Treatment Of Segmental Bone Defects Research Articles

Comparison of free vascularized fibular grafts and the Masquelet technique for the treatment of segmental bone defects with open forearm fractures: a retrospective cohort study

PurposeSevere open forearm fractures commonly involve segmental bone defects. Although several methods have been proposed to treat segmental bone defects with such fractures, research comparing the radiological and clinical outcomes of free vascularized fibular grafts (FVFG) and the Masquelet technique (MT) is rare.MethodsData on 43 patients with open forearm fractures and segmental bone defects treated surgically in our hospital from January 2005 to January 2021 were retrospectively analyzed, and these patients were divided into an FVFG group (18 cases) and an MT group (25 cases). Clinical and radiological evaluations were performed regularly, and the minimum follow-up was 18 months.ResultsAll 43 patients were followed up for 18 to 190 months, with a mean of 46.93 months. The mean follow-up time was significantly longer in the FVFG group than in the MT group (p = 0.000). Bone healing time was 3–16 months, with a mean of 4.67 months. The QuickDASH score at the last follow-up was 0–38.6, with a mean of 17.71, and there was no statistically significant difference between the two groups. Operative time, hospital stay, and intraoperative bleeding for bone defect reconstruction were higher in the FVFG group compared to the MT group (p = 0.000), whereas the number of procedures was lower in the FVFG group than in the MT group (p = 0.035).ConclusionsFVFG and the MT showed satisfactory clinical results for segmental bone defects of the forearm. Compared with FVFG, the MT exhibited a lower operative time, hospital stay, and intraoperative bleeding.Level of evidenceLevel IV.Trial registration This study was registered in the Chinese Clinical Trial Registry (registration no. ChiCTR2300067675; registered 17 January 2023), https://www.chictr.org.cn/showproj.html?proj=189458.

EXPERIENCE OF THE SEGMENTAL BONE DEFECTS' TREATMENT FOR PATIENTS WITH COMBAT TRAUMA USING THE METHOD OF DISTRACTION OSTEOGENESIS

Upper and lower limb injuries resulting from battlefield trauma is a complex multidisciplinary problem. Efficacy of the treatment of segmental bone defects in patients with combat trauma is a subject of analysis for improving its results. Purpose. An analysis of the modern treatment strategies of the segmental bone defects in patients with battlefield trauma under conditions of distraction osteogenesis (based on data available in the literature and own clinical experience). Methods. Analytical review of scientific works and analysis of treatment results of 39 patients with segmental bone defects associated with battlefield trauma and treated using distraction osteogenesis were conducted. Results. Patients with segmental limbs defects require special attention of a multidisciplinary team of specialists to identify reconstructive opportunities to save the limb. Distraction osteogenesis — is an effective method of treating of segmental fractures and shortening of the limbs, infectious complications that led to bone defect formation. Bone transport with ring external fixator (ExFix) is considered as a classical method. Authors analyzed and illustrated with three clinical cases their own results of application of different distraction osteogenesis technique. Conclusions. Different types of ExFix can be applied independently or in combination with internal fixators. The use of an intramedullar nail along which distraction osteogenesis is carried out allows to provide better control of the axis of the limb and transported fragment, reduce the residence time in the ExFix, and, moreover, external fixation devices with a simpler configuration can be used. Transport along the plate allows to maintain proper axial relationships in the presence of short periarticular fragments and improve the quality of fixation but it also increases the risks of FRI and re-operations.

The Use of Stromal Vascular Fraction in Long Bone Defect Healing in Sheep.

