Complications With the Use of BMP-2 in Scaphoid Nonunion Surgery

Scaphoid Bone Nonunions: Clinical and Functional Outcomes of Collagen/PGA Scaffolds and Cell-Based Therapy

In this study, the procedure for treating the nonunion complication of scaphoid fractures using collagen/poly glycolic acid (CPGA) scaffolds with bone marrow mesenchymal stem cell (BM-MSC) therapy was adopted and compared with the commonly employed autologous bone tissue graft. With conducting a two-armed clinical trial, 10 patients with scaphoid nonunions were enrolled in this investigation. Patients were randomly assigned to two groups treated with (1) CPGA + cell therapy and (2) autologous iliac crest bone graft standard therapy. Treatment outcomes were evaluated three months after surgery, measuring the grip and pinch strengths and wrist range of motion, with two questionnaires: Patient-Rated Wrist Evaluation (PRWE) and Quick form of Disabilities of the Arm, Shoulder, and Hand (QDASH). We have also assessed the union rate using clinical and radiologic healing criteria one and three months post-operatively. Restorative effects of CPGA + cell therapy were similar to those of the autologous bone graft standard therapy, except for the grip strength (P = 0.048) and QDASH score (P = 0.044) changes, which were higher in the CPGA + cell therapy group. Three months following the surgery, radiographic images and computed tomography (CT) scans also demonstrated that the scaphoid union rate in the test group was comparable to that of scaphoids treated with the standard autograft method. Our findings demonstrate that the CPGA + cell therapy is a potential alternative for bone grafting in the treatment of bone nonunions.

Bone Morphogenic Protein for Upper Extremity Fractures: A Systematic Review

BACKGROUND

This review discusses success, time to healing, and complications of bone morphogenic proteins (BMPs) 7 and 2 in treating upper extremity nonunions.

METHODS

Systematic review identified 26 of 479 studies that met inclusion criteria. Publications described application of BMPs to acute and chronic upper extremity delayed unions/nonunions. Unions, complications, patient demographics, and fracture/healing patterns were pooled and analyzed.

RESULTS

Nonunions treated with BMP-7 (n=302) involved the humerus (64%), forearm (22%), clavicle (11%), and hand/wrist (3%), with prior surgical correction attempted in 84%. Nonunions treated with BMP-2 (n=96) involved the humerus (58%), hand/wrist (27%), forearm (14%), and clavicle (1%), with prior surgical correction attempted in all. Most nonunions (80%) were present for over 12 months before BMP application. Union rates of BMP-7 varied according to site: hand/wrist (95%), humerus (74%), forearm (29%), and clavicle (6.2%) nonunions achieved union as defined by study authors in 232 days (confidence interval=96-369, Q<0.001) on average. While not significant across studies, BMP-2 union rates were 71% of hand/wrist and 75% of humerus nonunions. Comparison of the BMPs demonstrates different proportions of success in humerus and hand/wrist fractures (P<.001) but not forearm fractures (P<.77) and longer time to radiographic union with BMP-7 (P<.011).

CONCLUSIONS

Most hand/wrist and humerus nonunions treated with BMP-7 and BMP-2 achieved union, with significant similarity among BMP-7 studies not observed in BMP-2 studies. Nonunions treated with BMP-7 have longer healing times yet similar complication rates compared with BMP-2. Overall, BMPs are an effective adjunct to fracture healing with acceptable complication profile.

Thermoresponsive and Injectable Hydrogel for Tissue Agnostic Regeneration

Injectable hydrogels can support the body's innate healing capability by providing a temporary matrix for host cell ingrowth and neovascularization. The clinical adoption of current injectable systems remains low due to their cumbersome preparation requirements, device malfunction, product dislodgment during administration, and uncontrolled biological responses at the treatment site. To address these challenges, a fully synthetic and ready-to-use injectable biomaterial is engineered that forms an adhesive hydrogel that remains at the administration site regardless of defect anatomy. The product elicits a negligible local inflammatory response and fully resorbs into nontoxic components with minimal impact on internal organs. Preclinical animal studies confirm that the engineered hydrogel upregulates the regeneration of both soft and hard tissues by providing a temporary matrix to support host cell ingrowth and neovascularization. In a pilot clinical trial, the engineered hydrogel is successfully administered to a socket site post tooth extraction and forms adhesive hydrogel that stabilizes blood clot and supports soft and hard tissue regeneration. Accordingly, this injectable hydrogel exhibits high therapeutic potential and can be adopted to address multiple unmet needs in different clinical settings.

