Background: Aneurysmal bone cysts (ABCs) are benign but locally aggressive cystic lesions of the bone. Pelvic ABCs are extremely rare and hard to treat due to their high risk of local recurrence and the tough access to pelvic bones. Methods: In this retrospective study, we evaluated pediatric cases with pelvic ABC treated with curettage, cryotherapy and bone grafting treated in our institution between 2016 and 2022. Complications were recorded, as well as local recurrences. Patients’ post-operative functionality was assessed with the MSTS score. Results: Fourteen consecutive cases were included in our study. Their mean age at surgery was 13.5 years. The mean lesion size was 55 mm. The mean follow-up was 38 months. Two cases (11.8%) had local recurrences, which were successfully treated with further curettage. At their latest FU, 13 cases were continuously disease free (CDF), and one had no evidence of disease (NED). Only one case had a post-operative compilation (wound dehiscence). Patients’ mean post-operative MSTS score was 29.6. Conclusions: Pelvic ABCs are a challenge, even for the most experienced orthopedic surgeon. Our study suggests that the association of an accurate curettage, intraoperative cryotherapy and bone grafting can be a reliable and effective therapeutic option for large-sized ABCs of the pelvis.

Inroduction: Schwannomas are the most common tumors of the peripheral nervous system. Surgical eradication with excision or enucleation is the treatment for symptomatic and large schwannomas. Aim: Few studies have investigated the clinical outcomes related to the surgical approach to schwannomas. Our study aims to evaluate the clinical and functional results of surgery for the treatment of upper limb schwannomas. Materials and methods: Twenty-two cases of upper limb schwannomas were surgically treated in our institution between January 2016 and December 2023. All cases underwent preoperative and 6-month postoperative MRI. For each case, we recorded the diagnostic interval (symptom-diagnosis), symptoms (stenosis or sensory deficits, pain, and Tinel test), and both pre-and postoperative functional status (with DASH and MSTS scores). We also recorded complications and local recurrences. Results: On average, the diagnosis was made 16.7 months after the onset of the first symptom. The mean preoperative MSTS, DASH, and MRC values were 27.9, 5.7, and 4.8, respectively. We had no intra-operative complications. After a mean follow-up of 43.1 months, MSTS, DASH were 29.7/30 and 0.7, respectively. No case developed local recurrences. No case recorded stenosis deficits at the last follow-up. Only one patient developed local paresthesia (9%), while two reported modest dysesthesias. Conclusions: An adequate surgical approach, possibly preceded by a rapid diagnosis, can significantly improve the symptoms caused by schwannoma, restoring the functionality of the upper limb.

Background: Curettage represents a reliable therapeutic option for large-sized benign and locally aggressive bone tumors. In cases of impending fractures, internal fixation with plates and screws can be necessary to stabilize the treated bone after curettage. Metal plates have been the only fixation devices available on the market for decades, but Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK) now represents an alternative in orthopedic oncology. Methods: We reviewed our patients with benign or locally aggressive bone tumors treated with curettage and fixation with CFR-PEEK plates. Plate length and curettage technique were chosen considering the characteristics of each lesion. We recorded the size and location of the lesions, adjuvant treatments and fillers used after curettage, complications, and local recurrences. Postoperative functionality was assessed using the MSTS score. Results: Forty cases were included in our study. The tumors were located in the distal femur (19 cases), femur shaft (1), humerus (17), or proximal tibia (3). Local adjuvants were used in 20 cases. Cavities were filled with bone allografts in 30 cases and cement in 10 cases. Only four cases suffered postoperative complications, and two developed local recurrences. The mean postoperative follow-up was 29.2 months. The mean postoperative upper and lower limb MSTS was 28.0 and 26.7, respectively. Conclusions: After an accurate curettage and an adequate filling of the resulting bone gap, CFR-PEEK plates can provide good mechanical resistance, and their radio-transparency can ease the early diagnosis of local recurrences. CFR-PEEK plates should be considered in selected cases, in a personalized surgical approach.

This paper presents the design of a silicon test chip specially conceived to study the noise propagation trough the silicon substrate in order to build up a model to be used in simulating EMC performances -both emission (EME) and immunity (EMI)- and to be able to predict early in advance, before silicon fabrication, EME-EMI characteristics. The chip is realized in 40 nm CMOS technology, the one used for the realization of automotive microcontroller. Four versions of the chip are presented and some measurements are shown. This first paper focuses on emissions aspects, even if the schematic architecture and layout has been developed to cover immunity phenomenon too. To understand the role played by the silicon substrate as propagation medium (noise internally generated to outside or to convey the external environment interferences into the silicon circuitries), the ESD pin protections have been removed on two versions of the test chip. The same electrical architecture is also proposed in different layout designs: with and without the Deep N-Well (DNW) implant allowing isolation of p-well substrates, to evaluate the benefit of this process technique. Previous work is discussed, and new hypotheses and emission measurements are shown. This work is focused on the basic version of the test chip, without DNW and ESD protection, to highlight noise propagation due to the substrate only, without intervention of different physical structures.

In orthopedic oncology, total scapulectomy is necessary to allow a wide resection of extended malignancies of the scapula and scapular girdle. Scapular reconstruction is challenging even for the most experienced surgeon. This paper reports our experience with total scapular resections, followed by humeral suspension or custom-made prostheses. In this retrospective study, we evaluated all the oncologic patients treated in our institution between 2016 and 2023 with total scapulectomy and consequential reconstruction using humeral suspension or a custom-made prosthesis. Only cases suffering from malignant bone tumors were included. The postoperative functionality of the treated limbs was assessed using the Musculoskeletal Tumor Society (MSTS) scoring scale. Complications and local recurrences were also recorded. Nine patients were enrolled. Five had custom-made implants, and four had humeral suspensions. The mean postoperative MSTS score of patients treated with custom-made prostheses was 24.0 (22–26). Globally, our cohort’s mean MSTS score was 19.1 (9–26). Patients with custom-made prostheses had significantly better functional outcomes (MSTS 24 vs 13) and similar complication rates (40% vs 50%) than those who received humeral suspensions. Our outcomes suggest that, when feasible, custom-made scapular prostheses can represent a reliable reconstructive option after total scapulectomy for malignant scapular tumors.

Background: The extensor apparatus of the knee can be thought of a chain that transmits the muscular strength developed by the quadriceps muscles to the proximal tibia. This complex is essential to allow the extension of the tibia over the femur, being essential to provide knee mobility and stability. In case of lesions which irreparably damage the patella, such as a locally aggressive bone tumor, it is necessary to restore both the apparatus’ anatomical continuity and its strength.Case report: A 39-years-old Caucasian man with a history of lung carcinoma developed atraumatic swelling and soreness in his left knee. Imaging evidence reported a degeneration of the left patella. We performed an en bloc resection of the patella and the nearby soft tissues of the extensor apparatus. The resulting gap was fulfilled with a massive allograft consisting of a quadriceps tendon, a patella and a patellar ligament. No complication or local recurrences were observed. At the patient’s latest follow-up, he did not have any extension lag and quadriceps strength was completely restored.Conclusion: Massive allografts can represent a reliable alternative for the reconstruction of the patella and the knee extensor apparatus in orthopedic oncology.