When Do Orthopaedic Oncologists Consider the Implantation of Expandable Prostheses in Bone Sarcoma Patients?

Proximal Humerus Reconstruction in Skeletally Immature Patients

Proximal humerus reconstruction after oncologic resection is complex, with numerous muscular attachments, proximity of critical neurovascular structures, and dynamic stability granting multidirectional motion at the glenohumeral articulation. In skeletally immature patients, additional factors increase the complexity, including remaining limb growth and humerus size. Limb length discrepancy affects the limb's esthetics and function while the humerus size can limit fixation strategies and intramedullary device use. Reconstruction options used in isolation or combination include endoprostheses, osteoarticular allografts, allograft-prosthetic composites, autografts, and arthrodesis. Unique limb salvage options to address the unique factors in young, skeletally immature patients include vascularized fibular epiphyseal transfer, claviculo pro humeri, and expandible endoprostheses. Each option has advantages and disadvantages for anticipated function, durability, shoulder stability, and complications. This review aims to aid preoperative planning and decision making for surgeons and patients undergoing proximal humerus resection and reconstruction with notable remaining growth potential.

Foot growth disorder after surgery of lower limb malignant bone tumor in a pediatric series

BAKGROUND

Child malignant bone tumors often develop near growth cartilage. The gold standard surgery consists in large segmental resection. This resection often requires the sacrifice of growth cartilage, leading to inequality of limb length. Prothesis are used for reconstruction when the epiphysis is resected, otherwise different strategies of osteosyntheses and grafts may be an option.

HYPOTHESIS

The aim of the study was to analyze the foot size inequality after surgery of lower limb malignant bone tumor in patients with growth residual.

PATIENTS AND METHODS

A retrospective study analyzed the data of 60 patients followed in an oncology pediatric center, between January 2008 and December 2018, for surgically treated malignant bone tumor. All surgeries were realized between January 1992 and December 2013. The primary outcome was the foot size inequality at the last consultation. Categorical variables were described by frequencies and percentages, and compared with Student tests. Continuous variables were described by median and interquartile range, the linear relationship between the foot size inequality and the explanatory variables were analyzed with Pearson tests.

RESULTS

A foot size inequality of 1.15 cm [-0.5-3] was measured, a statistically significant difference (p < 0.0001). Younger children had a greater difference, as the patients with a greater final leg inequality. The children who required several surgeries because of mechanical issues also had a higher foot length difference.

DISCUSSION

The foot length inequality after bone tumor surgery of the lower limb in children with residual growth potential is a reality not enough described.

LEVEL OF EVIDENCE

IV.

Long-term outcomes of non-invasive expandable endoprostheses for primary malignant tumors around the knee in skeletally-immature patients

INTRODUCTION

Expandable endoprostheses are used to restore limb function and compensate for the sacrifice physis involved in carcinologic resection. Long-term outcomes of the last generation of knee "non-invasive" expandable endoprostheses are required. Objectives were to report on oncologic results of bone sarcoma resection around the knee with expandable endoprosthesis reconstruction and to compare the surgical outcomes of the "non-invasive" expandable endoprostheses used in our department.

MATERIALS AND METHODS

Retrospective study that included all children with bone sarcoma around the knee that underwent tumor resection reconstructed with non-invasive expandable prosthesis. Phenix-Repiphysis was used from 1994 to 2008 followed by Stanmore JTS non-invasive from 2008 to 2016. Survival and complications were recorded. Functional outcomes included Musculoskeletal Tumor Society (MSTS) score, knee range of motion, lower limb discrepancy (LLD).

RESULTS

Forty children (Sex Ratio = 1) aged a mean 8.8 years (range, 5.6-13.8) at surgery were included in the study. There were 36 osteosarcoma and 4 Ewing sarcoma that involved 33 distal femur and 7 proximal tibia. Cohort (n = 40) consisted of 28 Phenix-Repiphysis and 12 Stanmore with a mean follow-up of 9.8 ± 5.8 years and 6.1 ± 3.1 years, respectively. Postoperative infection rate was 7.5% in the cohort (3 Repiphysis). Functional results were significantly better in the Stanmore group with a mean MSTS of 87.6 ± 5.4% and knee flexion of 112 ± 38°. At last follow-up, implant survival was 100% in Stanmore group, whereas all living Phenix-Repiphysis were explanted. Mechanical failure was the primary cause for revision of Phenix-Repiphysis. Limb length equality was noted in 79% patients with Phenix-Repiphysis and 84% with Stanmore at last follow-up.

CONCLUSION

Chemotherapy and limb-salvage surgery yield good oncologic outcomes. Expandable endoprostheses are effective in maintaining satisfactory function and lower limb equality. With improvements made in the last generation of "non-invasive" prostheses, implants' survival has been substantially lengthened.