Bone Morphogenic Protein 2 Use for the Surgical Treatment of Acute Scaphoid Fractures and Scaphoid Non-unions

BACKGROUND

Bone morphogenic protein 2 (BMP-2) has demonstrated promise as an adjunct to surgically treating fractures. Its reported use in the upper extremity is limited. Questions/purpose: This study reports union rates, outcomes, and complications of scaphoid fractures treated with adjunctive BMP-2 to further characterize BMP-2 use in the hand and wrist.

METHODS

Retrospective review of scaphoid fractures treated surgically in one region of the military health system from 2009 to 2019 was conducted to identify cases employing BMP-2. Fracture healing was determined by computed tomography. Primary outcomes were union rate, time to union, and complications. Secondary outcomes included union rates for prior non-unions, union rates at 4 & 6 weeks, and functional outcomes.

RESULTS

Fourteen patients met inclusion criteria. Non-unions accounted for 50% of included fractures. The total union rate was 93%. Mean time to union was 6.2 weeks. All acute fractures healed with mean time to union of 4.8 weeks. Non-unions had a union rate of 86% with mean time to union of 7.7 weeks. Four patients (29%) developed radiographic heterotopic ossification (HO); however, there was no significant decrease in motion was appreciated. Thirteen patients (93%) resumed the push-ups portion of the military fitness test. No major complications were identified during follow up.

CONCLUSIONS

Adjunctive use of BMP-2 in operative fixation of scaphoid fractures resulted in desirable union rates without major complications. Larger, prospective studies are needed to assess if adjunctive BMP-2 use in scaphoid fractures provides significant benefit versus other treatments.

Bone Morphogenetic Protein in Scaphoid Nonunion: A Systematic Review

Background  Scaphoid nonunion can lead to carpal collapse and osteoarthritis, a painfully debilitating problem. Bone morphogenetic protein (BMP) has been successfully implemented to augment bone healing in other circumstances, but its use in scaphoid nonunion has yielded conflicting results. Case Description  The purpose of this study is to assess the outcomes and complications of scaphoid nonunion treated surgically with BMP. Literature Review  A literature review of all available journal articles citing the use of BMP in scaphoid nonunion surgery from 2002 to 2019 was conducted. We included studies that used BMP as an adjunct to surgical treatment for scaphoid nonunions in both the primary and revision settings with computed tomography determination of union. Demographic information, dose of BMP, tobacco use, outcomes, and complications were recorded. A total of 21 cases were included from four different studies meeting inclusion criteria. Clinical Relevance  The union rates were 90.5% overall, 100% for primary surgeries, and 77.8% for revision surgeries. Five patients (24%) experienced 11 complications, including four cases (19%) of heterotrophic ossification. Use of BMP in scaphoid nonunion surgery resulted in a 90.5% overall union rate but was also associated with complications such as heterotopic ossification. All included studies used BMP to augment bone graft, screw or wire fixation, or a combination of methods. The efficacy of BMP in scaphoid nonunion is unclear, and a sufficiently powered, randomized controlled trial is needed to determine optimal fixation methods, dosing, and morbidity of the use of BMP. Level of Evidence  This is a Level IC, therapeutic interventional study.

