Evidence-based Indications for Vertebral Body Tethering in Spine Deformity.

Posterior spinal fusion has long been established as an effective treatment for the surgical management of spine deformity. However, interest in nonfusion options continues to grow. Vertebral body tethering is a nonfusion alternative that allows for the preservation of growth and flexibility of the spine. The purpose of this investigation is to provide a practical and relevant review of the literature on the current evidence-based indications for vertebral body tethering. Early results and short-term outcomes show promise for the first generation of this technology. At this time, patients should expect less predictable deformity correction and higher revision rates. Long-term studies are necessary to establish the durability of early results. In addition, further studies should aim to refine preoperative evaluation and patient selection as well as defining the benefits of motion preservation and its long-term effects on spine health to ensure optimal patient outcomes.

Optogenetic ion pumps differ with respect to the secondary pattern of K+ redistribution.

We recently reported that strong activation of the optogenetic chloride pump, halorhodopsin leads to a secondary redistribution of K+ ions into the cell, through tonically open, "leak" K+ channels. Here we show that this effect is not unique to halorhodopsin but is also seen with activation of another electrogenic ion pump, archaerhodopsin. The two opsins differ however in the size of the rebound rise in extracellular potassium, [K+ ]o , after the end of activation, which is far larger with halorhodopsin than for archaerhodopsin activation. Multiple linear regression modeling indicates that the variance in the postillumination surge in [K+ ]o was explained both by the size of the preceding, illumination-induced drop in [K+ ]o and also by the type of opsin. These data provide additional support for the hypothesis that intense chloride-loading of cells, as occurs naturally following intense bursts of GABAergic synaptic bombardment, or artificially following halorhodopsin activation, is followed by extrusion of both Cl- and K+ coupled together. We discuss this with respect to the pattern of [K+ ]o rise that occurs at the onset of seizure-like events.

Clec12a tempers inflammation while restricting expansion of a colitogenic commensal.

Regulation of the microbiota is critical to intestinal health yet the mechanisms employed by innate immunity remain unclear. Here we show that mice deficient in the C-Type-lectin receptor, Clec12a developed severe colitis, which was dependent on the microbiota. Fecal-microbiota-transplantation (FMT) studies into germfree mice revealed a colitogenic microbiota formed within Clec12a -/- mice that was marked by expansion of the gram-positive organism, Faecalibaculum rodentium . Treatment with F. rodentium was sufficient to worsen colitis in wild-type mice. Macrophages within the gut express the highest levels of Clec12a. Cytokine and sequencing analysis in Clec12a -/- macrophages revealed heighten inflammation but marked reduction in genes associated with phagocytosis. Indeed, Clec12a -/- macrophages are impaired in their ability to uptake F. rodentium. Purified Clec12a had higher binding to gram-positive organisms such as F. rodentium . Thus, our data identifies Clec12a as an innate immune surveillance mechanism to control expansion of potentially harmful commensals without overt inflammation.

Indirect Effects of Halorhodopsin Activation: Potassium Redistribution, Nonspecific Inhibition, and Spreading Depolarization.

