Prediction of Late Dysplasia Based on Ultrasound and Plain X-Ray at 6 Months.

BACKGROUND: Developmental dysplasia of the hip represents a spectrum of deformity. Residual dysplasia at 2 years of age is associated with an increased risk for osteoarthritis and functional limitations. We compared the prognostic value of 6-month imaging modalities and aimed to identify optimal diagnostic metrics for the prediction of residual dysplasia. METHODS: After IRB approval, patients who underwent Pavlik treatment between 2009 and 2018 with 2-year follow-up were identified. Sonographs [ultrasound (US)] and radiographs (x-ray) were obtained at 6-month and 2-year-old visits. Dysplasia at 2 years was defined as an acetabular index (AI) >24 degrees. Receiver operating characteristic curves were constructed to quantitatively compare the prognostic ability of US and x-ray-based measures at 6 months. Youden's index [(YI) (values range from 0 (poor test) to 1 (perfect test)] was used to evaluate existing cutoffs at 6 months of age (normal measurements: alpha angle (AA) ≥60 degrees, femoral head coverage (FHC) ≥50%, and AI <30 degrees) relative to newly proposed limits. RESULTS: Fifty-nine patients were included, of which 28.8% of patients (95% CI: 17.3 to 40.4%) had acetabular dysplasia at 2 years. After adjusting for sex, AA [Area under the Curve (AUC): 80] and AI (AUC: 79) at 6 months of age were better tests than FHC (AUC: 0.77). Current diagnostic cutoffs for AA (YI: 0.08), AI (YI: 0.0), and FHC (YI: 0.06) at 6 months had poor ability to predict dysplasia at 2 years. A composite test of all measures based on proposed cutoffs (AA ≥73 degrees, FHC > 62% and AI ≤24 degrees) was a better predictor of dysplasia at 2 years (Youden's index (YI): 0.63) than any single metric. CONCLUSIONS: The rate of residual dysplasia remains concerning. The 6-month x-ray and US both play a role in the ongoing management of the developmental dysplasia of the hip. The prediction of dysplasia is maximized when all metrics are considered collectively. Existing parameters were not accurate; We recommend the following cutoffs: AA ≥73 degrees, FHC > 62%, and AI ≤24 degrees. These cutoffs must be validated. LEVEL OF EVIDENCE: Prognostic Level II.

Fassier-Duval Rod Failure: Is It Related to Positioning in the Distal Epiphysis?

BACKGROUND: The relationship between Fassier-Duval (FD) rod placement and rod failure rates has not previously been quantified. METHODS: Retrospective review was conducted on patients with osteogenesis imperfecta treated with FD rods between 2005 and 2017. Age at first surgery, sex, Sillence type of osteogenesis imperfecta, bisphosphonate treatment, location of rod (side of body and specific bone), and dates of surgeries, radiographs, and rod failures were collected. C-arm images determined rod fixation within the distal epiphysis at the time of surgery. C-arm variables included rod deviation (percent deviation from the midline of the distal epiphysis) and anatomical direction of deviation (anterior/posterior and medial/lateral). X-ray images were examined for rod failure, which was defined as bending, pulling out of the physis, protrusion out of the bone, and/or failure to telescope. Cox proportional hazards regression models were used to compare failure rates with location of placement within the distal epiphysis allowing for clustering of the data by side (left or right) and bone (femur or tibia). RESULTS: The cohort was 13 patients (11 female individuals and 2 male individuals) with a total of 66 rods and 75 surgeries. Mean time from the first surgery to the last follow-up visit was 8.9 years (SD=5 y). There was a 7% increase in hazard of failure per 1-mm increase in antero-posterior (AP) deviation [hazard ratio (HR), 1.07; 95% confidence interval (CI), 1.01-1.14; P=0.029)]. Similarly, there was a 9% increase in hazard of failure for every 1-mm increase in lateral deviation (HR, 1.09; 95% CI, 1.01-1.18; P=0.019). A 12% increase in hazard of failure per 10% increase in deviation from the midline for both AP and lateral radiograph views was also found, although this was only statistically significant for lateral deviation on the AP radiograph view (HR, 1.12; 95% CI, 1.01-1.25; P=0.030). CONCLUSIONS: FD rod placement within the distal epiphysis has significant impact on increasing rod survival. LEVEL OF EVIDENCE: Level III-therapeutic study.

Fassier-Duval Rods are Associated With Superior Probability of Survival Compared With Static Implants in a Cohort of Children With Osteogenesis Imperfecta Deformities.