Orthobiologics in Hand Surgery

Orthobiologic agents are used as innovative adjuvant therapy to treat common upper-extremity pathology, including carpal tunnel syndrome, de Quervain tenosynovitis, and distal radius fractures. In this article, we perform a narrative review and evaluate current literature on orthobiologics in the upper extremity. Orthobiologics evaluated include bone morphogenetic proteins, platelet-rich plasma, bone marrow aspirate concentrate, mesenchymal stem cells, and amniotic membrane. Studies selected include randomized control trials, case studies, and animal studies. Although there is some clinical evidence regarding the use of orthobiologic agents in the treatment of shoulder, elbow, and sports injuries, there is a paucity of literature regarding their use to treat pathology of the hand and wrist. Further investigation is necessary to determine their effectiveness and therapeutic value in treatment of upper extremity injuries.

Functionalized Scaffold and Barrier Membrane with Anti-BMP-2 Monoclonal Antibodies for Alveolar Ridge Preservation in a Canine Model

Introduction

The aim of this study was to investigate the ability of anti-bone morphogenetic protein 2 monoclonal antibody (anti-BMP-2 mAb) to functionalize scaffolds to mediate bone regeneration in a canine model.

Materials and Methods

The mandibular right premolar 4 (PM4) was extracted in eight beagle dogs and grafted with anti-BMP-2 mAb+anorganic bovine bone mineral with 10% collagen (ABBM-C) and porcine bilayer native collagen membrane (CM). The ABBM-C and CM were functionalized with either anti-BMP-2 mAb (test group) or an isotype matched control mAb (control group). Animals were euthanized at 12 weeks for radiographic, histologic, and histomorphometric analyses. Outcomes were compared between groups.

Results

3D imaging using cone beam computed tomography (CBCT) revealed that sites treated with ABBM-C and CM functionalized with anti-BMP-2 mAb exhibited significantly more remaining bone width near the alveolar crest, as well as buccal bone height, compared with control groups. Histologic and histomorphometric analyses demonstrated that in anti-BMP-2 mAb-treated sites, total tissue volume was significantly higher in the coronal part of the alveolar bone crest compared with control sites. In anti-BMP-2 mAb-treated sites, bone formation was observed under the barrier membrane.

Conclusion

Functionalization of the ABBM-C scaffold and CM appeared to have led to bone formation within healing alveolar bone sockets.

Ex vivo regional gene therapy with human adipose-derived stem cells for bone repair

BACKGROUND

The treatment of complex bone loss scenarios remains challenging. This study evaluates the efficacy of ex vivo regional gene therapy using transduced human adipose-derived stem cells (ASCs) overexpressing bone morphogenetic protein-2 (BMP-2) to treat critical-sized bone defects.

METHODS

Critical-sized femoral defects created surgically in immunocompromised rats were treated with ASCs transduced with a lentivirus encoding BMP-2 (Group 1, n = 14), or green fluorescent protein (Group 2, n = 5), nontransduced ASCs (Group 3, n = 5), or rhBMP-2 (Group 4, n = 14). At 12 weeks, femurs were evaluated for quantity and quality of bone formation with plain radiographs, micro-computed tomography, histology/histomorphometry, and biomechanical strength testing.

RESULTS

Thirteen of 14 samples in Group 1 and all 14 samples in Group 4 showed radiographic healing, while no samples in either Groups 2 or 3 healed. Groups 1 and 4 had significantly higher radiographic scores (p < 0.001), bone volume fraction (BV/TV) (p < 0.001), and bone area fraction (BA/TA) than Groups 2 and 3 (p < 0.001). Radiographic scores, BV/TV, and BA/TA were not significantly different between Groups 1 and 4. No difference with regards to mean torque, rotation at failure, torsional stiffness, and energy to failure was seen between Groups 1 and 4.

CONCLUSIONS

Human ASCs modified to overexpress BMP-2 resulted in abundant bone formation, with the quality of bone comparable to that of rhBMP-2. This strategy represents a promising approach in the treatment of large bone defects in the clinical setting.

CLINICAL RELEVANCE

Large bone defects may require sustained protein production to induce an appropriate osteoinductive response. Ex vivo regional gene therapy using a lentiviral vector has the potential to be part of a comprehensive tissue engineering strategy for treating osseous defects.