The movement of ions in and out of neurons can exert significant effects on neighboring cells. Here we report several experimentally important consequences of activation of the optogenetic chloride pump, halorhodopsin. We recorded extracellular K+ concentration ([K+]extra) in neocortical brain slices prepared from young adult mice (both sexes) which express halorhodopsin in pyramidal cells. Strong halorhodopsin activation induced a pronounced drop in [K+]extra that persisted for the duration of illumination. Pharmacological blockade of K+ channels reduced the amplitude of this drop, indicating that it represents K+ redistribution into cells during the period of hyperpolarization. Halorhodopsin thus drives the inward movement of both Cl- directly, and K+ secondarily. When the illumination period ended, a rebound surge in extracellular [K+] developed over tens of seconds, partly reflecting the previous inward redistribution of K+, but additionally driven by clearance of Cl- coupled to K+ by the potassium-chloride cotransporter, KCC2. The drop in [K+]extra during light activation leads to a small (2-3 mV) hyperpolarization also of other cells that do not express halorhodopsin. Its activation therefore has both direct and indirect inhibitory effects. Finally, we show that persistent strong activation of halorhodopsin causes cortical spreading depolarizations (CSDs), both in vitro and in vivo This novel means of triggering CSDs is unusual, in that the events can arise during the actual period of illumination, when neurons are being hyperpolarized and [K+]extra is low. We suggest that this fundamentally different experimental model of CSDs will open up new avenues of research to explain how they occur naturally.SIGNIFICANCE STATEMENT Halorhodopsin is a light-activated electrogenic chloride pump, which has been widely used to inhibit neurons optogenetically. Here, we demonstrate three previously unrecognized consequences of its use: (1) intense activation leads to secondary movement of K+ ions into the cells; (2) the resultant drop in extracellular [K+] reduces excitability also in other, nonexpressing cells; and (3) intense persistent halorhodopsin activation can trigger cortical spreading depolarization (CSD). Halorhodopsin-induced CSDs can occur when neurons are hyperpolarized and extracellular [K+] is low. This contrasts with the most widely used experimental models that trigger CSDs with high [K+]. Both models, however, are consistent with the hypothesis that CSDs arise following net inward ionic movement into the principal neuron population.

Sexuality Discourses and LGBQ Students' Interpretations of Campus Climate in the Contemporary US.

Recent US studies showed that perceptions of campus climate vary considerably across individual LGBQ students, with some students reporting friendly climates and others reporting persistent hostility. Although researchers have identified several factors that contribute to the perceptual variations, they have paid limited attention to the role of sexuality discourses. The present study sought to fill this gap in the literature by analyzing in-depth interviews. The analysis showed that LGBQ students drew on two major discourses to guide their interpretations of campus climate. A majority of students drew on post-closet discourse to celebrate their visibility on campus, LGBQ-friendly courses, and straight classmates' positive reactions. A smaller number of students drew on queer discourse to question the meaning of LGBQ students' visibility and criticize heterosexist biases in classrooms. Overall, these results highlighted the importance of the competing discourses, which set LGBQ students' expectations and guided their interpretations of campus experiences.

Intervertebral Disk Health Following Vertebral Body Tethering for Adolescent Idiopathic Scoliosis: A Preliminary Study.

BACKGROUND: Interest in vertebral body tethering (VBT) as an alternative to posterior spinal fusion for adolescent idiopathic scoliosis (AIS) continues to grow. The purpose of this study was to prospectively assess intervertebral disk health on magnetic resonance imaging (MRI) at 1 year following VBT in AIS patients. METHODS: AIS patients were enrolled in a prospective surgeon-sponsored Food and Drug Administration (FDA) Investigational Device Exemption (IDE) Study and underwent MRI at 1-year following VBT. All spanned disks and the untethered disks immediately adjacent to the upper instrumented vertebra and lowest instrumented vertebra levels were evaluated according to Pfirrmann grading criteria. Associations between patient factors and preoperative and postoperative disk health and patient-reported outcomes were evaluated. RESULTS: Twenty-two patients were enrolled with a postoperative MRI (25 curves, 188 disks), and 7 patients (7 curves) had both preoperative and postoperative MRIs (67 disks). The mean age was 12.7 years. Most were Risser 0 (65%) and either Sanders Skeletal Maturity Score 3 (35%) or 4 (53%). In the 7 patients with preoperative and postoperative MRI, the mean Pfirrmann grade of the disks spanned by the tether was 1.88 preoperatively and 2.31 postoperatively ( P =0.0075). No statistically significant differences in preoperative versus postoperative Pfirrmann grade were identified in the disks adjacent to the upper or lower instrumented vertebrae. No association was found between patient-reported outcomes and Pfirrmann grade. CONCLUSION: At 1 year postoperatively, increased degenerative changes in disks spanned by the tether was identifiable on MRI without evidence of adjacent segment disk disease. These changes were not associated with patient-reported outcomes. LEVEL OF EVIDENCE: Level III.

