Effects of static exercises on hip muscle fatigue and knee wobble assessed by surface electromyography and inertial measurement unit data.

Hip muscle weakness can be a precursor to or a result of lower limb injuries. Assessment of hip muscle strength and muscle motor fatigue in the clinic is important for diagnosing and treating hip-related impairments. Muscle motor fatigue can be assessed with surface electromyography (sEMG), however sEMG requires specialized equipment and training. Inertial measurement units (IMUs) are wearable devices used to measure human motion, yet it remains unclear if they can be used as a low-cost alternative method to measure hip muscle fatigue. The goals of this work were to (1) identify which of five pre-selected exercises most consistently and effectively elicited muscle fatigue in the gluteus maximus, gluteus medius, and rectus femoris muscles and (2) determine the relationship between muscle fatigue using sEMG sensors and knee wobble using an IMU device. This work suggests that a wall sit and single leg knee raise activity fatigue the gluteus medius, gluteus maximus, and rectus femoris muscles most reliably (p < 0.05) and that the gluteus medius and gluteus maximus muscles were fatigued to a greater extent than the rectus femoris (p = 0.031 and p = 0.0023, respectively). Additionally, while acceleration data from a single IMU placed on the knee suggested that more knee wobble may be an indicator of muscle fatigue, this single IMU is not capable of reliably assessing fatigue level. These results suggest the wall sit activity could be used as simple, static exercise to elicit hip muscle fatigue in the clinic, and that assessment of knee wobble in addition to other IMU measures could potentially be used to infer muscle fatigue under controlled conditions. Future work examining the relationship between IMU data, muscle fatigue, and multi-limb dynamics should be explored to develop an accessible, low-cost, fast and standardized method to measure fatiguability of the hip muscles in the clinic.

Exome sequencing of 1190 non-syndromic clubfoot cases reveals HOXD12 as a novel disease gene.

BACKGROUND: Clubfoot, presenting as a rigid inward and downward turning of the foot, is one of the most common congenital musculoskeletal anomalies. The aetiology of clubfoot is poorly understood and variants in known clubfoot disease genes account for only a small portion of the heritability. METHODS: Exome sequence data were generated from 1190 non-syndromic clubfoot cases and their family members from multiple ethnicities. Ultra-rare variant burden analysis was performed comparing 857 unrelated clubfoot cases with European ancestry with two independent ethnicity-matched control groups (1043 in-house and 56 885 gnomAD controls). Additional variants in prioritised genes were identified in a larger cohort, including probands with non-European ancestry. Segregation analysis was performed in multiplex families when available. RESULTS: Rare variants in 29 genes were enriched in clubfoot cases, including PITX1 (a known clubfoot disease gene), HOXD12, COL12A1, COL9A3 and LMX1B. In addition, rare variants in posterior HOX genes (HOX9-13) were enriched overall in clubfoot cases. In total, variants in these genes were present in 8.4% (100/1190) of clubfoot cases with both European and non-European ancestry. Among these, 3 are de novo and 22 show variable penetrance, including 4 HOXD12 variants that segregate with clubfoot. CONCLUSION: We report HOXD12 as a novel clubfoot disease gene and demonstrate a phenotypic expansion of known disease genes (myopathy gene COL12A1, Ehlers-Danlos syndrome gene COL9A3 and nail-patella syndrome gene LMX1B) to include isolated clubfoot.

Eye of the Carpenter: How Well do Orthopaedic Surgeons Estimate Angular Measurements in Derotational Osteotomies?

