Assessing the Safety and Efficacy of Tranexamic Acid Usage in Osteogenesis Imperfecta Patients.

BACKGROUND: Osteogenesis Imperfecta (OI) usually causes an increased fracture burden and bone deformity, with subsequent operations common. In addition to skeletal manifestations, there is a potential increase in bleeding susceptibility due to the increased frequency of orthopedic procedures, warranting investigation into methods to mitigate this risk. This study aims to evaluate the safety and efficacy of tranexamic acid (TXA) usage to reduce intraoperative blood loss in children with OI. We want to assess the potential benefits, risks, and complications involved with TXA use in this patient population. METHODS: TXA-receiving patients (cases) were matched 1:1 with non-TXA-receiving controls on the following criteria: age within 2 years, bone category, and OI Type. Descriptive statistics were used to summarize the data. Fisher Exact Test was performed to compare transfusion status between groups. A Wilcoxon Rank Sum test was performed to assess differences between the groups in days of stay, length of surgery, and estimated blood loss (EBL). All analyses were conducted using SAS version 9.4. P <0.05 was considered statistically significant. RESULTS: Our TXA-receiving population of 30 patients consisted of 11 females and 19 males. One patient was OI type I, 13 were OI type III, 14 were OI type IV, and 2 were categorized as Other (not Type I through Type IV). We found a significant difference in transfusion status ( P =0.02), with zero TXA patients requiring a transfusion compared with 20% of the control cases. There is also a significant difference in median EBL ( P =0.0004) between groups, with TXA patients having decreased intraoperative EBL (20 vs. 62.5 mL). There was also a difference in median days of postoperative stay between TXA-receiving and non-TXA-receiving patients ( P =0.001; 2.6 vs. 4 d). CONCLUSIONS: Our study concluded that TXA use in OI patients is associated with lower perioperative transfusions and intraoperative blood loss rates. These results support the standard usage of TXA in these patients to reduce intraoperative blood loss. LEVEL OF EVIDENCE: Level III.

"Osteogenesis Imperfecta Patients Wish Orthopedic Surgeons Had Better Strategies to Help with "-Results of a Patient and Parent-Oriented Survey.

Osteogenesis Imperfecta (OI) is a rare genetic disorder in Type I collagen characterized by bone fractures, fragility, and deformity. Current treatments are focused on decreasing fracture rates, improving bone strength, and improving overall global function. Recent research has focused primarily on fracture fixation and outcomes of intramedullary rodding of long bones. While surgical techniques continue to evolve, recent trends in OI research are focusing on patient quality of life and patient-reported outcomes. We created a 12-question survey seeking information regarding aspects of orthopedic care that OI patients and families feel are the most pressing to improve. The survey was electronically administered, and 341 individuals participated. A total of 75% of respondents who answered the age question (254/335) were adults. Regarding surgical intervention for long bones, only 16% of respondents recall being told they could not have surgery because they were too young. Of the 16%, 37.8% were told that <5 years was too young, 13.4% <4 years was too young, and 48.8% <3 years of age was too young for surgical intervention for fractures or deformities. Nearly 22% of respondents were told that their bones were too small for intramedullary fixation. The patient and family responses help elucidate the topics requiring focus for the improvement of OI orthopedic care. Patient concerns and insights should drive the research questions we ask to advance the orthopedic care of OI patients.

Outcomes of Pediatric Osteogenesis Imperfecta Patients Requiring Port-a-Cath Placement for Long-Term Vascular Access.