Cervical myelopathy in a patient with Klippel-Feil syndrome treated with a patient-specific custom cervical spine locking plate.

INTRODUCTION: Klippel-Feil Syndrome is the congenital fusion of at least two cervical vertebrae. Often asymptomatic, though in rare cases it may lead to severe cervical spine deformity and neurologic injury. CASE PRESENTATION: We report a case of a 48-year-old woman with a history of Klippel-Feil Syndrome and congenital scoliosis who developed progressive cervical myelopathy. She was surgically treated with anterior C5 corpectomy and arthrodesis. Pre-operative evaluation was facilitated by 3D printed models. The surgical decompression and spinal reconstruction was completed with the use of a patient-specific, custom-made cervical spine locking plate. DISCUSSION: Pre-operative evaluation with 3D printing technology was useful in understanding the patient's complex curve pattern and in designing a patient specific implant. Custom designed implant is a reasonable option to treat cervical myelopathy associated with complex cervical deformity.

Average Lumbar Hounsfield Units Predicts Osteoporosis-Related Complications Following Lumbar Spine Fusion.

STUDY DESIGN: Retrospective Study. OBJECTIVE: To compare methods of assessing pre-operative bone density to predict risk for osteoporosis related complications (ORC), defined as proximal junctional kyphosis, pseudarthrosis, accelerated adjacent segment disease, reoperation, compression fracture, and instrument failure following spine fusions. METHODS: Chart review of primary posterior thoracolumbar or lumbar fusion patients during a 7 year period. Inclusion criteria: preoperative dual-energy x-ray absorptiometry (DXA) test within 1 year and lumbar CT scan within 6 months prior to surgery with minimum of 1 year follow-up. Exclusion criteria: <18 years at time of index procedure, infection, trauma, malignancy, skeletal dysplasia, neuromuscular disorders, or anterior-posterior procedures. RESULTS: 140 patients were included. The average age was 67.9 years, 83 (59.3%) were female, and 45 (32%) had an ORC. There were no significant differences in patient characteristics between those with and without an ORC. Multilevel fusions were associated with ORCs (46.7% vs 26.3%, p = 0.02). Patients with ORCs had lower DXA t-scores (-1.62 vs -1.10, p = 0.003) and average Hounsfield units (HU) (112.1 vs 148.1, p ≤ 0.001). Multivariable binary logistic regression analysis showed lower average HU (Adj. OR 0.00 595% CI 0.0001-0.1713, p = 0.001) was an independent predictor of an ORC. The odds of an ORC increased by 1.7-fold for every 25 point decrease in average HU. CONCLUSIONS: The gold standard for assessing bone mineral density has been DXA t-scores, but the best predictor of ORC remains unclear. While both lower t-scores and average HU were associated with ORC, only HU was an independent predictor of ORC.

Is there consensus on the perioperative management of Xa inhibitors in patients undergoing elective spine surgery?-A survey of current spine surgeon practices.

BACKGROUND: Factor Xa inhibitors (Xai) are an increasingly common consideration in perioperative anticoagulation management. However, there no existing guidelines established for use in Spine Surgery. This survey study aims to capture current practice trends regarding the perioperative management of Xai among spine surgeons. METHODS: An 11-question survey was sent to all surgeon members of 3 spinal surgery societies. Responses were remitted anonymously. Questions characterized the background and experience of the respondent and inquired into their current perioperative Xai and other anticoagulant management. Questions were all single-best option, multiple-choice. RESULTS: A total of 116 surveys were received. Twenty-six (22.4%) were from neurosurgeons and 90 (77.6%) were from orthopedic surgeons. Practiced preoperative Xai hold length tended to be longer than recommended by the respondent's medical colleagues. Only 65.2% (P≤0.0001) of respondents practiced in agreement with the recommendations of their medical colleagues. Postoperative Xai holds trended toward longer holds than that of other anticoagulants with 37.9% (P=0.0125) of respondents showed differences within their own practice between length of Xai hold and length of other anticoagulant holds. One out of four respondents reported noticing a change in the rate of perioperative bleeding complications among Xai patients. Despite reported increased bleeding issues, only 39% of those who noted this increase in bleeding complications reported they would hold a Xai longer than other anticoagulants. CONCLUSIONS: There exists a wide range of recommended and practiced chronic anticoagulant hold lengths. This inconsistency likely highlights conflicting risk aversion among surgeons, between complications which are viewed as medical (i.e., thromboembolism and stroke) vs. surgical (i.e., compressive hematoma). Yet, survey responses suggest the length of Xai hold times did not necessarily reflect the surgeon's experience with postoperative bleeding complications in Xai patients. These inconsistent practices highlight the need for further research that can establish guidelines for perioperative management of Xai patients undergoing spine surgery. KEYWORDS: Anticoagulants; factor Xa inhibitors (factor Xai); spine; orthopedic surgery; neurosurgery.

