Citations

Abstract The Fracture Nonunion Symposium presented at the 2024 Orthopaedic Trauma Association Basic Science Focus Forum featured invited speakers who discussed current perspectives on this topic. Clinical approaches, diagnostic advancements, basic science perspectives, and novel treatment strategies were discussed. This symposium was curated to highlight this common and challenging clinical problem faced by orthopaedic and musculoskeletal practitioners from around the globe.

BACKGROUND AND OBJECTIVES: Surgery in NF2-related schwannomatosis (NF2-SWN) vestibular schwannoma (VS) carries a higher risk of facial nerve damage, hearing loss, and partial resection, than in sporadic cases. Radiosurgery is also associated with higher failure compared with sporadic schwannomas. Nowadays, bevacizumab (BEV) is frequently considered in the NF2-SWN population. However, some patients experience progression despite treatment. Among other surgical risks, in BEV-treated patients, hemorrhage and impaired healing are specific considerations. These concerns have led manufacturers to recommend stopping BEV 6 to 8 weeks preoperatively. The aim of our multicentric study was to assess the perioperative bleeding risk and postoperative outcomes in NF2-SWN patients undergoing VS surgery after preoperative BEV treatment. METHODS: Our retrospective analysis included medical and surgical records along with imaging reviews from 4 high-volume tertiary academic referral centers for NF2-SWN and VS. RESULTS: A total of 21 patients met the inclusion criteria. VS had a mean volume of 13.2 ±7.6 cm 3 corresponding to 1 KOOS III and 20 KOOS IV. BEV was stopped at a mean of 5.8 ± 4.0 months before surgery with a total mean treatment duration of 33.7 ± 20.7 months and a monthly dose of 10.2 ± 4.1 mg/kg. Intraoperatively, the tumor was assessed to be bloody by the operating surgeons in 7 patients. Late BEV discontinuation and high cumulative dose independently predicted perioperative bleeding and longer surgery duration. No other complication such as wound dehiscence was reported. CONCLUSION: Our findings suggest that a higher cumulative BEV dose (∼600 mg/kg) and a longer interval between BEV discontinuation and surgery (∼8 months) are associated with a modest but statistically significant increase in intraoperative bleeding risk. Based on these observations, a BEV-free window between 6 weeks and 6 months (depending on the clinical scenario) before tumor resection seems optimal, particularly for patients with high cumulative exposure.

When long bones fracture, healing occurs spontaneously in about 90% of cases, while the remaining 10% result in non-union, presenting significant clinical challenges. The standard treatment for non-unions is autologous bone grafting, but this approach has limitations, including high complication rates, donor site morbidity, and limited graft availability. An alternative strategy involves using growth factors to promote bone regeneration, with recombinant bone morphogenetic protein-2 (rBMP-2) being the most common. Although effective, rBMP-2 requires supra-physiological doses that cause inflammation, poor bone quality, and severe side effects. Our previous work suggests that genetic delivery of BMP-2 may offer more controlled healing. We aim to develop a more effective therapy for non-unions using adeno-associated viral vectors. By lyophilizing the vector onto a scaffold, we also aim to increase treatment potency, reduce leakage, and improve transduction using cryoprotectant buffers.AAV6-GFP-Luciferase was used to compare the activity of AAV6 stored at −80°C versus lyophilized in cryoprotectant buffer. A rat critical-sized defect model was employed, as described in [1]. For standard storage, AAV was added to the collagen sponge before implantation into a 5mm defect. For lyophilization, AAV was mixed with cryoprotectant, loaded onto the sponge, and lyophilized. Rats were imaged at 7- and 10-days using IVIS. To assess therapeutic relevance, the experiment was repeated with AAV6-BMP2-IL1Ra, implanted into 5mm femoral defects on collagen sponges, with healing monitored by X-ray every 4 weeks (continuing through 12-weeks post-operation).The reporter and therapeutic vectors showed improved transduction efficiency with lyophilization. The reporter vector exhibited higher transgene expression at days 7 and 10. This boost in expression either remained significant through 4 weeks or continued to show better signal at that time, correlating with improved healing seen in the X-rays (Fig. 2).Preliminary data suggest that lyophilization could reduce the therapeutic dose of AAV needed for treating osseous nonunion with a bicistronic vector. Lyophilization offers various benefits: enhanced transduction efficiency, improved stability of the gene product at logistically feasible conditions, and reduced off-target effects due to less AAV leakage from the implantation site. While in vivo experiments with AAV6-BMP2-IL1Ra are ongoing, these findings warrant further investigation into lyophilized AAV therapies for this application.For any figures or tables, please contact the authors directly.

