Autologous Bone Graft in Foot and Ankle Surgery

In Vivo feature of the regenerative potential of chitosan and alginate based osteoplastic composites doped with calcium phosphates, zinc ions, and vitamin D2

PURPOSE

In vivo comparison of the regenerative potential of two calcium phosphate-biopolymer osteoplastic composites: а) based on alginate (Alg) and hydroxyapatite (HA) - Alg/HA/CS/Zn/D2, b) based on chitosan (CS) and brushite (DCPD) - CS/DCPD/D2.

MATERIALS AND METHODS

36 white male laboratory rats aged six months were used. A defect to the bone marrow canal in the middle of the femur diaphysis was made with a dental bur of 2 mm. The bone defect healed under the blood clot (control) in the different animal groups and was filled with Alg/HA/CS/Zn/D2 and CS/DCPD/D2. The regeneration of the bone defect was studied on the 30th, 90th, and 140th days by computer tomography (CT).

RESULTS

On the 30th day, all groups' implantation site optical density (OD) was significantly lower than that of the adjacent maternal bone (MB). Intensity of bone formation for Alg/HA/CS/Zn/D2 exceeds CS/DCPD/D2. On the 90th day, the bone trauma site OD with Alg/HA/CS/Zn/D2 (1725.4 ± 86 HU) and CS/DCPD/D2 (1484.9 ± 69 HU) exceeded the OD of the control (942.5 ± 55 HU). On the 140th day, the OD of Alg/HA/CS/Zn/D2 and CS/DCPD/D2 implantation sites was higher than Control and MB OD. Visually, the area of the past injury with the Alg/HA/CS/Zn/D2 could be detected only by the presence of an endosteal bone callus and in the case of CS/DCPD/D2 - by the shadow of the remaining biomaterial in the bone marrow canal.

CONCLUSIONS

According to CT data, Alg/HA/CS/Zn/D2 and CS/DCPD/D2 contribute to the complete healing of the femoral diaphysis defect in 140 days, but the regenerative potential of Alg/HA/CS/Zn/D2 from 30 days to 140 days is higher than CS/DCPD/D2 biomaterial.

Effectiveness of synthetic versus autologous bone grafts in foot and ankle surgery: a systematic review and meta-analysis

BACKGROUND

All orthopaedic procedures, comprising foot and ankle surgeries, seemed to show a positive trend, recently. Bone grafts are commonly employed to fix bone abnormalities resulting from trauma, disease, or other medical conditions. This study specifically focuses on reviewing the safety and efficacy of various bone substitutes used exclusively in foot and ankle surgeries, comparing them to autologous bone grafts.

METHODS

The systematic search involved scanning electronic databases including PubMed, Scopus, Cochrane online library, and Web of Science, employing terms like 'Bone substitute,' 'synthetic bone graft,' 'Autograft,' and 'Ankle joint.' Inclusion criteria encompassed RCTs, case-control studies, and prospective/retrospective cohorts exploring different bone substitutes in foot and ankle surgeries. Meta-analysis was performed using R software, integrating odds ratios and 95% confidence intervals (CI). Cochrane's Q test assessed heterogeneity.

RESULTS

This systematic review analyzed 8 articles involving a total of 894 patients. Out of these, 497 patients received synthetic bone grafts, while 397 patients received autologous bone grafts. Arthrodesis surgery was performed in five studies, and three studies used open reduction techniques. Among the synthetic bone grafts, three studies utilized a combination of recombinant human platelet-derived growth factor BB homodimer (rhPDGF-BB) and beta-tricalcium phosphate (β-TCP) collagen, while four studies used hydroxyapatite compounds. One study did not provide details in this regard. The meta-analysis revealed similar findings in the occurrence of complications, as well as in both radiological and clinical evaluations, when contrasting autografts with synthetic bone grafts.

CONCLUSION

Synthetic bone grafts show promise in achieving comparable outcomes in radiological, clinical, and quality-of-life aspects with fewer complications. However, additional research is necessary to identify the best scenarios for their use and to thoroughly confirm their effectiveness.

LEVELS OF EVIDENCE

Level II.

Three-dimensional printed custom-made modular talus prosthesis in patients with talus malignant tumor resection

BACKGROUND

Talar malignant tumor is extremely rare. Currently, there are several alternative management options for talus malignant tumor including below-knee amputation, tibio-calcaneal arthrodesis, and homogenous bone transplant while their shortcomings limited the clinical application. Three-dimensional (3D) printed total talus prosthesis in talus lesion was reported as a useful method to reconstruct talus, however, most researches are case reports and its clinical effect remains unclear. Therefore, the current study was to explore the application of 3D printed custom-made modular prosthesis in talus malignant tumor.

METHODS

We retrospectively analyzed the patients who received the 3D printed custom-made modular prosthesis treatment due to talus malignant tumor in our hospital from February 2016 to December 2021. The patient's clinical data such as oncology outcome, operation time, and volume of blood loss were recorded. The limb function was evaluated with the Musculoskeletal Tumor Society 93 (MSTS-93) score, The American Orthopedic Foot and Ankle Society (AOFAS) score; the ankle joint ranges of motion as well as the leg length discrepancy were evaluated. Plain radiography and Tomosynthesis-Shimadzu Metal Artefact Reduction Technology (T-SMART) were used to evaluate the position of prosthesis and the osseointegration. Postoperative complications were recorded.