BACKGROUND: Femoral derotational osteotomies are used by orthopaedic surgeons to decrease version in a variety of pathologies. Intraoperatively, the goal of the surgery is to decrease the rotation of the femur to within physiological range. Surgeons generally visually estimate the angle of correction based on bone markers at the rotating cylindrical portion of the femur. This study sought first to assess the accuracy and inter-rater reliability of surgeons with respect to angle creation, and then to implement a training intervention. METHODS: A rotational femur model was constructed and tested among surgeons and nonsurgeons. Surgeons were then randomized into an experimental and control cohort with training on the model as the intervention. Subjects were asked to create target angles of 15, 30, 45, and 60 degrees using only Kirschner wires and then only bone marks for reference. Independent and paired t -tests were performed to determine variability between cohorts. RESULTS: The mean angle creation error and range of the surgeon cohort were significantly lower than those of the nonsurgeon cohort. Within the nonsurgeon cohort, the mean angle creation error and range of the wire modality were significantly lower than that of the mark modality. The mean angle creation error and range of the trained cohort were significantly lower than the untrained cohort. CONCLUSIONS: The considerable inter-subject range within the surgeon cohort highlights a need for the reinforcement of basic geometric principles within orthopaedic instruction. This model allows for immediate, accurate feedback on angle creation, and training appears to be both time and cost-effective. The physiological range allows for a level of variability between surgical outcomes without consequence. However, the more than 20 degree range determined by this study does not fall within those bounds and should be addressed. CLINICAL RELEVANCE: Moving forward, rotational estimation as a surgical skill should increase in prominence within orthopaedic instruction to maximize future joint health, and additional emphasis should be placed on fundamental spatial orientation during training.

Congenital Insensitivity to Pain due to a de novo L369P mutation in the SCN11A gene with Heterotrophic Ossification - A Case Report.

Introduction: A male child with congenital insensitivity to pain (CIP) due to a novel de novo L369P mutation in the SCN11A gene was found to have significant bilateral hip flexion contractures, followed by severe heterotopic ossification after contraction release. This is the first report to describe a patient with this specific mutation and subsequent clinical course. Case Report: A male child with CIP due to de novo L369P mutation in the SCN11A gene was found to have significant bilateral hip flexion contractures. The patient underwent bilateral hip contracture releases to improve his standing ability after failure of conservative treatment. In the coming months he developed significant heterotopic ossification that eventually bridged from the left pelvis to the left femur. Conclusion: Heterotrophic ossification (HO) in patients with CIP is a rare and poorly understood clinical manifestation. Our report describes a rare and aggressive manifestation of HO in a patient with CIP.

Aponeurosis structure-function properties: Evidence of heterogeneity and implications for muscle function.

Aponeurosis is a sheath-like connective tissue that aids in force transmission from muscle to tendon and can be found throughout the musculoskeletal system. The key role of aponeurosis in muscle-tendon unit mechanics is clouded by a lack of understanding of aponeurosis structure-function properties. This work aimed to determine the heterogeneous material properties of porcine triceps brachii aponeurosis tissue with materials testing and evaluate heterogeneous aponeurosis microstructure with scanning electron microscopy. We found that aponeurosis may exhibit more microstructural collagen waviness in the insertion region (near the tendon) compared to the transition region (near the muscle midbelly) (1.20 versus 1.12, p = 0.055), which and a less stiff stress-strain response in the insertion versus transition regions (p < 0.05). We also showed that different assumptions of aponeurosis heterogeneity, specifically variations in elastic modulus with location can alter the stiffness (by more than 10x) and strain (by approximately 10% muscle fiber strain) of a finite element model of muscle and aponeurosis. Collectively, these results suggest that aponeurosis heterogeneity could be due to variations in tissue microstructure and that different approaches to modeling tissue heterogeneity alters the behavior of computational models of muscle-tendon units. STATEMENT OF SIGNIFICANCE: Aponeurosis is a connective tissue found in many muscle tendon units that aids in force transmission, yet little is known about the specific material properties of aponeurosis. This work aimed to determine how the properties of aponeurosis tissue varied with location. We found that aponeurosis exhibits more microstructural waviness near the tendon compared to near the muscle midbelly, which was associated with differences in tissue stiffness. We also showed that different variations in aponeurosis modulus (stiffness) can alter the stiffness and stretch of a computer model of muscle tissue. These results show that assuming uniform aponeurosis structure and modulus, which is common, may lead to inaccurate models of the musculoskeletal system.

Short-term vancomycin and buffer soaking does not change rabbit achilles tendon tensile material properties.