Intravenous (iv) bisphosphonates are widely used to treat the skeletal manifestations of osteogenesis imperfecta (OI). Obtaining peripheral iv access in pediatric patients with OI is often difficult and traumatic. Although this may be mitigated with surgically placed iv ports (port-a-caths), surgeons may be hesitant to perform this procedure on these children because of the lack of safety data. This study aims to gain better insight into the safety and efficacy of port-a-cath use in this population and identify risk factors for port-a-cath complications. In the present study, we conducted a retrospective cohort analysis of patient characteristics and the incidence of port-a-cath-related complications in children with OI. Fifty-three port-a-caths were placed in 29 children (21 males and 8 females). Of the 29 patients, most are OI type III (n = 18), followed by type I (n = 4), type IV (n = 4), and type V (n = 3). At the time of initial port-a-cath placement, the median age was 52 months (10-191 months), and the median weight was 7.9 kg (5.1-41.1 kg). Most patients (n = 20) weighed less than 10 kg during initial placement. Weight correlated significantly with OI type (p = 0.048), sex (p = 0.03), and vessel used (p = 0.02). Median initial port-a-cath longevity was 43 months (1-113 months), and we found no significant difference in port-a-cath longevity between sexes, OI types, or vessels used. Most patients (n = 19) required multiple port-a-cath placements. There is a significant difference (p = 0.02) between the number of placements and OI type, with type IV having more than type III. Port-a-cath removal was almost always due to mechanical complications (n = 19) but also for infection (n = 1) and malposition (n = 1). Eight patients still had their initial port-a-caths in place at the conclusion of this study. These findings indicate that complications associated with port-a-cath placement are mild and can be used to safely deliver iv bisphosphonates to pediatric OI patients. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Interobserver and Intraobserver Agreement are Unsatisfactory When Determining Abstract Study Design and Level of Evidence.

BACKGROUND: Understanding differences between types of study design (SD) and level of evidence (LOE) are important when selecting research for presentation or publication and determining its potential clinical impact. The purpose of this study was to evaluate interobserver and intraobserver reliability when assigning LOE and SD as well as quantify the impact of a commonly used reference aid on these assessments. METHODS: Thirty-six accepted abstracts from the Pediatric Orthopaedic Society of North America (POSNA) 2021 annual meeting were selected for this study. Thirteen reviewers from the POSNA Evidence-Based Practice Committee were asked to determine LOE and SD for each abstract, first without any assistance or resources. Four weeks later, abstracts were reviewed again with the guidance of the Journal of Bone and Joint Surgery (JBJS) LOE chart, which is adapted from the Oxford Centre for Evidence-Based Medicine. Interobserver and intraobserver reliability were calculated using Fleiss' kappa statistic (k). χ2 analysis was used to compare the rate of SD-LOE mismatch between the first and second round of reviews. RESULTS: Interobserver reliability for LOE improved slightly from fair (k=0.28) to moderate (k=0.43) with use of the JBJS chart. There was better agreement with increasing LOE, with the most frequent disagreement between levels 3 and 4. Interobserver reliability for SD was fair for both rounds 1 (k=0.29) and 2 (k=0.37). Similar to LOE, there was better agreement with stronger SD. Intraobserver reliability was widely variable for both LOE and SD (k=0.10 to 0.92 for both). When matching a selected SD to its associated LOE, the overall rate of correct concordance was 82% in round 1 and 92% in round 2 (P<0.001). CONCLUSION: Interobserver reliability for LOE and SD was fair to moderate at best, even among experienced reviewers. Use of the JBJS/Oxford chart mildly improved agreement on LOE and resulted in less SD-LOE mismatch, but did not affect agreement on SD. LEVEL OF EVIDENCE: Level II.

Multicenter Series of Deformity Correction Using Guided Growth in the Setting of Osteogenesis Imperfecta.