RESULTS

The average patients' age and the follow-up period were respectively 31.5 ± 13.1 years; and 54.8 months (range 26-72). The medium operation time was 2.4 ± 0.5 h; the intraoperative blood loss was 131.7 ± 121.4 ml. The mean MSTS-93 and AOFAS score was 26.8 and 88.5 respectively. The average plantar flexion, dorsiflexion, varus, and valgus were 32.5, 9.2, 10.8, and 5.8 degree respectively. One patient had delayed postoperative wound healing. There was no leg length discrepancy observed in any patient and good osseointegration was observed on the interface between the bone and talus prosthesis in all subjects.

CONCLUSION

The modular structure of the prosthesis developed in this study seems to be convenient for prosthesis implantation and screws distribution. And the combination of solid and porous structure improves the initial stability and promotes bone integration. Therefore, 3D printed custom-made modular talus prosthesis could be an alternative option for talus reconstruction in talus malignant tumor patients.

Morbidity Associated With Distal Tibial Autograft Harvest

Distal tibial autograft harvesting has been studied in the past, but morbidity at the level of the donor site is unclear. The purpose of this retrospective review is to assess morbidity in distal tibial autograft harvesting associated with foot and ankle arthrodesis procedures. A retrospective analysis was performed utilizing patients treated in the last 13 years at a large, multicenter, academic, tertiary referral, research institution. Included patients were between the ages of 18 and 80 years old. One-hundred and seven patients (39 male; 68 female) underwent ipsilateral distal tibial bone graft (n = 110) harvesting to augment the index procedure. Patients were followed for an average of 11.2 months after surgery (Range: 1-73 months). The incidence rate of distal tibial stress fractures was 4.5%, with an overall postoperative complication rate of 8.2%. Overall, low complication rates associated with distal tibial autograft harvesting were found, supporting the use of the distal tibia as an appropriate site for autograft harvesting in foot and ankle surgery.

Comparative Studies of Bone Graft and Orthobiologics for Foot Ankle Arthrodesis: A Critical Review

Graft materials available to supplement hindfoot and ankle arthrodesis procedures include autologous (autograft) or allogeneic bone graft (allograft) but also bone graft substitutes such as demineralized bone matrix, calcium sulfate, calcium phosphate, and tricalcium phosphate/hydroxyapatite. In addition, biologic agents, such as recombinant human bone morphogenetic protein-2 or recombinant human platelet derived growth factor-BB (rhPDGF-BB), and preparations, including platelet-rich plasma or concentrated bone marrow aspirate, have been used to facilitate bone healing in ankle or hindfoot arthrodesis. The purpose of this review was to summarize the available clinical evidence surrounding the utilization and efficacy of the above materials and biological agents in ankle or hindfoot arthrodesis procedures, with emphasis on the quality of the existing evidence to facilitate clinical decision making.

Management of non-unions of the malleolar fractures- Current Evidence

Although malleolar non-union is uncommon, it is associated with significant morbidity. Managing this problem requires understanding ankle fracture biomechanics and bone healing. We present in this article the pertinent points to be considered in evaluating and managing patients with malleolar non-union. Our discussion will focus on the important risk factors contributing to this problem, and the need to carefully consider the biomechanical stability and the biological environment to ensure successful bony unions.

Biomaterials for bone defect repair: Types, mechanisms and effects

Bone defects or bone discontinuities caused by trauma, infection, tumours and other diseases have led to an increasing demand for bone grafts and biomaterials. Autologous bone grafts, bone grafts with vascular tips, anastomosed vascular bone grafts and autologous bone marrow components are all commonly used in clinical practice, while oversized bone defects require the use of bone tissue engineering-related biomaterials to repair bone defects and promote bone regeneration. Currently, inorganic components such as polysaccharides and bioceramics, as well as a variety of bioactive proteins, metal ions and stem cells can be loaded into hydrogels or 3D printed scaffold materials to achieve better therapeutic results. In this review, we provide an overview of the types of materials, applications, potential mechanisms and current developments in the repair of bone defects.

Physiologically engineered porous titanium/brushite scaffolds for critical-size bone defects: A design and manufacturing study

Repairing critical-size bone defects still represents a critical clinical challenge in the field of trauma surgery. This study focuses on a physiological design and manufacturing of porous composite scaffold (titanium Ti with 10 % mole iron doped brushite DCPD-Fe3+) which can mimic the biomechanical properties of natural cortical bone, specifically for the purpose of repairing critical-size defects. To achieve this, the principle of design of experiments (DOE) was applied for investigating the impact of sintering temperature, mineral ratio, and volume fraction of porosity on the mechanical properties of the fabricated scaffolds. The fabricated scaffolds had open porosity up to 60 %, with pore size approximately between 100 μm and 850 μm. The stiffness of the porous composite scaffolds varied between 3.30 GPa and 20.50 GPa, while the compressive strength ranged from approximately 130 MPa-165 MPa at sintering temperatures equal to or exceeding 1000 °C. Scaffolds with higher porosity and mineral content demonstrated lower stiffness values, resembling natural bone. Numerical simulation was employed by Ansys Workbench to investigate the stress and strain distribution of a critical size defect in mid-shaft femur which was designed to be replaced with the fabricated scaffold. The fabricated scaffolds showed flexible biomechanical behaviour at the bone/scaffold interface, generating lower stress levels and indicating a better match with the femoral shaft stiffness. The experimental and numerical findings demonstrated promising applications for manufacturing a patient-specific bone scaffold for critical and potentially large defects for reducing stress shielding and minimizing non-union risk.

