Implant Position, Survivorship, and Patient-Reported Outcomes in Manual Medial Unicompartmental Knee Arthroplasty.

BACKGROUND: Two related recent reports described high error rates for implant positioning and reduced implant survivorship in manual unicompartmental knee arthroplasty (MUKA) compared to robotic-assisted unicompartmental knee arthroplasty (RUKA). The present study scientifically replicated these reports by comparing MUKAs similarly performed by an experienced high-volume surgeon in similar patients using the same study methods as these reports. METHODS: A total of 216 consecutive MUKAs were retrospectively evaluated radiographically for achievement of implant positioning targets. Achievement of targets was compared to the published MUKA and RUKA outcomes and correlated with revision rates and patient-reported outcome measures. RESULTS: There were 20% of study MUKAs compared to 88.1% of comparison MUKAs (P < .001) and 31.4% of comparison RUKAs (P < .048) that failed to meet all 7 implant positioning targets. The MUKA revision rates were significantly lower in the study sample than for comparison MUKAs (3.2% versus 14.2%, P < .001). Implant survivorship was 91.7% (95% confidence interval 84.9, 98.5%) at 8.9 years compared to 70.0% (95% confidence interval 56.0, 80.0%) at 10.2 years, respectively. Most patient-reported outcome measures did not differ based on achievement of implant positioning targets (P ≥ .072). CONCLUSIONS: Present study findings indicate that observations in the 2 recent reports may not be generalizable to all UKA surgeons. Additional data on the relationship between implant positioning and revision as well as functional outcomes are needed to identify appropriate robotic arthroplasty applications.

Enhanced Risk Stratification for Short-Term Complications Following Vertebral Augmentation for Osteoporotic Vertebral Compression Fractures.

BACKGROUND: For patients with back pain from osteoporotic vertebral compression fractures (VCFs), vertebral augmentation remains the most utilized surgical intervention. Previous studies report 30-day readmission and mortality rates of up to 10% and 2%, respectively. These studies, however, have included patients with pathologic fractures and combined patients in different admission settings. We undertook the current study to address such shortcomings, which make risk stratification and appropriate counseling difficult. METHODS: Four consecutive years of the National Surgical Quality Improvement Program database were queried. Patients who underwent vertebral augmentation for osteoporotic VCFs were divided into 3 groups: (1) outpatient group (defined as patients with same-day discharge), (2) inpatient group (defined as those who were admitted postoperatively), and (3) preprocedure hospitalized group (defined as those who were already inpatient or were at acute/intermediate care facilities and transferred). Postoperative 30-day complications and readmission rates were compared between different groups and examined using multivariate analyses. RESULTS: A total of 1023 patients underwent outpatient surgery; 503 were admitted on the day of surgery; and 149 patients were already in-hospital or were transferred from other facility. Mortality rates were 0.68%, 0.60%, and 2.68%, and readmission rates were 6.26%, 6.76%, and 12.8%, for outpatient, inpatient, and preprocedure hospitalization cohorts, respectively. Multivariate analyses identified preprocedure hospitalization as an independent risk factor for urinary tract infection (UTI; OR = 3.98, 95% CI = 1.41-11.20, P = 0.028), pneumonia (OR = 19.69, 95% CI = 3.81-101.65, P < 0.001), readmission (OR = 1.86, 95% CI = 1.06-3.26, P = 0.032), and mortality (OR = 4.49, 95% CI = 1.22-16.53, P = 0.024). CONCLUSION: Our findings suggest that published rates of complications and mortality are substantially impacted by the cohort of patients who are already hospitalized or transferred from other facilities. Such patients are at a higher risk of UTI, pneumonia, readmission, and mortality. Conversely, we show that a relatively healthy patient being offered outpatient same-day augmentation has a readmission risk 40% lower and a mortality risk 3 times lower than previously reported.

Micromonas micros: A rare anaerobic cause of late implant failure following spinal surgery.