The objectives of the present study were to evaluate (a) the feasibility of using stromal vascular fraction (SVF) and nanocrystalline hydroxyapatite (nHA) paste in combination for the treatment of segmental bone defect, (b) the quality of the callus produced, (c) the potential improvement of the autograft technique, and (d) the direct comparison of the biomaterial to the use of autogenous cancellous bone. Unilateral, segmental mid-diaphyseal bone defect was created on the right metatarsus of skeletally mature sheep animals (n = 24) under anesthesia (D0). Residual segments were stabilized by stainless-steel plates and appropriate screws. Defects were managed as follows: group A: use of nHA paste to filling, group B: use of autogenous bone graft mixed with nHA bone paste, placed in defect, group C: use of SVF mixed with nHA bone paste injected into defect, group D: use of bone graft and SVF with nHA paste before apposition in bone defect. SVF had been previously isolated from adipose tissue of the animals intra-operatively after digestion with collagenase solution and neutralization. Animals were evaluated clinically and by X-raying and ultrasonographic examination of the defect, at regular intervals, until D90. Ultrasonographic assessment performed along the length of the defect included calculation of the length of the bone defect and assessment of vascularization. SVF was successfully isolated from group C and D animals, with the average yield being 1.77 × 106 cells. The comparison of clinical scores (based on the 'Kaler scale') on each post-operative day indicated significant differences between the four groups on D1 to D30 (p < 0.01); the median clinical score within group A was 2.5 for D1-D30 and 1 for the entire period; respective scores for other groups were 1.5 (p = 0.07) and 0 (p = 0.033). Differences in radiographic assessment scores were significant for scores obtained on D60 (p = 0.049) and D90 (p = 0.006). There was a significant difference between the four groups in the length of the bone defect, as assessed ultrasonographically, for the entire length of the study; median values were 8, 8.5, 6, and 8 mm for groups A, B, C, and D, respectively (p = 0.008). There was a significance in the differences between median scores obtained during the histopathological examination: 2, 11, 13.5, and 12 for group A, B, C, and D (p = 0.022). There was an inverse correlation between the overall scores of histopathological evaluations and the length of the bone defect (observed on D90) (p < 0.0001) and a correlation between the overall scores and the radiographic assessment scores (obtained on D90) (p < 0.0001). This is the first study in which the efficacy of fresh autologous Stromal Vascular Fraction (SVF) from adipose tissue in enhancing bone healing in a long, weight-bearing, diaphyseal bone was evaluated. It is concluded that the lumbosacral region was an attractive site for harvesting adipose tissue, the use of SVF contributed to faster rehabilitation post-operatively, and SVF significantly enhanced bone formation; in general, the results indicated an osteogenic potential of SVF comparable to the gold standard autologous bone graft.

3D-Printing for Critical Sized Bone Defects: Current Concepts and Future Directions.

The management and definitive treatment of segmental bone defects in the setting of acute trauma, fracture non-union, revision joint arthroplasty, and tumor surgery are challenging clinical problems with no consistently satisfactory solution. Orthopaedic surgeons are developing novel strategies to treat these problems, including three-dimensional (3D) printing combined with growth factors and/or cells. This article reviews the current strategies for management of segmental bone loss in orthopaedic surgery, including graft selection, bone graft substitutes, and operative techniques. Furthermore, we highlight 3D printing as a technology that may serve a major role in the management of segmental defects. The optimization of a 3D-printed scaffold design through printing technique, material selection, and scaffold geometry, as well as biologic additives to enhance bone regeneration and incorporation could change the treatment paradigm for these difficult bone repair problems.

Amniotic membrane attenuates heterotopic ossification following high-dose bone morphogenetic protein-2 treatment of segmental bone defects.

Treatment of large bone defects with supraphysiological doses of bone morphogenetic protein-2 (BMP-2) has been associated with complications including heterotopic ossification (HO), inflammation, and pain, presumably due to poor spatiotemporal control of BMP-2. We have previously recapitulated extensive HO in our rat femoral segmental defect model by treatment with high-dose BMP-2 (30 μg). Using this model and BMP-2 dose, our objective was to evaluate the utility of a clinically available human amniotic membrane (AM) around the defect space for guided bone regeneration and reduction of HO. We hypothesized that AM surrounding collagen sponge would attenuate heterotopic ossification compared with collagen sponge alone. In vitro, AM retained more BMP-2 than a synthetic poly(ε-caprolactone) membrane through 21 days. In vivo, as hypothesized, the collagen + AM resulted in significantly less heterotopic ossification and correspondingly, lower total bone volume (BV), compared with collagen sponge alone. Although bone formation within the defect was delayed with AM around the defect, by 12 weeks, defect BVs were equivalent. Torsional stiffness was significantly reduced with AM but was equivalent to that of intact bone. Collagen + AM resulted in the formation of dense fibrous tissue and mineralized tissue, while the collagen group contained primarily mineralized tissue surrounded by marrow-like structures. Especially in conjunction with high doses of growth factor delivered via collagen sponge, these findings suggest AM may be effective as an overlay adjacent to bone healing sites to spatially direct bone regeneration and minimize heterotopic ossification.

