Osteosarcoma After Total Knee Arthroplasty: A Case Report.

CASE: A 79-year-old woman presented with a periprosthetic fracture 8 years after a total knee arthroplasty (TKA). Radiographs demonstrated tibial implant loosening with severe osteolysis. A high-grade osteosarcoma around the prosthesis was diagnosed, and a supracondylar femoral amputation was performed. After 2 years, no complications have occurred. CONCLUSIONS: A malignant tumor around a TKA is extremely rare. Surgeons should remain vigilant with patients who present with rapidly progressive or very aggressive implant loosening with osteolysis. Owing to its complexity and potentially devastating prognosis, treatment should be guided by a specialist multidisciplinary team. Complex limb salvage procedures or amputation is usually required.

[Osteosarcoma Secondary to Polyostotoic Fibrous Dysplasia of the Ribs].

Sarcomatous transformation of fibrous dysplasia is extremely rare. We present the case of a 54-yearold man with multiple rib masses, multiple enlarged lymph nodes throughout the body, and multiple osteolytic lesions on computed tomography( CT). A positron emission tomography( PET) scan showed abnormal enhancement in each. A needle biopsy of the right supraclavicular fossa lymph node revealed sarcoidosis. Considering the possibility of malignancy associated with sarcoidosis, a rib tumor resection and mediastinal lymph node biopsy were performed to confirm the diagnosis of the rib lesion. The pathology results showed that the rib mass was a low-grade central osteosarcoma and the mediastinal lymph node was sarcoidosis. The distribution of the lesions was consistent with osteosarcoma secondary to multiple fibrous bone dysplasia. As the osteosarcoma was low grade, the patient was followed up. Three years after surgery, there was no increase in residual disease.

A Successful Clinical Outcome 29 Months Following Improper Placement of the Compress Implant: A Case Report.

CASE: A 24-year-old woman presented with dedifferentiated parosteal osteosarcoma of the proximal femur and was treated with limb salvage surgery using the Compress implant. It was implanted with a technical error, was not revised, and has demonstrated no negative outcomes 29 months postoperatively. CONCLUSION: An instance of incorrect pin placement during the implantation of a Zimmer Compress implant is presented with good survivorship. This report acts as information for other surgeons who might inadvertently obtain unicortical fixation. In this patient, revision surgery was avoided and an excellent, short-term outcome was achieved while avoiding the potentially devastating complications associated with revision implantation.

Slipped capital femoral epiphysis after tumor prosthesis implantation in a patient receiving chemotherapy.

While the usual etiology of slipped capital femoral epiphysis (SCFE) is idiopathic, there are many other factors that increase the predisposition to slippage. Chemotherapy can be one of them. In this article, we report a rare case of acute SCFE after tumor prosthesis implantation in a patient who received chemotherapy. A 10-year-old girl with osteosarcoma of the right distal femur underwent (neo-) adjuvant chemotherapy, wide tumor resection, and reconstruction using a growing tumor prosthesis and a short non-cemented femoral stem. Half a year after implantation, she developed aseptic loosening. Revision surgery was performed using a hydroxyapatite (HA)-coated cementless femoral stem. Postoperative plain radiographs revealed SCFE that was treated by closed reduction and screw fixation. The patient recovered without complications, and unaffected hip showed no radiographic signs of slippage on follow-up. The forces of implanting a tumor prosthesis, particularly with a non-cemented stem, can increase the risk of an acute SCFE. The controversy over prophylactic pinning of the uninvolved hip in chemotherapy-associated SCFE is unresolved. Pinning can be considered only in the presence of abnormal prodromal radiological findings.

Functional and oncological outcomes of patients with proximal humerus osteosarcoma managed by limb salvage.

