Impacts of Tumor Location, Nature and Bone Destruction of Extremity Osteosarcoma on Selection of Limb Salvage Operative Procedure

Contribution of Sonication to the Identification of Megaprosthesis Infection in Culture Negative Oncologic Patient

Conventional central osteosarcoma mainly affects the metaphysis of long bones in young people. The use of megaprostheses in oncological patients has increased in recent years. However, this type of surgery is not exempt from complications, with infections being the most common. In recent years, the presence of biofilm-forming bacteria has increased. Biofilm characteristics allow bacteria to resist hostile environmental conditions. The application of long wave ultrasound (process known as sonication) on the rescued inert material before culture interrupts the biofilm and generates a significantly higher recovery of bacterial growth compared to conventional tissue culture. We present the case of a 12-year-old patient with osteosarcoma of the femur, who, after surgery, developed a prosthetic infection detected by sonication, with negative soft tissue culture.

Surgical Advances in Osteosarcoma

Simple Summary

Osteosarcoma (OS) is the most common bone cancer in children. OS most commonly arises in the legs, but can arise in any bone, including the spine, head or neck. Along with chemotherapy, surgery is a mainstay of OS treatment and in the 1990s, surgeons began to shift from amputation to limb-preserving surgery. Since then, improvements in imaging, surgical techniques and implant design have led to improvements in functional outcomes without compromising on the cancer outcomes for these patients. This paper summarises these advances, along with a brief discussion of future technologies currently in development.

Abstract

Osteosarcoma (OS) is the most common primary bone cancer in children and, unfortunately, is associated with poor survival rates. OS most commonly arises around the knee joint, and was traditionally treated with amputation until surgeons began to favour limb-preserving surgery in the 1990s. Whilst improving functional outcomes, this was not without problems, such as implant failure and limb length discrepancies. OS can also arise in areas such as the pelvis, spine, head, and neck, which creates additional technical difficulty given the anatomical complexity of the areas. We reviewed the literature and summarised the recent advances in OS surgery. Improvements have been made in many areas; developments in pre-operative imaging technology have allowed improved planning, whilst the ongoing development of intraoperative imaging techniques, such as fluorescent dyes, offer the possibility of improved surgical margins. Technological developments, such as computer navigation, patient specific instruments, and improved implant design similarly provide the opportunity to improve patient outcomes. Going forward, there are a number of promising avenues currently being pursued, such as targeted fluorescent dyes, robotics, and augmented reality, which bring the prospect of improving these outcomes further.

Transepiphyseal resection for osteosarcoma in patients with open physes using MRI assessment

AIMS

For paediatric and adolescent patients with growth potential, preservation of the physiological joint by transepiphyseal resection (TER) of the femur confers definite advantages over arthroplasty procedures. We hypothesized that the extent of the tumour and changes in its extent after neoadjuvant chemotherapy are essential factors in the selection of this procedure, and can be assessed with MRI. The oncological and functional outcomes of the procedure were reviewed to confirm its safety and efficacy.

METHODS

We retrospectively reviewed 16 patients (seven male and nine female, mean age 12.2 years (7 to 16)) with osteosarcoma of the knee who had been treated by TER. We evaluated the MRI scans before and after neoadjuvant chemotherapy for all patients to assess the extent of the disease and the response to treatment.

RESULTS

The mean follow-up period was 64.3 months (25 to 148) after surgery and no patients were lost to follow-up. On MRI evaluation, 13 tumours were near but not in contact with the physes and three tumours were partially in contact with the physes before neoadjuvant chemotherapy. Bone oedema in the epiphysis was observed in eight patients. After neoadjuvant chemotherapy, bone oedema in the epiphysis disappeared in all patients. In total, 11 tumours were not in contact and five tumours were in partial contact with the physes. The postoperative pathological margin was negative in all patients. At the last follow-up, 12 patients were continuously disease-free and three had no evidence of disease. One patient died due to the disease. Functionally, the patients with retained allograft or recycled autograft had a mean knee range of flexion of 126° (90° to 150°). The mean Musculoskeletal Tumor Society functional score was 27.6 (23 to 30).