Resorbable polylactide membrane for the treatment of segmental bone defects

IntroductionSegmental bone defects are a challenging clinical problem. In animal studies and craniomaxillofacial surgery, resorbable polylactide membrane (OrthoMesh; DePuy Synthes, West Chester, PA) shows promise for treatment of bone defects. This study presents the results of the treatment of segmental bone defects with resorbable polylactide membrane, bone morphogenic protein-2 (BMP-2), and autograft. MethodsThis study was approved by the institutional review board. All patients with a segmental bone defect treated with a resorbable polylactide membrane by a single surgeon from 2010 to 2019 were retrospectively reviewed. Data related to demographic variables, surgical details, and union were collected. ResultsEleven patients with median age of 37 years (range 22–62 years) were included in the study with segmental bone defects in the tibia (n = 3), femur (n = 4), or forearm (n = 4). Median bone defect size was 6 cm (range 3–12 cm). Etiology of bone defects included osteomyelitis (n = 7), oncologic resection (n = 3), and post-traumatic aseptic nonunion (n = 1). Flap coverage was performed in two patients. Median radiographic follow-up was 24 months (range 5–75 months). Ten patients (10/11) achieved union at a median of 17 months (range 5–46 months). Seven patients required reoperation for any reason with six patients requiring repeat grafting. ConclusionsTo our knowledge, this study is the largest series of patients with segmental bone defects treated with resorbable polylactide membrane. Resorbable polylactide membrane in combination with BMP-2 and autograft represents a safe and effective method of bone graft containment in segmental bone defects measuring up to 12 cm in this series. Ten of 11 patients achieved union at a median time of 16 months with 6 patients requiring repeat grafting. These results compare favorably with the induced membrane technique. This study is limited by its retrospective design, absence of control and comparison groups, and low patient numbers. Future prospective randomized study of the induced membrane technique and resorbable polylactide membrane should be undertaken to determine preferred approaches for treatment of segmental bone defects.

Managing Bone Defects in the Femur With a Motorized Intramedullary Bone Transport Nail: Case Review With Follow-Up.

Bone transport is an effective treatment for segmental bone defects. Until now, the need for external fixation, at least during the transport phase, has been a major disadvantage. New developments such as the bone transport nail allow an all-internal bone transport. A segment transport nail and the therapy regimen are described, and first cases are presented.

Treatment of Tibial and Femoral Bone Defects With Bone Transport Over an Intramedullary Nail

To evaluate the results of the bone transport over an intramedullary nail (BTON) technique for the treatment of segmental bone defects. Retrospective review of case series. Level 1 trauma center. We included 40 patients who underwent reconstruction of the lower limb with BTON technique between 2000 and 2018. The technique was performed in the tibial segments in 21 patients and in the femoral segments in 19 patients. The surgical technique was performed in 2 stages for patients with infected nonunion. Infection was eradicated in all patients at the first stage. For the BTON at the second stage, monolateral external fixators and circular external fixators were used for femoral and tibial defects, respectively. In cases of defects without any infection, debridement with a single-stage BTON was performed. Complications as well as radiological and clinical results were evaluated according to the criteria of Paley-Maar. Minor complications occurred in 11 patients: pin site problems (9), cellulitis (1), and skin detachment due to Schanz screw (1). Major complications occurred in 8 patients: docking site nonunion (4), early consolidation and Schanz screw failure (1), knee flexion contracture (1), and ankle equinus contracture (2). Four patients had osteomyelitis as residual sequelae. Bone score was excellent in 27 patients. Excellent functional results were obtained in 31 patients. The BTON technique is associated with low cost because of the short treatment period, low complication risk, and rapid rehabilitation and is not limited by the amount of bone transport. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Characterization of Tissue-Engineered Human Periosteum and Allograft Bone Constructs: The Potential of Periosteum in Bone Regenerative Medicine