Abstract Bone morphogenetic proteins ‐2 and ‐7 (BMP‐2 and BMP‐7) are effective in treating large bone defects, but the required doses are high, resulting in side effects and elevated costs. Previously, this work has demonstrated that a chemically modified messenger RNA (cmRNA) coding for BMP‐2 induced rapid and reliable healing until consolidation in a bone segmental defect in rats. Here, this work shows that the simultaneous transfer of BMP‐2 and BMP‐7 cmRNAs to stem cells leads to increased osteogenic gene expression, extracellular matrix deposition, and mineralization, compared to single or sequential delivery of these cmRNAs. Using a murine model of ectopic ossification, this work finds that dual BMP‐2/BMP‐7 cmRNA delivery using collagen‐hydroxyapatite scaffolds, designed specifically for bone repair, ensured local BMP‐2 and ‐7 expression with abundant osteogenesis in the absence of adverse effects. This confirms the superior osteogenic potency achieved by local, controlled dual delivery of cmRNAs encoding BMP‐2 and BMP‐7, further enhancing the potential of this highly translatable technology for promoting bone healing.

Abstract Objective This study explores and documents the patient experience during the prodrome phase of migraine. Background Migraine attacks can be divided into four stages: the prodrome (or premonitory phase), the aura, the headache phase, and postdrome. Qualitative data on the range of symptoms during the prodrome and their timing relative to headache onset are sparse. Prodromal symptoms may predict the onset of migraine headache pain and provide a clinically useful benchmark for initiation of treatment early in an attack before pain begins. Design/Methods Eligible participants with a clinician‐confirmed diagnosis of migraine and at least one prodromal symptom were consented, screened, and then participated in 60‐min interviews. The interview guide included open‐ended questions to elicit spontaneous reports and specific probes about prodromal symptoms based on a clinician‐established list. A theory approach was used to analyze the qualitative data collected in interviews to identify key themes and gather insights; data were analyzed using ATLAS.ti. Results Data collection for this study occurred from March 8, 2022, to May 16, 2022. Twenty interviews were conducted, and analyses demonstrated that concept saturation was achieved. Participants reported 36 unique prodromal symptoms, and each participant experienced a mean of 13 symptoms (standard deviation [SD] = 6.6) and a median of 11 symptoms (interquartile range [IQR] = 7.8–17.0) during the prodrome phase. The most commonly reported prodromal symptoms were nausea ( n = 17/20, 85%), fatigue/tiredness ( n = 16/20, 80%), sensitivity to light ( n = 13/20, 65%), neck pain/stiffness ( n = 12/20, 60%), and dizziness/vertigo/light‐headedness ( n = 10/20, 50%). Of the symptoms reported by at least four participants ( n ≥ 4/20, 20%), neck pain/stiffness was rated most bothersome (8.9 out of 10) and sensitivity to light was rated most severe (8.5 out of 10). Almost 40% of all symptoms reported occurred less than 2 h before the start of migraine headache. Of the commonly reported symptoms, nausea (0.8h), sensitivity to light (1.0 h), and dizziness/vertigo/lightheadedness (2.0 h) began closest to headache onset; fatigue/tiredness (4.0 h) and neck pain/stiffness (4.8 h) were the most remote from headache onset. Conclusion This study identified frequently reported prodromal symptoms, with participants commonly reporting that a migraine headache would follow their experience of prodrome within a 1‐ to 6‐h window. Characterizing the prodrome experience may improve measurement strategies for the burden of migraine and create opportunities to treat during the prodromal phase to prevent the onset of moderate or severe headaches.