BACKGROUND: Allograft tendons are commonly used during orthopedic surgery to reconstruct tissue that is severely damaged. Soaking the tendon in an antibiotic solution, specifically vancomycin, has been shown to lower the risk of post-operative infections. While some material properties of tendon and ligament after antibiotic soaking have previously been characterized, extensive sub-failure allograft tendon material properties after soaking in antibiotic solutions have not. METHODS: Forty tendons were dissected from rabbits and soaked in either a phosphate buffered saline (PBS) only solution or vancomycin and PBS solution for five or 30 min. Immediately after soaking, quasi-static tensile experiments were performed in a materials testing system. FINDINGS: Tissue nominal stress, Lagrange strain, toe-region properties and elastic modulus were characterized. For all forty tendons, the average elastic modulus was found to be 455 ± 37 MPa, the average transition strain (from toe-region to linear elastic region) was 0.0487 ± 0.0035, and the average transition stress was 9.71 ± 0.79 MPa. No statistically significant differences in any of these material properties were found across soaking medium or soaking time. INTERPRETATION: From these results, we conclude that soaking an allograft tendon in antibiotic solution for up to 30 min prior to implantation does not change the tensile material properties of tendons, supporting current clinical practice.

Patellofemoral joint load and knee abduction/adduction moment are sensitive to variations in femoral version and individual muscle forces.

Torsional profiles of the lower limbs, such as femoral anteversion, can dictate gait and mobility, joint biomechanics and pain, and functional impairment. It currently remains unclear how the interactions between femoral anteversion, kinematics, and muscle activity patterns contribute to joint biomechanics and thus conditions such as knee pain. This study presents a computational modeling approach to investigating the interactions between femoral anteversion, muscle forces, and knee joint loads. We employed an optimal control approach to produce actuator and muscle-driven simulations of the stance phase of gait for femoral anteversion angles ranging from -8° (retroversion) to 52° (anteversion) with a typically developing baseline of 12° of anteversion and implemented a Monte Carlo analysis for variations in lower limb muscle forces. While total patellofemoral joint load decreased with increasing femoral anteversion, patellofemoral joint load alignment worsened, and knee abduction/adduction magnitude increased with both positive and negative changes in femoral anteversion (p < 0.001). The rectus femoris muscle was found to greatly influence patellofemoral joint loads across all femoral anteversion alignments (R > 0.8, p < 0.001), and the medial gastrocnemius was found to greatly influence knee abduction/adduction moments for the extreme version cases (R > 0.74, p < 0.001). Along with the vastus lateralis, which decreased with increasing femoral anteversion (R = 0.89, p < 0.001), these muscles are prime candidates for future experimental and clinical efforts to address joint pain in individuals with extreme femoral version. These findings, along with future modeling efforts, could help clinicians better design treatment strategies for knee joint pain in populations with extreme femoral anteversion or retroversion.

Risk of reoperation after primary anterior cruciate ligament reconstruction in children and adolescents.

OBJECTIVE: To examine the incidence and risk factors of any-cause reoperation after primary ACLR in children and adolescents. DESIGN: Retrospective Cohort. SETTING: Electronic medical records from a large tertiary care, single institution integrated healthcare delivery system. PATIENTS: Patients were under the age of 18 years and had anterior cruciate ligament reconstruction. They were excluded if they had a multi-ligamentous knee injury or <1 year follow-up. INTERVENTIONS: Patients were further identified to have undergone a subsequent knee operation ipsilaterally or contralateral ACLR. MAIN OUTCOME MEASURES: The rate of any-cause reoperation was our primary outcome measure. RESULTS: The median age was 16. There were 208 females (53.9%) and 178 males (46.1%) included. The median follow-up was 25 months with a minimum of 12 months (interquartile range: 16.0, 46.0). The rate of any-cause reoperation was 34.7%. There was no statistically significant difference between those who underwent reoperation versus those who did not undergo reoperation relative to age, sex, BMI, graft type, or the presence of concomitant meniscal injury. The rates of ipsilateral ACLR and contralateral ACLR at any time during the study period was 8.0% and 10.9% respectively. There was no statistically significant difference for rate of reoperation between graft types, between various concomitant injuries, between those who underwent meniscus repair or no repair. CONCLUSIONS: This study reflects a 34.7% rate of a subsequent knee operation after ACLR in patients younger than 18 years. These findings can be used to inform pediatric patients undergoing primary ACLR on their risk of returning to the operating room.

Sensitivity and Specificity of MRI in Diagnosing Concomitant Meniscal Injuries With Pediatric and Adolescent Acute ACL Tears.

