BACKGROUND:Surgical stabilization followed by postoperative radiotherapy (RT) is the standard of care for impending pathologic fractures due to bone metastases. Compared with conventional RT, stereotactic body RT (SBRT) provides more durable tumor control and palliation, but treatment volume constraints often preclude postoperative use. Preoperative SBRT limited to the tumor volume offers a solution by delivering an ablative dose before intraoperative tumor dissemination, but its safety is not established. METHODS:We conducted a phase I, nonrandomized clinical trial at a quaternary care cancer center, with accrual between June 2021 and April 2024. Eligible patients (N=38) had pelvic or long bone metastases with impending pathologic fractures requiring surgical stabilization. Patients received preoperative SBRT (27-30 Gy in 3 fractions or 18-24 Gy in 1 fraction) followed by surgical stabilization within 1 week. The primary endpoint was rate of wound complications within 6 weeks after preoperative SBRT and surgical stabilization. Secondary endpoints were rates of tumor recurrence and grade ≥3 treatment-related toxicities within 1 year. RESULTS:A total of 7 patients were excluded due to inability to receive treatment or death prior to the primary endpoint. Thirty-one patients were evaluated at 6 weeks postoperatively, 26 at 3 months, and 16 at 1 year. The median age was 66 years (IQR, 59-71), and 15 (48%) patients were male. At 6 weeks, 2 of 31 patients (6.5%; 95% CI, 0.79-21.4) experienced wound complications. At 3 months, 1 of 26 patients (3.8%; 95% CI, 0.10-19.6) experienced grade ≥3 treatment-related toxicity. At 12 months, 1 of 16 patients (6.3%; 95% CI, 0.16-30.2) had tumor recurrence. CONCLUSIONS:Preoperative SBRT is associated with a low risk of wound complications and durable local tumor control. A randomized controlled trial examining its efficacy, potential to facilitate less invasive surgery, and impact on functional outcomes is warranted. CLINICALTRIALS:gov identifier: NCT05038124.

Case: Wide resection of a synovial sarcoma of the anteromedial distal leg involving the dimetaphyseal tibia and posterior tibial tendon produced an 8.5-cm osseous defect. To keep the free flap from invaginating into the defect and prevent kinking of the anastomosis, six 1.5-mm Ilizarov wires (held in place by the external fixator) were placed under the flap to suspend it over the defect. No problems resulted with the vascularity or healing of the flap or with consolidation of the defect. Conclusion: Suspending the flap over the defect with Ilizarov wires can prevent tissue invagination while avoiding need for additional procedures.

BACKGROUND:While sustainable long-term function has been established for biological reconstruction with distraction osteogenesis (DO) following osseous resections, there is a paucity of published data informing surgeons and patients on important milestones in the reconstructive process. The objectives of this study were to determine when to expect complete bone healing and full weight-bearing as well as to quantify the influence of chemotherapy on the osseous regeneration process. METHODS:Prospectively, pathological and clinical data were collected for 30 consecutive patients who underwent primary or secondary DO-based reconstruction following osseous resection from 2018 to 2021. Serial radiographs indicated the times to cortex formation and full union. An unpaired t test was used to compare the time required for full bone remodeling of segments transported with and without concurrent chemotherapy. RESULTS:The average resection length was 13.6 cm (range, 4 to 22 cm). Patients underwent an average of 6.1 procedures (range, 1 to 14 procedures). Half (50%) of all procedures were planned, while half were unplanned procedures. All patients achieved full, independent weight-bearing at a median of 12 months (interquartile range [IQR], 9 to 16 months). For the 34 segments transported concurrently with chemotherapy, the mean bone healing index (BHI) was 2.3 ± 0.7, and the mean BHI was 1.2 ± 0.4 for the 25 segments without chemotherapy at any point during their transport (p < 0.0001). CONCLUSIONS:All 30 patients achieved full bone healing and independent weight-bearing at a median of 1 year postoperatively and continued to show functional improvement afterward. Surgeons and patients can expect bone healing to be nearly twice as fast for segments transported after completion of systemic chemotherapy compared with segments transported concurrently with adjuvant chemotherapy. LEVEL OF EVIDENCE:Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

CASE:Lynch syndrome (hereditary nonpolyposis colorectal cancer) is associated with extracolonic manifestations, but skeletal tumors are rare. Our patient, a 12-year-old boy with Lynch syndrome, developed osteosarcoma of the left femur. Treatment included cytotoxic chemotherapy, wide resection, and pembrolizumab. Two years later, he developed an aggressive lesion in the contralateral femur that was thought to be metastatic osteosarcoma but which histology revealed to be Langerhans cell histiocytosis. CONCLUSION:This case underscores the importance of advanced testing in patients with osteosarcoma and poor response to chemotherapy, and of tissue sampling when patients with a primary malignancy develop new bone lesions. LEVEL OF EVIDENCE:IV.