Delayed-union or non-union between a host bone and a graft is problematic in clinical treatment of segmental bone defects in orthopedic cases. Based on a preliminary study of human periosteum allografts from this laboratory, the present work has extensively investigated the use of human cadaveric tissue-engineered periosteum-allograft constructs as an approach to healing such serious orthopedic surgical situations. In this current report, human cadaveric periosteum-wrapped bone allografts and counterpart controls without periosteum were implanted subcutaneously in athymic mice (nu/nu) for 10, 20, and, for the first time, 40 weeks. Specimens were then harvested and assessed by histological and gene expression analyses. Compared to controls, the presence of new bone formation and resorption in periosteum-allograft constructs was indicated in both histology and gene expression results over 40 weeks of implantation. Of several genes also examined for the first time, RANKL and SOST expression levels increased in a statistically significant manner, data suggesting that bone formation and the presence of increasing numbers of osteocytes in bone matrices had increased with time. The tissue-engineering strategy described in this study provides a possible means of improving delayed-union or non-union at the healing sites of segmental bone defects or bone fractures. The potential of periosteum and its resident cells could thereby be utilized effectively in tissue-engineering methods and tissue regenerative medicine.

Outcomes of free vascularized fibular flaps for the treatment of radiation-associated femoral nonunions

Nonunion is a known complication following fracture in the setting of radiotherapy. Free vascularized fibular (FVF) flaps have been used successfully in the treatment of segmental bone defects; however, their efficacy in the treatment of radiated nonunions is limited. The purpose of the study was to evaluate the outcome following FVFG for radiation-associated femoral fracture nonunions. 23 (11 male and 12 female; mean age 60 ± 12 years) patients underwent FVF for radiation-associated femoral fracture nonunions. The most common indication for radiotherapy was soft tissue sarcomas (n = 16). The mean follow-up was 5 ± 4 years. Mean radiation dose was 51 ± 14 Gy at a mean of 11 ± 3 years prior to FVF. The mean FVF length was 17 ± 4 cm and placed commonly with an intramedullary nail (n = 18). First time union was 52% (n = 12) following additional bone grafting, the overall union was 78% (n = 18) at a mean of 13 ± 6 months. Musculoskeletal Tumor Society scores improved from 30% preoperatively to 73% at latest follow-up (p < 0.0001). Five fractures failed to unite; 3 were converted to proximal femoral replacements. FVF are a reasonable treatment option for radiation-associated femoral fracture nonunions, providing a union rate of 78% and an improvement in functional outcome. Therapeutic Level IV.