Background: Preoperative diagnosis of concomitant meniscal tears in pediatric and adolescent patients with acute anterior cruciate ligament (ACL) deficiency is challenging. Purpose: To investigate the diagnostic performance of magnetic resonance imaging (MRI) in detecting meniscal injuries for pediatric and adolescent patients with acute ACL tears. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The authors retrospectively identified patients aged ≤18 years who underwent acute ACL reconstruction between 2006 and 2018 at 2 tertiary academic hospitals. The primary outcomes were arthroscopically confirmed medial, lateral, or any (defined as medial and/or lateral) meniscal tears. To control for chronically deficient knees, patients must have received their MRI study within 4 weeks of injury and must have undergone surgery no more than 8 weeks after their MRI study. Preoperative MRI reports were compared with the gold standard of arthroscopically confirmed tears to calculate sensitivity, specificity, positive predictive value, and negative predictive value. In a secondary analysis, patients were stratified by age into 2 groups (≤13 or ≥14 years), body mass index-for-age data from the Centers for Disease Control were used to classify patients as obese or nonobese, and differences between sensitivity and specificity proportions were analyzed using chi-square test for homogeneity. Results: Overall, 406 patients with a mean age of 15.4 years (range, 10-18 years) were identified. The sensitivity, specificity, positive predictive value, and negative predictive value were as follows: for lateral meniscal (LM) tears, 51.0%, 86.5%, 78.3%, and 65.0%; for medial meniscal tears, 83.2%, 80.6%, 62.3%, and 92.5%; and for any meniscal tear, 75.0%, 72.1%, 81.5%, and 63.8%, respectively. In the stratified analysis, MRI was less specific for the following diagnoses: any meniscal tear in patients aged ≤13 years (P = .048) and LM tears in obese patients (P = .020). Conclusion: The diagnostic ability of MRI to predict meniscal injuries present at acute ACL reconstruction was moderate. Performance was poorest at the lateral meniscus, where MRI failed to detect 97 tears that were found arthroscopically. Specificity was significantly lower in younger patients for any meniscal tear and in obese patients for LM tears.

Orthopaedic Management of Loeys-Dietz Syndrome: A Systematic Review.

INTRODUCTION: Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder associated with aortic aneurysm/dissection in children. However, LDS may also present with a host of orthopaedic conditions. This study aimed to elucidate the management of orthopaedic conditions and associated outcomes in patients with LDS. METHODS: PubMed, Ovid MEDLINE, and Cochrane Library were systematically searched for primary articles regarding the management of orthopaedic conditions in patients with LDS. The goals and findings of each included study were described. Data regarding demographics, conditions studied, treatment modalities, and outcomes were extracted and analyzed. RESULTS: Three hundred sixty-two unique articles were retrieved, 13 of which were included, with 4 retrospective cohort studies and 9 case reports representing 435 patients. In total, 19.8% of patients presenting with orthopaedic conditions received surgical treatment;54.3% of them experienced adverse outcomes, and 44.4% required revision surgery. The mean age at surgery was 9.0 ± 2.1 years. CONCLUSION: Patients with LDS may require early surgical intervention for a variety of orthopaedic conditions and may be at an increased risk for surgical complications. The current LDS literature is primarily focused on spinal conditions with a relative paucity of data on the management of hip deformity, joint subluxation, clubfoot, and trauma. Additional research is required regarding orthopaedic management for this unique population.

ACL Reconstruction Delay in Pediatric and Adolescent Patients Is Associated with a Progressive Increased Risk of Medial Meniscal Tears.

