Treatment of benign bone tumors by allograft. About 40 cases.
Introduction: Benign bone tumors are common and can occur at any age, although they are most commonly seen in children, adolescents and young adults. They are of different histological types: bone, cartilaginous, fibrous and others. Material and methods: this is a study of a study carried out on a series of 80 patients presenting with a loss of segmental or cavitary bone substance who had benefited from bone reconstruction by allograft bone from cryopreserved femoral heads, the average age was 31.5 years, the loss of substance was greater than 10 mm in 33 cases. The results: after a 5-year follow-up: we note Osteo-integration of the graft in 34 cases. Partial lysis in 04 cases, total lysis in 02 cases. Discussion: Different means are available to perform bone reconstruction in benign tumors, these means differ according to their nature, autograft, allograft, biomaterials and bone substitutes. Their respective indications depend on the type of bone loss. The results are linked to their potential for osseointegration or, on the contrary, resorption. Bone allografts have three available forms: structural allografts, split allografts, and massive allografts. They are of human origin and can be cryopreserved, irradiated or lyophilized Conclusion: Allograft filling in benign bone tumors reduces operative time, with no donor site morbidity. Reliability of the filling appears to be the best prevention of recurrence.

Introduction: Management of ABC(Aneurysmal Bone Cysts) of the spine is challenging, as it requires adequate resection to ensure complete disease clearance and subsequent reconstruction of the involved functional spinal unit to address the resultant instability. Various treatment modalities described in literature have been used singly or in combination. Yet the recurrence rate ranges from 4% to 44%.We describe a strategy for the management of aneurysmal bone cysts of the spine. Methods:Our experience in the management of six patients with spinal ABCs[thoracic(n=4) and lumbar(n=2) spine] is presented.After a detailed radiological evaluation, the appropriate treatment plan was devised based on Enneking staging.Posterior stabilization, followed by enbloc resection with anterior column reconstruction was done through a transthoracic approach for dorsal spine lesions.Lumbar lesions were managed with posterior stabilization and intralesional curettage through transforaminal approach.Outcomes were analysed using VAS(Visual Analogue Scale) and SF-12 scores, neurological improvement and radiological evaluation of recurrence. Results:The mean age at presentation was 21.5+/-5.3 years.There was significant improvement in VAS and SF-12 scores at a mean follow-up of 39.2+/-6.7 months.Both patients who presented with neurological deficit showed complete recovery at final follow-up.One patient with lumbar spine lesion who had recurrence, was treated with reexploration, complete excision of the lesion and adjuvant therapy with denosumab.There were no intra-operative or post-operative complications. Conclusion:Pre-operative embolization facilitates complete removal of tumor by reducing tumor vascularity.Complete removal of lesion based on Enneking staging, along with reconstruction of the spine, through an all-posterior or separate anterior and posterior approaches, where appropriate is essential to prevent recurrence.

Introduction: Giant cell tumors (GCTs) are aggressive benign tumors that affect the metaphyseal region of long bones. Treatment includes resection curettage, adjuvant therapy, cementation, and plate fixation with or without subchondral bone grafting. This study investigates if subchondral bone grafting with Polymethylmethacrylate (PMMA) was associated with fewer non-oncological complications and if a difference in tumor recurrence exists. Methods: Retrospectively reviewed records of patients treated for GCT from 1996-2021 at a single institution. Two cohorts were made (with or without bone grafting). Surgical decision-making was the surgeon’s preference [graft (JB), No Graft (KB, FP)]. Results: 55 patients with a median age of 31 years were analyzed, 40% treated with bone graft. 55% were female. Median follow up time was 49 months, no statistical difference between treatments. There were 20 recurrences, 8 recurrences in the graft cohort. The risk of recurrence was not statistically different between the cohorts (RR=1.04, 95% CI 0.49–2.20). Median time to recurrence was 17 months, with no statistical difference between the groups. 22% of patients had non-oncological complications: 5 fractures and 7 osteoarthritis. All occurred in the PMMA alone group. Patients treated with bone graft were 94% less likely than those treated with PMMA alone to develop a fracture or osteoarthritis (RR=0.06, 95% CI 0.004–0.95). Median time to a non-oncological complication was 28 months. Median MSTS score was 93%, with no difference between the groups. Conclusion: Use of bone graft in patients with GCTs resulted in decreased risk of non-oncological complications without an increased likelihood of recurrence.

Introduction: Solitary bone plasmacytomas (SBP) are localized plasma cell malignancies involving bone marrow.It is a rare entity and in the spine, it mainly concerns the dorsolumbar spine. Involvement of the upper cervical spine is rare and more challenging condition.Objective: We report the case of a man with solitary plasmacytoma involving vertebral body and posterior arch of the axis. Case presentation:A 50-year-old man presented with neck pain and uncommon right sided cervicobrachial neuralgia evolving for 4 months and becoming resistant to symptomatic treatment. X-ray showed a lytic lesion of C2. MRI concluded in a high signal mass of the entire vertebral body, the odontoid process and the right posterior hemi-arch of C2 with invasion of the pre-vertebral soft tissue, the intervertebral disc and the anterior part of C3.A CT- sacan guided biopsy failed to confirm diagnosis. We decided to perform posterior biopsy with occipito-cervical fusion.The diagnosis of solitary plasmocytoma of the axis was confirmed based on histopathological examination, biologic and extension assesment. The patient was reviewed in the hematology department and he recieved both postoperative radiotherapy and chimiotherapy.He remains with no neck pain or neurological deficit and serum markers of multiple myeloma were normal at 2-year follow-up.Conclusion:SBP is a rare diagnosis especially in the upper cervical spine for which the primary treatment is local radiotherapy. However, instability is the main reason for pain, which can only be relieved completely by surgery.