Motorized Internal Limb Lengthening: International Perspectives

The remote-controlled, motorized, intramedullary lengthening nail is a disruptive technology that has fundamentally changed the approach to limb lengthening and reconstruction surgery globally. This new paradigm for limb reconstruction, marked by a decreased need for external fixation, has ignited a fervor among limb deformity surgeons. Although the origins of the Ilizarov method of distraction osteogenesis are deeply entwined with circular external fixation, the disadvantages of external fixators are well known and include pin track infections, skin pain, soft-tissue tethering, and joint stiffness. Integrated fixation techniques were developed combining internal and external fixation such as lengthening over a nail, lengthening and then nailing, lengthening and then plating, and bone transport over a nail to minimize the treatment time in external fixation. Building on these incremental advances, bone lengthening with a fully implantable device has enabled us to entirely avoid external fixation in most cases. Early designs of the internal lengthening nail (ILN) were telescopic and lengthened through a ratchet mechanism requiring mechanical rotation of the limb. Issues with mechanical integrity and accurate control of distraction by these implants have vastly improved over the last decade with the latest remote-controlled ILN delivering a predictable outcome. The remote-controlled ILN is available in different nail types with varied mechanics, material properties, and surgical indications. One design employs an electric motor imbedded into the telescopic rod, activated by intermittent transcutaneous transmission of radiofrequency waves to an implanted antennae/receiver which converts these waves into an electrical impulse discharged via a connecting cable. The second design, now most widely used in the United States, is a telescopic rod with a magnetic drive mechanism, activated by a hand-held external electromagnetic actuator. Furthermore, in addition to the functional mechanism differences, there are nails made from titanium or from stainless steel, and these have different biomechanical properties. The indications range by bone and nail orientation. The femur can be approached antegrade through a piriformis or greater trochanteric entry or can be entered retrograde. A short residual femur after amputation can be lengthened with a specially designed nail. The tibia is approached antegrade. Although the ILNs are primarily used for distraction osteogenesis bone lengthening, the magnetic ILN can also be used for compression of nonunions. In the last several years, there has been some experience with bone transport nails but recently, a motorized magnetic bone transport nail for treatment of segmental bone defects up to 10 cm has been launched, and the early experience is currently being accumulated. Creative, off-label uses of the commercially available nails have included humerus lengthening, retrograde tibia through an ankle/subtalar arthrodesis, extramedullary lengthening with a nail, and bone transport over a plate. Additional internal lengthening designs are in development including humerus nails, ankle fusion/retrograde tibia nails, and internal lengthening plates. In the absence of angular deformity, lengthening of a long bone with the ILN is an ideal surgical indication. Rotation may be corrected over the nail. Blocking screws may be needed to prevent predictable deformities that occur during lengthening. In the presence of preoperative angular deformity, adjuvant techniques such as fixator assisted nailing and blocking screws may be utilized in many, but not all cases, to acutely correct deformity and then gradually lengthen with the ILN. With increased periosteal disruption, latency and distraction may need to be modified. In addition, a staged approach may be used where deformity correction is performed and then at a second surgery, lengthening with the ILN is done. Furthermore, a bifocal approach may be used where deformity correction is performed at one end of the bone and lengthening with the ILN is done at the other end of the bone. The ILNs have created excitement among surgeons from separate sub specialties and diverse nationalities. Both pediatric and adult patients share common pathologies that require bone lengthening and deformity correction including congenital and posttraumatic deformity and leg length discrepancy. These pathologies have inspired global collaboration between orthopedists trained in pediatrics, trauma, foot and ankle, oncology, sports, knee/hip reconstruction, or limb deformity. Through annual meetings and a common body of literature, we all come together to teach and learn from each other. The motorized ILN is an ingenious technology has encouraged us to build new paradigms for limb reconstruction surgery. Although there is continued need for external fixation in selected cases, the modern limb deformity surgeon will use the ILN when possible. The ILN is, however, not available yet in many developing countries. In this edition of Techniques in Orthopedics, dedicated to internal limb lengthening, we have gathered an international panel of experts to discuss specialized applications of this most recent evolution of the Ilizarov method.

Use of a Reverse Metacarpal Bone Flap for the Treatment of Segmental Bone Defects of the Proximal Phalanges

The purpose of this retrospective study was to report the results of reconstruction of segmental bone defects of the proximal phalanges using a reverse metacarpal vascularized bone flap harvested from the third metacarpal bone. From August 2012 to May 2017, 17 patients with segmental osteomyelitis or necrotic bone of the proximal phalanges were treated. There were 15 male and 3 female patients, with a mean age of 36 years (range, 19-65 years). The mean size of bone defects was 26× 9× 9 mm (range, 16× 6× 7 mm to 35× 10× 7 mm); and the mean size of bone flaps was 27× 8× 7 mm (range, 15× 7× 4 mm to 40× 8× 7 mm). The mean follow-up period was 26 months. The mean motion arc of the metacarpophalangeal joints was 56° (range, 22°-90°). The mean pinch strength of the injured fingers was 3.1 kg (range, 2-3.6 kg), and the mean pinch strength of the normal contralateral side was 6.9 kg (range, 4.2- 8.5 kg). The reverse metacarpal bone flap may promote osseous healing in reconstructing segmental defects of the proximal phalanges. Therapeutic IV.

Role of the Ilizarov non-free bone plasty in the management of long bone defects and nonunion: Problems solved and unsolved.

