Background: Calcaneal lengthening osteotomy (CLO) is one of the main surgical options for treatment of pediatric idiopathic flexible flatfoot (FFF). Reportedly, calcaneocuboid (CC) joint subluxation occurs after CLO; however, its effect on the midfoot remains unclear. This study aimed to investigate the radiologic midterm results after CLO treatment in pediatric idiopathic FFF. Methods: We evaluated 23 pediatric patients with idiopathic FFF aged ≥8 years, who underwent CLO from 1999 to 2017 owing to moderate to severe flatfoot deformity (assessed by visual inspection). Patients aged between 8 and 14 years were included (mean follow-up: 6.3 years; range, 3.1-11.4 years). Anteroposterior and lateral weightbearing foot radiographs were assessed for radiologic parameters preoperatively and at the 3-month, 1-year, and final follow-ups postoperatively. Results: All patients had immediate postoperative radiologic correction of the flatfoot deformity, and these improvements were maintained until the final follow-up. The mean allograft length inserted was 9 (range, 8-10) mm. There was increased CC joint subluxation after CLO, but it improved continuously until the final follow-up. A CC joint spur was newly noted in 1 case. There were 24 cases (24/39, 61.5%) of talonavicular (TN) joint spurs at the final follow-up, but 19 of these were already present on the preoperative radiographs (19/24, 79.2%). Further, the new-onset TN joint spurs were not associated with preoperative clinicoradiologic factors. Conclusion: In pediatric patients with idiopathic FFF receiving CLO treatment, preoperative radiologic angles improved. CC joint subluxation increased after surgery; however, it gradually reduced without evidence of CC joint arthritic changes over the time period studied in this cohort.

This study aimed to evaluate the effect of increased body mass index (BMI) on patient-reported outcomes (PROs) and clinically significant outcomes (CSOs) obtained > two years postoperatively following arthroscopic superior capsular reconstruction (ASCR). A retrospective study was conducted on patients who underwent ASCR with a minimum two year follow-up. All patients were divided into normal (BMI < 25.0), overweight (BMI 25–30.0), and obese (BMI ≥ 30) according to preoperative BMI. Patients were assessed using the PROs preoperatively and at six months, one year, and two years postoperatively, including the visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES), and Constant–Murley scores. The time required to achieve each CSO was analyzed and compared. Multivariate analyses evaluated the predictor variables and time required to achieve CSOs. This study included 63 patients with a mean age of 64.8 ± 8.6 years, including 31 normal BMI, 25 overweight, and seven obese patients. Significant improvements in VAS and ASES scores after ASCR were observed in all three groups. Normal and overweight patients had significant improvements in the Constant score; however, no difference was observed in obese patients. No significant difference was observed in the probability distributions of CSOs between the BMI groups. Similarly, no significant differences were observed in the probability distributions of the CSOs, ASES, and Constant scores at each time point, among the BMI groups. Patients in the normal and overweight groups had significant improvements in the VAS, ASES, and Constant scores after ASCR. Patients in the obese group had a significant improvement in VAS score; however, there is no difference for the ASES and Constant scores in the obese group. However, no differences were observed in all PROMs and the likelihood of achieving CSOs among the different BMI groups.

The clinical application of growth factors such as recombinant human bone morphogenetic protein-2 (rh-BMP-2), for functional bone regeneration remains challenging due to limited in vivo efficacy and adverse effects of previous modalities. To overcome the instability and short half-life of rh-BMP-2 in vivo, we developed a novel osteogenic supplement by fusing a protein transduction domain (PTD) with BMP-2, effectively creating a prodrug of BMP-2. In this study, we first created an improved PTD-BMP-2 formulation using lipid nanoparticle (LNP) micellization, resulting in downsizing from micrometer to nanometer scale and achieving a more even distribution. The micellized PTD-BMP-2 (mPTD-BMP-2) demonstrated improved distribution and aggregation profiles. As a prodrug of BMP-2, mPTD-BMP-2 successfully activated Smad1/5/8 and induced mineralization with osteogenic gene induction in vitro. In vivo pharmacokinetic analysis revealed that mPTD-BMP-2 had a much more stable pharmacokinetic profile than rh-BMP-2, with a 7.5-fold longer half-life. The in vivo BMP-responsive element (BRE) reporter system was also successfully activated by mPTD-BMP-2. In the in vivo rat tibia distraction osteogenesis (DO) model, micro-computed tomography (micro-CT) scan findings indicated that mPTD-BMP-2 significantly increased bone volume, bone surface, axis moment of inertia (MOI), and polar MOI. Furthermore, it increased the expression of osteogenesis-related genes, and induced bone maturation histologically. Based on these findings, mPTD-BMP-2 could be a promising candidate for the next-generation osteogenesis drug to promote new bone formation in DO surgery. STATEMENT OF SIGNIFICANCE: This study introduces micellized bone morphogenetic protein-2 (mPTD-BMP-2), a next-generation osteogenic supplement that combines protein transduction domain (PTD) and nano-sized micelle formulation technique to improve transduction efficiency and stability. The use of PTD represents a novel approach, and our results demonstrate the superiority of mPTD-BMP-2 over rh-BMP-2 in terms of in vivo pharmacokinetic profile and osteogenic potential, particularly in a rat tibial model of distraction osteogenesis. These findings have significant scientific impact and potential clinical applications in the treatment of bone defects that require distraction osteogenesis. By advancing the field of osteogenic supplements, our study has the potential to contribute to the development of more effective treatments for musculoskeletal disorders.