Endoprosthetic replacement of the distal femur (DFR) is a widely used reconstructive technique for both primary and metastatic tumours involving the femur. The aim of this study is to evaluate our experience of the Stryker METS distal femoral replacement (Stryker, Mahwah, NJ, USA).
Clinical records of all patients undergoing distal femoral replacement for oncological indications between February 2010 and February 2016 were reviewed. Failures were classified according the system described by Henderson.[1] Patient and implant survivorship were estimated using the Kaplan-Meier method.
100 patients of mean age 50 years (range 14 to 90) were identified with mean follow up of 41 months (range 1-107). 63 patients had primary bone tumours and 37 metastatic bone disease. Half of the cohort died (50.0%) at a mean of 28 months (1-97 months).
Overall there were 12 revisions (12.1%), at a mean of 32 months (range 1-69 months), with Type 2 failures being the most common. Overall 5-year revision-free survival was 83%.
This study shows this modular DFR system provides comparable results to those in the literature in reconstruction of the distal femur for primary bone tumours or metastatic bone disease.

Introduction: Treatment of an infected prostheses that require two-stage endoprosthesis reconstruction (EPR) remains a challenge due to the instability of the resultant segmental bone defect. Methods: Retrospectively reviewed patients treated for revision total joint or endoprosthetic infection at the knee from 1998-2018. Stage 1, explant of prosthesis and debridement with intramedullary nail-stabilized antibiotic spacers for patients with residual skeletal defects of >6 cm. Intramedullary nails were used, with their junction stabilized at the knee joint, the bone defect was filled with antibiotic laden cement. Six weeks of intravenous antibiotics and six weeks of oral antibiotics were administered. Stage 2, with resolution of inflammatory markers and negative tissue cultures, antibiotic spacer removal followed by EPR. Results: Twenty-one patients at a mean age of 54±21 years were treated for PJI at the knee. Polymicrobial growth was detected in 38% of cases, coagulase-negative staphylococci in 24%, and Staphylococcus Aureus in 19%. Mean residual defect size was 20 cm. Patients with polymicrobial infections had more surgeries prior to infection [6.1 vs. 3.0; p=0.024] and required repeat debridements prior to EPR [50% vs. 8%, OR 12.0 p=0.048]. PJI eradication was achieved in 86% patients, with a mean MSTS score of 77% and mean knee range of motion of 100 degrees. 63% patients who have retained their limb and an EPR required flap coverage (9 gastrocnemius flaps, 2 free flaps, 1 fasciocutaneous flap). Conclusions: Use of intramedullary antibiotic spacers in segmental bone defects maintain stability and result in high rates of limb-salvage with conversion to endoprosthesis.

Osteosarcoma is the most common primary malignant bone tumor in adolescents. It has a rapid growth rate, particularly at puberty. The treatment protocol is multidisciplinary and consists of neoadjuvant chemotherapy, followed by surgery and adjuvant chemotherapy. We present the case of a 16-year-old adolescent with conventional osteoblastic osteosarcoma in the distal femur. After systemic treatment, he underwent a wide excision and reconstruction with a knee tumor stent. The histological result revealed negative margins and tumor necrosis >99%. Immediate postoperative without complications. Complete neoadjuvant chemotherapy. However, at 6 months she had a suspicious clinic and arthrocentesis diagnosed an infection (Staphylococcus Epidermidis). An attempt was made to retain the implant, with aggressive debridement and targeted antibiotics. After another 6 months, a clinical recurrence occurred, Staphylococcus Aureus was isolated, and the chronic infection was treated with a two-stage revision: removal of components and placement of a cement spacer with antibiotic, and 3 months later reimplantation of a new tumor endoprosthesis with local antibiotic. In both procedures, tissue was collected for microbiology and histology, and the prosthesis for sonication. With 3 months of favorable clinical and analytical evolution, the image control showed a rare image of bone reaction adjacent to the remaining femur. The biopsy described reactive, sterile fibroblast proliferation. Periprosthetic infection in orthopedic oncology can lead to increased morbimortality. Management of this complication is challenging, requiring an aggressive and planned approach. We present a rare finding of bone reaction with reactive fibroblast proliferation after treatment. The treatment protocol and prophylactic measures are need.

Introduction
Renal cell carcinoma accounts for 3% of all adult malignancies.Metastasizes in the lung, bone and liver, mainly affecting 30% of patients at the time of diagnosis.

Goals
Describe the emergency management, diagnosis and definitive treatment of a pathological subtrochanteric fracture of the femur in a young woman.

Material-method
A 43-year-old woman with no previous history complains of insidious pain in right hip for 4 months which is treated conservatively.She presents to the emergency room for sudden hip pain causing inability to walk.Plain X-ray of the hip shows a pathological fracture at the subtrochanteric level of the femur.A body CT scan is urgently performed to classify the bone lesion and rule out a primary tumour where a renal tumour is observed with signs of malignancy in addition to multiple bone metastases and pathological fracture in the right proximal femur.A bone biopsy is subsequently performed,classifying the lesion as metastatic clear cell renal carcinoma.After classifying the type of tumour and following embolization of the metastatic lesion,femoral replacement surgery is performed by posterior approach and implantation of the cemented cup and MUTARS tumor reconstruction stem.

Results
In the postoperative period,an epidural catheter was placed for analgesic control and anemia treatment. Four months after surgery,the patient is stable with independent gait with the help of crutches.

Conclusion
The treatment of long bone metastases of clear cell renal carcinoma must be individualized and requires CT angiography and embolization prior to resection and placement of a tumor prosthesis,increasing the quality of life of the patient.