BACKGROUND:The Fassier-Duval (FD) telescopic rod is the standard of care for treating long bone fractures and deformities in children with osteogenesis imperfecta (OI). Despite its advantages, revision surgery remains common. This study aimed to analyze the medium-to long-term outcomes of FD rodding and identify risk factors for revision surgery. METHODS:A retrospective review was conducted on all OI patients who received lower limb FD rods between 2009 and 2020. Data on patient demographics, OI type, surgical details, and follow-up were collected. The primary outcome was revision surgery. We used Kaplan-Meier survival analysis and Cox proportional hazards modeling to identify risk factors associated with earlier revision. RESULTS:The study included 169 operative limbs in 80 patients with a median follow-up of 64 months. The overall revision rate was 36.69%. The most common reasons for revision were refracture (41.94%), recurrence of deformity (29.03%), and rod bending (27.42%). Survival analysis identified the cut point of the age at surgery of ≤30 months ( P =0.0003) and OI type IV ( P =0.034) as significant risk factors for earlier revision. For each additional month of age at surgery, the risk of revision decreased by 1.4% (HR=0.986, 95% CI: 0.979-0.994, P <0.001). CONCLUSIONS:In our 12-year experience, FD rods demonstrated a medium-term revision rate of ∼37%. Younger age at surgery (≤30 mo) and a diagnosis of OI type IV are critical predictors of earlier implant failure. These findings highlight the unique surgical challenges in the youngest and the more ambulatory OI populations. Further study on surgical technique and implant modification for these very young OI patients is warranted to improve surgical outcomes and implant survival. LEVELS OF EVIDENCE:Level III-prognostic studies.

Neurofibromatosis type 1 (NF-1) leads to cutaneous, neurological, and musculoskeletal manifestations. Congenital pseudarthrosis of the tibia treatment is considered aggressive in achieving bone union. Most of those patients get a short limb at the end of treatment because of pathological bone resection and malalignment. One of the manifestations that can appear in patients is localized hemihypertrophy of the limb. In our case, we present the first time a coexistence of congenital pseudarthrosis of the tibia and hemihypertrophy in the same leg was reported.

Arthrogryposis multiplex congenita (AMC) represents a large, rare group of congenital conditions. This study addressed major challenges in AMC research posed by the lack of systematic frameworks for data collection and the use of inconsistent terminologies and text descriptions. We aimed to systematically review the Human Phenotype Ontology (HPO) terms, encode AMC phenotypic traits as HPO terms, and pilot test the encoding process in a cohort of children with AMC. An international consensus-based dataset for AMC was used to extract phenotypic traits from the fetal period to adulthood. The encoding process was developed by an international expert panel to expand and revise HPO ontology for joint contractures, as the main characterizing traits in AMC. Using a pre-tested mapping algorithm, the HPO mapping process resulted in a 62% complete match, a 12% incomplete match, and a 26% no match. The encoding process included 37 new terms and annotations and 13 re-structures across 10 different joints. The implemented annotations significantly increased the number of available HPO terms for joint contractures in a cohort of children with AMC (p-value = 0.04). Our encoding and annotation approach may be used as a blueprint for systematic HPO (re)annotations for musculoskeletal and non-musculoskeletal phenotypic traits of AMC.

Going to the hospital can be scary for children, especially when they must go through a painful procedure. Doctors, nurses, and other health professionals may use special distraction techniques to help take children’s minds off the pain. There is a cool new way to help distract children from painful procedures. It is called virtual reality (VR). A study was done at a children’s hospital that specializes in bone care. The researchers wanted to know if VR was easy to use at the hospital to help the children deal with pain. The study included 44 children who had different kinds of procedures done, like having a needle put in their vein, removing stitches, having blood taken, and more. The researchers concluded that VR can help. VR is fast and easy to use, almost everyone liked it, and it works. To help with pain relief, virtual reality has all the ingredients to be a recipe for success!

Objective To investigate the extent of extraskeletal manifestations along with inpatient outcomes and complications associated with osteogenesis imperfecta (OI). Study design This cross-sectional study utilized the Kids' Inpatient Database as a part of the Healthcare Cost and Utilization Project to investigate inpatient hospital outcomes and management in patients with OI from 1997 through 2016. Data regarding hospital characteristics, cost of treatment, inpatient outcomes, and procedures were collected and analyzed. Results There were 7291 admissions that listed OI as a diagnosis in the Kids' Inpatient Database from 1997 through 2016. Unexpectedly, more than one-third of all admissions in these children with OI presented with an extraskeletal manifestation. The rate of major complications was 3.85%. The rate of minor complications was 19.4%, most commonly respiratory problems. The mortality rate was 18.2% in the neonatal period and 1.0% in all other admissions. Total charges of hospital stay increased over the years. Conclusions We identified a striking prevalence of extraskeletal manifestations in OI along with inpatient outcomes and complications associated with OI, of which respiratory complications were predominant. We observed a significant financial burden for patients with OI and identified additional risks for financial crisis, in addition to disparities in care identified among socioeconomic groups. These data contribute to a more holistic understanding of OI from diagnosis to management.

The Wnt signaling pathway is a key molecular process during fracture repair. Although much of what we now know about the role of this pathway in bone is derived from in vitro and animal studies, the same cannot be said about humans. As such, we hypothesized that Wnt signaling will also be a key process in humans during physiological fracture healing as well as in the development of a nonunion (hypertrophic and oligotrophic). We further hypothesized that the expression of Wnt-signaling pathway genes/proteins would exhibit a differential expression pattern between physiological fracture callus and the pathological nonunion tissues. We tested these two hypotheses by examining the mRNA levels of key Wnt-signaling related genes: ligands (WNT4, WNT10a), receptors (FZD4, LRP5, LRP6), inhibitors (DKK1, SOST) and modulators (CTNNB1 and PORCN). RNA sequencing from calluses as well as from the two nonunion tissue types, revealed that all of these genes were expressed at about the same level in these three tissue types. Further, spatial expression experiments identified the cells responsible of producing these proteins. Robust expression was detected in osteoblasts for the majority of these genes except SOST which displayed low expression, but in contrast, was mostly detected in osteocytes. Many of these genes were also expressed by callus chondrocytes as well. Taken together, these results confirm that Wnt signaling is indeed active during both human physiological fracture healing as well as in pathological nonunions.