Context: Delayed, postoperative, spine infections are rare, most commonly occurring secondary to fastidious, less virulent pathogens. The etiology may involve a distant infectious focus, not related to the index operation. Patients may present months, or even years postoperatively with pain related to mechanical implant failure, often without additional signs of systemic infection.Findings: We present the case of a 59-year-old male who developed rapid disk degeneration and implant failure seven months following instrumented lumbar fusion surgery. The causal organism was found to be Micromonas micros, an anaerobic bacterium typically located in the oral cavity and associated with periodontal disease. The patient was found to have extensive oral caries, which were presumed to have occurred secondary to poor oral hygiene and his use of fentanyl lozenges for chronic back pain. The patient was treated with revision staged spinal surgery and long-term intravenous antibiotics.Conclusion/clinical relevance: This case highlights an unusual etiology of delayed postoperative spinal implant failure and provides evidence for periodontal disease as a source of hematogenous seeding in postoperative spinal infections. The orthopaedist should also be aware of the potential relationship between poor oral hygiene and the use of high sugar content fentanyl lozenges in treating chronic back pain in these patients.

Real-world comparison of curative open, laparoscopic and robotic resections for sigmoid and rectal cancer-single center experience.

There has been an increase in the utilization of robotic surgery in addition to traditional open or laparoscopic approaches. Aim of this study is to compare the short-term outcomes for open, laparoscopic, and robotic surgery for rectal and sigmoid cancer. One hundred and forty-seven patients (open n = 48, laparoscopic n = 49, robotic n = 50) undergoing curative resections by two surgeons between 2013 and 2020 were included. Data analyzed included patient demographics, tumor characteristics, length of stay, post-operative outcomes, and pathologic surrogates of oncologic results, including total mesorectal excision (TME) quality, circumferential resection margin (CRM) involvement and lymph node (LN) yield. Median age of population was 68 years (IQR 59-73), majority (68%) were males. Median distance from anal verge in the robotic surgery group was 8 cm, compared to 15 and 14.5 cm in the open and laparoscopic groups, respectively, p = 0.029, (laparoscopic vs robotic, p = 0.005 and open vs robotic, p = 0.027). Proportion of patients who received neoadjuvant radiotherapy in robotic surgery group was higher, p = 0.04. In sub-group of tumors between 3 and 7 cm from anal verge more patients in the robotic surgery group had sphincter preservation, p = 0.006. Length of stay, maximum C-reactive protein, and white blood cell rise favored minimally invasive approaches compared to open surgery. There were no differences in post-operative complications, lymph node yield or CRM positivity rate between the three groups. Robotic surgery approach is safe and allows sphincter preservation without compromising TME quality in rectal cancer surgery.

Identification of Risk Factors for Readmission in Patients Undergoing Anterior Cervical Discectomy Fusion: A Predictive Risk Scale.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The objective of this study was to analyze readmission rates among patients undergoing anterior cervical discectomy and fusion (ACDF), determine which factors were associated with higher readmission rates, and develop a scale for utilization during surgical planning. SUMMARY OF BACKGROUND DATA: ACDF is the most common surgical treatment for many cervical disk pathologies. With the Centers for Medicare and Medicaid Services selecting readmissions as a measure of health care quality, there has been an increased focus on reducing readmissions. MATERIALS AND METHODS: There were 114,174 recorded ACDF surgeries in the derivation cohort, the State Inpatient Database (SID) of New York and California between 2006 and 2014. There were 115,829 ACDF surgeries recorded in the validation cohort, the SID from Florida and Washington over the same time period. After identification of risk factors using univariate and multivariate analysis of the derivation cohort, a predictive scale was generated and tested utilizing the validation cohort. RESULTS: Overall, readmission rates within 30 days of discharge were 5.87% and 5.52% in the derivation and validation cohorts, respectively. On multivariate analysis of the derivation cohort, age older than 80 years [odds ratio (OR), 1.67] male sex (OR, 1.16), Medicaid insurance (OR, 1.90), Medicare insurance (OR, 1.64), revision ACDF (OR, 1.43), anemia (OR, 1.45), chronic lung disease (OR, 1.23), coagulopathy (OR, 1.42), congestive heart failure (OR, 1.31), diabetes (OR, 1.23), fluid and electrolyte disorder (OR, 1.56), liver disease (OR, 1.37), renal failure (OR, 1.59), and myelopathy (OR, 1.19) were found to be statistically significant predictors for readmission. These factors were incorporated into a numeric scale that, that when tested on the validation cohort, could explain 97.1% of the variability in readmission rate. CONCLUSIONS: Overall, 30-day readmission following ACDF surgery was 5%-6%. A novel risk scale based on factors associated with increased readmission rates may be helpful in identifying patients who require additional optimization to reduce perioperative morbidity. LEVEL OF EVIDENCE: Level III-prognostic.