BACKGROUND: Osteosarcoma is the most common primary bone malignancy in skeletally immature patients. The proximal humerus is the third most common site of osteosarcoma. The literature shows a paucity of published data concerning the outcome of proximal humerus osteosarcoma managed by limb salvage. The purpose of this study was to answer the following questions: (1) do patients with proximal humerus osteosarcoma managed by limb salvage and neoadjuvant chemotherapy show good functional and oncological outcomes, and (2) are there any prognostic factors that are associated with better oncological and functional outcomes? MATERIALS AND METHODS: The study was a retrospective case series study assessing the overall outcome of 34 patients with proximal humerus osteosarcoma. Eighteen patients were males (53%) while 16 were females. Biological reconstruction was done in 15 patients (44%), while nonbiological reconstruction was done in 19 patients. Resections were mainly intraarticular (82%). Functional outcome was assessed using the Musculoskeletal Tumor Society (MSTS) score, while oncological outcome was assessed based on local recurrence and development of chest metastasis. Comparisons between quantitative variables were done using the nonparametric Mann-Whitney test. To compare categorical data, the chi-square (χ2) test was performed. The exact test was used instead when the expected frequency was less than 5. Correlations between quantitative variables were examined using the Spearman correlation coefficient. RESULTS: The mean MSTS score was 25.5 (range 23-29). A younger age was statistically correlated with a poorer MSTS score (P = 0.0016). Six patients out of 34 (17.6%) had local recurrence and four of them (67%) were treated by forequarter amputation. 41% of patients developed chest metastasis, and the majority of them were treated by chemotherapy (71%). In comparison with patients with osteosarcoma at other sites who were also managed in our institution, proximal humerus osteosarcoma patients showed higher incidence rates of local recurrence and chest metastasis along with lower 5-year patient and limb survivorships compared to distal femur, proximal tibia and proximal femur osteosarcoma patients. CONCLUSION: Treatment of osteosarcoma of the proximal humerus by limb salvage and chemotherapy yields a good functional outcome. The method of reconstruction does not impact the resultant function. The 5-year survivorship of these patients is 65%. Younger patients have a better oncological outcome and an inferior functional outcome. LEVEL OF EVIDENCE: Level IV therapeutic study.

Proximal Humerus Reconstruction for Bone Sarcomas: A Critical Analysis.

¼ The proximal humerus is a common location for primary bone tumors, and the goal of surgical care is to obtain a negative margin resection and subsequent reconstruction of the proximal humerus to allow for shoulder function.¼ The current evidence supports the use of reverse total shoulder arthroplasty over hemiarthroplasty when reconstructing the proximal humerus after resection of a bone sarcoma if the axillary nerve can be preserved.¼ There is a lack of high-quality data comparing allograft prosthetic composite (APC) with endoprosthetic reconstruction of the proximal humerus.¼ Reverse APC should be performed using an allograft with donor rotator cuff to allow for soft-tissue repair of the donor and host rotator cuff, leading to improvements in shoulder motion compared with an endoprosthesis.

Reconstruction surgery using polypropylene mesh after extensive resection of a costal osteosarcoma in a dog.

Osteosarcoma is the most common tumour that develops in the chest wall of dogs; an extensive excision is the treatment of choice. Various methods have been reported for reconstruction of chest wall defects following extensive excision. The objective of this report was to describe the complete resection of an extensive costal osteosarcoma with an extended resection of the ribs and part of the diaphragm in a dog. An 11-year-old neutered, male, miniature pinscher was presented with dyspnoea: An extensive mass was observed, stretching from the right chest wall to the abdominal wall. On computed tomography, the mass originated from the right 9th rib and exceeded the 6th rib on the cranial side and the 13th rib on the caudal side; it was compressing the lungs, diaphragm, liver, stomach and duodenum. When the patient's condition was medically stabilized, the tumour was removed from the right 9th rib. In consideration of the surgical margin, the 5th-13th ribs were excised, and the tumour was resected with the thoracoabdominal wall and part of the diaphragm. The missing thoracoabdominal wall and section of the diaphragm were reconstructed using two sheets of a polypropylene mesh. Postoperatively, flail chest was observed, although dyspnoea was not observed in the patient. Histopathological examination confirmed the diagnosis of osteosarcoma with a clean margin. Although 60.6 months have passed post-surgery, no metastasis has reoccurred. In this case, complete resection and reconstruction of the chest wall and diaphragm were achieved using a polypropylene mesh without fatal postoperative complications, despite extensive osteosarcoma resection.

Quality assessment of online osteosarcoma-related videos in Mainland China: A cross-sectional study.

BACKGROUND: Information about orthopedics diseases on the Internet has not been extensively assessed. Our purpose was to evaluate the quality of online information of osteosarcoma on current video-sharing platforms in mainland China. METHOD: TikTok and Bilibili were independently queried from June to July 2023 by four independent researchers using the Microsoft Edge web browser. Information about the videos and creators was recorded, and descriptive analyses were conducted. RESULTS: After data extraction, a total of 95 videos were included, in which 43 videos were uploaded by certified doctors (45.3%), with 35 videos (36.8%) uploaded by certified orthopedic surgeons. Of the content of these videos, 78.9% were introduction (n = 75), 64.2% were on professional knowledge (n = 61), 28.4% were on treatment (n = 27), while 5.3% were on surgical techniques (n = 5). The mean DISCERN total score was 43.8 ± 13.4, and the mean JAMA score was 3.8 ± 0.3. CONCLUSIONS: Videos about osteosarcoma on current video-sharing platforms were extensive, but were not comprehensive and professional. Although current online videos have the potential to improve public awareness on osteosarcoma, due to their quality and content, were not assessed to be good sources for medical education.

