Knee Extensor Apparatus Reconstruction with Allograft after Patellar Resection: A Case Report.

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.

Clinical and functional results after total scapulectomy in orthopedic oncology: are custom-made scapular prostheses better than humeral suspension?

Background: 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. Methods: 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. Results: 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. Conclusion: Our outcomes suggest that, when feasible, custom-made scapular prostheses can represent a reliable reconstructive option after total scapulectomy for malignant scapular tumors.

Distal Femur Megaprostheses in Orthopedic Oncology: Evaluation of a Standardized Post-Operative Rehabilitation Protocol.

BACKGROUND AND OBJECTIVES: Megaprostheses are the most used reconstructive approach for patients who have undergone massive resection of their distal femurs due to bone tumors. Although the literature about their outcomes has flourished in recent decades, to date, a consensus on rehabilitative treatment is yet to be established. In this study, we report on our experience with our latest standardized rehabilitation program, evaluating our results in a mid-to-long-term scenario. MATERIALS AND METHODS: We evaluated the functional results of all our oncologic patients treated between 2016 and 2022 who could follow our standardized post-operative rehabilitative approach, consisting of progressive knee mobilization and early weight-bearing. RESULTS: Sixteen cases were included in our study. The average duration of the patients' hospitalization was 12.2 days. A standing position was reached on average 4.1 days after surgery, while assisted walking was started 4.5 days after surgery. After a mean post-operative follow-up of 46.7 months, our patients' mean MSTS score was 23.2 (10-30). Our data suggest that the sooner patients could achieve a standing position (R = -0.609; p = 0.012) and start walking (R = -0.623; p = 0.010), the better their final functional outcomes regarding their MSTS scores. CONCLUSIONS: Rehabilitation should be considered a pivotal factor in decreeing the success of distal femur megaprosthetic implants in long-surviving oncologic patients. Correct rehabilitation, focused on early mobilization and progressive weight-bearing, is crucial to maximizing the post-operative functional outcomes of these patients.

Preliminary Results of Preoperative Planning Using 3D Printing and Augmented Reality in Cryotherapy Treatment of Giant Cell Tumor of Bone-CRIO2AR Project.

Giant Cell Tumor of Bone is a benign tumor with high local aggressive expansion, which, in rare cases, spreads metastasis. Surgical treatment, which often consists of wide curettage to reduce recurrence risk, can lower the quality of life for those affected. Along with aggressive surgery, adjuvant intraoperative techniques have been implemented such as PMMA and cryotherapy. One of the most widely used cryotherapy techniques involves the use of probes to generate ice balls, which have been scientifically shown to have various impacts on the tumor. Although this has been acknowledged, no one has yet tested a way to accurately plan the positioning of cryotherapy probes before surgery, according to the research conducted by the authors. CRIO2AR is a randomized clinical prospective ongoing study by which it will be experimented via preoperative planning of ice probes placement using AR and 3D printing technologies. By studying a single clinical case with these technologies, the surgeon gains better awareness of patient's anatomy and tumor localization. Preliminary results are shown in the article. The first results are confirming that these technologies are applicable in clinical practice. Secondly, preoperative planning is proving to be reliable, easily replicable, and useful for the surgeon.

Directed self-assembly of a xenogeneic vascularized endocrine pancreas for type 1 diabetes.

Intrahepatic islet transplantation is the standard cell therapy for ß cell replacement. However, the shortage of organ donors and an unsatisfactory engraftment limit its application to a selected patients with type 1 diabetes. There is an urgent need to identify alternative strategies based on an unlimited source of insulin producing cells and innovative scaffolds to foster cell interaction and integration to orchestrate physiological endocrine function. We previously proposed the use of decellularized lung as a scaffold for ß cell replacement with the final goal of engineering a vascularized endocrine organ. Here, we prototyped this technology with the integration of neonatal porcine islet and healthy subject-derived blood outgrowth endothelial cells to engineer a xenogeneic vascularized endocrine pancreas. We validated ex vivo cell integration and function, its engraftment and performance in a preclinical model of diabetes. Results showed that this technology not only is able to foster neonatal pig islet maturation in vitro, but also to perform in vivo immediately upon transplantation and for over 18 weeks, compared to normal performance within 8 weeks in various state of the art preclinical models. Given the recent progress in donor pig genetic engineering, this technology may enable the assembly of immune-protected functional endocrine organs.