Optimizing Traumatic Limb Salvage: Ectopic Implantation and Staged Rotationplasty

Rotationplasty, a limb-saving procedure involving a 180-degree ankle rotation to function as a knee joint, is now standard for treating distal femur osteosarcoma. However, challenges related to self-identification persist within the Asian population. This study presents a case involving the successful application of temporary ectopic implantation followed by staged rotationplasty after a severe traumatic amputation, resulting in a favorable outcome. Additionally, a systematic review is conducted to summarize the various difficulties and complications encountered in different studies. This approach improves the feasibility of rotationplasty in traumatic cases and enhances patient and family comprehension.

Contemporary Review: Autograft Bone Use in Foot and Ankle Surgery

Bone autografts are frequently harvested for use in foot and ankle surgery. A commonly used harvest site is the iliac crest; however, because of known morbidity with this site, the tibia and calcaneus are attractive alternatives. There remains limited understanding regarding the osteogenic potential of autografts from each of these locations. In this review, we provided an update of the known data on bone autografts from the iliac crest, tibia, and calcaneus, focusing on the total cells harvested from each site as well as the presence of osteogenic osteoprogenitor cells.

Level of Evidence

Level V, expert opinion.

Alendronate-functionalized double network hydrogel scaffolds for effective osteogenesis

Development of artificial bone substitutes mimicking the extracellular matrix is a promising strategy for bone repair and regeneration. In views of the actual requirement of biomechanics, biodegradability, and bioactivity, herein, a double-network (DN) hydrogel was constructed by interspersing a methacrylated gelatin (GelMA) network into alendronate (ALN)-modified oxidized alginate (OSA) network via Schiff base reaction and photo-crosslinking process to promote in situ bone regeneration. This GelMA@OSA-ALN DN hydrogel possessed favorable network and pores, good biocompatibility, and enhanced biomechanics. Notably, the introduction of Schiff base furnished the ND hydrogel scaffold with pH-responsive biodegradation and sustained ALN drug release delivery, which could provide effective bioactivity, upregulate osteogenesis-related genes, and promote the cell viability, growth, proliferation, and osteogenesis differentiation for bone regeneration. Therefore, we provide a new insight to develop functional DN hydrogel scaffold toward governing the on-demand drug release and achieving the stem cell therapy, which will be developed into the minimally invasive gelling system to prolong local delivery of bisphosphonates for the bone-related diseases.

One-stage reconstruction of the complex defects of the Achilles tendon and the adjoining calcaneus using the chimeric superolateral thigh flap: A case report

Reconstruction of the composite defects of the Achilles tendon and the overlying skin is a great challenge. Should the tendon insertion and adjoining calcaneal defects coexist, such reconstruction becomes far more complicated. A chimeric superolateral thigh flap based on the ascending branch of the lateral circumflex femoral artery provides all the components for this complex defect. We aim to illustrate a case underwent one-stage reconstruction of such defects with this chimeric flap. A 55-year-old man presented with composite defects of Achilles tendon (11 cm), adjoining calcaneus (2 × 2 × 3 cm), and the overlying skin (15 × 3.5 cm) due to unsuccessful repair for his right chronic Achilles tendon rupture, which was complicated by infection. This complex defect was reconstructed using a chimeric superolateral thigh flap consisting of the superolateral thigh skin (8.5 × 17.5 cm), full-thickness iliac bone (4 × 3 cm), and the intervening iliotibial tract preserving the fascia-bone junction, which substituted for the lost insertion of the Achilles tendon. Bone union and full weight bearing were achieved by 11 and 24 weeks, respectively, after surgery. Two debulking procedures were performed. Isometric plantar flexion muscle strength was comparable to the healthy side, but isotonic strength was somewhat reduced at 18 months after reconstruction. This chimeric flap provided all the possible components necessary for the complex Achilles tendon defect, and led functional outcomes.

Tibiotalocalcaneal Arthrodesis with Structural Allograft for Management of Large Osseous Defects of the Hindfoot and Ankle: A Systematic Review and Meta-Analysis

Large osseous defects of the hindfoot and ankle pose a surgical challenge. Tibiotalocalcaneal (TTC) arthrodesis utilizing a structural allograft may be required to fill the osseous void, preserve limb length and achieve fusion. Several authors have reported small case series on this topic, however outcomes have varied and no systematic review of this data has been published to date. The primary aim of this study is to report rates of osseous union, limb salvage and complications in patients undergoing TTC arthrodesis with a structural allograft. A total of 11 publications were identified that met the inclusion criteria. One hundred seventy-five patients were included with a weighted mean age of 60.5 (range 50-72) years and follow-up period of 29.7 (range 3-62) months. Femoral head allograft was the most commonly utilized structural graft and a retrograde intramedullary nail was the most common fixation construct. Results demonstrated an overall union rate of 67.4%, limb salvage rate of 92.5% and complication rate of 26.6%. Allograft-related complications were rare with an allograft fracture rate of 0.1% and allograft collapse rate of 1.2%. There was no significant difference in union rate when using a retrograde intramedullary nail versus a plate construct (p = .9148). TTC arthrodesis with use of a structural allograft is a viable treatment option for limb salvage when faced with complex hindfoot and ankle pathology involving large osseous defects. Despite high rates of radiographic nonunion, this approach can provide patients with a stable and functional limb while avoiding amputation.