Ilizarov non-free bone plasty is a method of distraction osteogenesis using the Ilizarov apparatus for external fixation which originated in Russia and was disseminated across the world. It has been used in long bone defect and nonunion management along with free vascularized grafting and induced membrane technique. However, the shortcomings and problems of these methods still remain the issues which restrict their overall use. To study the recent available literature on the role of Ilizarov non-free bone plasty in long bone defect and nonunion management, its problems and the solutions to these problems in order to achieve better treatment outcomes. Three databases (PubMed, Scopus, and Web of Science) were searched for literature sources on distraction osteogenesis, free vascularized grafting and induced membrane technique used in long bone defect and nonunion treatment within a five-year period (2015-2019). Full-text clinical articles in the English language were selected for analysis only if they contained treatment results, complications and described large patient samples (not less than ten cases for congenital, post-tumor resection cases or rare conditions, and more than 20 cases for the rest). Case reports were excluded. Fifty full-text articles and reviews on distraction osteogenesis were chosen. Thirty-five clinical studies containing large series of patients treated with this method and problems with its outcome were analyzed. It was found that distraction osteogenesis techniques provide treatment for segmental bone defects and nonunion of the lower extremity in many clinical situations, especially in complex problems. The Ilizarov techniques treat the triad of problems simultaneously (bone loss, soft-tissue loss and infection). Management of tibial defects mostly utilizes the Ilizarov circular fixator. Monolateral fixators are preferable in the femur. The use of a ring fixator is recommended in patients with an infected tibial bone gap of more than 6 cm. High rates of successful treatment were reported by the authors that ranged from 77% to 100% and depended on the pathology and the type of Ilizarov technique used. Hybrid fixation and autogenous grafting are the most applicable solutions to avoid after-frame regenerate fracture or deformity and docking site nonunion. The role of Ilizarov non-free bone plasty has not lost its significance in the treatment of segmental bone defects despite the shortcomings and treatment problems encountered.

Management of forearm bone loss with induced membrane technique

There are very few published studies describing the treatment of segmental bone defects of the forearm using the induced membrane technique. The objectives of this study were to evaluate the time to bone union, the function of the joints above and below the treated bone segment and the patients’ quality of life over the long-term. We performed a retrospective study in all patients treated by the induced membrane for a forearm bone defect over at 13-year period. Demographics, bone union, complications, functional outcomes and occupational status were collected. Six patients were included: 2 posttraumatic injuries, 1 osteomyelitis, 1 septic arthritis, 1 aseptic nonunion, 1 tumor. The average defect length was 64mm (48–110). All defects were treated with internal fixation. Bone graft was harvested from the iliac crest in two patients, the femur (using the Reamer Irrigator Aspirator technique) in three patients and the radius in one patient. Five patients achieved bone union after a mean of 4months (3–6). Three complications were observed: 1 radioulnar instability, 1 infection of the fixation device, 1 abscess. At an average 8½ years’ follow-up, the pain level on the VAS was 0.6 (0–3), the Mayo Elbow Performance Score was 98 (90–100), the Herzberg score was 108 (85.6–140) and the QuickDASH was 14.9 (2.7–35). All patients returned to work. Using the induced membrane technique avoids the complications associated with vascularized autograft and yields good functional outcome and quality of life.

Surface mineralized biphasic calcium phosphate ceramics loaded with urine-derived stem cells are effective in bone regeneration