Abstract Craniopharyngiomas are rare parasellar tumors, and papillary craniopharyngiomas (PCPs) represent 8 to 20% of cases. Interim analysis of retrospective data collected from the Registry of Adenomas of the Pituitary and Related Disorders (RAPID). Fourteen U.S.-based academic skull base centers between 2011 and 2023. Patients with PCPs. Demographic, imaging, surgical, and outcome variables. Ninety-nine patients with PCPs were included. The mean age was 51.8 ± 14.7, and 57.6% were male. Most tumors showed mixed cystic/solid components (67.5%), were transinfundibular (50.0%), and were treated with an endoscopic endonasal approach (74.5%), with 51.1% demonstrating gross total resection (GTR). Pituitary stalk was preserved in 51.9%. Permanent arginine vasopressin deficiency was seen in 67.1% and was associated with pituitary stalk sacrifice (p = 0.003). Cerebrospinal fluid leak was the most common nonendocrine postsurgical, 30-day complication (9.1%), reason for return to the operating room (3.1%), and reason for 90-day readmission (8.1%). Most patients (63.9%) received no adjuvant therapy; GTR was associated with decreased radiotherapy use (p = 0.0001). BRAFV600E mutation was detected in 64/69 tumors tested, although only one patient was treated with a BRAF inhibitor. A mean follow-up of 12.3 ± 14.6 months was seen for the group. RAPID consortium enabled the largest real-world clinical information dataset for PCPs. Early findings support that GTR and stalk preservation are important to outcomes. Iterative analysis and discussion of data led to the generation of a framework for future studies to fully leverage the capabilities of multicenter registries.

ImportanceEtiologic heterogeneity in breast carcinogenesis needs to be well characterized for targeted prevention. Associations between menopausal hormonal therapy (MHT) and oral contraceptive (OC) use and breast cancer intrinsic-like subtypes are not well understood.ObjectiveTo examine whether exogenous hormone use is differentially associated with breast cancer subtypes and to evaluate heterogeneity by intrinsic-like subtypes.Design, Setting, and ParticipantsThis study pooled data from 31 nested and population-based case-control studies involved in the Breast Cancer Association Consortium. The study population included individuals with breast cancer and control participants from 13 case-control studies nested in prospective cohorts (recruited between 1982 and 2011) and 18 population-based case-control studies (recruited between 1990 and 2013). Data analysis was performed in June 2024.ExposureMHT use (estrogen-progestin therapy [EPT] or estrogen-only therapy [ET]) in postmenopausal women and OC use in premenopausal women (never, past use, or current use).Main Outcomes and MeasuresBreast cancer intrinsic-like subtypes (luminal A–like, luminal B–like, luminal B–ERBB2 [formerly HER2 or HER2/neu]-like, ERBB2 enriched–like, or triple-negative) were determined by immunohistochemistry of tumor sections. Polytomous logistic regression was performed to estimate the association between exogenous hormones and risk of breast cancer by intrinsic-like subtypes. Analyses by subtypes were stratified by body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]; healthy weight, 18.5-<25; overweight, 25-<30; or obesity, ≥30).ResultsThis study included 42 269 individuals with breast cancer (11 901 [28.2%] premenopausal and 30 368 [71.8%] postmenopausal; 23 353 [55.2%] had a known intrinsic-like subtype) and 71 072 control participants. The mean (SD) age of all participants was 57.9 (10.9) years. In postmenopausal women, associations between current MHT use (EPT or ET) and breast cancer differed by subtype. Current EPT users with healthy weight were more likely to be diagnosed with luminal A–like (odds ratio [OR], 2.51 [95% CI, 2.26-2.80]) or luminal B–ERBB2-like (OR, 1.95 [95% CI, 1.61-2.37]) subtypes. These associations were attenuated but remained for individuals with overweight (OR, 1.40 [95% CI, 1.02-1.92]) or obesity (OR, 1.68 [95% CI, 1.01-2.78]). EPT use increased the odds of being diagnosed with luminal B–like tumors solely in women with healthy weight (OR, 1.47 [95% CI, 1.17-1.86]). Current ET use was positively associated with luminal A–like disease in women with healthy weight only (OR, 1.16 [95% CI, 1.01-1.32]), showing inverse associations with higher BMI (obesity: OR, 0.65 [95% CI, 0.50-0.85]). In premenopausal women, recent OC use was associated with luminal B–ERBB2-like (OR, 1.50 [95% CI, 1.09-2.08]), ERBB2 enriched–like (OR, 2.33 [95% CI, 1.55-3.51]), and triple-negative (OR, 1.75 [95% CI, 1.33-2.29]; P < .04 for heterogeneity) tumors.Conclusions and RelevanceIn this study, clear differences were observed in associations between current EPT use and luminal-like breast cancer subtypes and other subtypes. EPT users with healthy weight were more likely to be diagnosed with luminal-like breast cancer compared with nonusers. Subtype heterogeneity was less apparent in associations of OC and ET use. Future studies on contemporary formulations, patterns of use, and routes of administration of exogenous hormone usage are warranted.