Lumbar Spine Injuries in Sports: Review of the Literature and Current Treatment Recommendations.

Low back pain is one of the most prevalent complaints of athletes at all levels of competition. The purpose of this literature review is to provide an overview of sport-specific injuries and treatment outcomes that can be used by healthcare providers to better recognize injury patterns and treatment options for different groups of athletes. To our knowledge, no prior comprehensive review of lumbar spine injuries in sports is currently available in the literature, and it is essential that healthcare providers understand the sport-specific injury patterns and treatment guidelines for athletes presenting with low back pain following an athletic injury. Injury mechanisms were found to vary significantly by sport, although some broad recommendations can be made with regards to optimal treatment for these injuries and return to play. Additionally, it was found that certain treatments were more beneficial and resulted in higher rates of return to play depending on the specific sport of the injured athlete. Healthcare providers need to be aware of the different injury patterns seen in specific sports in order to properly evaluate and treat these injuries. Furthermore, an individualized treatment plan needs to be selected in a sport-specific context in order to meet the needs of the athlete in the short and long term.

Identification of marine Important Bird and Biodiversity Areas for penguins around the South Shetland Islands and South Orkney Islands.

AIM: To provide a method of analyzing penguin tracking data to identify priority at-sea areas for seabird conservation (marine IBAs), based on pre-existing approaches for flying seabirds but revised according to the specific ecology of Pygoscelis penguin species. LOCATION: Waters around the Antarctic Peninsula, South Shetland, and South Orkney archipelagos (FAO Subareas 48.1 and 48.2). METHODS: We made key improvements to the pre-existing protocol for identifying marine IBAs that include refining the track interpolation method and revision of parameters for the kernel analysis (smoothing factor and utilization distribution) using sensitivity tests. We applied the revised method to 24 datasets of tracking data on penguins (three species, seven colonies, and three different breeding stages-incubation, brood, and crèche). RESULTS: We identified five new marine IBAs for seabirds in the study area, estimated to hold ca. 600,000 adult penguins. MAIN CONCLUSIONS: The results demonstrate the efficacy of a new method for the designation of a network of marine IBAs in Antarctic waters for penguins based on tracking data, which can contribute to an evidence-based, precautionary, management framework for krill fisheries.

Forensic Nursing Provides Closure in Workplace Fatality.

The Workers' Compensation Board of British Columbia in Canada is the provincial agency mandated to investigate workplace injuries and fatalities. In 2012, the Fatal and Serious Injuries Investigation section of this organization initiated the integration of forensic nursing expertise into the investigation of workplace incidents. The goals were to improve investigative outcomes and aid in prevention initiatives by achieving a more accurate understanding of incident causation through the application of forensic nursing science. An unexpected outcome of the use of forensic nursing expertise was providing closure for families through a deeper understanding of their loved one's tragic workplace incident.

What is the Risk of Developing Proximal Junctional Kyphosis During Growth Friendly Treatments for Early-onset Scoliosis?