CONCLUSION

TER is an effective limb-salvage technique for treating malignant metaphyseal bone tumours in paediatric and young osteosarcoma patients with open physes when a good response to chemotherapy and no progression of the tumour to the epiphysis have been confirmed by MRI. Cite this article: Bone Joint J 2020;102-B(6):772-778.

Skeletal impact of 17β-estradiol in T cell-deficient mice: age-dependent bone effects and osteosarcoma formation

Estrogen (E₂)-dependent ER+ breast cancer, the most common breast cancer subtype, is also the most likely to metastasize to bone and form osteolytic lesions. However, ER+ breast cancer bone metastasis human xenograft models in nude mice are rarely studied due to complexities associated with distinguishing possible tumoral vs. bone microenvironmental effects of E₂. To address this knowledge gap, we systematically examined bone effects of E₂ in developing young (4-week-old) vs. skeletally mature (15-week-old) female Foxn1^nu nude mice supplemented with commercial 60-day slow-release E₂ pellets and doses commonly used for ER+ xenograft models. E₂ pellets (0.05-0.72 mg) were implanted subcutaneously and longitudinal changes in hind limb bones (vs. age-matched controls) were determined over 6 weeks by dual-energy X-ray absorptiometry (DXA), microCT, radiographic imaging, and histology, concurrent with assessment of serum levels of E₂ and bone turnover markers. All E₂ doses tested induced significant and identical increases in bone density (BMD) and volume (BV/TV) in 4-week-old mice with high bone turnover, increasing bone mineral content (BMC) while suppressing increases in bone area (BA). E₂ supplementation, which caused dose-dependent changes in circulating E₂ that were not sustained, also led to more modest increases in BMD and BV/TV in skeletally mature 15-week-old mice. Notably, E₂-supplementation induced osteolytic osteosarcomas in a subset of mice independent of age. These results demonstrate that bone effects of E₂ supplementation should be accounted for when assessing ER+ human xenograft bone metastases models.

Efficacy of a Modified Scoring System to Facilitate Surgical Decision-making for Diaphyseal Malignancies: When is Devitalized Tumor-bearing Autograft of Value?

Objectives

To evaluate the validity of a modified scoring system (MSS) for inferring the bony quality of tumor‐bearing diaphyses and predicting the risk of reconstructive failure after devitalized bone replantation (DBR).

Methods

In this retrospective cohort study, we reviewed the records of 30 patients surgically treated for diaphyseal malignancies between 1996 and 2015. There were 18 male and 12 female subjects; the average age was 34.0 ± 24.5 years (8–82 years). Tumor locations comprised the femur (21), the humerus (4), the tibia (3), the radius (1), and the fibula (1). Histological diagnoses included osteosarcoma (13), metastases (4), Ewing sarcoma (3), chondrosarcoma (3), malignant fibrohistiocytoma (2), periosteal osteosarcoma (1), Langerhans cell sarcoma (1), lymphoma (1), rhabdomyosarcoma (1), and malignant giant cell tumor (1). All primary tumors were rated as stage IIB. Twenty patients underwent DBR. Prosthetic procedures and segmental autografting/allografting were performed in 7 and 3 cases, respectively. MSS (comprising 5 elements: pain, tumor location, bone destruction, localized dimension, and longitudinal dimension) for each patient was calculated in accordance with their preoperative presentations. Outcome measurements included oncological results, outcomes of reconstructions, complications, and functional preservation, presented using the musculoskeletal tumor society (MSTS) scale.

