Implant Survival, Clinical Outcome and Complications of Megaprosthetic Reconstructions Following Sarcoma Resection

Megaprosthetic reconstruction of segmental bone defects following sarcoma resection is a frequently chosen surgical approach in orthopedic oncology. While the use of megaprostheses has gained popularity over the last decades and such implants are increasingly used for metastatic reconstructions and in non-tumor cases, there still is a high risk of long-term complications leading to revision surgery. This article investigates current implant survivorship, frequency and types of complications as well as functional outcomes of upper and lower limb megaprosthetic reconstructions.

Masquelet technique in management of infective non-union of long bones- A prospective study

Introduction and Aim: Masquelet’s technique is a 2-staged procedure, for treatment of infected segmental bone defect. 1st stage involves radical debridement with antibiotic-induced cement spacer. During second stage, the spacer is removed and the autologous bone graft is applied into the biomembrane formed. In this study, we evaluate the Masquelet’s technique for the management of infective non-union of long bones. Materials and Methods: 15 patients with infective non-union of long bones- tibia, femur and a case of congenital pseudoarthrosis of tibia, were treated with Masquelet’s technique. They underwent 2 stages of procedures 6-8 weeks apart and was followed up for about 9 months and radiological and clinical outcomes were assessed. Results: Out of 15 patients with infective non-union, 8 patients attained union. Out of the 7 patients with failure of the technique, higher failure rates were attributed to Pseudomonas infection. Conclusion: Masquelet’s technique is a cost-effective method for treating infective segmental non-unions, not requiring special training or sophisticated instruments. This method shows good results with Gram positive infections. Although, the outcome with Pseudomonas aeruginosa infection, have not shown satisfactory results.

Large segmental defects in midshaft clavicle nonunion treated with autologous tricortical iliac crest bone graft

Background To evaluate the use of intercalary iliac crest bone graft in the treatment of clavicle nonunion with a large segmental bone defect (3–6 cm). Methods This retrospective study evaluated patients with large segmental bone defects (3–6 cm) after clavicle nonunion, treated with open reposition internal fixation and iliac crest bone graft between February 2003 and March 2021. At follow-up the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was administered. A literature search was performed to provide an overview of commonly used graft types per defect size. Results We included five patients treated with open reposition internal fixation and iliac crest bone graft for clavicle nonunion with a median defect size of 3.3 cm (range 3–6 cm). Union was achieved in all five, and all pre-operative symptoms resolved. The median DASH score was 23 out of 100 (IQR 8-24). An extensive literature search revealed that there are no studies describing the use of an used iliac crest graft for defects larger than 3 cm. Instead, a vascularized graft was typically used to treat defects sizes between 2.5 and 8 cm. Discussion An autologous non-vascularized iliac crest bone graft can be safely used and is reproducible to treat a midshaft clavicle non-union with a bone defect between 3 and 6 cm.

Plasty of shin bone defects with segmental loss using ring fixators of the wire-rod type

The problem of segmental bone loss of the tibia after fractures is an urgent and not completely resolved problem. The use of distraction osteogenesis by bone transport according to Ilizarov is the leading method of treatment. Improving this technology is a generally accepted way of improving treatment outcomes.To propose improvements in the technology of distraction osteosynthesis with the use of ring fixators, taking into account the problematic issues of their use; analyze the results obtained.Tasks: to formulate the disadvantages and problematic issues of distraction osteogenesis in patients with segmental defects of the leg bones after fractures; to propose a solution to the existing disadvantages of the method; analyze the results.78 victims met the inclusion criteria. 36 patients were operated on according to the proposed method; they made up the core group; 42 – comparison group, treatment was carried out according to the generally accepted method. The time spent in the external fixation apparatus and the index of external fixation were used as criteria for evaluating the results; the final assessment was carried out according to the anatomical and functional scale Modified Functional Evaluation System by Karlstrom–Olerud.Our results (good and excellent 77.8 %; unsatisfactory in 2.8 % are comparable to those of most researchers. Anatomical and functional results in the main group with a high degree of probability (˃95 %) exceeded the results in the comparison group.Bearing in mind the severity of the defeat, we find this result encouraging. Given the insufficient number of observations, it is necessary to recommend the use of the proposed improvements in the use of RF in the treatment of nonunions of the shin bones after fractures and further study of their effectiveness.Thus, nonunion of the tibia requires complex treatment using osteosynthesis with ring fixators. Spoke-rod designs of the apparatus, gentle technique, optimal ways of guiding the pins, transition to final fixation using Softcast/Scotchcast systems, drug correction of regeneration disorders made it possible to avoid many complications of extrafocal fixation and obtain good results.