RhBMP7 use for treating scaphoid non-union: 5 cases assessed at 10 years' follow-up

The scaphoid is the most common non-union site in the wrist. Fixation with vascularised or non-vascularised autograft is the gold standard when it comes to treating these non-unions. But, what can we offer if the autograft fails? Using osteoinductive proteins in difficult cases of long bone non-union yields good results. However, only a few studies have been published on their use for scaphoid non-union. In our study, five patients with an average age of 32 years (ranging from 21 to 44 years) with old non-union (more than 24 months) of the scaphoid were treated after autograft treatment had failed. The procedure consisted of reaming the non-union site, then adding bone autograft combined with BMP-7 (Osigraft®) in the defect and fixing it all with a screw or K-wire. Postoperative immobilisation was prescribed. Only one patient achieved bone union (20%) despite an average follow-up of 10 years (80-143 months). The average flexion-extension loss was 16.6° (0-30) relative to the contralateral side. The average strength deficit was 450 grams (0-2000) for pinch and 12.1kg (0-29) for grip compared to the contralateral side. Self-assessment questionnaires had an average PRWE at 28.9 (10.5-49) and an average QuickDASH at 28.6 (9.09-61.36). Our study could not demonstrate any real benefit of using BMP-7 for treating old scaphoid non-union despite an elevated cost. Further research is needed to look at other treatment approaches, for instance, the use of new scaffolds combining VEGF and BMP.

The Vascularity and Osteogenesis of a Vascularized Flap for the Treatment of Scaphoid Nonunion: The Pedicle Volar Distal Radial Periosteal Flap

Background: Vascularized periosteal flaps from the distal radius have been previously proposed. The purpose of this study was to investigate the vascularity and osteogenic potential of a vascularized volar distal radial periosteal flap for the treatment of scaphoid nonunion. Methods: In 5 fresh frozen cadavers, a rectangular periosteal flap was elevated from the distal radius with the pedicle just proximal to the watershed line. Latex dye was injected into the radial artery proximally and the vascularity of the flap characterized by microscopic evaluation. Patients with scaphoid nonunion were then treated with open reduction, internal fixation, and distal radius cancellous bone graft. Two groups of patients with midwaist nonunion scaphoid were then evaluated. The first group received the vascularized periosteal flap and the second group received a nonvascularized periosteal flap. A third group of proximal pole nonunions also received the vascularized flap. Results: Cadaveric dissections revealed that all of the injected flaps demonstrated vascularity to the distal edge of the flap. Vascularized flaps formed visible bone on imaging in 55% of cases. None of the nonvascularized flaps formed visible bone. In group 1, 12/12 midwaist nonunions united. In group 2, union was achieved in 6/6 of patients who completed the follow-up. In group 3, 6/7 proximal pole fractures united. Conclusions: Previously proposed vascularized periosteal flaps from the distal radius appear to possess notable osteogenic potential that may be of interest to surgeons treating scaphoid nonunion.

Activation of hedgehog signaling by systemic agonist improves fracture healing in aged mice

Fracture healing is a complex process of many coordinated biological pathways. This system can go awry resulting in nonunion, which leads to significant patient morbidity. The Hedgehog (Hh) signaling pathway is upregulated in fracture healing. We hypothesized that the Hh signaling pathway can be pharmacologically modulated to positively affect fracture healing. Diaphyseal femur fractures were created in elderly mice (18 months, C57BL/6 females), which have a blunted and delayed healing response compared to younger mice, and were stabilized with intramedullary pins. To activate the Hh pathway we targeted the receptor Smoothened using an agonist (Hh-Ag1.5 [Hh-Ag]) and compared this to a vehicle control. Expression of Hh target genes were significantly increased in the fracture callus of the agonist group compared to controls, indicating pathway activation. Expression of osteogenic and chondrogenic-related genes was greatly upregulated in fracture callus versus intact femora, although Hh agonist treatment did not consistently enhance this response. Blindly graded, radiographic callus healing scores were significantly higher in the Hh-Ag groups at post operative day (POD) 14, indicating earlier callus bridging. On microCT, Hh-Ag treatment led to greater callus volume (+40%) and bone volume (+25%) at POD21. By day 14, callus vascularity, as assessed by 3D microCT angiography vessel volume, was 85% greater in the Hh-Ag group. Finally, mechanical strength of the calluses in the Hh-Ag groups was significantly greater than in the control groups at POD21. In conclusion, systemic administration of a Hh agonist appears to improve the osseous and vascular healing responses in a mouse fracture healing-impaired model. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Bone morphogenetic proteins - 7 and - 2 in the treatment of delayed osseous union secondary to bacterial osteitis in a rat model