Incidence of Symptomatic Pediatric Tarsal Coalition in Olmsted County: A Population-Based Study.

BACKGROUND: Tarsal coalitions are an important reason for foot pain in children. Early estimates placed the prevalence at up to 2%, while more recent data suggest that it is as high as 11% to 13%. To our knowledge, there have been no population-based studies to determine the true incidence of symptomatic tarsal coalitions in a pediatric population. METHODS: A population-based database was used to identify all new diagnoses of symptomatic tarsal coalitions in children 18 years old or younger between 1966 and 2018. Patient records were reviewed for clinical data, and comparisons were made between the types and characteristics of the coalitions identified to determine differences in the affected populations. The annual age-specific, sex-specific, and type-specific incidence rates were estimated. RESULTS: During the study period, 58 patients with a total of 79 symptomatic tarsal coalitions were identified (annual incidence = 3.5 per 100,000 children). There were 43 calcaneonavicular (CN) coalitions (annual incidence = 1.9 per 100,000 children), 27 talocalcaneal (TC) coalitions (annual incidence = 1.2 per 100,000 children), as well as 9 other coalitions (7 talonavicular, 1 naviculocuboid, and 1 naviculocuneiform) (annual incidence = 0.4 per 100,000 children). The overall incidence peaked between the ages of 10 and 14 years for both boys and girls (8.1 per 100,000 and 7.4 per 100,000 children, respectively). Statistical differences were identified between the types of tarsal coalitions. TC coalitions present at an older age relative to CN and other coalitions (mean,13.9, 12.7, and 11.4 years, respectively; p = 0.02). While CN and TC coalitions were similar in composition (23% and 30%, respectively, were osseous as opposed to fibrocartilaginous), other coalitions were more likely to be osseous (78%) (p = 0.0035). Other coalitions were also less likely to require surgery than CN and TC coalitions (11%, 74%, and 56%, respectively; p = 0.0015). CONCLUSIONS: This population-based study demonstrates differences in the clinical presentation of tarsal coalitions and provides an estimate of the true incidence of symptomatic tarsal coalitions in a pediatric population.

Characteristics and reoperation rates of paediatric tarsal coalitions: a population-based study.

PURPOSE: Tarsal coalitions are congenital fusions of two or more tarsal bones and can lead to foot pain and stiffness. Few studies examine the long-term reoperation rates following paediatric tarsal coalition surgery. METHODS: A population-based database, linking medical records at all medical centres to capture the entire medical history of the full population of a Midwest county, was used to identify tarsal coalitions in children between 1966 and 2018. Records were reviewed for clinical data, surgical records and followed up to identify any subsequent surgical interventions. RESULTS: A total of 58 patients (85 coalitions) were identified; 46 calcaneonavicular (CN) coalitions, 30 talocalcaneal (TC) coalitions and nine other coalitions (seven talonavicular, one naviculocuboid, one naviculocuneiform). In all, 46 coalitions were treated surgically (43 coalition resections, three arthrodeses) and 39 were treated nonoperatively. Patients treated surgically were less likely to report ongoing symptoms at final follow-up compared with patients managed nonoperatively (33% versus 67%; p = 0.0017). With a median 14.4 years (interquartile range 9.3 to 19.7) follow-up, there was an overall re-operation rate of 8.7% (4/46). Differences in reoperation rates by initial surgery (resection versus arthrodesis; p = 0.2936), coalition type (CN versus TC versus Other; p = 0.6487) or composition (osseous versus fibrocartilaginous; p = 0.29) did not reach statistical significance. CONCLUSION: This is the first population-based study demonstrating the durability of surgical management of tarsal coalitions in a paediatric population. At final follow-up, patients treated surgically are less likely to report persistent symptoms compared with patients managed nonoperatively. Long-term reoperation rates appear to be low (8.7%). LEVEL OF EVIDENCE: III.