Background Treatment of bone lesions involved with the articular cartilage at the talus is challenging. We report the management of talus lesions, particularly tumors and avascular necrosis (AVN), at the articular surface through treatment with cement augmentation and autologous bone graft. Methods Eight benign bone tumors and three cases of AVN were reviewed retrospectively at a mean follow-up of 56 months (range, 12–162). The mean age of all patients was 36.1 years old (range, 15–73) when assessed between February 2005 and November 2021. Curettage of tumorous and necrotic lesions resulted in significant bone defects filled with bone cement augmentation. Cartilage defects of the talar dome were supported with autologous cancellous bone graft. Tolerable weight-bearing ambulation was permitted immediately after surgery. Radiological and functional evaluations were recorded. Results We observed an increase in the average The American Orthopaedic Foot and Ankle Score (AOFAS) ( p = .003) and a decrease in the average Visual Analogue Scale pain score ( p = .003). There was no statistically significant decrease in ROM before or after surgery ( p = .114). Additionally, no talus collapse of the ankle joint occurred. Talar dome status did not aggravate before or after surgery, except for one patient. Despite no radiographic osteoarthritis exacerbation before or after surgery in six patients, five patients had osteoarthritic change. Conclusion Cement implantation and autologous bone graft performed simultaneously for benign bone tumors with joint cartilage damage and AVN are technically simple, have good outcomes, and may be a suitable alternative to standard treatments.

Background: The osteogenic capabilities and biodegradability of octacalcium phosphate (OCP) composites make them unique. Despite the excellent characteristics of OCP, their use is limited due to handling difficulties. In this study, we aimed to evaluate and compare three types of OCPs (cemented OCP (C-OCP), C-OCP with collagen (OCP/Col), and synthetic OCP (S-OCP) with alginate (OCP/Alg)) versus commercially available 8-tricalcium phosphate (8-TCP) regarding their potential to accelerate bone formation in defective rat tibias.Methods: The specimens with OCP composite were manufactured into 5 mm cubes and inserted into the segmental defects of rat tibias fixed with an external fixator. In addition, 3 mm-hole defects in rat tibias were evaluated to compare the graft material properties in different clinical situations. Serial X-ray studies were evaluated weekly and the tibias were harvested at postoperative 6 weeks or 8 weeks for radiologic evaluation. Histological and histomorphometric analyses were performed to evaluate the acceleration of bone formation.Results: In the critical-defect model, OCP/Alg showed bone bridges between segmentally resected bone ends that were comparable to those of 8-TCP. However, differences were observed in the residual graft materials. Most 8-TCP was maintained until 8 weeks postoperatively; however, OCP/Alg was more biodegradable. In addition calcification in the 8-TCP occurred at the directly contacted area between graft particles and bony ingrowth was observed in the region adjacent resected surface of tibia. In contrast, no direct bony ingrowth was observed in OCP-based materials, but osteogenesis induced from resected surface of tibia was more active. In the hole-defect model, OCP/Col accelerated bone formation. 8-TCP and OCP/Alg showed similar patterns with relatively higher biodegradability. In histology, among the OCP-based materials, directly contacted new bone was formed only in OCP/Alg group. The new bone formation in the periphery area of graft materials was much more active in the OCP-based materials, and the newly formed bone showed a thicker trabecular and more mature appearance than the 8-TCP group.Conclusions: In this study, OCP/Alg was equivalent to 8-TCP in the acceleration of bone formation with better biodegradability appropriate for clinical situations in different circumstances. Our OCP/Col composite showed fast degradation, which makes it unsuitable for use in mechanical stress conditions in clinical orthopedic settings. The Translational Potential of this Article: In our research, we compared our various manufactured OCP composites to commercially available 8-TCP in critical-defect rat tibia model. OCP/Col showed acceleration in hole-defect