Motorized intramedullary lengthening nails allow for transport of a bone segment for limb lengthening, deformity correction, healing of nonunion, and intercalary distraction osteogenesis. Resection of tumors involving the bone can result in substantial defects that require reconstruction. Use of these nails allows for a biologic reconstruction with the incorporation of allograft or by distraction osteogenesis. Limb lengthening after an internal hemipelvectomy where the hip joint is resected can be performed to improve gait, decrease pain, and prevent the need for a custom shoe or shoe lift. Using these nails in compression aids the incorporation of intercalary allografts and prevents stress shielding and stress risers within the graft when compared with plating. It also allows for a subsequent lengthening of the limb using the same implant. Plate-assisted bone segment transport or the use of a bone transport nail allows for a true biologic reconstruction of an intercalary defect using distraction osteogenesis. These implants provide the orthopaedic oncologist with more options for reconstruction and the potential to improve the function and outcomes of their patients.

Fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitors (TKIs) are increasingly being used off label in pediatrics. Long‐term safety data are limited, and serious toxicities unique to pediatrics may emerge. In a retrospective analysis of patients less than 18 years of age with recurrent/refractory FGFR altered gliomas treated with FGFR TKIs at MSKCC ( n = 7), we observed slipped capital femoral epiphyses in three of seven patients along with increased linear growth velocity. Clinicians should closely monitor bone health and have a low index of suspicion for serious orthopedic complications including slipped capital femoral epiphyses and inform patients of related risks as part of consent when treating with FGFR TKIs.

Adamantinomas are primary, low‐grade malignant tumors of the bone that have metastatic potential to the lungs, lymph nodes, and other regions. The rarity of this disease and its nonspecific symptoms complicate diagnosis.

Oncogenic driver alterations in fibroblast growth factor receptors (FGFRs) are present in a subset of pediatric gliomas. Debio1347 is an orally available, highly selective FGFR 1–3 inhibitor with a favorable safety profile and encouraging preliminary clinical activity in an adult phase 1 study. We treated five children with progressive/refractory CNS tumors harboring an FGFR gene alteration with Debio1347 on single patient use protocols. Patients were treated using the 20 mg tablet formulation at the adult recommended phase 2 dose (80 mg/1.73 m2 ′ BSA once daily). All adverse events (AEs) were grade 1–2. Most common treatment-related AEs were hyperphosphatemia, ALT elevation and hypoalbuminemia. Two patients met criteria for partial response and two patients had stable disease. A 13-month-old patient with a spinal cord high-grade glioma harboring two FGFR1 mutations had tumor reduction of 96.3% maintained for 11 months. A 26 month-old patient with a pilomyxoid astrocytoma harboring an FGFR1-TACC1 fusion had a tumor reduction of 74.5% maintained for 9 months. Prolonged disease stabilization and clinically significant improvement in visual function was noted in an eight year-old patient with metastatic suprasellar pilomyxoid astrocytoma harboring two FGFR1 mutations (14 months overall and sustained for 6 months off therapy) and in a 14 year-old patient with posterior fossa glioneuronal tumor harboring an FGFR3-TACC3 fusion (26 months and ongoing). FGFR targeted therapy with Debio1347 demonstrated tolerable toxicity and promising anti-tumor efficacy in pediatric patients with recurrent/refractory FGFR altered gliomas. Further studies in this population are warranted.

Adamantinoma is an extremely rare disease that typically involves large portions of the tibial cortex requiring extensive resections, for which a myriad of complex reconstructions have been performed with varying success. Techniques of bone regeneration utilizing internal or external methods are used to manage bone defects in trauma, infection and congenital deformities, but less commonly used for oncological osseous defects. We present four cases of patients diagnosed between 2015 – 2018 with tibial adamantinoma in a background of osteofibrous dysplasia who underwent distraction osteogenesis reconstruction via a double level cable bone transport. In all cases wide resection of the adamantinoma was performed to achieve negative surgical margins and the defect reconstructed by double level bone transport using Ilizarov cables guiding distraction osteogenesis. Bone transport occurred at a combined mean rate of 2 mm per day: 1mm proximally and 1mm distally. Full weight-bearing and ambulation were encouraged immediately. The mean age at time of surgery was 18 years (14 – 25) and the mean size of tibial defect was 23 cm (17.5 – 26). The mean time in external fixation was 8.5 months (6 – 12 months), yielding a mean External-Fixation Index (EFI) of 0.44 month/cm (0.3 – 0.69). The average MSTS score at mean follow time of 20 months (13-27 months) is 28 (26 – 30). At last follow up all patients are infection free and without evidence of disease. Despite typical complications of prolonged external fixation, all four patients have excellent results with an average MSTS score of 28. The mean EFI of 0.44 month/cm is well below the standard EFI of 1 month/cm, suggesting this subset of patients may require less external fixation time than previously considered. The case series supports the hypothesis that double level D.

