Combined Supracondylar Humerus Fracture, Monteggia Injury, and Radial/Ulnar Shaft Fractures in a 3-Year-Old Child.

Ipsilateral pediatric elbow and forearm injuries are uncommon, particularly those comprising a supracondylar humerus fracture, radiocapitellar joint dislocation, proximal ulna fracture, and distal forearm fracture. We present the case of a boy who was 3 years, 6 months old and sustained this constellation of injuries. He underwent urgent treatment with closed reduction and percutaneous fixation of the humerus and flexible intramedullary nail fixation of the ulna. He presented with an ulnar sensory and motor neuropraxia that resolved, and he had full radiographic union and upper extremity range of motion by 3 months postoperatively. [Orthopedics. 2022;45(2):e107-e109.].

Eponyms in Pediatric Sports Medicine: A Historical Review.

The use of eponyms in the orthopedics literature has come under scrutiny, and there is a growing body of literature evaluating the utility of these terms in modern healthcare delivery. Although the field of pediatric orthopedic sports medicine is a relatively modern subspecialty, it is built on a foundation of over 100 years of pediatric musculoskeletal medicine. As a result, eponyms account for a significant portion of the vernacular used in the field. The purpose of this review is to summarize and describe the history of common eponyms relevant to pediatric sports pathology, examination maneuvers, classification systems, and surgical procedures. Use of eponyms in medicine is flawed. However, an improved understanding of these terms allows for informed use in future scientific discourse, patient care and medical education and may encourage future innovation and research into understanding pediatric orthopedic pathologies.

What Are the Predictors of Poor Patient-Reported Outcomes After Shoulder Instability Surgery?

BACKGROUND: Prospectively collected responses to Patient Acceptable Symptom State (PASS) questions after shoulder instability surgery are limited. Responses to these outcome measures are imperative to understanding their clinical utility. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate which factors predict unfavorable patient-reported outcomes after shoulder instability surgery, including "no" to the PASS question. We hypothesized that poor outcomes would be associated with male adolescents, bone loss, combined labral tears, and articular cartilage injuries. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients aged ≥13 years undergoing shoulder instability surgery were included in point-of-care data collection at a single institution across 12 surgeons between 2015 and 2017. Patients with anterior-inferior labral tears were included, and those with previous ipsilateral shoulder surgery were excluded. Demographics, American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numeric Evaluation (SANE) scores, and surgical findings were obtained at baseline. ASES and SANE scores, PASS responses, and early revision surgery rates were obtained at a minimum of 1 year after the surgical intervention. Regression analyses were performed. RESULTS: A total of 234 patients met inclusion criteria, of which 176 completed follow-up responses (75.2%). Nonresponders had a younger age, greater frequency of glenoid bone loss, fewer combined tears, and more articular cartilage injuries (P < .05). Responders' mean age was 25.1 years, and 22.2% were female. Early revision surgery occurred in 3.4% of these patients, and 76.1% responded yes to the PASS question. A yes response correlated with a mean 25-point improvement in the ASES score and a 40-point improvement in the SANE score. On multivariate analysis, combined labral tears (anterior-inferior plus superior or posterior tears) were associated with greater odds of responding no to the PASS question, while both combined tears and injured capsules were associated with lower ASES and SANE scores (P < .05). Sex, bone loss, and grade 3 to 4 articular cartilage injuries were not associated with variations on any patient-reported outcome measure. CONCLUSION: Patients largely approved of their symptom state at ≥1 year after shoulder instability surgery. A response of yes to the PASS question was given by 76.1% of patients and was correlated with clinically and statistically significant improvements in ASES and SANE scores. Combined labral tears and injured capsules were negative prognosticators across patient-reported outcome measures, whereas sex, bone loss, and cartilage injuries were not.

Early Sport Specialization.