Biomimetic Methacrylated Gelatin Hydrogel Loaded With Bone Marrow Mesenchymal Stem Cells for Bone Tissue Regeneration

Large-segment bone defect caused by trauma or tumor is one of the most challenging problems in orthopedic clinics. Biomimetic materials for bone tissue engineering have developed dramatically in the past few decades. The organic combination of biomimetic materials and stem cells offers new strategies for tissue repair, and the fate of stem cells is closely related to their extracellular matrix (ECM) properties. In this study, a photocrosslinked biomimetic methacrylated gelatin (Bio-GelMA) hydrogel scaffold was prepared to simulate the physical structure and chemical composition of the natural bone extracellular matrix, providing a three-dimensional (3D) template and extracellular matrix microenvironment. Bone marrow mesenchymal stem cells (BMSCS) were encapsulated in Bio-GelMA scaffolds to examine the therapeutic effects of ECM-loaded cells in a 3D environment simulated for segmental bone defects. In vitro results showed that Bio-GelMA had good biocompatibility and sufficient mechanical properties (14.22kPa). A rat segmental bone defect model was constructed in vivo. The GelMA-BMSC suspension was added into the PDMS mold with the size of the bone defect and photocured as a scaffold. BMSC-loaded Bio-GelMA resulted in maximum and robust new bone formation compared with hydrogels alone and stem cell group. In conclusion, the bio-GelMA scaffold can be used as a cell carrier of BMSC to promote the repair of segmental bone defects and has great potential in future clinical applications.

Studying the strength of the tibia during the replacement of a post-resection defect with a segmental allograft using locked intramedullary nailing (experimental clinical study)

Background. To achieve success in the incorporation of allografts and bone of the recipient, many factors are taken into account, which can be divided into two main groups: those related to sterilization and processing of the bone allograft and factors affecting the reliability of implant fixation in the bone of the recipient. The second important factor is the method for fixing the allografts and the bone of the recipient. The purpose was to determine the mechanical properties of bone after segmental bone alloplasty. Materials and methods. Female patient Sh., 30 years old, diagnosed with osteosarcoma of the left distal tibia T2N0M0 GIII, degree II, clinical group II, underwent polychemotherapy courses, surgical intervention according to the developed method. The tumor was removed en block, a post-resection defect was replaced with an articulating segmental bone allograft, fixed to the recipient’s bone through a stepped osteotomy and an intramedullary locked nail. Bone autografts were additionally placed into the area of the allograft contact with the recipient’s bone. After 2 years, the patient underwent surgery: amputation at the left third of the thigh. Radiographically, fusion of the allograft and the recipient’s bone was noted. An experimental study of the tensile strength of the tibia after segmental alloplasty of a post-resection defect was carried out using the developed surgical technique and a segmental allograft. Results. To compare the results of an experimental study of the tibia preparation after segmental bone alloplasty, data about the values of the ultimate strength of the bone tissue under compression and bending loads were selected. As shown by the experiment, the ultimate strength of the tibia preparation after its bone alloplasty was 51.82 MPa. This value corresponds to the minimum ultimate strength of a compact bone in bending — 51 MPa. Although this is twice as low as the maximum value of the ultimate strength of a compact bone in bending (133 MPa), it should be borne in mind that all the given reference values were obtained when testing intact preparations of a compact bone. Conclusions. The use of a segmental bone allograft to replace a post-resection defect in a long bone with its fixation to the recipient’s bone through a stepped osteotomy and locked intramedullary nailing with additional bone autoplasty in the area of the allograft contact with the recipient’s bone makes it possible to obtain in the osteotomy zone the bone, the ultimate strength of which corresponds to that of the intact tissue.