts (P < 0.001). Severe malnutrition was associated with a 2-fold increase in the odds of postoperative complications and mortality when compared with mild malnutrition (P < 0.001). Increasing severity of malnutrition was associated with significantly longer lengths of stay and higher odds of experiencing a related readmission (P < 0.001). Conclusions: Increasing severity of hypoalbuminemia is independently associated with poorer outcomes in the 30 days after hip fracture surgery. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Study Design: Retrospective cohort study. Objectives: Epidemiologic studies suggest that the prevalence of moderate to severe obstructive sleep apnea (OSA) is increasing. OSA has been linked to increased rates of postoperative complications following surgery. Large studies, however, regarding surgical outcomes in this patient population, particularly in the spine literature, are limited. Consequently, the purpose of this study was to assess the prevalence of and postoperative risks conferred by OSA in the elective spine population. Methods: Using data from the National Inpatient Sample from 2008 to 2012, an estimated 56 372 (5.1%) patients with OSA undergoing elective cervical and thoracolumbar spine surgery were selected and compared to 1 052 837 patients without OSA undergoing the same procedures. Our primary outcome measures included postoperative complication rates, inpatient mortality, length of stay, and total hospital charges. Results: Patients with OSA were, on average 2.6 years older than those without OSA ( P < .001) and had a higher comorbidity burden. The prevalence of OSA increased between 2008 and 2012 from 3.5% to 6.8%; P < .001. OSA was associated with a 3-fold increase in major complications ( P < .001) and was confirmed as an independent risk factor for major complications based on multivariate analysis (odds ratio [OR] = 2.82; 95% CI = 2.59-2.79; P < .001). Rates of deep venous thrombosis were doubled in patients with OSA. OSA was determined to be an independent predictor of pulmonary complications (OR = 2.69; 95% CI = 2.59-2.79; P < .001). OSA did not increase the risk of postoperative mortality. Conclusions: Patients with OSA often have multiple concomitant comorbidities and consequently are at increased risk of experiencing a more difficult postoperative course following elective spine surgery. Specifically, increased risks of pulmonary complications and deep venous thrombosis should be anticipated.

Study Design. A retrospective cohort study. Objective. The aim of this study was to evaluate the effect of metabolic syndrome (MetS) on 30-day morbidity and mortality following elective lumbar spinal fusion. Summary of Background Data. MetS is a variable combination of hypertension, obesity, elevated fasting plasma glucose, and dyslipidemia. MetS has been associated with an increased risk of postoperative morbidity and mortality in multiple surgical settings. To our knowledge, the effect of MetS on 30-day outcomes following elective lumbar spinal fusion has not been well studied. Methods. An analysis of ACS-NSQIP data was performed between 2006 and 2013. Patients undergoing elective posterior lumbar fusion were identified. Emergency procedures, infections, tumor cases, and revision surgeries were excluded. Patients were defined as having MetS if they had a history of hypertension requiring medication, diabetes, and a body mass index (BMI) ≥30 kg/m2. Results. One thousand five hundred ninety (10.2%) patients with MetS were identified. A mild increase in major (P = 0.040) and minor complications (P = 0.003) in patients with MetS was noted. MetS was associated with increased rates of pulmonary complications (1.9% compared with 1.0%; P = 0.001), sepsis (1.7% compared with 0.9%; P = 0.005), and acute post-op renal failure (0.4% compared with 0%; P < 0.001). Multivariate analysis confirmed MetS to be an independent predictor of pulmonary complications [odds ratio (OR) 1.51; 95% confidence interval (95% CI 1.00–2.27); P = 0.048], sepsis (OR 1.56; 95% CI 1.01–2.42; P = 0.039), and acute postoperative renal failure (OR 6.95; 95% CI 2.23–21.67; P = 0.001). MetS status was associated with a mild increase in total hospital length of stay (4.38 compared with 3.81 days; P < 0.001). Conclusion. While MetS is a predictor of postoperative acute renal failure, it only slightly increases the risk of overall complications and is not associated with increased rates of 30-day reoperations or readmissions following elective lumbar fusion. Level of Evidence: 3

ABSTRACT Pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with poor outcomes and frequently merits empirical antibiotic consideration despite its relatively low incidence. Nasal colonization with MRSA is associated with clinical MRSA infection and can be reliably detected using the nasal swab PCR assay. In this study, we evaluated the performance of the nasal swab MRSA PCR in predicting MRSA pneumonia. A retrospective cohort study was performed in a tertiary care center from January 2009 to July 2011. All patients with confirmed pneumonia who had both a nasal swab MRSA PCR test and a bacterial culture within predefined time intervals were included in the study. These data were used to calculate sensitivity, specificity, positive predictive value, and negative predictive value for clinically confirmed MRSA pneumonia. Four hundred thirty-five patients met inclusion criteria. The majority of cases were classified as either health care-associated (HCAP) (54.7%) or community-acquired (CAP) (34%) pneumonia. MRSA nasal PCR was positive in 62 (14.3%) cases. MRSA pneumonia was confirmed by culture in 25 (5.7%) cases. The MRSA PCR assay demonstrated 88.0% sensitivity and 90.1% specificity, with a positive predictive value of 35.4% and a negative predictive value of 99.2%. In patients with pneumonia, the MRSA PCR nasal swab has a poor positive predictive value but an excellent negative predictive value for MRSA pneumonia in populations with low MRSA pneumonia incidence. In cases of culture-negative pneumonia where initial empirical antibiotics include an MRSA-active agent, a negative MRSA PCR swab can be reasonably used to guide antibiotic de-escalation.