Background

Bone infections due to trauma and subsequent delayed or impaired fracture healing represent a great challenge in orthopedics and trauma surgery. The prevalence of such bacterial infection-related types of delayed non-union is high in complex fractures, particularly in open fractures with additional extensive soft-tissue damage. The aim of this study was to establish a rat model of delayed osseous union secondary to bacterial osteitis and investigate the impact of rhBMP-7 and rhBMP-2 on fracture healing in the situation of an ongoing infection.

Methods

After randomization to four groups 72 Sprague-Dawley rats underwent a transverse fracture of the midshaft tibia stabilized by intramedullary titanium K-wires. Three groups received an intramedullary inoculation with Staphylococcus aureus (10³ colony-forming units) before stabilization and the group without bacteria inoculation served as healing control. After 5 weeks, a second surgery was performed with irrigation of the medullary canal and local rhBMP-7 and rhBMP-2 treatment whereas control group and infected control group received sterile saline. After further 5 weeks rats were sacrificed and underwent biomechanical testing to assess the mechanical stability of the fractured bone. Additional micro-CT analysis, histological, and histomorphometric analysis were done to evaluate bone consolidation or delayed union, respectively, and to quantify callus formation and the mineralized area of the callus.

Results

Biomechanical testing showed a significantly higher fracture torque in the non-infected control group and the infected rhBMP-7- and rhBMP-2 group compared with the infected control group (p < 0.001). RhBMP-7 and rhBMP-2 groups did not show statistically significant differences (p = 0.57). Histological findings supported improved bone-healing after rhBMP treatment but quantitative micro-CT and histomorphometric results still showed significantly more hypertrophic callus tissue in all three infected groups compared to the non-infected group. Results from a semiquantitative bone-healing-score revealed best bone-healing in the non-infected control group. The expected chronic infection was confirmed in all infected groups.

Conclusions

In delayed bone healing secondary to infection rhBMP treatment promotes bone healing with no significant differences in the healing efficacy of rhBMP-2 and rhBMP-7 being noted. Further new therapeutic bone substitutes should be analyzed with the present rat model for delayed osseous union secondary to bacterial osteitis.

Photocrosslinked Dextran-Based Hydrogels as Carrier System for the Cells and Cytokines Induce Bone Regeneration in Critical Size Defects in Mice

Modified biomaterials have for years been the focus of research into establishing new bone substitutes. In our preceding in vitro study employing different cell cultures, we developed chemically and mechanically characterized hydrogels based on photocrosslinkable dextran derivatives and demonstrated their cytocompatibility and their beneficial effects on the proliferation of osteoblasts and endothelial cells. In the present in vivo study, we investigate photocrosslinked dextran-based hydrogels in critical size defects in mice to evaluate their potential as carrier systems for cells or for a specific angiogenesis enhancing cytokine to induce bone formation. We could demonstrate that, with optimized laboratory practice, the endotoxin content of hydrogels could be reduced below the Food and Drug Administration (FDA)-limit. Dextran-based hydrogels were either loaded with a monoculture of endothelial cells or a co-culture of human osteoblasts with endothelial cells, or with stromal-derived-growth factor (SDF-1). Scaffolds were implanted into a calvarial defect of critical size in mice and their impact on bone formation was assessed by µCt-analyses, histology and immunohistology. Our study demonstrates that promotion of angiogenesis either by SDF-1 or a monoculture of endothelial cells induces bone regeneration at a physiological level. These in vivo results indicate the potential of dextran-based hydrogel composites in bone regeneration to deliver cells and cytokines to the defect site.