BACKGROUND: The mainstay of deformity correction and fracture prevention for patients with osteogenesis imperfecta (OI) includes osteotomies and intramedullary rodding. Guided growth, described in the setting of skeletal dysplasias, offers a less invasive means of deformity correction. We report a multicenter case series of guided growth procedures in the setting of OI. METHODS: We retrospectively reviewed patients with OI at three institutions from April 2012 to April 2019: 18 patients underwent guided growth for angular deformity correction with minimum 1-year follow-up or full deformity correction and removal of guided growth hardware. Clinical characteristics, deformity measurements, and complications were collected. Distal femoral and proximal tibial hemiepiphysiodesis was performed using figure-of-eight plates and screws, and distal tibial medial hemiepiphysiodesis with cannulated screws. Preoperative and postoperative lateral distal femoral angle, medial proximal tibial angle, and lateral distal tibial angle were measured. Frequency and descriptive statistics were completed. RESULTS: Eighteen patients with OI (five-I, four-III, six-IV, three-V) underwent 33 guided growth procedures with mean follow-up of 3.09 years; all received routine bisphosphonate treatment. Preoperative and postoperative mean joint angles were measured. The location for hemiepiphysiodesis included 8 distal femoral medial, 2 distal femoral lateral, 8 proximal tibial medial, 3 proximal tibial lateral, and 12 distal tibial medial. Twelve of the 33 procedures were in patients who had an intramedullary rod; 1 demonstrated backout of the epiphyseal and metaphyseal screws of a distal femoral medial figure-of-eight plate. It was revised to a larger plate with longer screws and removed upon completion of deformity correction. CONCLUSION: Guided growth may be used as an effective means of angular deformity correction with dysplastic OI bone. Having an intramedullary rod did not preclude the use of a guided growth technique. One procedure demonstrated screw backout. Given the short stature associated with OI, performing a guided growth procedure at an early enough age to allow time for correction should be considered. LEVEL OF EVIDENCE: Level IV-case series.

Targeting TGF-ß for treatment of osteogenesis imperfecta.

BACKGROUNDCurrently, there is no disease-specific therapy for osteogenesis imperfecta (OI). Preclinical studies demonstrate that excessive TGF-ß signaling is a pathogenic mechanism in OI. Here, we evaluated TGF-ß signaling in children with OI and conducted a phase I clinical trial of TGF-ß inhibition in adults with OI.METHODSHistology and RNA-Seq were performed on bones obtained from children. Gene Ontology (GO) enrichment assay, gene set enrichment analysis (GSEA), and Ingenuity Pathway Analysis (IPA) were used to identify dysregulated pathways. Reverse-phase protein array, Western blot, and IHC were performed to evaluate protein expression. A phase I study of fresolimumab, a TGF-ß neutralizing antibody, was conducted in 8 adults with OI. Safety and effects on bone remodeling markers and lumbar spine areal bone mineral density (LS aBMD) were assessed.RESULTSOI bone demonstrated woven structure, increased osteocytes, high turnover, and reduced maturation. SMAD phosphorylation was the most significantly upregulated GO molecular event. GSEA identified the TGF-ß pathway as the top activated signaling pathway, and IPA showed that TGF-ß1 was the most significant activated upstream regulator mediating the global changes identified in OI bone. Treatment with fresolimumab was well-tolerated and associated with increases in LS aBMD in participants with OI type IV, whereas participants with OI type III and VIII had unchanged or decreased LS aBMD.CONCLUSIONIncreased TGF-ß signaling is a driver pathogenic mechanism in OI. Anti-TGF-ß therapy could be a potential disease-specific therapy, with dose-dependent effects on bone mass and turnover.TRIAL REGISTRATIONClinicalTrials.gov NCT03064074.FUNDINGBrittle Bone Disorders Consortium (U54AR068069), Clinical Translational Core of Baylor College of Medicine Intellectual and Developmental Disabilities Research Center (P50HD103555) from National Institute of Child Health and Human Development, USDA/ARS (cooperative agreement 58-6250-6-001), and Sanofi Genzyme.

Obstructive Constipation in Two Patients With Severe Osteogenesis Imperfecta and Acetabular Protrusio.

Osteogenesis imperfecta (OI) is a rare genetic condition resulting in decreased bone density and bony deformity and a wide variety of extraskeletal manifestations. Acetabular protrusio and constipation are both commonly associated with OI. We present two cases of severe pelvic deformity resulting in mechanical colonic outlet obstruction, which were successfully treated with a colostomy. Colostomy as the definitive treatment of severe constipation in OI has not previously been reported in the literature.

Histological and radiographic evaluation of three common tendon transfer techniques in an un-ossified bone porcine model: implications for early anterior tibialis tendon transfers in children with clubfeet.