Osteoporosis in spine surgery patients: what is the best way to diagnose osteoporosis in this population?

OBJECTIVE: The goal of this study was to compare different recognized definitions of osteoporosis in patients with degenerative lumbar spine pathology undergoing elective spinal fusion surgery to determine which patient population should be considered for preoperative optimization. METHODS: A retrospective review of patients in whom lumbar spine surgery was planned at 2 academic medical centers was performed, and the rate of osteoporosis was compared based on different recognized definitions. Assessments were made based on dual-energy x-ray absorptiometry (DXA), CT Hounsfield units (HU), trabecular bone score (TBS), and fracture risk assessment tool (FRAX). The rate of osteoporosis was compared based on different definitions: 1) the WHO definition (T-score ≤ -2.5) at total hip or spine; 2) CT HU of < 110; 3) National Bone Health Alliance (NBHA) guidelines; and 4) "expanded spine" criteria, which includes patients meeting NBHA criteria and/or HU < 110, and/or "degraded" TBS in the setting of an osteopenic T-score. Inclusion criteria were adult patients with a DXA scan of the total hip and/or spine performed within 1 year and a lumbar spine CT scan within 6 months of the physician visit. RESULTS: Two hundred forty-four patients were included. The mean age was 68.3 years, with 70.5% female, 96.7% Caucasian, and the mean BMI was 28.8. Fracture history was reported in 53.8% of patients. The proportion of patients identified with osteoporosis on DXA, HUs, NBHA guidelines, and the authors' proposed "expanded spine" criteria was 25.4%, 36.5%, 75%, and 81.9%, respectively. Of the patients not identified with osteoporosis on DXA, 31.3% had osteoporosis based on HU, 55.1% had osteoporosis with NBHA, and 70.4% had osteoporosis with expanded spine criteria (p < 0.05), with poor correlations among the different assessment tools. CONCLUSIONS: Limitations in the use of DXA T-scores alone to diagnose osteoporosis in patients with lumbar spondylosis has prompted interest in additional methods of evaluating bone health in the spine, such as CT HU, TBS, and FRAX, to inform guidelines that aim to reduce fracture risk. However, no current osteoporosis assessment was developed with a focus on improving outcomes in spinal surgery. Therefore, the authors propose an expanded spine definition for osteoporosis to identify a more comprehensive cohort of patients with potential poor bone health who could be considered for preoperative optimization, although further study is needed to validate these results in terms of clinical outcomes.

Intercalary Allograft Reconstruction of the Proximal Tibia With and Without a Free Fibula Flap in Pediatric Patients.