BACKGROUND: Rib-based and spine-based systems are commonly used distraction-based growth friendly treatments for early-onset scoliosis (EOS). Our primary purpose was to determine the risk of developing postoperative proximal junctional kyphosis (PJK) during distraction-based growth friendly surgery. METHODS: A multicenter, retrospective, radiographic comparison was performed for a group of 40 children with EOS who were treated with posterior distraction-based implants. PJK was defined as proximal junction sagittal angle (PJA)≥10 degrees and PJA at least 10 degrees greater than preoperative. RESULTS: Eight subjects (20%) at immediate postoperative follow-up and 11 subjects (27.5%) at minimum 2-year follow-up had developed PJK. The risk of developing PJK between rib-based and spine-based growing systems was not significantly different at immediate postoperative (17% vs. 25%) or at final (25% vs. 31%) follow-ups.Further analysis combining both treatment groups demonstrated that PJK subjects were significantly older at time of initial surgery (7.1 y PJK vs. 5.0 y no PJK). Radiographic comparisons between PJK versus no PJK: Preoperative scoliosis (69.9 vs. 76.0 degrees), thoracic kyphosis (45.1 vs. 28.7 degrees), lumbar lordosis (53.1 vs. 44.0 degrees), PJA (2.2 vs. 2.8 degrees), sagittal vertical axis (1.5 vs. 2.6 cm), pelvic incidence (52.8 vs. 47.4 degrees), pelvic tilt (14.3 vs. 8.7 degrees), and sacral slope (37.7 vs. 35.9 degrees). At both initial postoperative and at final follow-up visits, a significant difference was found for cervical lordosis 32.2 versus 14.0 degrees and 42.0 versus 16.6 degrees, respectively. Risk ratio for developing PJK at final follow-up was 2.8 for subjects with preoperative thoracic hyperkyphosis and was 3.1 for subjects with high pelvic incidence (P<0.05). CONCLUSIONS: The risk of developing PJK during distraction-based growth friendly treatment for EOS was 20% immediately after implantation and 28% at minimum 2-year follow-up, with no difference observed between rib-based and spine-based treatment groups. As this study identifies a significant risk of developing PJK during the treatment of EOS, it allows clinicians to preoperatively council patients and their families about this possible complication. In addition, several potential risk factors for the development of postoperative PJK were identified, but should be investigated further in future studies. LEVEL OF EVIDENCE: Level III-therapeutic study (retrospective, comparative).

Neuromonitoring with pulse-train stimulation for implantation of thoracic pedicle screws: a blinded and randomized clinical study. Part 1. Methods and alarm criteria.

OBJECT: Reports of the accuracy of existing neuromonitoring methods for detecting or preventing medial malpositioning of thoracic pedicle screws have varied widely in their claimed effectiveness. The object of this study was to develop, test, and validate a novel neuromonitoring method for preventing medial malpositioning of pedicle screws in the thoracic spine during surgery. METHODS: This is a prospective, blinded and randomized study using a novel combination of input (4-pulse stimulus trains delivered within the pedicle track) and output (evoked electromyography from leg muscles) to detect pedicle track trajectories that-once implanted with a screw-would cause that screw to breach the pedicle's medial wall and encroach upon the spinal canal. For comparison, the authors also used screw stimulation as an input and evoked electromyogram from intercostal and abdominal muscles as output measures. Intraoperative electrophysiological findings were compared with postoperative CT scans by multiple reviewers blinded to patient identity or intraoperative findings. RESULTS: Data were collected from 71 patients, in whom 802 screws were implanted between the T-1 and L-1 vertebral levels. A total of 32 screws ended up with screw threads encroaching on the spinal canal by at least 2 mm. Pulse-train stimulation within the pedicle track using a ball-tipped probe and electromyography from lower limb muscles correctly predicted all 32 (100%) of these medially malpositioned screws. The combination of pedicle track stimulation and electromyogram response from leg muscles proved to be far more effective in predicting these medially malpositioned screws than was direct screw stimulation and any of the target muscles (intercostal, abdominal, or lower limb muscles) we monitored. Based on receiver operating characteristic analysis, the combination of 10-mA (lower alarm) and 15-mA stimulation intensities proved most effective for detection of pedicle tracks that ultimately gave rise to medially malpositioned screws. Additional results pertaining to the impact of feedback of these test results on surgical decision making are provided in the companion report. CONCLUSIONS: This novel neuromonitoring approach accurately predicts medially malpositioned thoracic screws. The approach could be readily implemented within any surgical program that is already using contemporary neuromonitoring methods that include transcranial stimulation for monitoring motor evoked potentials.

