High accuracy of positioning custom triflange acetabular components in tumour and total hip arthroplasty revision surgery.

Aims: Custom triflange acetabular components (CTACs) play an important role in reconstructive orthopaedic surgery, particularly in revision total hip arthroplasty (rTHA) and pelvic tumour resection procedures. Accurate CTAC positioning is essential to successful surgical outcomes. While prior studies have explored CTAC positioning in rTHA, research focusing on tumour cases and implant flange positioning precision remains limited.

What Factors Are Associated With Stem Breakage in Distal Femoral Endoprosthetic Replacements Undertaken for Primary Bone Tumors?

Background: The advantages of distal femoral replacement prostheses for reconstructions after tumors are well known; one such implant, the Global Modular Replacement System (GMRS), has been widely used since 2003. Although implant breakage has been reported, the frequency of this event has varied across different studies.

Questions/purposes: (1) What percentage of patients who underwent distal femur resection and replacement using the GMRS for primary bone tumors at one center experienced stem breakage? (2) At what timepoints did these breakages occur, and what factors were common among the stems that broke?

Methods: We performed a retrospective study of all patients who underwent distal femur resection and replacement using the GMRS for a diagnosis of primary bone sarcoma by the Queensland Bone and Soft-tissue Tumor service from 2003 to 2020 who had a minimum of 2 years of follow-up.

Constrained or unconstrained shoulder replacement for musculoskeletal tumor resections?

Background: Many options exist for reconstructing the shoulder after large bony resections of the proximal humerus. One of the more widely used is endoprosthetic replacement. Proximal migration of unconstrained hemiarthroplasty articulations may cause difficulties particularly in the setting of loss of the rotator cuff and/or deltoid musculature.

Auranofin improves overall survival when combined with standard of care in a pilot study involving dogs with osteosarcoma.

Osteosarcoma is the most common paediatric primary bone malignancy. The major cause of death in osteosarcoma is drug-resistant pulmonary metastasis. Previous studies have shown that thioredoxin reductase 2 is a driver of metastasis in osteosarcoma and can be inhibited by auranofin (AF).

Is an Acetabular Cage and Cement Fixation Sufficiently Durable for the Treatment of Destructive Acetabular Metastases?

Background: Destructive bony acetabular metastases cause pain, pathological fractures, and loss of mobility. Although multiple fixation options are available, we have favored a rigid stainless steel partial pelvic cage for acetabular fixation in these patients; however, little is known about the durability of this approach. QUESTION/PURPOSES: (1) How common was loss of fixation in a small series of metastatic acetabular defects treated with an acetabular cage and cemented total hip replacement? (2) What is the implant survival free from reoperation or revision at 2 and 4 years using a competing-risks survivorship estimator in patients thus treated? (3) What complications were associated with the treatment? (4) What level of postoperative mobility was achieved?

Methods: Between 2006 and 2017, we treated all acetabular metastases that needed surgical intervention, not amenable to conventional cemented THA alone with our single technique of acetabular partial pelvic cage and cemented total hip replacement.

Expanding the Spectrum of Intraosseous Rhabdomyosarcoma: Correlation Between 2 Distinct Gene Fusions and Phenotype.

Primary intraosseous rhabdomyosarcomas (RMSs) are extremely rare. Recently 2 studies reported 4 cases of primary intraosseous RMS with EWSR1/FUS-TFCP2 gene fusions, associated with somewhat conflicting histologic features, ranging from spindle to epithelioid. In this study we sought to further investigate the pathologic and molecular abnormalities of a larger group of intraosseous RMSs by a combined approach using targeted RNA sequencing analysis and fluorescence in situ hybridization (FISH).

Novel MEIS1-NCOA2 Gene Fusions Define a Distinct Primitive Spindle Cell Sarcoma of the Kidney.

We describe 2 cases of a distinct sarcoma characterized by a novel MEIS1-NCOA2 gene fusion. This gene fusion was identified in the renal neoplasms of 2 adults (21-y-old male, 72-y-old female). Histologically, the resected renal neoplasms had a distinctively nodular appearance, and while one renal neoplasm was predominantly cystic, the other demonstrated solid architecture, invasion of perirenal fat, and renal sinus vasculature invasion.

The impact of non weight bearing: A prospective cohort study.

Background: Patients with lower limb injuries are commonly advised to non weight bear (NWB) on their injured limb as part of treatment. Occasionally, patients complain that offloading one limb, associated with the use of crutches or other mobility aids, may lead to pain on one of the other supporting limbs. This has led to compensation claims (1) but has never been the subject of formal research.