BackgroundSegmental bone defects caused by trauma, tumors, or infection are a serious challenge for orthopedists in the world. Recent developments in tissue engineering have provided a new treatment for segmental bone defects. Urine-derived stem cells (USCs) can be obtained noninvasively and might be a new kind of seed cells used in bone tissue regeneration. Therefore, the first aim of the present study was to investigate the biological characteristics of USCs. The second aim of the present study was to study the osteogenic effect of surface mineralized biphasic calcium phosphate ceramics (BCPs) loaded with USCs in vitro and in vivo.MethodsWe isolated USCs from the urine of healthy adult donors and evaluated the biological characteristics of USCs in vitro. We mineralized the surface of BCPs by simulated body fluid (SBF). Cell adhesion and proliferation of USCs on the surface mineralized BCPs were evaluated. Osteogenic proteins and genes of USCs on the surface mineralized BCPs were texted by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR) assay. Critical-sized segmental bone defects model in New Zealand white rabbits were established and randomly divided into 4 groups (surface mineralized BCPs loaded with USCs, BCPs loaded with USCs, surface mineralized BCPs, and BCPs) based on the implant they received. The therapeutic efficacy of the scaffolds in a large bone defect at post-implantation was evaluated by imaging and histological examination.ResultsUSCs isolated in our study expressed stem cell-specific phenotypes and had a stable proliferative capacity and multipotential differentiation capability. Surface mineralized BCPs promoted osteogenic proteins and genes expression of USCs without affecting the proliferation of USCs. After 10 weeks, the amount of new bone formation was the highest in the group of surface mineralized BCPs loaded with USCs.ConclusionUSCs, from non-invasive sources, have good application prospects in the field of bone tissue engineering. Surface mineralized BCPs can significantly enhance osteogenic potential of USCs without changing biological characteristics of BCPs. Surface mineralized BCPs loaded with USCs are effective in repairing of critical-sized segmental bone defects in rabbits.

Application of multiple wrapped cancellous bone graft methods for treatment of segmental bone defects

BackgroundThe aims of this study were to discuss the principle, therapeutic effect and influencing factors of multiple wrapped cancellous bone graft methods for treatment of segmental bone defects.MethodsThis study retrospectively analyzed the therapeutic effect of different wrapped autologous cancellous bone graft techniques on 51 patients aged (34.5 ± 11.5) years with segmental bone defects. Cancellous bones were wrapped with titanium mesh (n = 9), line mesh (n = 10), line suturing or line binding cortical block, (n = 13), or induced membrane (n = 19). The bone defeats were as follows: tibia (n = 23), radial bone (n = 10), humerus (n = 8), ulnar bone (n = 7), and femur (n = 3). The defect lengths were (5.9 ± 1.1) cm. The functionary recovery of adjacent joint was evaluated by the Paley‘s method and DASH, respectively.ResultsThe incision healed by first intention in 48 cases and secondary healing in 3 cases. All patients were followed up for 19.1 ± 7.1 (12–48) months. Other than one patient with nonunion who received a secondary bone graft, all the patients were first intention of bone healing (the healing rate was 98.0%). The healing time was 6.1 ± 2.1 (3–15) months. There were no significant differences in the healing time among the 4 groups (χ2 = 1.864, P = 0.601). The incidence of complications in the grafted site was 11.8%, whereas it was 21.6% in the harvest site. At the last follow-up, all the patients had recovered and were able to engage in weight-bearing activities. The functional recovery was good to excellent in 78.4% of cases, there were no significant difference among the 4 groups (χ2 = 5.429, P = 0.143).ConclusionsWrapped cancellous bone grafting is a modified free bone graft method that can be used in the treatment of small and large segmental bone defects as it prevents loosening and bone absorption after bone grafting. The effect of bone healing is related with the quality and quantity of grafted bone, stability of bone defects, property of wrapping material and peripheral blood supply.

Autologous cell-coated particles for the treatment of segmental bone defects\u2014a new cell therapy approach

BackgroundAdipose tissue-derived mesenchymal stem cells (AT-MSCs) are one of the most potent adult stem cells, capable of differentiating into bone, cartilage, adipose, muscle, and others. An innovative autologous AT-MSC-derived cell-based product (BonoFill-II) for bone tissue regeneration was developed to be suited as a bone graft for segmental bone defects.MethodsBonoFill-II was transplanted into 8 sheep with 3.2-cm full cortex segmental defect formed in the tibia. Bone regeneration was followed by X-ray radiographs for 12 weeks. At experiment termination, the healed tibia bones were analyzed by computed tomography, histology, and mechanical tests.ResultsOur results indicate that one dose of BonoFill-II injectable formula led to an extensive bone growth within the transplantation site and to a complete closure of the critical gap in the sheep’s tibia in a relatively short time (8–12 weeks), with no inflammation and no other signs of graft rejection. This new and innovative product opens new prospects for the treatment of long bone defects.ConclusionsInjection of BonoFill-II (an innovative autologous cell therapy product for bone tissue regeneration) into a critical size segmental defect model (3.2 cm), generated in the sheep tibia, achieved full bridging of the gap in an extremely short period (8–12 weeks).

