Preliminary results of a new intercalary modular endoprosthesis for the management of diaphyseal bone metastases

Abstract

Objectives: This study aims to evaluate functional outcomes of patients and to analyze complication rates of modular intercalary endoprosthetic reconstruction after resection of metastatic diaphyseal bone lesions. Patients and methods: Between December 2017 and February 2020, 22 patients (15 males, 7 females; median age: 64.2 years; range, 49 to 91) who underwent reconstruction with modular intercalary endoprostheses for metastatic bone tumors at five different centers were retrospectively analyzed. Age, sex, diagnosis, follow-up duration, previous treatments of patients, and resection lengths were recorded. The Musculoskeletal Tumor Society Scores (MSTS) were used to assess functional status of available patients at the final follow-up. Failures were categorized according to the Henderson classification. Results: Locations of the resected tumors included 10 humeri (45.5%), five tibiae (22.7%), and seven femurs (31.8%). The length of the resected tissues ranged from 35 mm to 180 mm. Seven patients (31.8%) died of disease, and one patient died of pneumonia within follow-up period. The functional outcomes of surviving patients were satisfying with a median MSTS score of 86.9% (range, 70 to 100%) at a median follow-up of 17 months (range, 8 to 26). There were two cases of type II (9%), one cases of type IIIa (4.5%), two cases of type IIIb (9%), and one case of type IV (4.5%) failure. Complications were most commonly observed in tibial reconstructions. Conclusion: The good short-term functional results were achieved in surviving patients. Uncomplicated patients were able to perform daily living activities without limitations. The overall rate of complications was relatively low and, among them, mechanical problems were the most commonly encountered problems.

What Is the Prosthetic Survival After Resection and Intercalary Endoprosthetic Reconstruction for Diaphyseal Bone Metastases of the Humerus and Femur?

“…Similarly, Pu et al [15] and Huang et al [13] reported total MSTS scores of 84.6% and 95.3% at the final follow-up interval in patients with humeral and femoral diaphyseal metastatic lesions, respectively. Another study that included tibial implants noted early short-term gains in functional outcome scores [5]. Our patients with femoral implants consistently returned early to ambulation, and most patients did not rely on any external support.…”

“…However, prior studies have emphasized the treatment of primary sarcomas, and there is little research examining outcomes specifically in the setting of metastatic lesions [8,13,15,17,18]. In one recent study of 22 patients with metastases, short-term improvements were noted in pain and functional outcome, but six of the 22 patients had implant failures of different modes including aseptic loosening, breakage, and infection [5]. Furthermore, there have not been attempts in the past at estimating the cumulative risk of implant revision or aseptic loosening while considering death as a competing risk for patients with metastatic disease and limited overall survival.…”

Finite Element Analysis of New Designed Intercalary Prosthesis Implant (Ulna Bone)

“…This analysis also revealed that the highest deformation recorded was 1.3871e-008 m, Fig (16). In the tensile test, the maximum stress seen was recorded as 6.6012e+006 Pa, Fig (17), while the corresponding largest deformation was measured at 1.0458e-006 m, Fig (18). All the numerical results of the tests were summarized in Table 2.…”