BACKGROUND: We sought to investigate the relationship between the time from an anterior cruciate ligament (ACL) tear to the surgical procedure and meniscal tears in the pediatric and adolescent population. METHODS: Patients who were ≤18 years of age and had undergone an ACL reconstruction from 2006 to 2018 were identified in a retrospective, multicenter cohort. The primary outcomes were arthroscopically confirmed medial meniscal or lateral meniscal tears specifically and, in general, if any meniscal tear was present (medial and/or lateral). A multivariable Poisson regression model was used to determine whether the time from the injury to the surgical procedure was a risk factor for subsequent meniscal injury, after controlling for sex, age, and body mass index (BMI). Multivariable Poisson regression was also used to characterize associations of age, sex, and BMI with meniscal injury. RESULTS: In this study, 546 patients with a mean age (and standard deviation) of 15.3 ± 1.6 years were identified. For each week that the surgical procedure was delayed, there was a 2% increased risk of a medial meniscal tear (adjusted relative risk [ARR], 1.02 [95% confidence interval (CI), 1.01 to 1.03]). The weekly increase in risk of a medial meniscal injury was significant for male patients (ARR, 1.03 [95% CI, 1.01 to 1.05]), but not for female patients (ARR, 1.00 [95% CI, 0.97 to 1.04]), even though the effect modification was not significant (p = 0.24). Obese male patients had a 77.9% increased risk of medial meniscal tear for each 10-week delay (p < 0.001). The use of crutches was associated with a decreased risk of medial meniscal tears (ARR, 0.47 [95% CI, 0.34 to 0.64]). CONCLUSIONS: In pediatric and adolescent patients, the risk of meniscal injury is substantial after an ACL tear. A delay from the injury to the surgical procedure was associated with a 3% weekly increased risk of medial meniscal injury for male patients, but not for female patients. The increased risk of medial meniscal injury with delays to the surgical procedure was particularly high for obese male patients. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Novel Presentation of Pediatric Complex Regional Pain Syndrome with Concurrent Chromhidrosis: A Case Report.

CASE: An 11-year-old female patient presented to our clinic with a low-grade lateral ankle sprain that was subsequently treated with a lace-up ankle brace. On the reintroduction of weight bearing, the patient developed recurrent ankle pain and symptoms consistent with complex regional pain syndrome (CRPS) Type 1. On physical examination, the patient was found to have a concurrent chromhidrosis in the injured area, which is a novel presentation of CRPS. CONCLUSION: Patients with CRPS found to have superficial skin discoloration should be evaluated further to investigate for chromhidrosis. Early diagnosis can improve the treatment of CRPS and allow for appropriate management of varying manifestations, such as chromhidrosis.

Improving resident education through unstable chicken hips: a novel way to teach an infant hip examination.

Current clinical screening for infantile hip dysplasia relies on combined Ortolani and Barlow maneuvers, which have a quoted sensitivity and specificity of 74-98 and 84-99%, respectively. Teaching this delicate physical examination maneuver is difficult as it requires a distinct tactile feel. The purpose of this study is to validate a benchtop learning grocery-bought chicken simulator model of newborn hip instability through a pre- and post-test surveys. This model of hip dysplasia uses whole chickens. A posterior capsulotomy of the chicken's hip joint was performed to create instability. Provocative maneuvers to dislocate and relocate the hip were taught by a pediatric orthopedic surgeon. All participants completed an anonymous pre- and post-training surveys. A total of 58 participants were included in the study: 10 medical students, 13 pediatric residents, 15 orthopedic residents, and 20 orthopedic or pediatric attending physicians. The pediatric residents had performed the Barlow/Ortolani tests more than the orthopedic residents (96.15 ± 83.19 vs. 37.53 ± 60.89; P = 0.01); however, fewer pediatric residents reported feeling a positive examination (31 vs. 67%). The majority of the group agreed that the simulation felt and moved like an infant's hip (3.95 and 4.13; Likert five-point scale). The participants unanimously agreed that the model could be used to teach someone new to pediatrics the basic steps of the examination (4.91; Likert five-point scale) and should be implemented in the teaching curriculum (100%). The current study validates the benchtop model in teaching the clinical steps in detecting hip dysplasia. The model improved confidence and comfort level for all participants and proved to be a valuable tool for resident education in multiple specialties. By improving education with this model, we hope to improve early identification of hip dysplasia with increased accuracy across subspecialties.

Hip Dysplasia and Osteogenesis Imperfecta: A Case Report.

CASE: A 1-week-old female patient presented to our clinic with bilateral dislocated hips and was subsequently treated in a Pavlik harness. Harness treatment failed requiring a closed reduction and spica cast application. In the Post-Anesthesia Care Unit (PACU), the patient was found to have a right humerus fracture. Six weeks after cast application, the patient was found to have nondisplaced bilateral femur fractures prompting a genetics evaluation. The patient was subsequently found to have osteogenesis imperfecta type 3. CONCLUSION: Perioperative fractures in pediatric patients should raise suspicion for osteogenesis imperfecta. Early diagnosis can improve the management of hip dysplasia and allow for early bisphosphonate therapy.

