Background: Pediatric patients with leg length discrepancies and complex deformities may require multiplanar external fixators for correction. We have encountered 4 cases of half-pin breakage with the Orthex hexapod frame. The purpose of this study is to report factors associated with half-pin breakage and compare various deformity correction characteristics between 2 hexapod frames – Taylor Spatial Frame (TSF) and Orthex. Methods: Pediatric patients with lower extremity deformities treated with an Orthex or TSF at a single tertiary children’s hospital between 2012 and 2022 were included for retrospective review. Variables compared between frame groups include frame configuration, half-pin/wire fixation, length achieved, angular correction, and frame time. Results: There were 23 Orthex frames (23 patients) and 36 TSF (33 patients) included. Four Orthex and zero TSF had proximal half-pin breakage. The Orthex group was younger on average (10 vs. 12 y, P=.04*) at the time of frame placement. The majority (52%) of Orthex frames were used for simultaneous lengthening and angular correction, while the majority (61%) of TSF was used for only angular correction. Orthex had more half-pins used for proximal fixation (median 3 vs. 2, P<0.0001*) and more frames with nonstandard configuration (7 (30%) vs. 1 (3%), P=0.004*). Orthex group had a longer total frame time (median 189 vs. 146 days, P=0.012*) and longer time required for regenerate healing (117 vs. 89 d, P=0.02*). There were no significant differences in length gained, angular correction, or healing index between Orthex and TSF. Nonstandard configuration, increased number of proximal half-pins, younger age at index surgery, and increased lengthening were associated with pin breakage. Conclusions: This is the first study to report half-pin breakage while using multiplanar frames in pediatric lower extremity deformity correction. The Orthex and TSF groups consisted of significantly different patients and frame configurations, making it difficult to identify any specific cause for pin breakage. This study shows that pin breakage is likely caused by multiple factors and is associated with the increased complexity of deformity correction. Level of Evidence: Level III—Retrospective Comparison Study.

Background: Chronic Recurrent Multifocal Osteomyelitis (CRMO) is a rare aseptic autoinflammatory disease with a wide and vague clinical presentation that often mimics infection, malignancy, or benign conditions, leading to a delayed diagnosis. We aimed to evaluate the clinical characteristics, differential diagnoses from evaluating pediatric orthopaedic surgeons, and compared the number of patients that could have avoided a biopsy in 80 patients with CRMO.Methods: Children diagnosed with CRMO at a single tertiary pediatric hospital in the United States between 2012 and 2022 who were evaluated by a pediatric orthopaedic surgeon were retrospectively reviewed. The differential diagnoses from the surgeons were recorded from their initial presentation. The Jansson criteria and Bristol Criteria were retrospectively applied to evaluate patients who could have been spared a biopsy.Results: 80 children (65% female) with CRMO were identified. The mean age at diagnosis was 10.28 ± 3.52 years, follow-up of 37.13 ± 27.67 months, and delay in diagnosis of 6.21 ± 9.75 months. Common presenting symptoms were antalgic gait (45%), local inflammation (30%), and fever/fatigue (26.25%). 58% presented clinically with unifocal symptoms, but 81% had multifocal disease on imaging. Radiographs were unremarkable in 35%, had periosteal reaction/sclerosis (23%), or a lytic lesion (22%). On MRI, 72% of patients had marrow edema, periosteal reaction (23%), and/or osteitis (19%). 69% of patients received a whole-body MRI, and 75% received a bone biopsy. The femur, tibia, pelvis, and spine were involved in >30% of patients. The most common initial differential diagnoses were

Background: Compression fractures are often associated with lower energy trauma and may occur in the setting of abnormal bone health associated with genetic disorders and endocrine disorders, neoplastic disease, infection, and inflammatory disorders. There is no significant series in the literature describing the prevalence or etiology of pathologic pediatric compression fractures. Methods: IRB-approved retrospective study was performed at a tertiary children’s hospital from 2012-2022. Patients <18 years old diagnosed with atraumatic vertebral compression fractures were included and reviewed for demographics, underlying diagnosis/comorbidity, presentation, mobility, deformities, imaging data, treatments, and outcomes. Results: 181 patients (54% Male) were included with mean age 14.17 years and follow-up of 20 months. A compression fracture was the presenting symptom of an underlying diagnosis in 32% of patients. Primary osteoporosis was the cause in 15%, and secondary osteoporosis was in 65% of patients; primarily due to immunosuppressants (46%) and ALL (10%). Primary lesions were the etiology in 20% of patients. There was a median of 3 fractures per patient, mostly of the midthoracic (82%) and thoracolumbar spine (51%). Radiographs revealed wedge fractures in 82% and vertebra plana in 11%. Patients were managed with careful observation or bracing (78%) and only 6% received an operation. By last follow-up, more patients developed scoliosis and were wheelchair-bound. Overall, there was a 16% mortality rate which was mostly associated with cancer. Conclusion: About 32% of patients presented with a compression fracture as the presenting symptom of an underlying disease. Pathologic vertebral compression fractures in children frequently occurred due to immunosuppressants, ALL, and metastatic disease. The fractures are often wedge or non-structural in the thoracolumbar and mid-thoracic regions of the spine. MRI’s may be useful for distinguishing between benign fractures and malignancy. Most children were treated by observation, but bracing for kyphosis was often necessary.