PURPOSE: To compare the histological healing and radiographic effects of tendons transferred to ossified or unossified bone using different tendon fixation techniques. METHODS: Nine new-born piglets underwent bilateral tendon transfers to either the ossified boney calcaneal body or unossified apophysis. The tendons were fixed using metallic suture anchors, sutures alone or a bone tunnel. At six weeks of age, calcanei were harvested, radiologically imaged and then prepared for histology. A semi-quantitative aggregated scoring system with values ranging from 0 (poor) to 15 (excellent), was used to grade healing at the surgical enthesis and the apophyseal ossification was graded by five independent reviewers in triplicate using a modified (1 to 4) validated scoring system. RESULTS: Histologically, the cartilaginous transfers utilizing the tunnel and suture techniques also demonstrated the best average aggregated scores of entheses healing rivalling that measured in transfers using the classic bone tunnel technique (clinical benchmark), whereas suture anchor fixation demonstrated the worst healing in both the ossified and unossified samples. All three transfer techniques caused at least minor alterations in apophyseal ossification, with the most significant changes observed in the metallic suture anchor cohort. The tunnel and suture techniques demonstrated similar and more mild abnormalities in ossification. CONCLUSION: Tendon transfers to unossified bone heal histologically as well as transfers classically performed through tunnels in bone. Suture fixation or tunnel techniques appear radiographically and histologically superior to suture anchors in our newborn porcine model.

Neuraxial and regional anesthesia in surgical patients with osteogenesis imperfecta: a narrative review of literature.

BACKGROUND AND OBJECTIVES: Regional and neuraxial anesthesia techniques have become instrumental in the perioperative period yet have not been well described in patients with osteogenesis imperfecta (OI), a congenital connective tissue disorder characterized by skeletal dysplasia and fragility. Patients with skeletal dysplasia present unique perioperative challenges that warrant consideration of these techniques despite their relative contraindication in this population due to reports of increased bleeding with surgery, skeletal fragility concerns with positioning, and risk of spinal cord injury with continuous neuraxial catheters. The aim of this narrative review was to evaluate literature describing the use of regional and neuraxial techniques in patients with OI and any associated clinical outcomes. METHODS: All available literature from inception to July 2020 was retrieved, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, from MEDLINE, Embase, Google Scholar and The Cochrane Library. Three authors reviewed all references for eligibility, abstracted data, and appraised quality. RESULTS: Of 412 articles initially identified, 42 met our inclusion criteria, yielding 161 cases with regional and/or neuraxial techniques described. In 117 (72.6%) of the 161 cases, neuraxial technique was performed, including 76 (64.9%) epidural, 7 (5.9%) caudal, 5 (4.2%) combined spinal epidural, and 29 (24.7%) spinal procedures. In 44 (27.4%) of the 161 cases, the use of regional anesthesia was described. Our review was confounded by incomplete data reporting and small sample sizes, as most were case reports. There were no randomized controlled trials, and the two single-center retrospective data reviews lacked sufficient data to perform meta-analysis. While complications or negative outcomes related to these techniques were not reported in any of the cases, less than half specifically discuss outcomes beyond placement and immediate postoperative course. CONCLUSIONS: There is insufficient evidence to validate or refute the potential risks associated with the use of regional and neuraxial techniques in patients with OI. This review did not uncover any reports of negative sequelae related to the use of these modalities to support relative contraindication in this population; however, further research is needed to adequately assess clinically relevant outcomes such as complications and opioid-sparing effect.

Bilateral Anterior Inferior Iliac Spine Avulsion Fractures in an Adolescent with Type I Osteogenesis Imperfecta: A Case Report.

CASE: A 13-year-old boy with known type I osteogenesis imperfecta (OI) presented with bilateral asynchronous anterior inferior iliac spine (AIIS) apophyseal avulsion fractures 6 weeks apart. Each happened while running. These were successfully treated nonoperatively, and he went on to heal. CONCLUSION: Apophyseal avulsion fractures in patients with OI have been reported in the literature around the elbow and knee; however, to the author's knowledge, this is the first report of an AIIS avulsion fracture in a patient with type I OI. The fractures were treated successfully nonoperatively with activity modification and healed well.

Osteogenesis Imperfecta: A Pediatric Orthopedic Perspective.