BACKGROUND: Limb salvage of the proximal tibia can be difficult due to the growth potential of and functional demands of the pediatric patients. Multiple reconstruction techniques exist, however, the ideal form of reconstruction is yet to be elucidated. The purpose of the current study is to evaluate outcomes in patients with an intercalary resection of the proximal tibia reconstructed with an allograft with or without a free vascularized fibula flap (FVF). METHODS: Seventeen pediatric patients (9 males, 8 females) underwent lower extremity limb salvage with the use of intercalary cadaveric allograft at a mean age of 12±4 years. The most common diagnoses were osteosarcoma (n=6) and Ewing sarcoma (n=6). Patients were reconstructed with an allograft alone (n=6) or supplemented with an FVF (n=11). RESULTS: All surviving patients had at least 2 years of clinical follow-up, with the mean follow-up of 12±7 years. The mean time to union of the allograft was 11±4 months, with 6 patients requiring additional bone grafting. There was no difference in the need for an additional bone graft (odds ratio=1.14, P=1.0) between patients with an FVF and those without. Four patients underwent an amputation, all with an allograft alone, due to disease recurrence (n=2) and due to infection (n=2). As such, there was a higher 10-year overall limb-salvage rate when the allograft was combined with an FVF compared with an allograft alone (100% vs. 33%, P=0.001). At last follow-up, the mean Mankin and Musculoskeletal Tumor Society rating was 86%, with a higher mean score in patients reconstructed with an FVF (94% vs. 70%, P=0.002). CONCLUSION: Use of an intercalary allograft supplemented with an FVF to reconstruct the proximal tibia provides a durable means of reconstruction with an excellent functional outcome following oncologic proximal tibia resection in a pediatric population. LEVEL OF EVIDENCE: Level III-therapeutic level.

Simulation Training of Orthopaedic Residents for Distal Radius Fracture Reductions Improves Radiographic Outcomes.

BACKGROUND: Most distal radius fractures can be treated with closed reduction and casting in pediatric patients. These skills are traditionally developed treating real patients, however, there is growing interest in the use of simulation training to supplement traditional learning strategies. METHODS: Seventy-eight children with distal radius fractures that underwent closed reduction and casting by novice orthopaedic surgery residents were retrospectively reviewed. Radiographic measures of patients treated by simulation-trained residents were compared with patients treated by residents without simulation training. RESULTS: Patients treated by simulation-trained residents had less residual angulation in the anteroposterior radiograph (3.7 vs. 6.3 degrees, P=0.006) and translation on the lateral (14% vs. 21%, P=0.040) and anteroposterior radiograph (10% vs. 16%, P=0.029). Patients treated by simulation-trained residents also had lower rates of redisplacement (50% vs. 79%, P=0.016). CONCLUSIONS: Loss of reduction is common, particularly when novice trainees perform their first independent reductions. Residents who underwent simulation training had lower rates of loss of reduction, thus simulation training has potential as a supplement to the traditional apprentice model of medical education. LEVEL OF EVIDENCE: Level III.

Divergent paths to seizure-like events.

Much debate exists about how the brain transitions into an epileptic seizure. One source of confusion is that there are likely to be critical differences between experimental seizure models. To address this, we have compared the evolving activity patterns in two widely used in vitro models of epileptic discharges. Brain slices from young adult mice were prepared in the same way and bathed either in 0 Mg2+ or 100 µmol/L 4AP artificial cerebrospinal fluid. We have found that while local field potential recordings of epileptiform discharges in the two models appear broadly similar, patch-clamp analysis reveals an important difference in the relative degree of glutamatergic involvement. 4AP affects parvalbumin-expressing interneurons more than other cortical populations, destabilizing their resting state and inducing spontaneous bursting behavior. Consequently, the most prominent pattern of transient discharge ("interictal event") in this model is almost purely GABAergic, although the transition to seizure-like events (SLEs) involves pyramidal recruitment. In contrast, interictal discharges in 0 Mg2+ are only maintained by a very large glutamatergic component that also involves transient discharges of the interneurons. Seizure-like events in 0 Mg2+ have significantly higher power in the high gamma frequency band (60-120Hz) than these events do in 4AP, and are greatly delayed in onset by diazepam, unlike 4AP events. We, therefore, conclude that the 0 Mg2+ and 4AP models display fundamentally different levels of glutamatergic drive, demonstrating how ostensibly similar pathological discharges can arise from different sources. We contend that similar interpretative issues will also be relevant to clinical practice.

The Surgical Management of Tibial Spine Fractures in Children: A Survey of the Pediatric Orthopaedic Society of North America (POSNA).