The challenges of promoting osteogenesis in segmental bone defects and osteoporosis

Conventional clinical management of complex bone healing scenarios continues to result in 5-10% of fractures forming non-unions. Additionally, the aging population and prevalence of osteoporosis-related fractures necessitate the further exploration of novel ways to augment osteogenesis in this special population. This review focuses on the current clinical modalities available, and the ongoing clinical and pre-clinical research to promote osteogenesis in segmental bone defects, delayed unions, and osteoporosis. In summary, animal models of fracture repair are often small animals as historically significant large animal models, like the dog, continue to gain favor as companion animals. Small rodents have well-documented limitations in comparing to fracture repair in humans, and few similarities exist. Study design, number of studies, and availability of funding continue to limit large animal studies. Osteoinduction with rhBMP-2 results in robust bone formation, although long-term quality is scrutinized due to poor bone mineral quality. PTH 1-34 is the only FDA approved osteo-anabolic treatment to prevent osteoporotic fractures. Limited to 2 years of clinical use, PTH 1-34 has further been plagued by dose-related ambiguities and inconsistent results when applied to pathologic fractures in systematic human clinical studies. There is limited animal data of PTH 1-34 applied locally to bone defects. Gene therapy continues to gain popularity among researchers to augment bone healing. Non-integrating viral vectors and targeted apoptosis of genetically modified therapeutic cells is an ongoing area of research. Finally, progenitor cell therapies and the content variation of patient-side treatments (e.g., PRP and BMAC) are being studied. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1559-1572, 2018.

Molecular pathogenesis of fracture nonunion

Fracture nonunion, a serious bone fracture complication, remains a challenge in clinical practice. Although the molecular pathogenesis of nonunion remains unclear, a better understanding may provide better approaches for its prevention, diagnosis and treatment at the molecular level. This review tries to summarise the progress made in studies of the pathogenesis of fracture nonunion. We discuss the evidence supporting the concept that the development of nonunion is related to genetic factors. The importance of several cytokines that regulate fracture healing in the pathogenesis of nonunion, such as tumour necrosis factor-α, interleukin-6, bone morphogenetic proteins, insulin-like growth factors, matrix metalloproteinases and vascular endothelial growth factor, has been proven in vitro, in animals and in humans. Nitric oxide and the Wnt signalling pathway also play important roles in the development of nonunion. We present potential strategies for the prevention, diagnosis and treatment of nonunion, and the interaction between genetic alteration and abnormal cytokine expression warrants further investigation.

The translational potential of this article

A better understanding of nonunion molecular pathogenesis may provide better approaches for its prevention, diagnosis and treatment in clinical practice.

3D printed hyperelastic "bone" scaffolds and regional gene therapy: A novel approach to bone healing

The purpose of this study was to evaluate the viability of human adipose-derived stem cells (ADSCs) transduced with a lentiviral (LV) vector to overexpress bone morphogenetic protein-2 (BMP-2) loaded onto a novel 3D printed scaffold. Human ADSCs were transduced with a LV vector carrying the cDNA for BMP-2. The transduced cells were loaded onto a 3D printed Hyperelastic "Bone" (HB) scaffold. In vitro BMP-2 production was assessed using enzyme-linked immunosorbent assay analysis. The ability of ADSCs loaded on the HB scaffold to induce in vivo bone formation in a hind limb muscle pouch model was assessed in the following groups: ADSCs transduced with LV-BMP-2, LV-green fluorescent protein, ADSCs alone, and empty HB scaffolds. Bone formation was assessed using radiographs, histology and histomorphometry. Transduced ADSCs BMP-2 production on the HB scaffold at 24 hours was similar on 3D printed HB scaffolds versus control wells with transduced cells alone, and continued to increase after 1 and 2 weeks of culture. Bone formation was noted in LV-BMP-2 animals on plain radiographs at 2 and 4 weeks after implantation; no bone formation was noted in the other groups. Histology demonstrated that the LV-BMP-2 group was the only group that formed woven bone and the mean bone area/tissue area was significantly greater when compared with the other groups. 3D printed HB scaffolds are effective carriers for transduced ADSCs to promote bone repair. The combination of gene therapy and tissue engineered scaffolds is a promising multidisciplinary approach to bone repair with significant clinical potential. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1104-1110, 2018.