Osteogenesis imperfecta is a genetically and phenotypically heterogeneous disorder related to a defect or deficiency in the production of type I collagen. It is characterized by brittle bones, fractures, spine and extremity deformity, and a host of extraskeletal manifestations. Type I collagen is present in bone, tendons, ligaments, skin, dentin, and the sclera of the eye and other connective tissues. Osteogenesis imperfecta includes a multitude of disease manifestations that may be present at birth or develop over time and vary depending on the severity of the disease. This article describes the disease presentation and management considerations from a pediatric orthopedic perspective.

Initial Experience With Percutaneous IM Rodding of the Humeri in Children With Osteogenesis Imperfecta.

BACKGROUND: To report a single-center surgical experience treating humeral deformity and fractures in children with osteogenesis imperfecta (OI) using the Fassier-Duval (FD) intramedullary elongating rods. METHODS: A retrospective review was conducted between December 2005 and July 2013 of all OI patients who underwent FD rodding with a minimum of 1-year follow-up. All patients were also being concurrently treated with bisphosphonates. RESULTS: Eighteen patients underwent internal fixation on a total of 35 humeri: 7 males and 11 females with an average age of 49 months. Thirty-five procedures were performed using FD rodding, with 5 utilizing only the male portion. Thirty procedures were primary FD implantation and 5 were revisions. Twelve patients had type III OI and 6 patients type IV OI. Indications for surgery included recurrent fracture, severe bowing deformity, and pain. Osteotomy methods included closed osteoclasis, percutaneous, or open osteotomies. Two patients required transfusions during their hospital stay. At our determined endpoint, 23 humeri (65.7%) had acceptable results with a mean follow-up time of 43 months (SD=27) with no revision. The remaining 12 humeri (34.3%) necessitated revision with a mean time to revision of 35 months (SD=29). Reasons for revision included: migration resulting in pain and functional difficulty (8.6%), migration with bowing (8.6%), and hardware failure secondary to trauma (8.6%). In addition, 2 revisions were required for nonunion (5.7%) and 1 for malunion (2.9%). To our knowledge, all other osteotomies performed during surgery resulted in bony union. CONCLUSIONS: The use of the FD system for correction of humeral deformity demonstrates a reasonable option to improve comfort and function in children with recurrent fractures and deformity secondary to OI. The FD system allows for decreased revision rates and less morbid instrumentation. LEVEL OF EVIDENCE: Level IV-retrospective case series.

The Spine in Patients With Osteogenesis Imperfecta.

Osteogenesis imperfecta is a genetic disorder of type I collagen. Although multiple genotypes and phenotypes are associated with osteogenesis imperfecta, approximately 90% of the mutations are in the COL1A1 and COL1A2 genes. Osteogenesis imperfecta is characterized by bone fragility. Patients typically have multiple fractures or limb deformity; however, the spine can also be affected. Spinal manifestations include scoliosis, kyphosis, craniocervical junction abnormalities, and lumbosacral pathology. The incidence of lumbosacral spondylolysis and spondylolisthesis is higher in patients with osteogenesis imperfecta than in the general population. Use of diphosphonates has been found to decrease the rate of progression of scoliosis in patients with osteogenesis imperfecta. A lateral cervical radiograph is recommended in patients with this condition before age 6 years for surveillance of craniocervical junction abnormalities, such as basilar impression. Intraoperative and anesthetic considerations in patients with osteogenesis imperfecta include challenges related to fracture risk, airway management, pulmonary function, and blood loss.

Factors Related to Increased Ulnar Collateral Ligament Thickness on Stress Sonography of the Elbow in Asymptomatic Youth and Adolescent Baseball Pitchers.