BACKGROUND: The survival of Fassier-Duval (FD) telescoping rods as compared with static implants in children affected by osteogenesis imperfecta is not well characterized. The purpose of this study was to compare risk of lower extremity implant failure in FD rods versus static implants. METHODS: Data were retrospectively collected from patients with osteogenesis imperfecta who underwent surgical treatment using either FD rods or static implants (Rush rods, flexible nails, or Steinmann pins) between 1995 and 2015. The timing of implant failure was the primary outcome variable of interest. Comparisons were limited to limbs with no previous history of implants. Cox-proportional hazards regression analyses were used to compare the hazard of implant failure across implants. Negative binomial regression analyses were used to compare the incidence of surgical procedures in the 2 implant groups. RESULTS: The final cohort consisted of 64 limbs (n=21 patients). The static implant group (n=38) consisted of 24 Rush rods (63%), 14 flexible nails (37%), and 2 Steinmann pins (5%). The hazard of implant failure in the static implant group was 13.2 times [95% confidence interval (CI), 2.5-69.6; P=0.0024] the hazard of implant failure in the FD rod group. The hazard of implant failure among females was 4.8 (95% CI, 1.4-16.7; P=0.0125) times the hazard of implant failure among males. The total surgery rate in the static implant group was 7.8 (95% CI, 1.8-33.0; P=0.0056) times the total surgery rate in the FD group. CONCLUSIONS: Among surgically naive limbs, FD rods were associated with significantly improved probability of survival compared with static implants. LEVEL OF EVIDENCE: Level II-retrospective study.

Preimmunization with a heat-killed preparation of Mycobacterium vaccae enhances fear extinction in the fear-potentiated startle paradigm.

The hygiene hypothesis or "Old Friends" hypothesis proposes that inflammatory diseases are increasing in modern urban societies, due in part to reduced exposure to microorganisms that drive immunoregulatory circuits, and a failure to terminate inappropriate inflammatory responses. Inappropriate inflammation is also emerging as a risk factor for trauma-related, anxiety, and affective disorders, including posttraumatic stress disorder (PTSD), which is characterized as persistent re-experiencing of the trauma after a traumatic experience. Traumatic experiences can lead to long-lasting fear memories and exaggerated fear potentiation of the acoustic startle reflex. The acoustic startle reflex is an ethologically relevant reflex and can be potentiated in both humans and rats through Pavlovian conditioning. Mycobacterium vaccae NCTC 11659 is a soil-derived bacterium with immunoregulatory and anti-inflammatory properties that has been demonstrated to confer stress resilience in mice. Here we immunized adult male Sprague Dawley rats 3×, once per week, with a heat-killed preparation of M. vaccae NCTC 11659 (0.1mg, s.c., in 100µl borate-buffered saline) or vehicle, and, then, 3weeks following the final immunization, tested them in the fear-potentiated startle paradigm; controls were maintained under home cage control conditions throughout the experiment (n=11-12 per group). Rats were tested on days 1 and 2 for baseline acoustic startle, received fear conditioning on days 3 and 4, and underwent fear extinction training on days 5-10. Rats were euthanized on day 11 and brain tissue was sectioned for analysis of mRNA expression for genes important in control of brain serotonergic signaling, including tph2, htr1a, slc6a4, and slc22a3, throughout the brainstem dorsal and median raphe nuclei. Immunization with M. vaccae had no effect on baseline acoustic startle or fear expression on day 5. However, M. vaccae-immunized rats showed enhanced between-session and within-session extinction on day 6, relative to vehicle-immunized controls. Immunization with M. vaccae and fear-potentiated startle altered serotonergic gene expression in a gene- and subregion-specific manner. These data are consistent with the hypothesis that immunoregulatory strategies, such as preimmunization with M. vaccae, have potential for prevention of stress- and trauma-related psychiatric disorders.

Pediatric and Adult Fracture Incidence: A Decreasing Trend With Increasing Hospital Admissions.

Large-scale studies examining fracture trends and epidemiological data are lacking. The purpose of this study was to evaluate the incidence of fractures presenting to US emergency departments using the National Electronic Injury Surveillance System. A total of 7,109,078 pediatric and 13,592,548 adult patients presenting to US emergency departments with a fracture between 2008 and 2017 were analyzed for patterns. Fractures accounted for 13.9% of pediatric injuries and 15% of adult injuries. Among children, fracture incidence was highest in the group 10 to 14 years old and most frequently involved the forearm (19.0%). Fracture incidence was highest in adults 80 years and older and most frequently involved the lower trunk (16.2%). On average, the rate of pediatric fractures decreased by 2.34% per year (95% CI, 0.25% increase to 4.88% decrease; P=.0757). Among adults, fracture incidence increased 0.33% per year (95% CI, 2.34% decrease to 2.85% increase; P=.7892). This change was significantly different between the pediatric and adult populations (P=.0152). There was an increase in the annual proportion of adults with fractures who were admitted (odds ratio per 1-year increase, 1.05; 95% CI, 1.03-1.07; P<.0001). There was no change in the proportion of pediatric patients with fractures who were admitted (odds ratio, 1.02; 95% CI, 0.99-1.05; P=.0606). The incidence of fractures decreased in pediatric patients yet was relatively stable in adult patients. Conversely, the proportion of patients with fractures who were admitted increased, particularly among adults. These findings may suggest that less severe fractures are presenting elsewhere, falsely inflating the observed rise in admissions. [Orthopedics. 2023;46(6):e369-e375.].