Fabrication of Naturally Derived Double-Network Hydrogels With a Sustained Aspirin Release System for Facilitating Bone Regeneration

Continuous efforts on pursuit of effective drug delivery systems for engineering hydrogel scaffolds is considered a promising strategy for the bone-related diseases. Here, we developed a kind of acetylsalicylic acid (aspirin, ASA)–based double-network (DN) hydrogel containing the positively charged natural chitosan (CS) and methacrylated gelatin (GelMA) polymers. Combination of physical chain-entanglement, electrostatic interactions, and a chemically cross-linked methacrylated gelatin (GelMA) network led to the formation of a DN hydrogel, which had a suitable porous structure and favorable mechanical properties. After in situ encapsulation of aspirin agents, the resulting hydrogels were investigated as culturing matrices for adipose tissue–derived stromal cells (ADSCs) to evaluate their excellent biocompatibility and biological capacities on modulation of cell proliferation and differentiation. We further found that the long-term sustained ASA in the DN hydrogels could contribute to the anti-inflammation and osteoinductive properties, demonstrating a new strategy for bone tissue regeneration.

Union Rates of Talar Neck Fractures With Substantial Bone Defects Treated With Autograft

BACKGROUND

This study evaluated the union rate of talar neck fractures with substantial bone defects treated acutely with autologous tibial bone graft during primary osteosynthesis.

METHODS

A case series at a level 1 trauma center was performed to identify consecutive patients who underwent operative fixation of talar neck fracture with autograft (Current Procedural Terminology codes 28445 and 20902) between 2015 and 2018. "Substantial bone defect" was defined as a gap greater than 5 mm in the sagittal plane and greater than one-third of width of the talar neck in the coronal plane. Postoperative foot computed tomographic (CT) scans were obtained for all patients. Primary outcome was union, and secondary outcomes were malunion, avascular necrosis (AVN), post-traumatic arthritis (PTA), and patient-reported outcomes (PROs).

RESULTS

Twelve patients with 12 fractures were included in the series, with an average length of follow-up of 26 months (range: 7-55) The average age was 34 years (17-59), and the most common mechanism of injury was motor vehicle crash. The Hawkins classification of the fractures was 4 type II (2 type IIA and 2 type IIB) (33%) and 8 type III (67%). Four fractures (33%) were open fractures. Union was achieved in 11 patients (92%). There was 1 malunion (8%). AVN was identified on postoperative CT scans in 11 patients (92%). Three of these 11 eventually showed collapse. Ten patients (83%) had radiographic evidence of some degree of ankle PTA, and 12 patients (100%) had radiographic evidence of some degree of subtalar PTA. Average Patient-Reported Outcomes Measurement Information System-Short Form score was 37 (32-45) and average Foot and Ankle Ability Measure activities of daily living and sports subscale scores were, respectively, 61 (31-87) and 31 (0-71), respectively. Average visual analog scale score was 5 (0-10), and average Foot Function Index was 49 (7-89). SF-36 scores showed fair to poor outcomes in the majority of patients.

CONCLUSION

In this relatively small series, tibial autograft in primary osteosynthesis of comminuted talar neck fractures with substantial bone defects is associated with excellent union rates and low malunion rates. Despite high union rates, secondary outcomes of AVN with or without collapse, ankle and subtalar PTA, and relatively low PROs were common.

LEVEL OF EVIDENCE

Level IV, case series.

Low Donor Site Morbidity Associated With Tricortical Calcaneal Bone Graft

BACKGROUND

Autologous grafting is widely used in orthopaedic surgery because of its high osteogenic capacity, immunologic compatibility, for the absence of risk of disease transmission, and for not requiring a bone bank. The posterior-superior calcaneal tuberosity is an option for obtaining a cortical and cancellous structural bone. This study aims to describe the operative technique and complications observed at the donor site of the posterior-superior calcaneal tuberosity.

METHODS

Patients who underwent graft harvesting from the posterior-superior calcaneal tuberosity were retrospectively evaluated by pain outcomes, imaging tests, and intra- and postoperative complications.

RESULTS

Twenty patients with a median age of 69 years (range 48-77) and follow-up of 16 months (12-26) were assessed. Median postoperative pain at the donor site was 0 (0-6), with 2 patients reporting persistent local pain. No case of Achilles tendon rupture or intra- or postoperative calcaneal fracture were identified. One patient developed a superficial infection that was quickly resolved using oral antibiotic therapy.

CONCLUSION

The posterior-superior calcaneal tuberosity is an alternative source of autologous graft with low donor site morbidity.

LEVEL OF EVIDENCE

Level IV, case series.

Recent advances in the local antibiotics delivery systems for management of osteomyelitis

Chronic osteomyelitis is a challenging disease due to its serious rates of mortality and morbidity while the currently available treatment strategies are suboptimal. In contrast to the adopted systemic treatment approaches after surgical debridement in chronic osteomyelitis, local drug delivery systems are receiving great attention in the recent decades. Local drug delivery systems using special carriers have the pros of enhancing the feasibility of penetration of antimicrobial agents to bone tissues, providing sustained release and localized concentrations of the antimicrobial agents in the infected area while avoiding the systemic side effects and toxicity. Most important, the incorporation of osteoinductive and osteoconductive materials in these systems assists bones proliferation and differentiation, hence the generation of new bone materials is enhanced. Some of these systems can also provide mechanical support for the long bones during the healing process. Most important, if the local systems are designed to be injectable to the affected site and biodegradable, they will reduce the level of invasion required for implantation and can win the patients’ compliance and reduce the healing period. They will also allow multiple injections during the course of therapy to guard against the side effect of the long-term systemic therapy. The current review presents different available approaches for delivering antimicrobial agents for the treatment of osteomyelitis focusing on the recent advances in researches for local delivery of antibiotics.