Recent estimates are that close to 30 million children between the ages of 6 and 18 years participate in team sport and close to 60 million in some type of organized athletics in the United States. This has resulted in an increase in sport-related injuries, but the reasons for this are complex and multifactorial. Sport participation offers multiple benefits for children and adolescents, but there is concern that early sport specialization (ESS) may lead to adverse health and social effects. ESS has been defined as intensive training or competition in organized sport by prepubescent children (<12 years of age) for more than 8 months per year, with focus on a single sport to the exclusion of other sport and free play. An increased prevalence of ESS has been attributed to multiple variables, including coach/caregiver influence and the perception that developing athletes can attain mastery and gain a competitive advantage. Trends vary across individual and team sport and by sex. It has been proposed in the literature and lay press that a lack of diversified activity in youth leads to overuse injury, psychological fatigue, and burnout. ESS may not be necessary for elite athletic achievement, and the contrary has been proposed that early sport diversification leads to superior results. This review will summarize the current understanding of ESS, report evidence for and against its merits, highlight areas of future research, and provide recommendations for orthopaedic providers involved in the care of young athletes.

The Impact of Transphyseal Anterior Cruciate Ligament Reconstruction on Lower Extremity Growth and Alignment.

PURPOSE: To evaluate the effect of transphyseal anterior cruciate ligament (ACL) reconstruction on lower extremity radiographic growth and alignment. METHODS: We retrospectively reviewed patients who underwent transphyseal ACL reconstruction and were followed to skeletal maturity or at least 2 years, with the nonoperative limb used as an internal control. Changes in coronal plane alignments and tibial slope of the operative limb were compared with a Wilcoxon test. Associations among sex, tunnel, and graft characteristics and failure; changes in coronal plane measures and tunnel size; and tunnel angles and the development of deformity were examined by χ-square and correlation coefficients. RESULTS: Fifty-nine patients (41 boys and 18 girls) underwent surgery at a mean age of 12.5 years (range, 6.8-16.0 years). There were differences in changes in the mechanical lateral distal femoral angle comparing operative and nonoperative limbs (decreased 1.1° in girls and 1.9° in boys ≤13 years of age, P = .0008 and .025, respectively) and in changes in tibial slope of the operative limb (decreased 2.1° in male patients >13 years, P = .012). No patient developed a new limb length difference >1 cm. Two boys were treated for deformities. Eight additional patients developed >5° difference in alignment for a rate of radiologic deformity of 10 of 59 or 17%. Neither graft failure nor the presence of deformity was associated with sex, tunnel size, mode of femoral tunnel positioning, inclination of tunnels, or the use of allograft. CONCLUSIONS: Radiographically evident limb deformities following transphyseal ACL reconstruction occurred at a rate of 17%, although these deformities were clinically evident in only 5% of patients. Tunnels intersecting physes near cortical margins may increase the risk of developing deformity. Regular follow-up should include alignment radiographs to detect deformities despite the clinical appearance of neutral limb alignment. LEVEL OF EVIDENCE: Level III, case-control study.

Patellar Instability in the Skeletally Immature.

PURPOSE OF REVIEW: This review will focus on the evaluation and management of patellar instability in the developing patient. RECENT FINDINGS: A large number of surgical techniques have been described to prevent recurrent patellofemoral instability in the pediatric population, including both proximal and distal realignment procedures. The wide variety of treatment options highlights the lack of agreement as to the best surgical approach. However, when a comprehensive exam and workup are paired with a surgical plan to address each of the identified abnormalities, outcomes are predictably good. Patellar instability is a common knee disorder in the skeletally immature patient that presents a unique set of challenges. Rates of re-dislocation in pediatric and adolescent patients are higher than in their adult counterparts. Careful consideration of the physeal and apophyseal anatomy is essential in these patients. While the majority of primary patellar instability events can be treated conservatively, multiple events often require surgical intervention.

A role for matrix stiffness in the regulation of cardiac side population cell function.