Looking Through a Different Lens: Patient Satisfaction With Telemedicine in Delivering Pediatric Fracture Care.

Telemedicine may transform health care by overcoming geographical and travel-associated barriers to patient care. This study assesses patient satisfaction with telemedicine for fracture care. METHODS: Two groups of patients were compared from suburban/rural Pennsylvania. One group reported to a regional medical center for real-time video consultation with a pediatric orthopaedic surgeon facilitated by a physician's assistant. The other group underwent conventional outpatient clinic visits at a tertiary care hospital. The distance between the tertiary care hospital and the regional medical center was 69 miles. New or follow-up fracture patients not living in the vicinity of either medical center were included. A satisfaction survey and questionnaire were administered to both groups at the end of their visit. RESULTS: One hundred sixty-seven patients returned the questionnaires (66 conventional and 101 telemedicine). Telemedicine visits decreased indirect and direct costs (P = 0.032). Travel costs and travel times were lower (P < 0.001) in the telemedicine group. Patient satisfaction was similar. Only 8 of 101 patients in the telemedicine cohort preferred their next visit to be a conventional follow-up. DISCUSSION: Utilization of video consultation and trained physician assistants to provide pediatric orthopaedic care across suburban/rural areas can increase pediatric orthopaedic surgeon access and decrease travel costs while maintaining patient satisfaction.

Medial Epicondyle Nonunions in Children: Case Report With Overview and Management.

Up to 90% of medial epicondyle fractures treated with conservative measures result in nonunion. However, only 21% become symptomatic. The current case review discusses the history and treatment of a symptomatic medial epicondyle nonunion in a 14-year-old over a 2-year period. Initial conservative treatment was insufficient. However, open reduction and internal fixation afforded the patient a full resolution of symptoms with return to all activities at 10 weeks postoperatively. The patient remains asymptomatic more than 2 years after the initial injury. Open reduction and internal fixation achieved excellent outcomes in the treatment of a symptomatic medial epicondyle nonunion.

Iatrogenic Hip Instability After Hip Arthroscopy: Is There a Role for Open Capsular Reconstruction?: A Case Report.

CASE: A 23-year-old female athlete presented with postoperative hip pain and laxity following 3 arthroscopic hip procedures. CONCLUSIONS: Open reconstruction of the anterior hip capsule with Achilles allograft can correct arthroscopy-induced hip laxity.

Distal chromosome 16p11.2 duplications containing SH2B1 in patients with scoliosis.

INTRODUCTION: Adolescent idiopathic scoliosis (AIS) is a common musculoskeletal disorder with strong evidence for a genetic contribution. CNVs play an important role in congenital scoliosis, but their role in idiopathic scoliosis has been largely unexplored. METHODS: Exome sequence data from 1197 AIS cases and 1664 in-house controls was analysed using coverage data to identify rare CNVs. CNV calls were filtered to include only highly confident CNVs with >10 average reads per region and mean log-ratio of coverage consistent with single-copy duplication or deletion. The frequency of 55 common recurrent CNVs was determined and correlated with clinical characteristics. RESULTS: Distal chromosome 16p11.2 microduplications containing the gene SH2B1 were found in 0.7% of AIS cases (8/1197). We replicated this finding in two additional AIS cohorts (8/1097 and 2/433), resulting in 0.7% (18/2727) of all AIS cases harbouring a chromosome 16p11.2 microduplication, compared with 0.06% of local controls (1/1664) and 0.04% of published controls (8/19584) (p=2.28×10-11, OR=16.15). Furthermore, examination of electronic health records of 92 455 patients from the Geisinger health system showed scoliosis in 30% (20/66) patients with chromosome 16p11.2 microduplications containing SH2B1 compared with 7.6% (10/132) of controls (p=5.6×10-4, OR=3.9). CONCLUSIONS: Recurrent distal chromosome 16p11.2 duplications explain nearly 1% of AIS. Distal chromosome 16p11.2 duplications may contribute to scoliosis pathogenesis by directly impairing growth or by altering expression of nearby genes, such as TBX6. Individuals with distal chromosome 16p11.2 microduplications should be screened for scoliosis to facilitate early treatment.