CD34+ cells seeded in collagen scaffolds promote bone formation in a mouse calvarial defect model

Bone tissue engineering (BTE) holds promise for managing the clinical problem of large bone defects. However, clinical adoption of BTE is limited due to limited vascularization of constructs, which could be circumvented by pre-cultivation of osteogenic and endothelial derived cells in natural-based polymer scaffolds. However, until now not many studies compared the effect of mono- and cocultures pre-seeded in collagen before implantation. We utilized a mouse calvarial defect model and compared five groups of collagen scaffolds: a negative control of a collagen scaffold alone, a positive control treated with BMP-7, monocultures of either human osteoblasts (hOBs) or CD34+ cells, and a coculture of hOB and CD34⁺ cells. Each pre-seeded collagen scaffold was implanted in mice. After 6 weeks mice were sacrificed and their skulls prepared for volumetric and histologic analysis. We found that a monoculture of CD34⁺ cells and a coculture of hOB and CD34⁺ cells pre-cultured in the collagen scaffold increased bone regeneration to a similar extend. In these groups, greater amounts of new bone were found compared with hOB monocultures. Interestingly, monoculture of CD34⁺ cells demonstrated better fracture healing than monoculture of hOBs, emphasizing the possible role of angiogenesis. Our results are promising regarding a cellular based collagen BTE construct, but more work is needed to understand the complex interaction between the osteogenic and endothelial cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1505-1516, 2018.

Biologic Approaches to Problems of the Hand and Wrist

Orthobiologics are not used as frequently in the hand and wrist as in other sites. The most frequently reported is the use of bone morphogenetic protein for the treatment of Kienböck disease. Animal studies have described improved tendon healing with the use of platelet-rich plasma (PRP), but no clinical studies have confirmed these results. PRP has been reported to produce improvements in the outcomes of distal radial fractures and osteoarthritis of the trapeziometacarpal in small numbers of patients. The use of orthobiologics in the hand and wrist are promising, but clinical trials are necessary to establish efficacy and safety.

Bone Morphogenetic Protein: Is There Still a Role in Orthopedic Trauma in 2017?

Approximately 10 years ago bone morphogenic protein (BMP) was seen as a miraculous adjuvant to assist with bone growth. However, in the face of an increasing number of complications and a lack of understanding its long-term effects, it is unclear what role BMP has in the current treatment of orthopedic trauma patients. This article reviews the current recommendations, trends, and associated complications of BMP use in fracture care.

Ilizarov fixation for the treatment of scaphoid nonunion: a novel approach

OBJECTIVES

To evaluate the safety and efficacy of the Ilizarov fine-wire compression/distraction technique in the treatment of scaphoid nonunion (SNU), without the use of bone graft.

DESIGN

This is a prospective study of 20 consecutive patients in one center.

PATIENTS AND METHODS

This study included 20 patients (19 males) with a mean SNU duration of 14.5 months. Four patients had proximal pole, 15 had waist, and 1 had a distal SNU. Patients with carpal instability, humpback deformities, carpal collapse, avascular necrosis, and marked degenerative change were excluded. Following frame application, the treatment comprises three stages: The frame is distracted by 1 mm per day until the radiographs show a 2-3 mm opening at the SNU site (mean 10 days); the SNU site is compressed for 5 days, at a rate of 1 mm per day, with the wrist in 15 degrees of flexion and 15 degrees of radial deviation; the wrist is then immobilized in the Ilizarov fixator for 8 weeks.

RESULTS

Radiographic (radiography and CT scan) and clinical bony union was achieved in all 20 patients after a mean of 90.3 days (70-130 days). All patients returned to their pre-injury occupations. Thirteen patients had excellent results, four good, and three fair, according to the Mayo wrist score.

CONCLUSIONS

In these selected patients, this technique safely achieved bony union without the need to open the SNU site and without the requirement of bone graft.