The mechanical properties of the local microenvironment may have important influence on the fate and function of adult tissue progenitor cells, altering the regenerative process. This is particularly critical following a myocardial infarction, in which the normal, compliant myocardial tissue is replaced with fibrotic, stiff scar tissue. In this study, we examined the effects of matrix stiffness on adult cardiac side population (CSP) progenitor cell behavior. Ovine and murine CSP cells were isolated and cultured on polydimethylsiloxane substrates, replicating the elastic moduli of normal and fibrotic myocardium. Proliferation capacity and cell cycling were increased in CSP cells cultured on the stiff substrate with an associated reduction in cardiomyogeneic differentiation and accelerated cell ageing. In addition, culture on stiff substrate stimulated upregulation of extracellular matrix and adhesion proteins gene expression in CSP cells. Collectively, we demonstrate that microenvironment properties, including matrix stiffness, play a critical role in regulating progenitor cell functions of endogenous resident CSP cells. Understanding the effects of the tissue microenvironment on resident cardiac progenitor cells is a critical step toward achieving functional cardiac regeneration.

Morphology of the extensor carpi ulnaris groove and tendon.

PURPOSE: Injury to the extensor carpi ulnaris (ECU) fascial supports on the distal ulna can result in ulnar-sided wrist pain, particularly when the tendon subluxates medially out of the fibroosseous groove with forearm rotation. To better understand the potential risk factors for injury and the indications for modifying the ECU groove, we have evaluated and quantified the morphology of the ECU groove and tendon. METHODS: Axial plane magnetic resonance imaging of the wrist obtained for triangular fibrocartilage complex and intercarpal pathology in 60 patients were reviewed. Mean and standard error of the mean were calculated and unpaired Student t tests performed to compare groove width and depth, radius of curvature of the groove, carrying angle, and tendon-to-groove ratio. RESULTS: There were 23 females (38%), and the mean patient age was 40 years (range, 17-71 y). The average ECU groove depth and standard error of the mean was 1.4 mm ± 0.1 mm. The radius of curvature for the ulnar ECU groove was found to be 7.0 mm ± 0.4 mm with a carrying angle of 143° ± 2°. In neutral forearm rotation, the average ratio of the width of the ECU tendon to groove was 0.7 ± 0.02. The data approximated a normal distribution. There were no statistically significant differences in these measurements between the triangular fibrocartilage complex and the intercarpal pathology subgroups. CONCLUSIONS: Variability in the relationship of the ECU groove and tendon may combine to represent risk factors for tendinosis or tendon subluxation. There may be a more normal distribution of ECU groove morphology than previously recognized. CLINICAL RELEVANCE: ECU injuries may require clinical imaging of the tendon and subsheath, in addition to potential surgical reconstruction and ulnar groove deepening. This report establishes the normative morphology and depth of the ECU groove and provides a comparative baseline when considering treatment modalities.

Adult cardiac progenitor cell aggregates exhibit survival benefit both in vitro and in vivo.

BACKGROUND: A major hurdle in the use of exogenous stems cells for therapeutic regeneration of injured myocardium remains the poor survival of implanted cells. To date, the delivery of stem cells into myocardium has largely focused on implantation of cell suspensions. METHODOLOGY AND PRINCIPAL FINDINGS: We hypothesize that delivering progenitor cells in an aggregate form would serve to mimic the endogenous state with proper cell-cell contact, and may aid the survival of implanted cells. Microwell methodologies allow for the culture of homogenous 3D cell aggregates, thereby allowing cell-cell contact. In this study, we find that the culture of cardiac progenitor cells in a 3D cell aggregate augments cell survival and protects against cellular toxins and stressors, including hydrogen peroxide and anoxia/reoxygenation induced cell death. Moreover, using a murine model of cardiac ischemia-reperfusion injury, we find that delivery of cardiac progenitor cells in the form of 3D aggregates improved in vivo survival of implanted cells. CONCLUSION: Collectively, our data support the notion that growth in 3D cellular systems and maintenance of cell-cell contact improves exogenous cell survival following delivery into myocardium. These approaches may serve as a strategy to improve cardiovascular cell-based therapies.

Regeneration in heart disease-Is ECM the key?