HIGHLIGHTS

Chronic osteomyelitis is a challenging disease due to its serious mortality and morbidity rates and limited effective treatment options.

Local drug delivery systems are receiving great attention in the recent decades.

Osteoinductive and osteoconductive materials in the local systems assists bones proliferation and differentiation

Local systems can be designed to provide mechanical support for the long bones during the healing process.

Designing the local system to be injectable to the affected site and biodegradable will reduces the level of invasion and win the patients’ compliance.

Craniofacial Bone Tissue Engineering: Current Approaches and Potential Therapy

Craniofacial bone defects can result from various disorders, including congenital malformations, tumor resection, infection, severe trauma, and accidents. Successfully regenerating cranial defects is an integral step to restore craniofacial function. However, challenges managing and controlling new bone tissue formation remain. Current advances in tissue engineering and regenerative medicine use innovative techniques to address these challenges. The use of biomaterials, stromal cells, and growth factors have demonstrated promising outcomes in vitro and in vivo. Natural and synthetic bone grafts combined with Mesenchymal Stromal Cells (MSCs) and growth factors have shown encouraging results in regenerating critical-size cranial defects. One of prevalent growth factors is Bone Morphogenetic Protein-2 (BMP-2). BMP-2 is defined as a gold standard growth factor that enhances new bone formation in vitro and in vivo. Recently, emerging evidence suggested that Megakaryocytes (MKs), induced by Thrombopoietin (TPO), show an increase in osteoblast proliferation in vitro and bone mass in vivo. Furthermore, a co-culture study shows mature MKs enhance MSC survival rate while maintaining their phenotype. Therefore, MKs can provide an insight as a potential therapy offering a safe and effective approach to regenerating critical-size cranial defects.

Bone Graft Harvesting From the Calcaneus Using Lateral Wall Corticotomy Technique by an Osteotome

Background: The aim of this study was to evaluate the complications following calcaneal autologous bone graft harvesting using an osteotome in patients who underwent foot and ankle surgery with follow-up of at least 1 year. Methods: In a cohort study, all consecutive patients underwent forefoot or midfoot surgeries in conjunction with harvesting bone graft from the calcaneus using lateral wall corticotomy technique by an osteotome from 2015 till 2018 were asked to follow. The outcome and morbidity were assessed by visual analogue scale (VAS) pain, numbness in territory of the sural nerve, surgical site numbness or tenderness, infection, hematoma formation, or pathologic fracture. Also any possible restrictions on wearing desired shoes were asked. Results: Totally, 50 patients (11 males, 39 females; 29 right foot, 21 left foot) with the mean age of 48.2 ± 13.8 years (range 8-66 years) were assessed. There were no major complications on donor site such as infection, hematoma formation, or pathologic fracture. The following results were seen; 90% without any pain (VAS 0/10), 96% without numbness at the incision site, 96% without point tenderness on lateral of heel, 98% without paresthesia or numbness in the sural nerve territory, and 84% were able to wear their favorite shoes. Forty-one (82%) cases said if they need another foot surgery, they would permit to harvest bone graft from their heel. Conclusions: Autologous bone graft harvesting from the calcaneus using lateral wall corticotomy technique by an osteotome could be a useful method with very low complications.Levels of Evidence: Therapeutic, level IV: cohort, case series.

Partial Calcaneus Reconstruction using 'Opportunistic Grafts': A Case Report

Although replantation of an amputated extremity has been successfully performed, occasionally the surgeon is forced to amputate in the case of an unsalvageable open fracture. These appendages can theoretically act as an autologous 'bone and tissue bank' for patients if they have reconstructable contralateral injuries. We present a case of an athlete who sustained a Gustilo and Anderson IIIC injury on 1 leg resulting in a below knee amputation. Her other lower leg had a traumatic amputation of the heel pad, partial amputation of the calcaneus, and complete Achilles tendon loss. Tissues from this amputated appendage were utilised to restore the anatomy of the contralateral extremity. The distal tibia and the tibialis anterior from the amputated limb were used to reconstruct the missing posterior tuberosity of the calcaneus and the Achilles tendon respectively. The soft tissue deficiency of the heel pad was restored with an anterolateral thigh free flap. At 2-year follow-up, the patient is pain free and back to playing soccer. This case highlights the opportunistic use of amputated parts to reconstruct a calcaneus and Achilles tendon. A multidisciplinary approach with plastic surgeons is required. The main advantage of this 'Spare Part Surgery' philosophy is to provide autologous graft of a similar geometry and to avoid harvesting tissues from an additional donor site.

Surgical Reconstruction of Nonunion after Iatrogenic Scarf Osteotomy

We present the case of a young patient, 32 years old, with nonunion in the diaphysis of the first metatarsal after scarf osteotomy for correction of hallux valgus. After removal of the failed osteosynthesis material and preparation of the bone fragments, a calcaneal bone autograft, previously extracted from the patient, was placed in the nonunion area. The new physiological position of the first metatarsal in the three planes was checked intraoperatively, and autograft and fragment fixation was performed using a combination of a low-profile plate with six screws and two interfragmentary screws. The advantage of using an autogenous graft is that it provides corticocancellous bone and great osteogenic capacity with little antigenic capacity. This makes it an excellent option in many situations in foot and ankle surgery. Regarding the fixation method, we used the two most commonly used techniques for osteosynthesis of bone grafts in cases of bone nonunion, combining plates with locking screws and two interfragmentary screws. This provides greater stability of the bone fragments in the three planes and makes it possible to bring forward when the patient starts postsurgical loading.