Outcomes of displaced adolescent distal third tibia fractures: can we do better?

Because adolescent distal third tibia fractures pose treatment challenges, we aimed to identify factors predictive of failure among common treatment methods: casting without manipulation, closed reduction and casting (CRC) and open treatment. Among displaced fractures, we compared outcomes between CRC versus open treatment. Skeletally immature individuals (10-17 years) with extra-articular distal third tibia fractures at a level 1 trauma center (2011-2017) were retrospectively reviewed. Patient demographics, injury and treatment characteristics and complications were recorded. Radiographs were evaluated for unacceptable alignment (angulation >5°, translation >50%, and shortening >1 cm) and time to union. Of 140 individuals, casting was the most common treatment method (n = 81), followed by CRC under anesthesia/sedation (n = 38), and open treatment (n = 34). For fractures casted without manipulation, increased fracture severity based upon our novel grading system [hazard ratio (HR): 10.5, 95% CI, 4.2-27.5, P < 0.0001] was significantly related to treatment failure. Outcomes for a selected group of 47 initially displaced fractures (33 CRC and 14 open treatments) were evaluated. For CRC, 9 (27.3%) healed with malunion and 6 (18.2%) failed initial CRC, resulting in a treatment failure rate of 36.7%. For open treatment, 2 (14.3%) underwent hardware removal, 2 (14.3%) healed with malunion and one developed infection requiring reoperation. No fractures healed with malunion required surgical correction during the study period. The odds of persistent malalignment in CRC was 3.77 [95% CI, 0.44-32.60, P = 0.2274] times open treatment. Adolescent minimally displaced distal tibial fractures can undergo successful treatment with casting. However, displaced fractures have a higher chance of short-term failure with CRC. Close monitoring of displaced fractures in the adolescent is essential during conservative management.

Trends in Trampoline Fractures: 2008-2017.

OBJECTIVES: In this study, we aim to evaluate the current trends in pediatric fractures related to trampolines. METHODS: The National Electronic Injury Surveillance System was queried for fractures occurring between 2008 and 2017 in individuals aged 0 to 17 years. Sex, anatomic region, locale of injury, admission status, and year of injury were recorded. Incidence rates were calculated by using national census data. Poisson regression analysis was used to test for changes in fracture incidence across the time period. Logistic regression analyses were used to test temporal trends in the odds of a fracture occurring at a place of recreation or sport and a patient with a fracture being admitted. RESULTS: Between 2008 and 2017, there was a 3.85% (95% confidence interval [CI]: 0.51-7.30) increase in the incidence of trampoline-related pediatric fractures per person-year. The incidence of pediatric trampoline-related fractures increased from 35.3 per 100 000 person-years in 2008 to 53.0 per 100 000 person-years in 2017. There was no change in the odds of a trampoline fracture requiring hospitalization (odds ratio per 1 year: 1.02; 95% CI: 0 6-1.07; P = .5431). There was a significant increase in the odds of a fracture occurring at a place of recreation or sport (odds ratio per year: 1.32; 95% CI: 1.21-1.43; P < .0001). CONCLUSIONS: Between 2008 and 2017, there was a significant increase in the national incidence of trampoline-related fractures. We identified a significant increase in the proportion of trampoline fractures that occurred at a place of recreation or sport. Advocacy campaigns should consider these sites in their prevention efforts.

Lateral semi-circular canal asymmetry in females with idiopathic scoliosis.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal structural deformity that occurs in otherwise normal individuals. Although curve progression and severity vary amongst individuals, AIS can lead to significant cosmetic and functional deformity. AIS etiology has been determined to be genetic, however, exact genetic and biological processes underlying this disorder remain unknown. Vestibular structure and function have potentially been related to the etiopathogenesis of AIS. Here, we aimed to characterize the anatomy of the semicircular canals (SCC) within the vestibular system through a novel approach utilizing T2-weighted magnetic resonance images (MRI). METHODS: Three dimensional, MRI-based models of the SCCs were generated from AIS subjects (n = 20) and healthy control subjects (n = 19). Linear mixed models were used to compare SCC morphological measurements in the two groups. We compared side-to-side differences in the SCC measurements between groups (group*side interaction). RESULTS: Side-to-side differences in the lateral SCC were different between the two groups [false discovery rate adjusted p-value: 0.0107]. Orientation of right versus left lateral SCC was significantly different in the AIS group compared to the control group [mean side-to-side difference: -4.1°, 95% CI: -6.4° to -1.7°]. Overall, among subjects in the AIS group, the left lateral SCC tended to be oriented in a more horizontal position than subjects in the control group. SIGNIFICANCE: Asymmetry within the SCCs of the vestibular system of individuals with AIS potentially results in abnormal efferent activity to postural muscles. Consequences of this muscular activity during periods of rapid growth, which often coincides with AIS onset and progression, warrant consideration.