Single institution retrospective review of perioperative chemotherapy in adult and adolescent patients with operable osteosarcoma.

Aims: Perioperative chemotherapy has improved the prognosis for patients with operable osteosarcoma. The literature is conflicting about which regimen is optimal. The aim of this study was to evaluate the survival outcomes of two cohorts of patients with operable osteosarcoma treated with different perioperative chemotherapy regimens.

Treatment of long bone defects and non-unions: from research to clinical practice.

The treatment of long bone defects and non-unions is still a major clinical and socio-economical problem. In addition to the non-operative therapeutic options, such as the application of various forms of electricity, extracorporeal shock wave therapy and ultrasound therapy, which are still in clinical use, several operative treatment methods are available. No consensus guidelines are available and the treatments of such defects differ greatly.

Loss of osteoclasts contributes to development of osteosarcoma pulmonary metastases.

We conducted a transcriptomic screen of osteosarcoma (OS) biopsies and found that expression of osteoclast-specific tartrate-resistant acid phosphatase 5 (ACP5/TRAP) is significantly downregulated in OS compared with nonmalignant bone (P < 0.0001). Moreover, lesions from OS patients with pulmonary metastases had 2-fold less ACP5/TRAP expression (P < 0.

Establishment of a preclinical ovine model for tibial segmental bone defect repair by applying bone tissue engineering strategies.

Currently, well-established clinical therapeutic approaches for bone reconstruction are restricted to the transplantation of autografts and allografts, and the implantation of metal devices or ceramic-based implants to assist bone regeneration. Bone grafts possess osteoconductive and osteoinductive properties; however, they are limited in access and availability and associated with donor-site morbidity, hemorrhage, risk of infection, insufficient transplant integration, graft devitalization, and subsequent resorption resulting in decreased mechanical stability. As a result, recent research focuses on the development of alternative therapeutic concepts.

E2F7 can regulate proliferation, differentiation, and apoptotic responses in human keratinocytes: implications for cutaneous squamous cell carcinoma formation.

The E2F family of transcription factors plays a crucial role in the regulation of genes involved in cell proliferation, differentiation, and apoptosis. In keratinocytes, the inhibition of E2F is a key step in the control and initiation of squamous differentiation. Because the product of the recently identified E2F7a/E2F7b gene has been shown to repress E2F-regulated promoters, and to be abundant in skin, we examined its role in the epidermis.

Contralateral total hip arthroplasty after hindquarter amputation.

We describe the management and outcome of a 62-year old lady who developed severe osteoarthritis of the hip, nine years after a hindquarter amputation for radiation-induced sarcoma of the contralateral pelvis. The difficulties of stabilising the pelvis intraoperatively and the problems of postoperative rehabilitation are outlined. The operation successfully relieved her pain and restored limited mobility.

Clinical outcomes of deep atypical lipomas (well-differentiated lipoma-like liposarcomas) of the extremities.

Aim: Controversy exists with regard to the nomenclature, treatment and outcome of a group of well-differentiated lipomatous tumours sometimes labelled as atypical lipomas. The purpose of the present paper is to attempt to clarify these controversies by reporting our experience with this lesion.

Methods: The clinical features and follow up of 61 patients with the diagnosis of deep atypical lipoma and a minimum two-year follow up were examined.

Management and outcome after local recurrence of osteosarcoma.

We report on the management and outcome of 96 patients who developed local recurrence (LR) after having definitive primary treatment with chemotherapy and surgery for non-metastatic osteosarcoma. LR developed at a median of 11 months from initial surgical treatment. 18% of patients had metastases prior to the diagnosis of LR and 23% were found to have metastases synchronously.

Possible metastasis of osteosarcoma to a remote biopsy site: a case report.

In a patient who presented with an osteosarcoma of the proximal humerus, systemic staging revealed a lesion in the contralateral humerus, which was shown to be an enchondroma after open biopsy. The patient had a local recurrence develop, which necessitated forequarter amputation. Shortly thereafter, the patient had pain develop at the contralateral biopsy site, and examinations and repeat biopsy revealed metastatic osteosarcoma.

The management of extra-abdominal desmoid tumours.

We performed a retrospective analysis of 35 cases of desmoid tumours (aggressive fibromatoses) that underwent treatment at our institutions between 1987 and 2002. The purpose was to evaluate the rate of local recurrence of desmoid tumours treated with surgical excision, to assess the impact of surgical margins on local recurrence and to define the role of radiotherapy in the treatment. Nine patients experienced a recurrence at an average of 16 months after initial treatment.