Occupational injury and fatality investigations: the application of forensic nursing science.

The forensic evaluation of trauma in occupational injuries and fatalities can provide the benefit of a more thorough analysis of incident causation. Forensic nursing science applied during workplace investigations can assist investigators to determine otherwise unknown crucial aspects of the incident circumstances that are important to event reconstruction, the enforcement of occupational health and safety requirements, and the direction of workplace prevention initiatives. Currently, a medical and forensic medical knowledge gap exists in the subject-matter expertise associated with occupational accident investigations. This gap can be bridged with the integration of forensic nursing in the investigation of workplace fatalities and serious injuries.

Sagittal Spinopelvic Parameters of Young Children With Scoliosis.

STUDY DESIGN: Retrospective, multicenter review of the spinopelvic parameters in young children with scoliosis. OBJECTIVES: To describe sagittal alignment of the spine and pelvis in young children with scoliosis. SUMMARY OF BACKGROUND DATA: The natural history of spinopelvic parameters has been defined for the first 10 years of life in normal children; however, they have not been described for children with scoliosis. Such information is important because these values can be used as a baseline for the assessment of radiographic outcomes after surgical intervention. METHODS: Seven measures of sagittal alignment were taken from standing lateral radiographs of 80 children with scoliosis (coronal Cobb angle greater than 50°) and compared with age-matched normal children described in the literature. Statistical analysis was performed using 2-tailed Student t tests (level of significance = .05) and Pearson correlation coefficient. RESULTS: Patients had a mean age of 4.8 years (range, 1-10 years) and a mean Cobb angle of 72.0° ± 16°. Mean sagittal spine parameters were sagittal balance (2.2 ± 4 cm), thoracic kyphosis (38.0° ± 20.8°), and lumbar lordosis (49.0° ± 16.6°). These values were similar to those of children without scoliosis. Mean sagittal pelvic parameters were: pelvic incidence (46.5° ± 15.8°), pelvic tilt (10.7° ± 13.6°), sacral slope (35.5° ± 12.1°), and pelvic radius (55.7° ± 21.3°). Pelvic incidence was not significantly different from that of age-matched normal children; however, pelvic tilt was significantly higher and sacral slope was significantly lower in children with scoliosis. CONCLUSIONS: Sagittal plane spine parameters and some pelvic parameters were similar for young children with scoliosis versus age-matched normal children; however, children with scoliosis showed signs of increased pelvic tilt and decreased sacral slope. These values can be used as a baseline for both the natural history and the assessment of radiographic outcomes after surgical intervention.

The Pyramid Trough Wetland: environmental and biological diversity in a newly created Antarctic protected area.

The Pyramid Trough (Lat 78°S) has recently gained protection under the Antarctic Treaty system, owing to its wetland values. Here, we describe the microbial diversity of this system, with emphasis on cyanobacteria, and evaluate environment-biota relationships. Geochemistry separates ponds along hydrological gradients receiving recent inflows of dilute meltwater, from a second group that is rarely inundated and where chemistry is dominated by evaporation. Cyanobacteria-based microbial mats dominated the biota throughout. Mats were characterized by light-microscopy, pigment analysis, automated ribosomal intergenic spacer analysis and 16S rRNA gene clone libraries. A total of 17 morphotypes and 21 ribotypes were identified, mostly Oscillatoriales and several taxa that are usually rare in continental Antarctica, including Chroococcales and scytomin-rich Calothrix/Dichothrix, were abundant. There was a general decline in cyanobacterial diversity with increasing conductivity, but weak support for either differences in community composition between the two groups of ponds or sorting of taxa along the hydrological gradients with the pond groups. This implies a broad environmental tolerance and a prevalence of neutral assembly mechanisms in cyanobacterial communities of Antarctic wetland ecosystems.

Tooth decay in alcohol abusers compared to alcohol and drug abusers.