Early Experience with Local Custom Made Synthetic Bone Construct for the Treatment of Bone Defect

Introduction: Segmental bone defect can be treated with autologous bone graft and bone transport. Synthetic bone graft has successfully been used for the treatment of metaphyseal fracture or bone cyst. However, their use for the treatment of segmental bone defect has not been establish. Recently, a local company has produced a biodegradable custom made synthetic bone construct phosphate-based materials that is used to treat fractures and bone defect. Materials and Methods: After getting approval from Medical Device Agency, we used SBC to treat segmental bone defect in our patients. A case series review was conducted in these cases. Results: Three patients underwent surgery using SBC as a spacer to fill the defect at the docking site to prevent soft tissue collapse in one patient and as a replacement for bone autologous bone grafting in two patients. In our observation granules resorbtion ranged from 40-80% by 6 months with no radiological evidence of new bone formation. SBC mixed with bone marrow aspirate failed to harden into a palette. Although no new bone formation was seen at the docking site, insertion of SBC prevents soft tissue invagination and reduced the need of a second surgery to remove other conventional spacers. Conclusion: SBC may be used as a spacer to prevent soft tissue interposition and skin invagination in bone transport. However mixing it with bone marrow aspirate resulted in failure to form beads and does not form bone.

Vascularized 3D printed scaffolds for promoting bone regeneration

3D printed scaffolds hold promising perspective for bone tissue regeneration. Inspired by process of bone development stage, 3D printed scaffolds with rapid internal vascularization ability and robust osteoinduction bioactivity will be an ideal bone substitute for clinical use. Here, we fabricated a 3D printed biodegradable scaffold that can control release deferoxamine, via surface aminolysis and layer-by-layer assembly technique, which is essential for angiogenesis and osteogenesis and match to bone development and reconstruction. Our in vitro studies show that the scaffold significantly accelerates the vascular pattern formation of human umbilical endothelial cells, boosts the mineralized matrix production, and the expression of osteogenesis-related genes during osteogenic differentiation of mesenchymal stem cells. In vivo results show that deferoxamine promotes the vascular ingrowth and enhances the bone regeneration at the defect site in a rat large bone defect model. Moreover, this 3D-printed scaffold has excellent biocompatibility that is suitable for mesenchymal stem cells grow and differentiate and possess the appropriate mechanical property that is similar to natural cancellous bone. In summary, this 3D-printed scaffold holds huge potential for clinical translation in the treatment of segmental bone defect, due to its flexibility, economical friendly and practicality.

Artificial Membrane Induced by Novel Biodegradable Nanofibers in the Masquelet Procedure for Treatment of Segmental Bone Defects

The Masquelet induced-membrane technique for the treatment of segmental bone defects includes a two-stage surgical procedure, and polymethylmethacrylate (PMMA) plays a major role in the treatment. However, the PMMA spacer must be surgically removed. Here, we investigated the potential of poly(lactic-co-glycolic acid) (PLGA) nanofibers, a biodegradable material to replace the PMMA spacer, allowing the bioactive membrane to be induced and the spacer to degrade without the additional surgery on a rabbit femoral segmental bone defect model. PLGA nanofibers were shown to degrade completely six weeks after implantation in the investigated animals, and a thick membrane was found to circumferentially fold around the segmental bone defects. Results from image studies demonstrated that, in the group without the bone graft, all studied femurs exhibited either nonunion or considerable malunion. In contrast, the femurs in the bone graft group had a high union rate without considerable deformities. Histological examinations suggested that the membranous tissue in this group was rich in small blood vessels and the expression of BMP2 and VEGF increased. Our results demonstrate that the biodegradable PLGA nanofibers may be useful for replacing the PMMA spacer as the bioactive-membrane inducer, facilitating the process of healing and removing the need for repeated surgeries.