Tonnis Angle and Acetabular Retroversion Measurements in Asymptomatic Hips Are Predictive of Future Hip Pain: A Retrospective, Prognostic Clinical Study.

BACKGROUND: This study evaluated the prevalence of radiographic abnormalities potentially indicative of femoroacetabular impingement on AP pelvic radiographs in asymptomatic adolescents and young adults and aimed to determine whether the abnormalities were predictive of future hip pain. METHODS: AP pelvis images from scoliosis radiographs were obtained from patients 12 to 25 years of age free of any clinical hip/lower extremity symptoms between January 2006 and September 2009. The following radiographic abnormalities were collected: lateral center-edge angle of Wiberg >40° or <25°, Tönnis angle <0° or >10°, acetabular retroversion (crossover sign with a posterior wall sign), acetabular overcoverage (crossover sign without a posterior wall sign), and anterior offset alpha angle, calculated using alpha angle of Nötzli >50°. Patients were retrospectively followed (average 3.11 years) to identify those who subsequently developed hip pain. RESULTS: Of the 233 patients (466 hips) who were asymptomatic at the time of radiographic evaluation, at least one radiographic abnormality was present in 60% (281/466) of the hips. Within that group of hips (n = 281), 69% (195/281) of hips demonstrated a single abnormality, whereas 31% (86/281) of hips were associated with multiple abnormalities. Among all hips (n = 466), a lateral center-edge angle <25° or >40° was the most common radiographic abnormality, present in 27% (127/466) of hips. Anterior offset alpha angle and acetabular overcoverage were the most common abnormalities to present together, found in 5% (25/466) of hips. In the multivariable model, a decreasing Tönnis angle (hazard ratio per 1-degree decrease: 1.25, 95% confidence interval, 1.10-1.42, P = 0.0006) and the presence of acetabular retroversion (hazard ratio: 3.55, 95% confidence interval, 1.15-10.95, P = 0.0272) were predictive of the development of future hip pain. CONCLUSIONS: Our study demonstrates a high prevalence of radiographic abnormalities indicative of femoroacetabular impingement in asymptomatic adolescents and young adults. A decrease in Tönnis angle and the presence of acetabular retroversion were predictive of future hip pain.

Complications, Results, and Risk Factors of Spinal Fusion in Patients With Myelomeningocele.

STUDY DESIGN: Retrospective prognostic study. OBJECTIVE: The purpose of this study assess was to assess the results of spinal fusion and identify factors associated with the development of post-spinal fusion infections in patients with myelomeningocele. BACKGROUND: Surgical correction of neuromuscular scoliosis secondary to myelomeningocele is known to be associated with a high complication rate. METHODS: A retrospective cohort study design was used to collect data on patients with myelomeningocele who underwent spinal fusion between the years of 1997-2013. Only subjects with a minimum of two years of continuous follow-up were included in the study. Demographic, surgical, clinical, and radiographic variables of interest were collected. Univariate and multivariable logistic regression analyses were used to identify factors predictive of an infection. Linear mixed model regression analyses were used to analyze postsurgical changes in radiographic parameters. RESULTS: Of the 33 subjects included in the study, 33.3% developed a postoperative infection. Overall, 69.0% of patients achieved a >50% correction of primary curvature at the one-month time point. Of the measured variables, lumbar and thoracolumbar kyphosis (odds ratio: 10.9, 95% confidence interval [CI]: 1.2-158.3, p = .0465) and a low preoperative hematocrit odds ratio per 1% increase, 0.7 (95% CI: 0.5-0.9, p = .0145) were associated with developing a postoperative infection. There was a significant improvement in the proportion of subjects with a pelvic obliquity measurement <5° one month postsurgery (p = .0339), kyphosis (p = .0401), and Cobb angle of the primary curvature across all time points (p <.0001). CONCLUSION: Type of procedure, neurosegmental level, transfusion rates, age at surgery, gender, length of operation, preoperative urinary tract infection, estimated blood loss, and the number of levels fused were not modifiable risk factors for future complications for patients with scoliosis secondary to myelomeningocele, whereas lumbar and thoracolumbar kyphosis or low hematocrit levels may lead to an increased risk for developing a postspinal fusion infection. LEVEL OF EVIDENCE: Level II.