Noninvasive Expandable Endoprostheses From Reconstruction to Skeletal Maturity: A Surgical Technique and Lengthening Guide

Limb salvage is the benchmark for pediatric extremity bone sarcomas. However, reconstructive strategies must account for any anticipated remaining growth potential and the resultant limb inequality. Expandable endoprostheses offer the theoretical advantage of immediate weight-bearing, predictable function, and reliable maintenance of leg-length equality. The evolution of the lengthening mechanism now permits noninvasive lengthening, opposed to the multiple open procedures of the past. These design improvements have contributed to their growing popularity. Experience has indicated that these noninvasive implants more reliably achieve leg-length equality, have longer failure-free survival, and decreased complications, although some have noted gearbox and lengthening failures. Currently, no standardize technique exists for managing patients with noninvasive expandable implants from the time of reconstruction to final lengthening at skeletal maturity. This blueprint aims to provide a detailed surgical technique, lengthening schedule, and recommendations for the mitigation and management of complications to achieve successful limb salvage with noninvasive expandable endoprostheses.

Lower limb reconstruction for malignant bone tumours in children

Malignant bone tumours of the lower limb represent the majority of cases in both osteosarcoma and Ewing sarcoma in the growth period. Surgical treatment represents a key element of treatment. Different localizations and age groups require a differentiated surgical approach. Life and limb salvage are first on the list of treatment goals, followed by functional and cosmetic considerations. This review article delivers and discusses current surgical treatment strategies and outcomes for lower limb malignant bone tumours in children.

Biology and technology in the surgical treatment of malignant bone tumours in children and adolescents, with a special note on the very young

PURPOSE

The main challenge in reconstruction after malignant bone tumour resection in young children remains how and when growth-plates can be preserved and which options remain if impossible.

METHODS

We describe different strategies to assure best possible long-term function for young children undergoing resection of malignant bone tumours.

RESULTS

Different resources are available to treat children with malignant bones tumours: a) preoperative planning simulates scenarios for tumour resection and limb reconstruction, facilitating decision-making for surgical and reconstructive techniques in individual patients; b) allograft reconstruction offers bone-stock preservation for future needs. Most allografts are intact at long-term follow-up, but limb-length inequalities and corrective/revision surgery are common in young patients; c) free vascularized fibula can be used as stand-alone reconstruction, vascularized augmentation of structural allograft or devitalized autograft. Longitudinal growth and joint remodelling potential can be preserved, if transferred with vascularized proximal physis; d) epiphysiolysis before resection with continuous physeal distraction provides safe resection margins and maintains growth-plate and epiphysis; e) 3D printing may facilitate joint salvage by reconstruction with patient-specific instruments. Very short stems can be created for fixation in (epi-)metaphysis, preserving native joints; f) growing endoprosthesis can provide for remaining growth after resection of epi-metaphyseal tumours. At ten-year follow-up, limb survival was 89%, but multiple surgeries are often required; g) rotationplasty and amputation should be considered if limb salvage is impossible and/or would result in decreased function and quality of life.

CONCLUSION

Several biological and technological reconstruction options must be merged and used to yield best outcomes when treating young children with malignant bone tumours.

LEVEL OF EVIDENCE

Level V Expert opinion.

Imaging following surgery for primary appendicular bone tumours

Primary bone tumours are uncommon, with sarcomas accounting for < 0.2% of all malignancies. The survival rate of primary bone sarcomas has significantly improved due to (neo)adjuvant therapy, while improved surgical techniques and development of new prostheses have shifted the surgical focus from amputation to limb preservation in the vast majority of patients. A wide variety of surgical options are available for the treatment of primary bone tumours which depend upon histological diagnosis, their appearance at the time of presentation and response to any (neo)adjuvant therapy as required. This review is intended to help radiologists familiarise themselves with the management of primary appendicular bone tumours and expected normal postoperative appearances for the various surgical techniques, and to recognise potential complications.

Functional and Surgical Outcomes After Endoprosthetic Reconstruction With Expandable Prostheses in Children: A Systematic Review

Treatment of bone sarcomas in children is associated with wide tumor re-section and segmental reconstruction. The optimal surgical approach is still under debate in the literature. During the past decade, the application of expandable prostheses has gained remarkable attention because it improves patients' appearance and allows limb growth preventing leg length discrepancy. A systematic review of the literature was performed to identify studies focusing on the functional and surgical outcomes of the application of expandable endoprostheses. [Orthopedics. 2019; 42(4):184-190.].

Current review of surgical management options for extremity bone sarcomas

Modern surgical management of extremity bone sarcomas is governed by limb-sparing surgery combined with adjuvant and neoadjuvant chemotherapy.

All the resection and reconstruction techniques have to achieve oncologic excision margins, with survival rates and functional results superior to amputation.

The main reconstruction techniques of bone defects resulted after resection are: modular endoprosthetic reconstruction; bone graft reconstruction; bone transport; resection arthrodesis; and rotationplasty.

Oncologic resection and modular endoprosthetic reconstruction are the generally approved surgical options adopted for the majority of cases in major specialized bone sarcoma centres.

Good basic principles, efficient multidisciplinary approach and sustained research in the field can provide a better future for the challenge posed by extremity bone sarcoma treatment.

Cite this article: EFORT Open Rev 2019;4:174-182. DOI: 10.1302/2058-5241.4.180048