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.Orthopaedics, Trauma Surgery and Rehabilitatio

Long-Term Clinical Outcomes of Intercalary Allograft Reconstruction for Lower-Extremity Bone Tumors

Background: Improved survival rates for patients with primary bone tumors of the extremities have increased the demand for reliable and durable reconstruction techniques. Some authors have stated that, after successful ingrowth, allografts are a durable long-term solution. This hypothesis is largely based on small studies with short-to-midterm follow-up. In order to determine the durability of intercalary allograft reconstructions in the lower extremities, we evaluated the long-term clinical outcomes at a minimum of 10 years. Methods: All patients who received an intercalary allograft reconstruction in a lower extremity between 1980 and 2006 were included in this retrospective multicenter cohort study. One hundred and thirty-one patients with a median age of 19 years were included. Eighty-nine (68%) had a femoral reconstruction, and 42 (32%) had a tibial reconstruction. The most prevalent diagnoses were osteosarcoma (55%), Ewing sarcoma (17%), and chondrosarcoma (12%). The median follow-up was 14 years. A competing risk model was employed to estimate the cumulative incidences of mechanical failure and infection. Patient mortality or progression of the disease was used as a competing event. Results: Nonunion occurred in 21 reconstructions (16%), after a median of 16 months, and was associated with intramedullary nail-only fixation (p 10 years. With failure for mechanical reasons as the end point, the cumulative incidences of reconstruction failure at 5, 10, and 15 years were 9%, 14%, and 21%, respectively. Conclusions: Intercalary allograft reconstruction is an acceptable reconstructive option, mainly because of the absence of superior alternatives with a known track record. However, a considerable and continuing risk of mechanical complications should be taken into account.Development and application of statistical models for medical scientific researc