Results

Follow up was available in 29 cases for an average duration of 61.0 ± 49.9 months (12–152 months). Infection occurred in 2 patients (6.9%), primary nonunion in 6 (27.3%), metastases in 9 (31.9%), recurrences in 4 (13.8%), and deaths in 7 (24.1%); 1 subject underwent amputation due to recurrence following endoprosthetic replacement (3.4%). In the DBR group, fractures occurred in 4 cases (21.1%) and nonunion in 5 (25%); internal fixation was related to nonunion (nails, 44.4% vs plates, 9.1%, P = 0.02). MSS was associated with fractures of devitalized autografts (11.0 ± 1.2 vs 8.3 ± 1.8, P = 0.01); the system was efficacious in predicting chances of fractures of these grafts (P = 0.02). MSS ≥ 10 (with false positive rate ≤ 6.7%) suggested increased fracture probability (≥22.7%) after DBR; therefore, 10 was considered a cutoff value.

Conclusions

Diaphyseal malignancies with MSS ≥10 may contraindicate DBR for increased chances of reconstructive failure. In this situation, alternative procedures are advisable. Further investigations are warranted to assess the efficacy of MSS in implying the validity of DBR for diaphyseal malignancies.

Outcome of segmental prosthesis reconstruction for diaphyseal bone tumors: a multi-center retrospective study

Background

The optimal reconstructive method after diaphyseal malignant bone tumor resection remains controversial. This multicenter clinical study was designed to investigate the clinical value and complications of segmental prosthesis in the repair of diaphyseal defects.

Methods

We present 49 patients from three clinical centers treated with wide resection for primary or metastatic bone tumors involving the diaphysis of the femur, tibia, humerus, or ulna, followed by reconstruction using a modular intramedullary segmental prosthesis.

Results

Enrolled patients included 23 men and 26 women with a mean age of 63.3 years. Of these, seven patients had primary bone tumors and 42 patients had metastatic lesions. At the mean follow-up of 13.7 months, 17 patients were alive, 31 patients were deceased due to tumor progression, and one patient was dead of another reason. There were eight nononcologic complications (two with radial nerve injury, three with delayed incision healing, two with aseptic loosening in the proximal humerus prosthetic stem and one with structural failure) and three oncologic complications (three with primary tumor recurrence) among all patients. The incidence of complications in primary tumor patients (4/7, 57.1%) was higher than that in patients with metastatic tumors (7/42, 16.7%) (p = 0.036). Aseptic loosening and mechanical complications were not common for patients with primary tumors, although the reconstruction length difference was statistically significant (p = 0.023). No statistically significant differences were observed in limb function, while the mean musculoskeletal tumor society score was 21.2 in femora, 19.6 in humeri, and 17.8 in tibiae (p = 0.134).

Conclusions

Segmental prostheses represent an optional method for the reconstruction of diaphyseal defects in patients with limited life expectancy. Segmental prostheses in the humerus experienced more complications than those used to treat lesions in the femur.

Limb salvage surgery with joint preservation for malignant humeral bone tumors: operative procedures and clinical application

BACKGROUND

However, the application of limb salvage with joint preservation is controversial. The purpose of this study is to propose a selection strategy of joint-sparing operative procedures for humeral malignancies based on tumor origin, site and bone strength.

METHODS

The medical data of 28 patients with humeral malignancies treated at our institute from January 2010 to December 2016 were analyzed retrospectively. The patients had a median age of 51 years (range, 8-82 years). Bone strength scoring system was utilized to evaluated bone strength of the tumor. Four joint-sparing surgical methods were performed on selected patients. Evaluation of limb function was based on the Musculoskeletal Tumor Society scoring system. Two-sample t-test was used to compare patient group data such as bone strength score and postoperative Musculoskeletal Tumor Society score.