An innovative staged prosthetic lengthening reconstruction strategy for osteosarcoma-related leg discrepancy.

Correction of leg length discrepancy (LLD) in skeletally mature patients with osteosarcoma was rarely reported and quite challenging. This study aimed to propose a treatment strategy of staged lengthening and reconstruction with a standard static prosthesis to address LLD and restore limb function. It also evaluated the effectiveness of the strategy in terms of leg lengthening, functional outcomes, and complications. The strategy for lengthening included three stages. In stage 1, the previous prosthesis was removed and an external fixator with a temporary rod-cement spacer was placed. In this stage, the external fixator was used to lengthen the limb to the appropriate length. In stage 2, the external fixator was removed and the old rod-cement spacer was replaced with a new one. In stage 3, the rod-cement spacer was removed and the standard static prosthesis was planted. Nine skeletally mature distal femoral osteosarcoma patients with unacceptable LLD were treated in our institution from 2019 to 2021. We performed a chart review on nine patients for the clinical and radiographic assessment of functional outcomes, LLD, and complications. The mean (range) leg lengthening was 7.3 cm (3.6-15.6). The mean (range) LLD of the lower limbs decreased from 7.6 cm (4.1-14.2) before the lengthening to 0.3 cm (- 0.3 to 2.1) at the final follow-up with statistical significance (P = 0.000). The mean (range) Musculoskeletal Tumor Society score improved from 30.3% (16.7%-53.3%) before the lengthening to 96.3% (86.7%-100%) at the final follow-up with statistical significance (P = 0.000). Three patients (33.3%) had a minor complication; none needed additional surgical intervention. In the short term, the current staged lengthening and reconstruction with standard static prosthesis provided satisfactory functional outcomes and LLD correction with few complications. The long-term effects of this method need further exploration.

Pulmonary metastatectomy in pediatric cancer patients at National Cancer Institute, Egypt: prognostic factors and outcome.

BACKGROUND: Metastatic tumors account for 80% of all lung tumors in children. Wilms tumour and osteosarcoma are the most tumors of childhood that produce lung metastases. The aim of the current study is to assess the prognostic factors of pulmonary metastatectomy in pediatric solid tumours as age, number, size, site,laterality, resectability of pulmonary nodules, and number of Thoracotomies. Calculate overall survival among patients who underwent pulmonary metastatectomy. METHODS: It is a retrospective study including all pediatric patients with metastatic solid tumors to lungs treated at pediatric oncology department, National Cancer Institute, Cairo University from 2008 to 2014. Fifty-five patients were included, 43 (78.2℅) patients of them had Osteosarcoma. RESULTS: Thirty (54.5℅)patients were male. The mean age was 15 years ranging from (4.5- 23) years. The site of primary disease was at lower limbs in 43 (78.2%) patients. All patients underwent complete surgical resection of the primary disease with negative margin, 22(51.1%) of the osteosarcoma patients did amputation with tumor necrosis less than 90%. All patients received chemotherapy and only 9 received radiation therapy. The patients were classified into four groups according to time of diagnosis of pulmonary metastasis: at time of diagnosis in 13 (21.8%) patients, within treatment in 16 (30.9%) patients, within first year follow up in 18 (32.7%) patients and detected late in 8 (14.5%) patients. Bilateral lung metastasis diagnosed by CT chest were detected in 42 (76.4%) patients. Size of metastatic nodules was ranging from (0.5 to 10 cm) with mean 3.4 cm. Number of metastatic nodules was ranging from (1 to 28) median 4.Metastatic complications were detected in 19 patients. 5-year OS was 74.8% in the study group, and 68% in osteosarcoma patients. Effect of prognostic factors as sex, time of respectability, laterality, tumor necrosis of the 1ry disease, Timing of lung metastasis, size and site of the primary, Surgical approach of metastatectomy, postoperative complications on overall survival of the studied patients was done with significant P-value of tumor necrosis of the 1ry disease and Timing of lung metastasis 0.017, 0.001 respectively. CONCLUSION: Resection of pulmonary metastases of pediatric solid tumours is a safe and effective treatment that offers better survival.