Recent Trends in the Development of Bone Regenerative Biomaterials

The goal of a biomaterial is to support the bone tissue regeneration process at the defect site and eventually degrade in situ and get replaced with the newly generated bone tissue. Biomaterials that enhance bone regeneration have a wealth of potential clinical applications from the treatment of non-union fractures to spinal fusion. The use of bone regenerative biomaterials from bioceramics and polymeric components to support bone cell and tissue growth is a longstanding area of interest. Recently, various forms of bone repair materials such as hydrogel, nanofiber scaffolds, and 3D printing composite scaffolds are emerging. Current challenges include the engineering of biomaterials that can match both the mechanical and biological context of bone tissue matrix and support the vascularization of large tissue constructs. Biomaterials with new levels of biofunctionality that attempt to recreate nanoscale topographical, biofactor, and gene delivery cues from the extracellular environment are emerging as interesting candidate bone regenerative biomaterials. This review has been sculptured around a case-by-case basis of current research that is being undertaken in the field of bone regeneration engineering. We will highlight the current progress in the development of physicochemical properties and applications of bone defect repair materials and their perspectives in bone regeneration.

A clinical study on bone defect reconstruction and functional recovery in benign bone tumors of the lower extremity, treated by bone marrow mesenchymal stem cell rapid screening-enrichment-composite system

BACKGROUND

With the development of medical technology, credible options for defect reconstructions after the resection of benign bone tumors of the lower extremities have become a high priority. As the current reconstructive methods commonly used in clinical practice have some flaws, new methods of reconstruction need to be explored. We aimed to prepare a new kind of bioactive scaffold for the repair of bone defects through a stem cell rapid screening-enrichment-composite technology system developed by our team. Furthermore, we aimed to investigate the curative effects of these bioactive scaffolds.

METHODS

Firstly, cell count, trypan blue exclusion rate, and ALP staining were used to evaluate changes in enrichment efficiency, cell activity, and osteogenic ability before and after enrichment. Then, the scaffolds were placed under the skin of nude mice to verify their osteogenic effects in vivo. Finally, the scaffolds were used for the reconstruction of bone defects after operations for benign bone tumors in a patient's lower limb. The healing status of the defect site at 1 and 3 months was assessed by X-ray, and the Musculoskeletal Tumor Society (MSTS) score was applied to reflect the recovery of patient limb function.

RESULTS

The system effectively enriched stem cells without affecting the activity and osteogenic abilities of the bone marrow mesenchymal stem cells (BMSCs). Meanwhile, the bioactive scaffolds obtained better osteogenic effects. In patients, the active scaffolds showed better bone integration and healing status, and the patients also obtained higher MSTS scores at 1 and 3 months after surgery.

CONCLUSION

As a new technique, the rapid screening-enrichment-composite technology of stem cells demonstrates a better therapeutic effect in the reconstruction of bone defects after surgery for benign bone tumors of the lower extremities, which will further improve patient prognosis.

Nanomaterial Nitric Oxide Delivery in Traumatic Orthopedic Regenerative Medicine

Achieving bone fracture union after trauma represents a major challenge for the orthopedic surgeon. Fracture non-healing has a multifactorial etiology and there are many risk factors for non-fusion. Environmental factors such as wound contamination, infection, and open fractures can contribute to non-healing, as can patient specific factors such as poor vascular status and improper immunologic response to fracture. Nitric oxide (NO) is a small, neutral, hydrophobic, highly reactive free radical that can diffuse across local cell membranes and exert paracrine functions in the vascular wall. This molecule plays a role in many biologic pathways, and participates in wound healing through decontamination, mediating inflammation, angiogenesis, and tissue remodeling. Additionally, NO is thought to play a role in fighting wound infection by mitigating growth of both Gram negative and Gram positive pathogens. Herein, we discuss recent developments in NO delivery mechanisms and potential implications for patients with bone fractures. NO donors are functional groups that store and release NO, independent of the enzymatic actions of NOS. Donor molecules include organic nitrates/nitrites, metal-NO complexes, and low molecular weight NO donors such as NONOates. Numerous advancements have also been made in developing mechanisms for localized nanomaterial delivery of nitric oxide to bone. NO-releasing aerogels, sol- gel derived nanomaterials, dendrimers, NO-releasing micelles, and core cross linked star (CCS) polymers are all discussed as potential avenues of NO delivery to bone. As a further target for improved fracture healing, 3d bone scaffolds have been developed to include potential for nanoparticulated NO release. These advancements are discussed in detail, and their potential therapeutic advantages are explored. This review aims to provide valuable insight for translational researchers who wish to improve the armamentarium of the feature trauma surgeon through use of NO mediated augmentation of bone healing.