BACKGROUND: Stress ultrasound (SUS) of the elbow has demonstrated changes in the anterior band of the ulnar collateral ligament (UCL) in professional and high school-aged pitchers. However, there have been no large reports correlating pitching history data with SUS changes in youth and adolescent baseball pitchers. HYPOTHESIS: Changes of the UCL on SUS will correlate with pitching volume in youth and adolescent baseball pitchers. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: SUS of the elbow was performed in both elbows of 102 youth and adolescent baseball pitchers. UCL thickness and the width of the ulnohumeral joint, at rest and with 150 N of valgus stress, were measured using a standardized, instrumented device. Demographic data, arm measurements, and a pitching history questionnaire were recorded as well. The pitchers were separated into 2 groups based on age: group 1 (12-14 years) and group 2 (15-18 years). SUS findings of the dominant elbows were compared between the 2 groups. Correlation analysis and linear regression were used to identify relationships between SUS findings and pitching history data. RESULTS: In all pitchers, the mean UCL thickness was 4.40 mm in the dominant elbow and 4.11 mm in the nondominant elbow (P =.03). There was no significant difference between elbows in any joint space characteristics. A comparison of group 1 versus group 2 demonstrated significant differences in UCL thickness (4.13 vs 4.96 mm; P < .001), resting joint space width (6.56 vs 4.04 mm; P < .001), and stressed joint space width (7.68 vs 4.07 mm; P < .001). There was no difference in the change in joint space width between the 2 groups (1.11 vs 0.76 mm; P = .05). The UCL was significantly thicker in pitchers who threw more than 67 pitches per appearance (4.69 vs 4.14 mm), who pitched more than 5 innings per appearance (4.76 vs 4.11 mm), and who had more than 5.5 years of pitching experience (4.71 vs 4.07 mm; P < .001). Linear regression demonstrated that age, weight, and pitches per appearance (R 2 = 0.114, 0.370, and 0.326, respectively) significantly correlated with UCL thickness. CONCLUSION: These findings suggest that UCL thickness increases as pitchers get older and heavier and as they increase their pitch volumes.

Arthroscopic Treatment of Discoid Lateral Meniscus Tears in Children With Achondroplasia.

BACKGROUND: Achondroplasia is the most common form of skeletal dysplasia that presents to the pediatric orthopaedist. More than half of achondroplasia patients are affected with knee pain. It is thought that the majority of this pain may be due to spinal stenosis, hip pathology, or knee malalignment. Discoid menisci can be a source of lateral knee joint pain in skeletally immature patients in general. We present the first case series of patients with achondroplasia who had symptomatic discoid lateral menisci treated with arthroscopic knee surgery. METHODS: The charts of 6 patients (8 knees) with achondroplasia who underwent arthroscopic knee surgery for symptomatic discoid lateral menisci were collected. History and physical examination data, magnetic resonance imaging findings, and operative reports were reviewed. Meniscal tear configuration and treatment type (meniscectomy vs. repair) were noted. RESULTS: Each patient was found to have a tear of the discoid meniscus. All menisci were treated with saucerization. In addition, meniscal repair was performed in 2 cases, partial meniscectomy in 3 cases, and subtotal meniscectomy in 3 cases. Two patients had bilateral discoid meniscal tears which were treated. Average follow-up was 2.4 years (range, 1 to 4.5 y) and the average pediatric International Knee Documentation Committee (pedi-IKDC) score was 85.3% (range, 75% to 95.4%). At final follow-up, all patients were pain free and able to return to full activities. CONCLUSIONS: Discoid meniscus tears may be a source of lateral joint line pain in patients with achondroplasia. These injuries can be successfully treated with arthroscopic surgery in this patient population. Future studies need to be done to determine the exact incidence of discoid menisci in achondroplasia patients and also to determine whether there is a genetic relationship between the 2 conditions. LEVEL OF EVIDENCE: Level IV-case series.

MRI findings of post-traumatic subperiosteal hematoma of the iliac bone with resultant femoral nerve palsy in an adolescent boy.

Post-traumatic subperiosteal hematoma of the iliac bone may present insidiously without external evidence of bleeding or go undetected in the acute setting. In some cases, the patient may come to medical attention due to femoral nerve palsy rather than hip or groin pain. In this report, we describe a case of femoral nerve palsy caused by acute post-traumatic subperiosteal hematoma of the iliac bone using MRI to highlight the subperiosteal location. Anatomy of the femoral nerve is also discussed.

An evaluation of posttraumatic stress disorder and parent stress in children with orthopaedic injuries.