Hemicalcaneal reconstruction with a 3D printed custom-made prosthesis after partial calcanectomy due to a malignant bone tumor.

The malignant bone tumors of the calcaneus are extremely uncommon lesions. Surgical approach can consist in either an amputation or in a limb sparing procedure, depending on the width and the location of the neoplasm. Although several reconstructive options have been proposed to fulfill the bone defect in those cases that received a selective resection, to this date a consensus reconstructive approach is far from being established. Among the alternatives described in literature, 3D printed custom-made prostheses represent one of the most intriguing and promising reconstructive options. Herein, we report our experience of a spindle cell bone sarcoma of the calcaneus treated with selective resection of the anterior segment of the calcaneus and further reconstruction with a 3D printed custom-made prosthesis, based on patients' own anatomy. The posterior calcaneus and the insertion of the Achilles tendon were preserved. The resection was performed with wide margins and no major complication occurred through the intra-operative or post-operative intercourse. At her latest follow-up, our patient showed good functional results and was continuously disease free. Our outcomes therefore suggest that a partial prosthetic replacement of the anterior calcaneus with preservation of the Achilles insertion site may represent a safe and effective solution for cases that required the resection of the anterior calcaneus due to a malignant bone tumor.

Bioengineering the Vascularized Endocrine Pancreas: A Fine-Tuned Interplay Between Vascularization, Extracellular-Matrix-Based Scaffold Architecture, and Insulin-Producing Cells.

Intrahepatic islet transplantation is a promising ß-cell replacement strategy for the treatment of type 1 diabetes. Instant blood-mediated inflammatory reactions, acute inflammatory storm, and graft revascularization delay limit islet engraftment in the peri-transplant phase, hampering the success rate of the procedure. Growing evidence has demonstrated that islet engraftment efficiency may take advantage of several bioengineering approaches aimed to recreate both vascular and endocrine compartments either ex vivo or in vivo. To this end, endocrine pancreas bioengineering is an emerging field in ß-cell replacement, which might provide endocrine cells with all the building blocks (vascularization, ECM composition, or micro/macro-architecture) useful for their successful engraftment and function in vivo. Studies on reshaping either the endocrine cellular composition or the islet microenvironment have been largely performed, focusing on a single building block element, without, however, grasping that their synergistic effect is indispensable for correct endocrine function. Herein, the review focuses on the minimum building blocks that an ideal vascularized endocrine scaffold should have to resemble the endocrine niche architecture, composition, and function to foster functional connections between the vascular and endocrine compartments. Additionally, this review highlights the possibility of designing bioengineered scaffolds integrating alternative endocrine sources to overcome donor organ shortages and the possibility of combining novel immune-preserving strategies for long-term graft function.

Innate Immunity Mediated Inflammation and Beta Cell Function: Neighbors or Enemies?

Type 1 diabetes (T1D) is still considered a huge burden because the available treatments are not effective in preventing the onset or progression of the disease. Recently, the idea that diabetes is an autoimmune disease mediated exclusively by T cells has been reshaped. In fact, T cells are not the only players with an active role in beta cell destruction. Macrophages and neutrophils, which physiologically reside in pancreatic tissue, can also participate in tissue homeostasis and damage by promoting innate immune responses and modulating inflammation. During the development of the pancreatic islet inflammation there is a strong interplay of both adaptive and innate immune cells, and the presence of innate immune cells has been demonstrated both in exocrine and endocrine pancreatic compartments during the earliest stages of insulitis. Innate immune cell populations secrete cytokines, which must be considered both as physiological and pathological mediators. In fact, it has been demonstrated that cytokines could regulate directly and indirectly insulin secretion and, simultaneously, trigger inflammatory reaction. Indeed, cytokines pathways could represent targets both to improve glucose metabolism and to prevent autoimmune damage. Concordantly, the combination of immunomodulatory strategies against both innate and adaptive immunity should be tested in the next future, as they can be more efficient to prevent or delay islet damage and T1D onset.