The Few Who Made It: Commercially and Clinically Successful Innovative Bone Grafts

Bone reconstruction techniques are mainly based on the use of tissue grafts and artificial scaffolds. The former presents well-known limitations, such as restricted graft availability and donor site morbidity, while the latter commonly results in poor graft integration and fixation in the bone, which leads to the unbalanced distribution of loads, impaired bone formation, increased pain perception, and risk of fracture, ultimately leading to recurrent surgeries. In the past decade, research efforts have been focused on the development of innovative bone substitutes that not only provide immediate mechanical support, but also ensure appropriate graft anchoring by, for example, promoting de novo bone tissue formation. From the countless studies that aimed in this direction, only few have made the big jump from the benchtop to the bedside, whilst most have perished along the challenging path of clinical translation. Herein, we describe some clinically successful cases of bone device development, including biological glues, stem cell-seeded scaffolds, and gene-functionalized bone substitutes. We also discuss the ventures that these technologies went through, the hindrances they faced and the common grounds among them, which might have been key for their success. The ultimate objective of this perspective article is to highlight the important aspects of the clinical translation of an innovative idea in the field of bone grafting, with the aim of commercially and clinically informing new research approaches in the sector.

Effect of bone morphogenetic protein-2/hydroxyapatite on ankle fusion with bone defect in a rabbit model: a pilot study

Background

Revision ankle-fusion surgery after a failure of total ankle arthroplasty has a problem with bone-defect management by implant removal. For the reconstruction of bone defects, autogenous bone often causes minor and major complications. Recombinant human-bone morphogenetic protein-2 (rhBMP-2) plays essential roles in bone regeneration strategies, and hydroxyapatite (HA) is beneficial as the rhBMP-2 carrier. In this study, we evaluate whether rhBMP-2/HA can replace autogenous bone in a rabbit ankle-fusion model with distal tibia bone defect.

Methods

The bone defect was created in the distal tibia. The ankle fusion was performed by a cannulated screw from lateral malleolus and various treatments on bone defect. Thirty male white New Zealand rabbits were divided into three groups of 10 animals on each group dependent on treatment methods as control group (no treatment into defect), auto-bone group (autogenous bone treatment), and rhBMP-2/HA group (40 μL of 1 μg/mL rhBMP-2/100 μL HA). Bone formation on defect and the union of the ankle joint were evaluated by X-ray, micro-CT, and histological analysis at 8 weeks and 12 weeks, postoperatively.

Results

Radiographic assessment found the control and auto-bone groups still had the bone defect present, but rhBMP-2/HA group showed complete replacement of the defect with newly formed bone at 12 weeks. Micro-CT showed significantly higher new bone formation within the defect in the rhBMP-2/HA group than in the auto-bone and control groups at 8 weeks (p > 0.05 and p < 0.01, respectively) and 12 weeks (p < 0.05, p < 0.001, respectively). Fusion rate (%) analysis of micro-CT showed a higher percentage of union in the rhBMP-2/HA group than in the auto bone and control groups at 8 weeks (p > 0.05, p < 0.001, respectively) and 12 weeks (p < 0.001 and p < 0.001, respectively). The histological showed the highest osteointegration between distal tibia and talus in the rhBMP-2/HA group at 12 weeks.

Conclusions

This study indicated that rhBMP-2/HA showed much better bone fusion than did the autogenous bone graft and was effective in promoting fusion rate and improving the quality of the ankle joint fusion.

Bone Grafting Options

Union rates vary for arthrodesis sites and bone healing in foot and ankle surgery. The ultimate goal is to achieve complete bone healing within a reasonable time. There are many factors that surgeons cannot control, such as the patient's compliance and ability to heal. However, surgeons can control osseous preparation, stable fixation, preservation of soft tissue, and the osseous fusion initial healing environment. Modification of the healing environment can be achieved with the use of bone graft and orthobiologics. This article discusses the grafts and orthobiologics that can be used in bone healing for the foot and ankle.

The effects of morin on bone regeneration to accelerate healing in bone defects in mice

Restoring bone defects are the major challenge facing clinical trial therapy, particularly skull related problems. Morin, a naturally occurring compound, has pro-osteogenesis. This research focuses on assessing the role of morin for its pro-osteogenesis activities. We utilized in vivo and in vitro models to investigate the molecular-level mechanisms of morin's osteoblastic biological activity. The effectiveness of morin on pro-osteogenesis (100 mg/kg/day) was assessed by monitoring modifications in the bone histomorphometry score, the development of immature osteoblasts from mesenchymal stems cells and improvements in the expression of pro-osteogenic cytokines in skull defected (SD) mice. Quantitative-PCR, Western blot analysis, and immunofluorescence were studied to investigate the signaling pathways. Morin has a substantial in vivo pro-osteogenesis effect which can facilitate the development of osteoblasts, the production of osteoblast related marker genes, and in vitro protein markers for osteoblasts. From a molecular biology standpoint, morin contributes to the development of osteoblasts and stimulation of the Wnt pathway with the activation and translocation of β-catenin nuclei. Our findings from the study revealed that morin may be a beneficial substitute for helping regenerate bone defects.

A Tetra-PEG Hydrogel Based Aspirin Sustained Release System Exerts Beneficial Effects on Periodontal Ligament Stem Cells Mediated Bone Regeneration

Bone defects, massive bone defects in particular, is still an issue clinically. Acetylsalicylic acid (ASA), also known as aspirin, has been proven to be conducive for mesenchymal stem cells osteogenic differentiation, which may be benefited for bone regeneration. In order to achieve a more appealing prognosis of bone defect, here we develop a well-defined tetra-PEG hydrogel sealant with rapid gelation speed, strong tissue adhesion, and high mechanical strength. After in-situ encapsulation of aspirin, this drug-loaded tetra-PEG hydrogel possessed a sustained release, anti-inflammation, and osteoinductive properties. In vitro experiments showed that the cell proliferation was slightly facilitated, and the osteogenic differentiation was notably augmented when periodontal ligament stem cells (PDLSCs) were co-incubating with the hydrogel materials. Moreover, in vivo study manifested that the aspirin sustained release system significantly facilitated the PDLSCs mediated bone defect regeneration. Overall, tetra-PEG hydrogel-based aspirin sustained release system is applicable not only for enhancing the osteogenesis capacity of PDLSC but also providing a new thought of bone regenerative therapy.