Background: This article describes a new bone transport technique for femoral and tibial bone defects using lengthening nails combined with locking plates. We term it plate-assisted bone segment transport (PABST). Methods: Nine patients with five femoral and four tibial bone defects from open fractures or malignancies were treated between 2016 and 2018. Mean femoral defect length was 9.3 cm (range 7 to 11.5). Mean tibial defect was 8.9 cm (range 4.8 to 15). The patients were evaluated for time to weight bearing, consolidation index, mechanical axis deviation, and limb length discrepancy. Results: Seven of nine patients have fully consolidated. The mean consolidation time was 6.6 months. The consolidation index was 0.9 (femur) and 1.26 (tibia) mo/cm. Two patients required supplementary lengthening. One patient had mild varus, one mild valgus; the remainder had a normal mechanical axis. Limb length discrepancy remained acceptable in all patients. The main complications were heterotopic ossification, delayed healing, and reduced knee motion. Conclusion: Bone transport with lengthening nails and locking plates is an effective and patient-friendly way of treating bone defects, eliminating the adverse effects of external fixation and reducing treatment time. The plate provides stability during transport and docking; it can address concomitant fractures and facilitates acute shortenings.

Background and Objectives Patients undergoing cement fixation for hip arthroplasty are at increased risk of developing bone cement implantation syndrome (BCIS). We sought to determine: what is the occurrence of BCIS in patients with cancer after hip arthroplasty? What are the risk factors in patients with cancer for the development of this syndrome? What is the outcome for patients with cancer having BCIS? Methods We identified 374 patients with cancer who underwent cemented hip arthroplasty between 2010 and 2014. Patient characteristics, operative variables, and outcomes were collected. Results BCIS occurred in 279 (75%) patients. A total of 353 (94%) patients had bone metastases and 179 (48%) patients had lung metastases at the time of surgery. Age greater than 60 (hazard ratio [HR] 2.09, P = .02) and the presence of lung metastases (HR 1.77, P = .019) were associated with increased risk of BCIS. Increased perioperative use of vasopressors (HR 1.72, P = .023) and increased hospital stay beyond 10 days (HR 2.67, P = .003) was associated with BCIS. Conclusions BCIS is a frequent clinical event in patients with cancer undergoing femoral cemented arthroplasty with increased risk for patients over age 60 and those with compromised lung function due to lung metastases and lung cancer. Patients who develop BCIS are more likely to require longer postoperative hospitalization. Careful preoperative assessment and intraoperative communication are crucial steps to reduce the consequences of BCIS.

BACKGROUND:Chronic Recurrent Multifocal Osteomyelitis (CRMO) is an autoinflammatory skeletal disease characterized by unifocal or multifocal nonbacterial inflammatory bone lesions in the metaphysis of long bones. Common sites of CRMO are tibia, pelvis, proximal femur, clavicle, calcaneum and vertebrae. However, unifocal presentation or presentation in adults, atypical locations, and absence of recurrence have also been reported.METHODS AND FINDINGS:We describe two cases of female patients with unifocal presentation of nonbacterial inflammatory bone lesions in the upper and lower extremity. Furthermore, a review of literature is presented.CONCLUSION:Although CRMO is seen primarily in children and adolescents, and usually occurs in a multifocal pattern, our cases illustrate that this disease can arise in adult patients and in a single location. The diagnosis of CRMO should be made in a multi-disciplinary approach amongst orthopedic surgeons, radiologists and pathologists.