BACKGROUND: Tibial spine fractures are rare, complex injuries. Management remains varied given a lack of consensus about the optimal approach. Thus, the purpose of this study is to determine prevailing strategies among pediatric orthopaedists and establish areas of agreement and ongoing controversy in the management of tibial spine fractures. METHODS: An electronic survey was distributed to the Pediatric Orthopaedic Society of North America (POSNA) membership. Surgeon demographics, experience, and responses to clinical vignettes were collected. Surgeons were grouped according to how frequently they treat tibial spine fractures and responses were compared. RESULTS: Of the 180 POSNA members who completed the survey, all were attending surgeons and nearly all (90.4%) had academic affiliations, treated mostly skeletally immature patients (88.5%), and 3 or fewer fractures per year (62.4%). In younger patients, respondents were more likely to treat type II fractures closed and less likely to cross the physis. Arthrofibrosis was the most commonly reported complication and postoperative duration of immobilization was identified as a risk factor by most. However, high-frequency surgeons identified this risk factor more often (P=0.015) and recommended immobilization for <2 weeks more frequently (P=0.018). There was, however, considerable discrepancy regarding the duration of immobilization. Although there were areas of agreement on general principles, there continues to be disagreement regarding specific treatment strategies. CONCLUSIONS: Surgeons within POSNA agree on general principles of treatment for tibial spine fractures. Members, regardless of high-volume or low-volume caseload, are all less likely to pursue surgical options when treating younger patients and treating arthrofibrosis during the first 2 postoperative months. The most commonly reported adverse outcome after treatment was arthrofibrosis, for which high-frequency surgeons identified length of immobilization as a significant risk factor more often and thus, recommended shorter periods of immobilization. Although surgeons may agree on general principles in some cases, there continues to be disagreement regarding specific strategies suggesting that a prospective multicenter study of this topic is warranted. LEVEL OF EVIDENCE: Level V.

Comparison of Anderson-Green Growth-Remaining Graphs and White-Menelaus Predictions of Growth Remaining in the Distal Femoral and Proximal Tibial Physes.

BACKGROUND: Epiphysiodesis of the distal femoral and/or proximal tibial physes is commonly performed in children and adolescents to treat lower-limb length discrepancy. It is important to determine the amount of growth remaining in the physes of these patients. Two main methods are used to make this determination: the White-Menelaus arithmetic method, which assumes a consistent amount of growth per year until skeletal maturity, and the Anderson-Green growth-remaining charts, which diagram average growth per year ± 2 standard deviations. The purpose of the present study was to evaluate these apparently disparate predictions of growth remaining in a cohort of patients managed with epiphysiodesis. METHODS: From a database of patients managed with epiphysiodesis for lower-limb length discrepancy, we identified all healthy, unoperated leg segments with follow-up to skeletal maturity. We compared the amount of observed growth with the growth predicted by the White-Menelaus method and the Anderson-Green growth-remaining graphs, for both skeletal and chronological ages. RESULTS: A total of 441 healthy segments (201 femora and 240 tibiae) in 221 patients (105 boys and 116 girls) with an age range of 9.0 to 16.5 years at the time of epiphysiodesis were analyzed. We observed no relationship between the length percentile of the leg segments at the time of epiphysiodesis and the amount of growth that actually occurred. Growth in the distal femoral and proximal tibial physes was relatively constant (9 and 6 mm per year of skeletal growth, respectively). Skeletal age was a better predictor of growth remaining than chronological age for both methods of estimation. Although the distribution of growth remaining in the present study resembled the Anderson-Green growth-remaining charts, that distribution was not associated with the initial length of leg segments. CONCLUSIONS: The White-Menelaus method predicted the amount of growth remaining more accurately than the Anderson-Green growth-remaining charts. The distribution of growth remaining observed in the present study resembled that of the Anderson-Green growth-remaining graphs but was not predicted by the initial bone segment length. CLINICAL RELEVANCE: The present study found no positive association between the length percentile of leg segments and the amount of growth that occurred in an epiphysiodesis-age group. This finding can explain the comparative accuracy of the White-Menelaus method and the possible source of prediction errors in the straight-line graph and multiplier methods.

Epidemiology, Injury Patterns, and Treatment of Meniscal Tears in Pediatric Patients: A 16-Year Experience of a Single Center.