Orthobiologics

Use of orthobiologics in sports medicine and musculoskeletal surgery has gained significant interest. However, many of the commercially available and advertised products are lacking in clinical evidence. Widespread use of products before fully understanding their true indications may result in unknown adverse outcomes and may also lead to increased health care costs. As more products become available, it is important to remain judicial in use and to practice evidence-based medicine. Likewise, it is important to continue advances in research in hopes to improve surgical outcomes. This article reviews clinical evidence behind common orthobiologics in the treatment of foot and ankle pathology.

The Use of Bone Grafts, Bone Graft Substitutes, and Orthobiologics for Osseous Healing in Foot and Ankle Surgery

Achieving fusion in osseous procedures about the foot and ankle presents unique challenges to the surgeon. Many patients have comorbidities that reduce osseous healing rates, and the limited space and high weightbearing demand placed on fusion sites makes the choice of bone graft, bone graft substitute, or orthobiologic agent of utmost importance. In this review, we discuss the essential characteristics of grafts, including their osteoconductive, osteoinductive, osteogenic, and angiogenic properties. Autologous bone graft remains the gold standard and contains all these properties. However, the convenience and lack of donor site morbidity of synthetic bone grafts, allografts, and orthobiologics, including growth factors and allogenic stem cells, has led to these being used commonly as augments.

Titanium Scaffolding: An Innovative Modality for Salvage of Failed First Ray Procedures

Shortening of the first ray is a potential complication associated with first metatarsal procedures. Correction of this deformity conventionally has required the use of a tricortical bone graft to lengthen the bone. Graft complications, including donor site morbidity, poor graft stability, and graft resorption, have revealed a need for an alternative procedure. The present report shows that titanium cage scaffolding has lower extremity applications beyond its previous uses in the ankle and spine. Two patients underwent surgical correction for failed first ray procedures using a titanium cage apparatus with a calcaneal autograft and other biologic agents. The scaffolds were appropriately sized to fill the defect. Patients remained non-weightbearing until radiographic evidence of healing appeared. Success was determined by diminished pain, a return to activity, ambulation, and patient satisfaction. Patients exhibited faster-than-anticipated healing, including a return to protected weightbearing activities and increased stability within 6 weeks. Titanium cage implants provide long-term stability and resistance to stress and strain in the forefoot. The implant we have described, newly applied to the first ray, is analogous to a system used in salvage of failed ankle replacements. In addition to reducing reliance on the iliac crest bone graft, the titanium cage apparatus is advantageous because it is customized to fill a defect using computed tomography scanning, thereby reducing graft failure secondary to an improper shape. These cases demonstrate the potential beneficial applications for titanium cages in failed first ray reconstruction.

Living Cryopreserved Bone Allograft as an Adjunct for Hindfoot Arthrodesis

Hindfoot arthrodesis is a frequently performed procedure by foot and ankle surgeons. The relatively high nonunion rate associated with these procedures has led surgeons to use adjunctive bone graft to help augment osseous union. Cellular bone allografts are a specific type of graft that incorporates osteoconductive, osteoinductive, and osteogenic properties while also eliminating the common disadvantages of autografts and traditional allografts. This article discusses the role of cellular bone allografts in hindfoot arthrodesis procedures, a review of current literature, and a comparison of available products.

Surgical treatment for diffused-type giant cell tumor (pigmented villonodular synovitis) about the ankle joint

Background

Diffused-type giant cell tumor(Dt-GCT) is a rare, aggressive disorder of the joint synovium, bursa and tendon sheaths. Osseous erosions and subchondral cysts may develop as the result of synovium infiltration in Dt-GCT. We present a retrospective study of a series of patients who are diagnosed with Dt-GCT about the ankle joint, there clinical outcome is evaluated in this study.

Material and method

Fifteen patients with radiologically and histologically confirmed Dt-GCT about the ankle joint were identified in our foot and ankle department. Patients were managed with open synovectomy for the tumor tissue and bone grafting for bony erosions. X-rays and MRI scans were used for evaluation of the tumor and bony erosions pre- and post-operatively. Pre- and post-operative ankle function was assessed using the American Orthopedic Foot and Ankle Society –Ankle and Hindfoot (AOFAS-AH) score and the Muscularskeletal Tumor Society (MSTS) score.

Results

The mean follow-up duration was 37.4 months (range 25 to 50 months). There were 6 males and 9 females, with a mean age of 35 years old (range 18 to 65 years). All patients had talar erosion with the average size of 10.1*9.1*8.2 mm, distal tibia was affected in 5 patients with the average size of 6.2*5.6*5.8 mm. 7 patients had tendon involvement, 2 patients had recurrence and progression of ankle osteoarthritis. Both of them underwent ankle fusion. At the time of last follow-up, the mean AOFAS-AH score increased from 49 to 80 points (p < 0.05), the MSTS score increased from 12 to 22 points (p < 0.05).

Conclusion

For Dt-GCT with bony erosions, open synovectomy combined with bone grafting seems to be a safe and effective operation for the salvage of ankle joint. Fusion is recommended for failed and severe cartilage destruction of the ankle joint.