OBJECTIVES: Trauma has more than physical effects on pediatric patients and their families. The purpose of this study was to evaluate pediatric orthopaedic trauma patients and patients with isolated nonoperative upper extremity (UE) fractures for emotional/psychologic symptoms associated with posttraumatic stress disorder (PTSD) and parent stress. METHODS: An institutional review board-approved prospective study of patients aged 8-18 years who sustained a traumatic injury or isolated UE fracture from October 2009 to May 2010 was performed. Demographic data were obtained and the Child PTSD Symptom Scale was used. The Parent Stress Index was used to evaluate the stress of the parents/guardian. For 80% power, we needed 32 per group. P value was set at <0.05. RESULTS: A total of 76 children and their parents/guardians participated in the study. The mean age was 12.6 years (8-17 years). There were 56 males (74%) and 20 females (26%). The average time since injury was 12 months (3-89 months). The prevalence of PTSD between the high-energy trauma patients and the low-energy nonoperative UE patients was not significant. Overall, 33% of the children had PTSD. Involvement in music was significant between patients with and without PTSD (P = 0.037) and may be protective against PTSD. CONCLUSIONS: PTSD commonly affects pediatric patients who sustain injuries as a result of a traumatic event, whether low- or high-energy mechanisms. We found no factors significantly associated with or predictive of PTSD and did not find an association of PTSD with parent stress. We need to maintain a high index of suspicion in pediatric trauma patients regardless of the energy associated with the traumatic event. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Relationship of cortical thickness of the proximal humerus and pullout strength of a locked plate and screw construct.

BACKGROUND: No study to date has evaluated cortical thickness as it relates to locking plate failure or screw pullout in the proximal humerus. The purpose of this study is to determine the relationship between proximal humerus cortical thickness and locked plate hardware failure in a cadaveric proximal humerus fracture model. METHODS: Twelve humerus specimens were placed into two groups based on the proximal humerus cortical thickness on an anteroposterior radiograph: less than 4 mm and greater than 4 mm. The specimens were plated with a six-hole proximal humerus locking plate and a 15-mm resection osteotomy at the surgical neck was performed. The specimens were tested in a materials testing machine at a displacement of 5 mm/min to failure. RESULTS: Load at failure, stiffness, maximum load, failure, and fracture gap closure were all statistically similar (P > 0.05) between the groups. CONCLUSION: Our biomechanical study used modern locked plate-screw construct fixation of a simulated two-part proximal humerus fracture. The mechanical strength was unaffected based on a threshold combined proximal humerus cortical thickness of 4 mm.

What effect does anterior cruciate ligament tibial guide orientation have on tibial tunnel length?

PURPOSE: To evaluate the effects of alteration in tibial guide pin insertion angle and external starting point on tibial tunnel length for anterior cruciate ligament (ACL) reconstruction. METHODS: Ten cadaveric tibial specimens were used. One pin was placed at each of variable insertion angles (55°, 50°, and 45°) of the tibial targeting device aimed at the center of the tibial ACL footprint. These 3 pins started externally along the anterior border of the superficial medial collateral ligament. A fourth pin at 50° was placed at a different external tibial starting point 1.5 cm anterior to the anterior border of the superficial medial collateral ligament. The intraosseous length of each pin was measured. Statistic analyses were performed with the Kruskal-Wallis test, with significance set at P < .05. RESULTS: The mean length for the 55° tibial tunnel was 50.3 mm (range, 42 to 56 mm); for the 50° tunnel, it was 48.9 mm (range, 44 to 55 mm); for the 50° anterior tunnel, it was 47.6 mm (range, 39 to 55 mm); and for the 45° tunnel, it was 47.3 mm (range, 41 to 52 mm). Changing the angle of the tibial guide did not significantly affect the length of the tibial tunnel (P = .18). Changing the external tibial starting point did not affect the length of the tibial tunnel (P = .39). CONCLUSIONS: Changing the tibial guide angle between 45°, 50°, and 55° does not appreciably change tibial tunnel length. Moving the starting point anterior 1.5 cm toward the tibial tubercle also has no effect on the tibial tunnel length. The lack of significant changes in tunnel length with these interventions may reflect the associated changes that occur in proximal tibial morphometry with change in external tibial starting position. CLINICAL RELEVANCE: Changing tibial tunnel length in ACL reconstruction likely requires more distalization of the external tibial starting point than is achieved simply by altering the tibial aiming guide angle by 10° or less.