Loss of bone stock is a common problem in revision arthroplasty, specifically in large distal femur replacements (DFRs) after tumor resection. It can lead to worse functional outcomes and increased risk of revision procedures. Restoration of bone using distraction osteogenesis (DO) with an intramedullary nail may be an appropriate solution for this problem, especially in younger adults who may require future surgical interventions. In this series of three patients, we describe the successful use of DO through an internal device to address bone loss after a large osseous resection and revision endoprosthetic reconstruction. Bone stock was restored with a combination of lengthening and bone transport using a multistage revision strategy: removal of existing hardware, treatment of infection if present, lengthening of proximal femur with a temporary antibiotic spacer in the distal femur, and reimplantation of a definitive DFR after bone stock restoration. A magnetically actuated internal lengthening intramedullary rod was utilized to perform the proximal femur osteoplasty. Conversion to a definitive weight-bearing DFR was achieved in two patients; one patient required an above-the-knee amputation for chronic osteomyelitis which could not be controlled after numerous debridements and courses of IV antibiotics. In this patient, the infection could be eradicated from the lengthened bone, the regenerate bone served to provide length to the amputation stump and fully remodeled to provide full weight-bearing and prosthetic use. DO was successfully used in three patients for revision DFR and bone stock restoration. In one of the two patients who required revision surgery for infection, amputation was ultimately required. All three patients achieved successful bone regeneration.

Successful cure is achieved in almost 70% of patients with primary bone sarcomas with currently available therapies. Some soft tissue sarcomas require wide bone resection in order to achieve appropriate margins for cure of disease, and patients undergoing these procedures need durable reconstruction. Biological reconstruction has been shown to provide patients with superior long-term results over other alternatives. Distraction osteogenesis is well studied in the correction of deformities as well as in addressing some congenital musculoskeletal pathologies. The use of this technique in tumor settings has been avoided by many surgeons for a multitude of concerns, including infection risk, potential tumor activation, and uncertainty regarding the effect of systemic therapy on the callus regenerate. We review the use of this reconstruction technique using cases from our institutional experience to illustrate its incorporation into the successful management of orthopedic oncology patients. Distraction osteogenesis is an effective method for reconstructing even large bony defects and is safe in the setting of systemic therapy. This technique has the potential to address some of the common problems associated with orthopedic oncology resection, such as infection and leg length discrepancy.

The primary goal of this study was to identify nitric oxide (NO)-induced apoptosis in traumatized chondrocytes in intra-articular lower extremity fractures and the secondary goal was to identify the timeline of NO-induced apoptosis after injury.

Treatment of congenital femoral deficiency is a complex, multistage protocol and a variety of strategies have been devised to address joint instability, limb length inequality, and deformities. Despite being an important part of the algorithmic approach to the overall treatment of patients with congenital femoral deficiency, a reproducible, safe, and functional treatment for femoral length discrepancy in patients with mild and moderate congenital femoral deficiency has not been reported.

Implantable limb lengthening using noninvasively adjusted telescopic nails dates back to 1983. The newest technology is the Precice (Ellipse Technologies). A retrospective study of the first 65 Precice nails was carried out for the treatment of limb length discrepancy (unilateral) and short stature (bilateral). Successful lengthening was achieved in all patients. There were numerous distraction and hardware complications. Despite these, implantable limb lengthening appears to be the direction for the future of limb lengthening.

STUDY DESIGN:The review of multicenter national pediatric scoliosis database.OBJECTIVE:The purpose of this study was to compare the radiographic outcomes of patients who underwent scoliosis surgery utilizing different rod diameter constructs by the posterior approach.BACKGROUND:Little attention has specifically been focused on the effect of rod diameter on correction of spinal deformity after posterior spinal instrumentation and fusion in children with adolescent idiopathic scoliosis (AIS).METHODS:The review of national database comprised of 1125 patients, of which 352 patients had a minimum follow-up of 2 years. Of these, 163 patients received 5.5 mm and 189 patients received 6.35 mm diameter rods for posterior spinal instrumentation.RESULTS:The 6.35 mm rods were used more often for patients who were male, taller, heavier, with larger coronal curves, and more flexible curves. Larger diameter rods were also more likely to be stainless steel, implanted with an increased number of implants per level, and an increased number of pedicle screws used on the concavity of the curve. Univariate analysis of coronal curve showed a significant difference between 5.5 and 6.35 mm rods in correction (67.0% vs. 57.3%) at 2 years. Multivariate analysis revealed that the most significant factors affecting coronal curve correction at 2 years were rod diameter, the patient's preoperative coronal major curve and flexibility, and the implant density. In the sagittal plane, preoperative sagittal curve and rod diameter are the predictors of sagittal correction at 2 years.CONCLUSIONS:The study did not support our hypothesis that larger rods would be associated with a greater correction of frontal and sagittal plane in patients with AIS. In addition to rod diameter, implant density and the inherent flexibility and deformity of the patient were found to be influential factors contributing for the correction and maintenance of coronal and sagittal curves in AIS.