High-grade osteosarcoma arising in DCIA flap reconstruction after a prior resection of maxillar cemento-ossifying fibroma: A case report.

Cemento-ossifying fibroma is a rare benign odontogenic tumour of the tooth-bearing jaws. Its concomitant occurrence with osteosarcoma, a malignant maxillofacial bone tumour, has never been described before. We present an uncommon case of a 43-year-old woman in whom a cemento-ossifying fibroma in the right maxilla was treated by resection and reconstruction using a deep circumflex iliac artery flap. During surgical prosthetic rehabilitation one-year post-operative, an osteosarcoma extending from the contralateral maxilla was coincidentally discovered in the deep circumflex iliac artery flap. The aim of this case report is to raise awareness on the extremely rare but possible simultaneous and independent occurrence of a cemento-ossifying fibroma and an osteosarcoma.

Tracked ultrasound registration for intraoperative navigation during pediatric bone tumor resections with soft tissue components: a porcine cadaver study.

PURPOSE: Resection of pediatric osteosarcoma in the extremities with soft tissue involvement presents surgical challenges due to difficult visualization and palpation of the tumor. Therefore, an adequate image-guided surgery (IGS) system is required for more accurate tumor resection. The use of a 3D model in combination with intraoperative tracked ultrasound (iUS) may enhance surgical decision making. This study evaluates the clinical feasibility of iUS as a surgical tool using a porcine cadaver model. METHODS: First, a 3D model of the porcine lower limb was created based on preoperative scans. Second, the bone surface of the tibia was automatically detected with an iUS by a sweep on the skin. The bone surface of the preoperative 3D model was then matched with the bone surface detected by the iUS. Ten artificial targets were used to calculate the target registration error (TRE). Intraoperative performance of iUS IGS was evaluated by six pediatric surgeons and two pediatric oncologic orthopedists. Finally, user experience was assessed with a post-procedural questionnaire. RESULTS: Eight registration procedures were performed with a mean TRE of 6.78 ± 1.33 mm. The surgeons agreed about the willingness for clinical implementation in their current clinical practice. They mentioned the additional clinical value of iUS in combination with the 3D model for the localization of the soft tissue components of the tumor. The concept of the proposed IGS system is considered feasible by the clinical panel, but the large TRE and degree of automation need to be addressed in further work. CONCLUSION: The participating pediatric surgeons and orthopedists were convinced of the clinical value of the interaction between the iUS and the 3D model. Further research is required to improve the surgical accuracy and degree of automation of iUS-based registration systems for the surgical management of pediatric osteosarcoma.

Controversies in Oncologic Pediatric Limb Salvage.

With advances in chemotherapy and radiation therapy, surgical treatment of patients with bone sarcomas has advanced from most patients undergoing an amputation to now most patients undergoing a limb salvage procedure. With the advances of limb salvage surgical techniques, reconstructive procedures have expanded to include autografts, allografts, endoprosthetic replacements, and rotationplasty. In a growing child, the decision to perform each of these reconstructive options is individualized and each needs to be considered to provide the patient with the optimal oncologic and functional outcome, while being durable to minimize the risk of complications and subsequent surgeries.

Diagnostic challenges in low-grade central osteosarcoma.

Aims: Low-grade central osteosarcoma (LGCOS), a rare type of osteosarcoma, often has misleading radiological and pathological features that overlap with those of other bone tumours, thereby complicating diagnosis and treatment. We aimed to analyze the clinical, radiological, and pathological features of patients with LGCOS, with a focus on diagnosis, treatment, and outcomes. Methods: We retrospectively analyzed the medical records of 49 patients with LGCOS (Broder's grade 1 to 2) treated between January 1985 and December 2017 in a single institute. We examined the presence of malignant features on imaging (periosteal reaction, cortical destruction, soft-tissue invasion), the diagnostic accuracy of biopsy, surgical treatment, and oncological outcome. Results: Based on imaging, 35 of 49 patients (71.4%) exhibited malignant features. Overall, 40 of 49 patients (81.6%) had undergone a biopsy before en-bloc resection: 27 of 40 patients (67.5%) were diagnosed on the first biopsy, which was more accurate when carried out by open rather than needle biopsy (91.3% vs 35.3% diagnostic accuracy, respectively; p < 0.001). Of the 40 patients treated by en-bloc resection, surgical margins were wide in 38 (95.0%) and marginal in two (5.0%). Furthermore, nine of 49 patients (18.4%) underwent curettage (intralesional margin) without previous biopsy. All patients with a positive margin developed local recurrence. Distant metastases occurred in five of 49 patients (10.2%). The mean five-year overall survival (OS) and distant relapse-free survival (D-RFS) were 89.3% (SD 5.1%) and 85.7% (SD 5.5%), respectively. Univariate analysis showed that the occurrence of distant metastasis was a poor prognostic factor for OS (hazard ratio 11.54, 95% confidence interval (CI) 1.92 to 69.17; p < 0.001). Local recurrence was a poor prognostic factor for D-RFS (HR 8.72, 95% CI 1.69 to 45.0; p = 0.002). Conclusion: The diagnosis of LGCOS can be challenging because it may present with non-malignant features and has a low diagnostic accuracy on biopsy. If precisely diagnosed, LGCOS can be successfully treated by surgical excision with wide margins.

