The use of distraction osteogenesis for reconstruction of bone defects after tumor resection of high-grade lesions

Developing a novel calcium magnesium silicate/graphene oxide incorporated silk fibroin porous scaffold with enhanced osteogenesis, angiogenesis and inhibited osteoclastogenesis

Recently, biofunctional ions (Mg2+, Si4+, etc.) and graphene derivatives are proved to be promising in stimulating bone formation. In this study, a novel inorganic/organic composite porous scaffold based on silk fibroin (SF), graphene oxide (GO), and calcium magnesium silicate (CMS) was developed for bone repair. The porous scaffolds obtained by lyophilization showed a little difference in pore structure while GO and CMS displayed a good interaction with SF matrix. The addition of CMS with good mineralization potential and sustainedly release ability of biofunctional ions (Ca2+, Mg2+ and Si4+) increased the strength of SF scaffolds a little and facilitated the osteogenic differentiation of bone mesenchymal stem cells (BMSCs) by upregulating bone formation-related genes (ALP, COL1, OC and Runx2). The further incorporation of GO in SF scaffolds enhanced the compressive strength and water retention, and also remarkably promoted the osteogenic differentiation of BMSCs. Besides, the angiogenesis of human umbilical vein endothelial cells was significantly promoted by CMS/GO/SF scaffold extract through the upregulation of angiogenesis genes (eNOs and bFGF). Moreover, the osteoclastic formation ability of RAW264.7 cells was suppressed by the released ions from CMS/GO/SF scaffold through the down-regulation of CAK, MMP9 and TRAP. The promoted osteogenesis, angiogenesis and inhibited osteoclastogenesis functions of CMS/GO/SF composite scaffold may enable it as a novel therapy for bone repair and regeneration.

Frequency and reason for reoperation following non-invasive expandable endoprostheses: A systematic review

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Implant failure is the most common reason for revision of growing prostheses.

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Maximum prosthesis growth with a residual LLD is the most common mode of failure.

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Functional outcomes are good, but 1/ 5 patients have a persistent LLD over 2 cm.

Background

Non-invasive expandable endoprostheses (NIEPR) utilize an external electromagnetic field to drive an innate mechanical gearbox. This lengthens the extremity following oncological resections in children with a predicted limb length discrepancy (LLD), facilitating limb-salvage. This review was conducted to assess NIEPR implant survival rates and identify modes of implant failure unique to these prostheses.

Methods

Medline, EMBASE and the Cochrane Library databases were searched for all manuscripts evaluating implant survival of NIEPRs implanted into skeletally immature patients following resection of extremity sarcomas. Minimum follow-up of 12 months or implant failure was required for inclusion. Failures were classified using the latest ISOLS classification and exact implant-specific failure modality was also identified.

Results

19 studies met inclusion criteria. Mean age was 10.0 years (7.7 – 11.4 years). The most common locations for NIEPR implantation were the distal femur (343, 76.7%) and proximal tibia (53, 119%). Mean follow-up was 65.3 months (19.4 – 163 months). The overall implant revision rate was 46.2% (0 – 100%); implant specific revisions included maximal prosthesis lengthening with persistent LLD (10.4%), failed extension mechanism (6.1%), implant fracture (7.7%), hinge fracture (1.4%) and bushing wear (0.9%). Persistent clinically significant (>20 mm) LLD at final follow-up was present in 19.2% (0 – 50%) of patients. The mean MSTS score was 85.1% (66.7–96.3%) at final follow-up.

Conclusion

Implant-related failures are the most common reason for NIEPR revision. Implant reliability appears to be improved with current designs. A sub-classification to the current classification system based on implant-specific failures for NIEPRs is proposed.

La-Doped biomimetic scaffolds facilitate bone remodelling by synchronizing osteointegration and phagocytic activity of macrophages

The capacity of osteoconduction held by HA/CS, osteoinduction by La³⁺, and biodegradability by a La-HA/CS composite, contributes to an ideal scaffold for osteointegration and remodelling.

Limb saving surgery for Ewing's sarcoma of the distal tibia: a case report

Background

Ewing’s sarcoma is a primary malignant tumor of bone occurring mostly in childhood. Few effective reconstruction techniques are available after wide resection of Ewing’s sarcoma at the distal end of the tibia. Reconstruction after wide resection is especially difficult in children, as it is necessary to consider the growth and activity of the lower limbs.

Case presentation

A 12-year-old Japanese boy had presented with right lower leg pain at age 8 years. Imaging examination showed a bone tumor accompanied by a large extra-skeletal mass in the distal part of his tibia. The tumor was histologically diagnosed as Ewing’s sarcoma. The patient received chemotherapy, followed by wide resection. Reconstruction consisted of a bone transport method involving external fixation of Taylor Spatial Frame. To prevent infection after surgery, the external fixation pin was coated with iodine. One year after surgery, the patient showed poor consolidation of bone, so iliac bone transplantation was performed on the extended bones and docking site of the distal tibia. After 20 months, tibia formation was good. Three years after surgery, there was no evidence of tumor recurrence or metastases; bone fusion was good, and he was able to run.

Conclusions

The bone transport method is an effective surgical method of reconstruction after wide resection of a bone tumor at the distal end of the tibia, if a pin can be inserted into the distal bone fragment. Coating external fixation pins with iodine may prevent postoperative infection.