BACKGROUND: Meniscal injuries in children continue to increase, which may be attributable to increasing levels of athletic participation and may be associated with additional injuries or need for additional surgeries. PURPOSE: To better understand the patterns of pediatric meniscal injuries by analyzing tear location, morphologic features, and associated injury patterns over a 16-year period. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Pediatric patients were identified and were included in the study if age at the time of initial surgery for meniscal tear was between 5 and 14 years for female patients and 5 and 16 years for male patients. Patients were observed until age 18, and any subsequent surgeries were noted. Demographic factors, tear type and location, associated injuries, and treatment type were analyzed. RESULTS: Mean patient age at surgery was 13.3 years, and 37% of patients were female. A total of 1040 arthroscopic meniscal surgeries in 880 pediatric patients were evaluated. There were 160 reoperations in 138 patients, representing a reoperation rate of 15%. These included 98 reoperations on the ipsilateral knee in 88 patients and 62 operations for injuries to the contralateral knee in 50 patients; 53% of surgeries were meniscal repair, as opposed to partial meniscectomy, and the most common technique was an all-inside repair (91%). Significant differences were identified between male and female patients. Male patients were more likely to have lateral meniscus (74% vs 65%), posterior horn (71% vs 60%), peripheral (45% vs 30%), and vertical tears (31% vs 21%); concomitant ACL injury (50% vs 40%); and an associated osteochondritis dissecans lesion (7% vs 4%). Female patients were more likely to have medial meniscus (24% vs 17%), anterior horn (25% vs 15%), and degenerative tears (34% vs 26%); discoid meniscus (33% vs 24%); and isolated meniscal tears (47% vs 33%). CONCLUSION: This evaluation of a large series of patients has helped characterize injury patterns associated with pediatric meniscal surgeries. Most meniscal tears were repaired (53%) and were associated with additional injuries (62%), especially anterior cruciate ligament injuries (48%). More than 25% of patients had a discoid meniscus. Injury patterns differed significantly between male and female patients.

Is Routine Spine MRI Necessary in Skeletally Immature Patients With MHE? Identifying Patients at Risk for Spinal Osteochondromas.

BACKGROUND: Multiple hereditary exostoses (MHE) is an autosomal dominant condition leading to development of osteochondromas throughout the body. Although long bones are most often affected, spine involvement may occur and usually requires advanced imaging for diagnosis. However, the high cost of detection, infrequent occurrence, and very low likelihood of spinal cord compression and neurological injury, create a management conundrum. The purpose of our investigation is to identify patients at greatest risk for spinal lesions and refine indications for advanced imaging. METHODS: All MHE patients in a 24-year period were retrospectively reviewed. Skeletally immature patients with advanced imaging of the spine were further evaluated. The demographic characteristics, family history, clinical presentation, past surgical history, tumor burden, and distribution of patients with spinal lesions were compared with those without. RESULTS: In total, 227 MHE patients were identified and 21 underwent advanced spinal imaging. Spinal lesions were found in 8 of the 21 screened patients (38.1%, 3.5% overall), of which 4 were intracanal and 1 was symptomatic (4.8%, 0.4% overall). Only the symptomatic patient underwent excision of the spinal lesion. Patients with spinal lesions had higher tumor burden than those without (median, 28.5 vs. 19 locations; P=0.010). There was a significant association with rib (P=0.018) and pelvic (P=0.007) lesions, which may serve as "harbinger" lesions. The presence of both a rib and a pelvic lesion used as a screening tool for spinal lesions produces a sensitivity of 100% and specificity of 69%. CONCLUSIONS: Symptomatic spinal involvement in children with MHE is rare and tends to occur in patients with higher tumor burden. We recommend limiting advanced spine imaging to children with neurological symptoms or with rib and pelvic "harbinger" lesions. Patients without these findings are unlikely to have spine involvement needing intervention. This approach offers an opportunity to avoid unnecessary testing and substantially reduce costs of diagnostic imaging. LEVEL OF EVIDENCE: Level III.