Anterior Knee Pain in Children and Adolescents: Overview and Management.

Anterior knee pain (AKP) is a common presenting complaint for pediatricians and orthopaedic surgeons and is often seen in young athletes. AKP is multifactorial and has a broad differential diagnosis. The growth changes, biomechanics, and anatomy around the knee add to the complexity of diagnosis and treatment of AKP. Common causes of AKP include Osgood-Schlatter's disease, patellar tendinitis, and patellofemoral instability. In the diagnosis of AKP, it is important to rule out serious and morbid causes of pain, including infection and tumor. It is crucial to complete a detailed history and physical examination and obtain appropriate imaging studies. In general, the majority of patients will respond to nonoperative measures targeted to correct neuromuscular control and kinetic chain dysfunction.

Teaching the Basics: Development and Validation of a Distal Radius Reduction and Casting Model.

BACKGROUND: Approximately one-third of reduced pediatric distal radius fractures redisplace, resulting in further treatment. Two major modifiable risk factors for loss of reduction are reduction adequacy and cast quality. Closed reduction and immobilization of distal radius fractures is an Accreditation Council for Graduate Medical Education residency milestone. Teaching and assessing competency could be improved with a life-like simulation training tool. QUESTIONS/PURPOSES: Our goal was to develop and validate a realistic distal radius fracture reduction and casting simulator as determined by (1) a questionnaire regarding the "realism" of the model and (2) the quantitative assessments of reduction time, residual angulation, and displacement. METHODS: A distal radius fracture model was created with radiopaque bony segments and articulating elbows and shoulders. Simulated periosteum and internal deforming forces required proper reduction and casting techniques to achieve and maintain reduction. The forces required were estimated through an iterative process through feedback from experienced clinicians. Embedded monofilaments allowed for quantitative assessment of residual displacement and angulation through the use of fluoroscopy. Subjects were asked to perform closed reduction and apply a long arm fiberglass cast. Primary performance variables assessed included reduction time, residual angulation, and displacement. Secondary performance variables consisted of number of fluoroscopic images, casting time, and cast index (defined as the ratio of the internal width of the forearm cast in the sagittal plane to the internal width in the coronal plane at the fracture site). Subject grading was performed by two blinded reviewers. Interrater reliability was nearly perfect across all measurements (intraclass correlation coefficient range, 0.94-0.99), thus disagreements in measurements were handled by averaging the assessed values. After completion the participants answered a Likert-based questionnaire regarding the realism of simulation. Eighteen participants consented to participate in the study (eight attending pediatric orthopaedic surgeons, six junior residents, four senior residents). The performances of junior residents (Postgraduate Year [PGY] 1-2), senior residents (PGY 3-5), and attending surgeons were compared using one-way ANOVA with Tukey's-adjusted pairwise comparisons. RESULTS: The majority of participants (15 of 18) felt that the model looked, felt, and moved like a human forearm. All participants strongly agreed that the model taught the basic steps of fracture reduction and should be implemented in orthopaedic training. Attending surgeons reduced fractures in less time than junior residents (60 ± 27 seconds versus 460 ± 62 seconds; mean difference, 400 seconds; 95% CI, 335-465 seconds; p < 0.001). Residual angulation was greater for junior residents when compared with attending surgeons on AP (7° ± 5° versus 0.7° ± 0.9°; mean difference, 6.3°; 95% CI, 3°-11°; p = 0.003) and lateral (27° ± 7° versus 7° ± 5°; mean difference, 20°; 95% CI, 13°-27°; p = 0.001) radiographs. Similarly, residual displacement was greater for junior residents than either senior residents (mean difference, 16 mm; 95% CI, 2-34 mm; p = 0.05) or attending surgeons (mean difference, 15 mm; 95% CI, 3-27 mm; p = 0.02) on lateral images. There were no differences identified in secondary performance variables (number of fluoroscopic images, casting time, and cast index) between groups. CONCLUSIONS: This is the first distal radius fracture reduction model to incorporate an elbow and shoulder and allow quantitative assessment of the fracture reduction. This simulator may be useful in an orthopaedic resident training program to help them reach a defined minimum level of competency. This simulator also could easily be integrated in other accreditation and training programs, including emergency medicine. LEVEL OF EVIDENCE: Level II, therapeutic study.