Surgical Treatment of Sacral Chordoma: En Bloc Resection with Negative Margins is a Determinant of the Long-Term Outcome.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To report the outcome of a series of patients with sacral chordoma who were surgically treated at a single center. SUMMARY: Chordomas are low-grade malignant tumors that arise from remnants of the notochord. They are most often found in the sacrum, spine and skull-base. These tumors have a slow clinical evolution and may eventually metastasize, even after adequate treatment. Rarely, they can dedifferentiate into high-grade sarcomas. Traditionally, chordomas were considered to be resistant to chemotherapy and standard radiation therapy. However, recently, adrotherapy has been shown to be effective for local and systemic control of the disease. In this study, clinical outcomes and local and systemic recurrence were reviewed to identify prognostic factors for local and systemic control. METHODS: Thirty-three patients with sacral chordoma (19 males, 14 females; median age 61 y, range 43-80) who were surgically treated at our institution between 1994 and 2015 were reviewed. In 24 patients, resection was performed above S2. No patients received pre-operative radiotherapy (RT). Three cases received RT (carbon ion therapy) as treatment for local recurrence. Wide (R0) surgical margins were achieved in 17 patients, marginal (R1) margins in 14 patients and intralesional (R2) margins in 2 patients. RESULTS: At a median follow-up of 53 months (range 0-198), 19 patients were continuously disease-free, 6 were disease-free after local recurrence (5) or metastases (1), 3 were alive with disease (2 local recurrence and 1 metastasis), 4 were dead of disease (1 patient died intraoperatively) and 1 was dead of another cause. Local recurrence was observed in 9 cases (27%); all 9 were treated surgically and 3 received carbon ion therapy after surgical intralesional excision. Overall survival at 10 years was 86.6%. Local recurrence-free survival at 10 years was 51%. A statistical analysis confirmed the importance of negative surgical margins (R0) to achieve local control of the disease (p = 0.0007). High resections (above S2) were associated with lower survival and higher risk of local recurrence. CONCLUSION: Surgical en bloc resection is the primary treatment for sacral chordoma. Carbon ion therapy is used when it is difficult to obtain wide surgical margins. Due to morbidity and the disabling sequelae of surgery, adrotherapy may be considered an alternative to high (above S2-S3) sacral chordoma resections.

Biological Intercalary Reconstruction with Bone Grafts After Joint-Sparing Resection of the Lower Limb: Is this an Effective and Durable Solution for Joint Preservation?

Due to advances in neoadjuvant therapies and preoperative imaging modalities, joint-sparing resections have become appealing in bone tumor surgery. However, the intercalary reconstruction of metadiaphyseal bone defects of the femur and the tibia after juxta-articular tumor resection remains challenging. Both biological and prosthetic reconstructions have been used for joint-sparing resections, but little is known about the long-term outcome of these procedures. The authors reviewed a consecutive series of 64 patients treated with joint-sparing intercalary resection and reconstruction with bone grafts. Inclusion criteria were an osteotomy line within 5 cm from the knee and ankle joint surface and an osteotomy line proximal to 1 cm below the lesser trochanter at the hip level. Intra-epiphyseal resection was performed in 25 patients (39%)and intercalary resection was performed in 39 (61%). Reconstruction included 49 allograft + vascularized fibular graft (VFG), 10 allografts, and 5 VFG + structural allogenic grafts. At a mean follow-up of 117 months (range 12-305), 51 patients (80%) were continuously disease-free, and 6 showed no evidence of disease after treatment of local recurrence or metastatic lesion. One patient was alive with lung metastases at 26 months of follow-up and six patients died of disease. In the entire series of 64 patients, 26 had a non-oncological complication that required surgical revision (40.6%). Overall survival (OS) of reconstruction was 92% at 5 years and 90% at 10 and 15 years. Limb salvage survival (LSS) was 94% at 5, 10 and 15 years. Twenty-two fractures occurred in 17 patients (26.5%). There were a total of nine non-unions (14%). Six patients (9.3%) presented early wound dehiscence (average 1.8 months, range 0-6). A deep infection occurred in 3 cases (4.7 %). In 12 patients treated with VGF reconstruction (12/54:22%), a donor-site complication was observed. The overall Musculoskeletal Tumor Society (MSTS) functional score in 54 evaluable patients, who were alive with reconstruction in situ, was 27 points (range 18-30). Biologic intercalary reconstructions with bone grafts resulted in effective joint-sparing resections of the lower limb, allowing joint preservation in all but one case who required a total knee replacement for varus osteoarthritis. Despite the high rate of complications requiring surgical revision, at 15 years, overall survival of the reconstruction was 90% and limb salvage survival was 94%. In our experience, revision-free survival was better with VFG reconstruction than with allograft alone and the combination of VFG and allogenic graft seems to favor spontaneous fracture-healing and to decrease the non-union rate.