RESULTS

The mean follow-up period for the 7 patients with primary malignancies was 45 months (range, 15-66 months). One patient died due to recurrence and lung metastasis, while the remaining 6 patients (6/7, 85.7%) survived without recurrence. For the 21 patients with metastases, 5 survived with tumors, with an average survival time of 25.8 months (range, 9-48 months). The rest died from progression of the primary tumors. The mean bone strength score for the biological reconstruction group and non-biological reconstruction group was respectively 9.7 ± 1.3 and 12.9 ± 1.2. A significant difference between the 2 groups (p < 0.05) was found. Mean postoperative Musculoskeletal Tumor Society score was respectively 27.2 ± 1.8 and 26.1 ± 1.7 for the 2 groups. There was no significant difference between the 2 groups (p > 0.05). Non-oncological complications included fracture (1), aseptic loosening (1) and radial nerve injury (1).

CONCLUSIONS

Alcohol devitalized autograft replantation is applicable for diaphyseal humeral primary malignancies, with a good response to chemotherapy and a low bone strength score (≤10). In situ microwave ablation is suitable for diaphyseal and (or) metaphyseal low-grade malignant bone tumors or metastases with a low bone strength score (≤10). Intercalary prosthetic reconstruction is preferred for diaphyseal metastases with a high bone strength score (> 10).

The current status of MRI in the pre-operative assessment of intramedullary conventional appendicular osteosarcoma

Osteosarcoma is the commonest primary malignant bone tumour in children and adolescents, the majority of cases being conventional intra-medullary high-grade tumours affecting the appendicular skeleton. Treatment is typically with a combination of neo-adjuvant chemotherapy, tumour resection with limb reconstruction and post-operative chemotherapy. The current article reviews the role of magnetic resonance imaging (MRI) in the pre-operative assessment of high-grade central conventional osteosarcoma.

Treatment of osteosarcoma around the knee in skeletally immature patients

Limb sparing surgery in growing young patients with malignant tumors is difficult as invasion of the physis by the tumor or surgical resection through the metaphysis may cause significant limb discrepancy following surgery. At present, hinged tumor prosthesis or biological reconstructions are the main methods following tumor resection in these patients. The aim of the present study was to assess different procedures for the treatment of osteosarcoma around knee joints in immature patients. A retrospective study of 56 patients (<15 years old, open physis) who had been treated for osteosarcoma around the knee joint between January 2007 and December 2015 was performed. Clinical data collected included patient demographics (age at diagnosis, sex and date of diagnosis), tumor characteristics [location, Enneking stage and subtype on magnetic resonance imaging (MRI)], treatment (response to neoadjuvant chemotherapy and type of primary surgery) and clinical outcomes (limb function, discrepancy and overall survival). The median age at the time of diagnosis was 12.14 years (range, 3–15 years). There were 32 male patients (57.1%). A total of 41 (82%) tumors were located at the distal femur, and 15 (18%) at the proximal tibia. A total of 49 (87.5%) patients were diagnosed with stage IIB tumors, and 7 (12.5%) had stage III, according to the Enneking stage classification. Different surgical methods, including amputation, rotation-plasty, endoprosthesis and biological instructions (e.g., allograft) were performed according to MRI type classification. During follow-up, 21 patients (37.5%) succumbed to disease. The Musculoskeletal Tumor Society score ranged from excellent to fair functional result. Recurrence (2 cases, 16.67%) and infection (2, cases, 16.67%) were the main complications following endoprosthesis replacement, while delayed union (12 cases, 57.14%) and fracture (3 cases, 14.29%) were the main causes for biological reconstructions. Limb-length discrepancy ranged from 0–10 cm in limb-saving surgery. The overall survival rate was 57.66% with different cohorts in Enneking stages IIB and III, with or without involvement of the physis and different cycles of chemotherapy. Results of the present study indicated that different limb saving surgeries, including epiphysis/physis preservation with biological construction in patients with MRI types I to III and endoprosthetic/osteoarticular reconstruction in patients with MRI types IV and V, are useful in the management of osteosarcoma in growing young patients with proper surgery indications, and knee joint function was maintained with acceptable complications including limb discrepancy, delayed union, infection, recurrence and fracture.