Osteogenesis imperfecta (OI) is an inherited skeletal dysplasia characterized by bone fragility and skeletal deformities. While the majority of cases are associated with pathogenic variants in COL1A1 and COL1A2, the genes encoding type I collagen, up to 25% of cases are associated with other genes that function within the collagen biosynthesis pathway or are involved in osteoblast differentiation and bone mineralization. Clinically, OI is heterogeneous in features and variable in severity. In addition to the skeletal findings, it can affect multiple systems including dental and craniofacial abnormalities, muscle weakness, hearing loss, respiratory and cardiovascular complications. A multi-disciplinary approach to care is recommended to address not only the fractures, reduced mobility, growth and bone pain but also other extra-skeletal manifestations. While bisphosphonates remain the mainstay of treatment in OI, new strategies are being explored, such as sclerostin inhibitory antibodies and TGF beta inhibition, to address not only the low bone mineral density but also the inherent bone fragility. Studies in animal models have expanded the understanding of pathomechanisms of OI and, along with ongoing clinical trials, will allow to develop better therapeutic approaches for these patients.

Background A congruent hip frequently is cited in the literature as a prerequisite for performing a reconstructive pelvic osteotomy for hip dysplasia. The designation as congruent is important as incongruent joints generally are regarded as requiring a salvage-type procedure. Several measures of congruency are described in the literature, but it is unclear whether these measures are reliable. Questions/purposes We therefore evaluated the intraobserver and interobserver reliabilities of three measures of hip congruency in patients with mild to severe dysplasia.Methods We selected radiographs of 30 skeletally mature patients with symptomatic hip dysplasia who were potential candidates for a periacetabular osteotomy. All radiographs were rated by six reviewers on two occasions. Reviewers were shown a series of AP and von Rosen views of either the symptomatic hip or the contralateral side and asked to rate congruency using two previously published measuresthe classifications of Yasunaga et al. and Okano et al. The reviewers also were asked to determine whether the hip was congruent based on their subjective opinion (yes/no). The radiographs were reviewed and measurements were repeated 1 month later. Kappa analysis was performed to determine intraobserver and interrater reliabilities between and among individual raters, respectively.

The fragility of the EDS patient population cannot be overlooked. Despite a conservative surgical approach, half of our patients experienced complications. The surgeon choosing to operate on EDS patients must do so with extreme caution.

Infant positioning in daily life may affect hip development. While neonatal animal studies indicate detrimental relationships between inactive lower extremities and hip development and dysplasia, no research has explored infant hip biomechanics experimentally. This study evaluated hip joint position and lower-extremity muscle activity of healthy infants in common body positions, baby gear, and orthopedic devices used to treat hip dysplasia (the Pavlik harness and the Rhino cruiser abduction brace). Surface electromyography (EMG) and marker-based motion capture recorded lower-extremity muscle activity and kinematics of 22 healthy full-term infants (4.2 ± 1.6 months, 13 M/9 F) during five conditions: Pavlik harness, Rhino brace, inward-facing soft-structured baby carrier, held in arms facing inwards, and a standard car seat. Mean filtered EMG signal, time when muscles were active, and hip position (angles) were calculated. Compared to the Pavlik harness, infants exhibited similar adductor activity (but lower hamstring and gluteus maximus activity) in the Rhino abduction brace, similar adductor and gluteus maximus activity(but lower quadriceps and hamstring activity) in the baby carrier, similar but highly variable muscle activity in-arms, and significantly lower muscle activity in the car seat. Hip position was similar between the baby carrier and the Pavlik harness. This novel infant biomechanics study illustrates the potential benefits of using inwardfacing soft-structured baby carriers for healthy hip development and highlights the potential negative impact of using supine-lying container-type devices such as car seats for prolonged periods of time. Further study is needed to understand the full picture of how body position impacts infant musculoskeletal development.