Percutaneous treatment of traumatic talus extrusion: a case report.

BACKGROUND AND AIM OF WORK: Total traumatic extrusion of talus with interruption of all ligaments (missing talus) is a very rare injury. We represent the case of a 44-years-old male who reported total extrusion of talus and Lisfranc dislocation after a motorbike accident. This rare injury has a wide choice of treatment but usually there is not a successful functional restore. METHODS: We decided to treat the patient with an immediate reimplantation of extruded talus using 3 Kirschner wires and antibiotic therapy. We performed a temporary fixation of talus with calcaneus, tibia and scaphoid. RESULTS: Usually, this kind of injuries are treated with a tibiocalcaneal arthrodesis and show common complications such as avascular necrosis and infection. Against our expectations we managed to treat successfully our patient. CONCLUSIONS: After 5 years of follow up the patient reported good clinical outcomes without performing arthrodesis and recording major complications.

Giant schwannoma of the foot: a case report and literature review.

A schwannoma is a rare, benign tumor originating from Schwann cells of peripheral nerve sheath. It commonly occurs in subjects between 20 and 50 years of age, and its malignant transformation is exceptional. While schwannomas usually affect the head and neck region, localization in the lower extremity is exceptionally rare, and even fewer cases have described schwannomas occurring in the foot. We report a case of a giant schwannoma of the foot diagnosed in a 65-year-old woman. A giant schwannoma of the foot is an extremely rare soft tissue tumor. MRI may allow an earlier diagnosis and provide valuable information about the size and possible bone invasion. This case report noted that a complete excision of the schwannoma may prevent the risk of local recurrence, regardless of its size.

Catastrophic metallosis after tumoral knee prosthesis failure: A case report.

INTRODUCTION: Metallosis is a condition characterized by an infiltration of periprosthetic soft tissues and bone by metallic debris resulting from wear or failure of joint arthroplasties. PRESENTATION OF CASE: Authors describe a case of a 45-year-old man treated for an osteosarcoma of the distal femur with a modular prosthesis when he was 18 years old, he developed massive metallosis with skin dyspigmentation after 17 years. His medical\surgical history was remarkable for a left tumoral knee prosthesis implanted 21 years ago. Two years before revision, the patient had a car accident with a two-points prosthesis breakage and despite the surgeon's advice, the patient refused surgery. In two years, prosthesis malfunction caused a progressive catastrophic soft tissues infiltration of metallic debris. DISCUSSION AND CONCLUSION: Authors suggest that if prosthesis fracture is detected, revision surgery should be attempted as earlier as possible.

Modular megaprosthesis reconstruction for oncological and non-oncological resection of the elbow joint.

BACKGROUND: Reconstruction of large bone defects around the elbow joint is surgically demanding due to sparse soft tissue coverage, complex biomechanics and the close proximity to neurovascular structures. Modular megaprostheses are established reconstruction tools for the elbow, but only small case series have been reported in the literature. METHODS: Thirty-six patients who underwent reconstruction of the elbow joint with a modular megaprosthesis were reviewed retrospectively. In 31 patients (86.1%), elbow replacement was performed after resection of a bone tumour, whereas five non-oncological patients (13.9%) underwent surgery because of a previous failed elbow reconstruction. Functional outcome, rate of complications and oncological results were considered as primary endpoints. RESULTS: The mean follow-up was 25 months. The average achieved Mayo Elbow Performance Score (MEPS) was 77.08 (range 40-95) and the average Musculoskeletal Tumor Society (MSTS) score was 22.9 (range 8-30). Six complications (16.7%) were observed: two radial palsies, one temporary radial nerve dysfunction, one ulnar palsy, one disassembling of the articular prosthesis component and one deep infection necessitating the only implant removal. The overall 5-year survival rate of the patients was poor (25.1%) because of rapid systemic progression of the oncological disease in patients with metastatic lesion. However, the 5-year survival rate of the implant was very satisfactory (93%). CONCLUSIONS: Modular megaprosthesis is a reliable and effective reconstruction tool in large bone defects around the elbow joint. The complication rates are lower than seen in osteoarticular allografts and allograft-prosthesis composites while the functional outcome is equal. In palliative situations with metastatic disease involving the elbow, modular megaprosthesis enables rapid recovery and pain relief and preserves elbow function.