Alcohol and drug abuse are detrimental to general and oral health. Though we know the effects of these harmful habits on oral mucosa, their independent and combined effect on the dental caries experience is unknown and worthy of investigation. We compared 363 "alcohol only" abusers to 300 "alcohol and drug" abusers to test the hypothesis that various components of their dental caries experience are significantly different due to plausible sociobiological explanations. After controlling for the potential confounders, we observe that the "alcohol and drug" group had a 38% higher risk of having decayed teeth compared to the "alcohol only" group (P < .05). As expected, those who belonged to a higher social class (OR = 1.98; 95% CI = 1.43-2.75) and drank wine (OR = 1.85; 95% CI = 1.16-2.96) had a higher risk of having more filled teeth. We conclude that the risk of tooth decay among "alcohol only" abusers is significantly lower compared to "alcohol and drug" abusers.

Use of stand-up magnetic resonance imaging for evaluation of a cervicothoracic injury in a patient with ankylosing spondylitis.

BACKGROUND CONTEXT: Injuries at the cervicothoracic junction are common in patients with ankylosing spondylitis. These injuries present challenges for both initial and follow-up imagings. PURPOSE: To describe a case of a patient with ankylosing spondylitis who was treated with laminectomy and a cervicothoracic orthosis for a spinal epidural hematoma after a nondisplaced fracture at the cervicothoracic junction and to discuss the merits of stand-up magnetic resonance imaging (MRI) for follow-up evaluation of this type of injury. STUDY DESIGN/SETTING: Case report. METHODS: Clinical data of a patient with ankylosing spondylitis who sustained a nondisplaced C7 fracture are presented, followed by a detailed review of the literature concerning imaging techniques available for the evaluation of cervical spine trauma in this patient population. RESULTS: The patient was treated with emergent laminectomy and evacuation of the epidural hematoma, followed by definitive management in a cervicothoracic orthosis secondary to medical comorbidities. The patient was then successfully followed postoperatively with stand-up MRI because conventional imaging techniques could not adequately image the injury level in an upright position. CONCLUSIONS: Cervicothoracic injuries are common in patients with ankylosing spondylitis and may be difficult to follow with conventional imaging techniques. Stand-up MRI is a relatively new modality that may offer significant advantages over conventional imaging because of the ability to evaluate the cervicothoracic junction in a more functional position and the lack of a confining space such as that found in standard MRI units.

Mortality risk after head injury increases at 30 years.

BACKGROUND: Age has long been recognized as a critical factor in predicting outcomes after head injury, with individuals older than 60 years predicted to have a worse outcome than those younger than 60. The object of this study was to determine the effect of age by decade of life beginning at birth in patients with head injuries of all levels of severity. STUDY DESIGN: The New York State Trauma Registry was searched for head injuries from January 1, 1994 to December 31, 1995; the 13,908 cases found were placed into age groups by decade. Data were sought for each patient on demographics, Glasgow Coma Score, ICD-9 injury code, New Injury Severity Score (NISS), and mechanism of injury. These data were analyzed with chi-square and one-way ANOVA tests, with significance set at p < 0.05. RESULTS: The risk of dying was significantly increased in patients beginning at 30 years of age compared with those in the younger age groups, with the greatest increases occurring after age 60 (p < 0.001). For the population with available Glasgow Coma Score data (n = 12,844), the mortality rate for patients ages 0 to 30 was 10.9%, and for patients ages 31 to 50 was 12.4%. The mean Glasgow Coma Score for nonsurvivors ages 0 to 20 (3.9) and for nonsurvivors ages 31 to 50 (5.1) were significantly different, with a risk ratio of 1.3 (p < 0.001). CONCLUSIONS: The risk of dying for patients suffering head injuries increases as early as 30 years of age, making it necessary for health-care providers to consider increased monitoring and treatment for patients in this younger age group.

Fluoride content of alcoholic beverages.

BACKGROUND: In view of the conflicting reports of the extent and severity of dental caries in alcohol misusing subjects, a systematic survey of the fluoride content of alcoholic beverages was undertaken. RESULTS: The fluoride content of beverages varied widely particularly if non-UK European products were considered. CONCLUSIONS: Beers brewed in locations with high fluoride water levels may contribute significantly to the daily fluoride intake, particularly in alcohol misusing subjects and this may contribute to alcohol-associated bone disease.