The heart possesses a regeneration potential derived from endogenous and exogenous stem and progenitor cell populations, though baseline regeneration appears to be sub-therapeutic. This limitation was initially attributed to a lack of cells with cardiomyogenic potential following an insult to the myocardium. Rather, recent studies demonstrate increased numbers of cardiomyocyte progenitor cells in diseased hearts. Given that the limiting factor does not appear to be cell quantity but rather repletion of functional cardiomyocytes, it is crucial to understand potential mechanisms inhibiting progenitor cell differentiation. One of the extensively studied areas in heart disease is extracellular matrix (ECM) remodeling, with both the composition and mechanical properties of the ECM undergoing changes in diseased hearts. This review explores the influence of ECM properties on cardiomyogenesis and adult cardiac progenitor cells.

Wnt signaling exerts an antiproliferative effect on adult cardiac progenitor cells through IGFBP3.

RATIONALE: Recent work in animal models and humans has demonstrated the presence of organ-specific progenitor cells required for the regenerative capacity of the adult heart. In response to tissue injury, progenitor cells differentiate into specialized cells, while their numbers are maintained through mechanisms of self-renewal. The molecular cues that dictate the self-renewal of adult progenitor cells in the heart, however, remain unclear. OBJECTIVE: We investigate the role of canonical Wnt signaling on adult cardiac side population (CSP) cells under physiological and disease conditions. METHODS AND RESULTS: CSP cells isolated from C57BL/6J mice were used to study the effects of canonical Wnt signaling on their proliferative capacity. The proliferative capacity of CSP cells was also tested after injection of recombinant Wnt3a protein (r-Wnt3a) in the left ventricular free wall. Wnt signaling was found to decrease the proliferation of adult CSP cells, both in vitro and in vivo, through suppression of cell cycle progression. Wnt stimulation exerted its antiproliferative effects through a previously unappreciated activation of insulin-like growth factor binding protein 3 (IGFBP3), which requires intact IGF binding site for its action. Moreover, injection of r-Wnt3a after myocardial infarction in mice showed that Wnt signaling limits CSP cell renewal, blocks endogenous cardiac regeneration and impairs cardiac performance, highlighting the importance of progenitor cells in maintaining tissue function after injury. CONCLUSIONS: Our study identifies canonical Wnt signaling and the novel downstream mediator, IGFBP3, as key regulators of adult cardiac progenitor self-renewal in physiological and pathological states.

Arthrodesis of the first metatarsophalangeal joint: a robotic cadaver study of the dorsiflexion angle.

BACKGROUND: Arthrodesis of the first metatarsophalangeal joint is indicated for severe osteoarthritis or as a revision of failed treatment for hallux valgus. The literature suggests that an optimum fused dorsiflexion angle is between 20 degrees and 25 degrees from the axis of the first metatarsal. The purpose of this study was to investigate the relationship between dorsiflexion angle and plantar pressure in the postoperative gait. We assumed that there is a fused dorsiflexion angle at which pressures are minimized under the hallux and the first metatarsal head. METHODS: Six cadaver foot specimens underwent incremental changes in simulated fused metatarsophalangeal joint dorsiflexion angle followed by dynamic gait simulation. A robotic gait simulator performed at 50% of body weight and one-fifteenth of physiologic velocity. In vitro tibial kinematics and tendon forces were based on normative in vivo gait and electromyographic data and were manually tuned to match the in vitro ground reaction force and tendon force behavior. Regression lines were calculated for peak pressure and pressure-time integral under the hallux and the metatarsal head by dorsiflexion angle. RESULTS: Peak pressure and pressure-time integral under the hallux were negatively correlated with dorsiflexion angle (p < 0.004), while peak pressure and pressure-time integral under the metatarsal head were positively correlated with dorsiflexion angle (p < 0.004). The intersection of the regression lines that represented the angle at which peak pressure and pressure-time integral were minimized was 24.7 degrees for peak pressure and 21.3 degrees for pressure-time integral. CONCLUSIONS: Our findings support the hypothesis that an angle-pressure relationship exists following arthrodesis of the first metatarsophalangeal joint and that it is inversely related for the hallux and the metatarsal head. Our results encompass the suggested range of 20 degrees to 25 degrees.