Delay in Diagnosis and Treatment of Primary Bone Tumors.

BACKGROUND: Delay in the diagnosis and treatment of bone tumors continues to be a common problem. Prolonged diagnosis can significantly reduce the chances of successful treatment of the disease. Accordingly, the aim of this study was to assess the delay in the diagnosis of primary bone tumors, identify the most common symptoms and analyze the course of the diagnostic and therapeutic path. MATERIAL AND METHODS: Thirty-two (K=18; M=14) patients treated surgically for primary bone tumors were included in the retrospective study. Patient records were analyzed. Delay in diagnosis was defined as the time from the onset of symptoms to the initial diagnosis and referral to an orthopedic oncology center. RESULTS: The median delay in diagnosis was 7 (3-12) months. For tumors located in the pelvis, the delay was 10 months, compared to 5 months for the upper limb and 7 months for the lower limb (p=0.2312). The delay was 6 months In patients with osteosarcoma, and 8 months in chondrosarcoma patients (p=0.1786). At the first office visit, an x-ray was ordered in 19 cases (59.4%), of whom 9 patients (47.4%) were referred on to the oncology center. The most common symptoms were pain in the affected area (90.6%), limited mobility (28.1%) and pathological fracture (25%). After admission to an orthopedic department, a biopsy was performed after 5.5 (3-8.2) days. The histology results were ready after another 14 (8-18) days, and surgical treatment was performed after 95 (76-100) days. CONCLUSIONS: 1. Although patients show typical symptoms of bone tumors, only a small proportion are referred directly to an oncology center. After a primary bone tumor is suspected, further diagnostic and therapeutic activities proceed efficiently, in accordance with the current guidelines.

Pediatric parosteal osteosarcoma of the distal radius causing extensive erosive mass effect of the adjacent ulna: a case report.

INTRODUCTION: Parosteal osteosarcomas are low-grade bony malignancies that are treated primarily with surgical resection and reconstruction. This report discusses a unique case of a pediatric patient who presented with a parosteal osteosarcoma of the distal radius causing extensive erosive mass effect and growth disturbance of the adjacent ulna. Likely due to their slow-growing nonaggressive nature, parosteal osteosarcomas have not been previously described to abut adjacent bony structures through direct contact. The patient presented in a significantly delayed manner due to social circumstances, inadvertently revealing this novel behavior. This report reviews this rare case and describes the current understanding of this tumor. CASE PRESENTATION: The patient is a 13-year-old male who presented with a parosteal osteosarcoma of his distal radius. He presented with a palpable wrist mass and wrist stiffness. He presented in a delayed manner with advanced local disease due to social factors. Imaging revealed an osseous radial mass that abutted the ulna and likely stunted its growth. The patient ultimately underwent complex resection and allograft reconstruction of both his distal radius and ulna. Intraoperative pathology was confirmed to have negative tumor margins. Allograft reconstruction of the radius and ulna was performed utilizing patient-specific custom cutting guides. At the 6-month postoperative visit, the patient had no recurrence of the mass, minimal pain, and had almost regained range of motion of the extremities. Clinical radiographs at the 6-month postoperative visit demonstrated allograft incorporation. CONCLUSIONS: A previously unreported case of pediatric parosteal osteosarcoma of the distal radius with erosion of the adjacent ulna through direct contact is presented. The challenges in and the importance of arriving at a definitive diagnosis in a timely manner for the proper treatment of this malignancy are emphasized.