Clinical effectiveness of Osigraft in long-bones non-unions

Efficacy and safety of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with autologous bone for the treatment of long bone nonunion: A report of a prospective case series

INTRODUCTION

Recombinant human Bone morphogenetic proteins have been used for the treatment of nonunions with promising results. We have been investigating both experimentally and clinically the efficacy of the rhBMP-2 with the macro / micro-porous hydroxyapatite carrier granules on the potency on the reconstruction of long bone defect. The purpose of this study was to prospectively evaluate the efficacy and safety of this specific rhBMP-2 with HA carrier granules mixed with autologous cancellous bone in patients with nonunion and bone defect resulted from the fracture related infection.

MATERIALS AND METHODS

This was a retrospective review of a prospective cohort at a university hospital. Patients diagnosed with nonunion under the definition of the United States Food and Drug Administration with bone defect after long bone fractures were enrolled from January 2020 to February 2021. We included patients with atrophic and oligotrophic nonunion, and hypertrophic nonunion with malalignment that needed to be corrected. The other patient group was consisted of segmental bone defect resulted from FRI. The maximum amount of rhBMP-2 allowed in this clinical study was 6 mg and was added to autologous bone at a 1:1 ratio. Autologous bone was added to the mixture if the volume of mixed graft was insufficient to fill the bone defect. Patients were followed 3, 6, and 12 months post-operatively. Each visit, a radiograph was taken for assessment. Visual analog scale (VAS), questionnaire for quality of life (SF-12 physical component summary [PCS], mental component summary [MCS]), and weight-bearing status were collected for functional outcome assessment. Drug safety was assessed by examining BMP-2 antibodies.

RESULTS

Of the 24 enrolled patients (mean age: 57 years), 15 (62.5 %), 2 (8.33 %), and 7 (29.17 %) presented atrophic nonunion, hypertrophic nonunion with deformity, and bone defect after fracture related infection, respectively. Thirteen patients had nonunion in the femur, 9 in the tibia, and 1 in the humerus and radius. The average amount of harvested autologous bone was 9.25 g and 4.96 mg of rhBMP-2. All 24 patients achieved union after 1-year follow up. The union rate was 95.83 % and 100 % at 6 and 12 months postoperatively, respectively. Preoperative SF-12 PCS (mean: 34.71) improved at 6 and 12 months postoperatively, respectively. Preoperative SF-12 MCS (mean: 42.89) improved 12 months postoperatively (49.13, p = 0.0338). Change of VAS was statistically significant 3 months postoperatively (p = 0.0012). No adverse effects or development of BMP-2 antibodies were observed.

CONCLUSION

BMP-2 combined with autogenous bone resulted in excellent radiographical and functional outcomes in a relatively small prospective series of patients with nonunion and bone defect, without adverse effects. Further investigations are necessary to support our finding and optimize treatment strategies in nonunion patients.

Phase III clinical trial of autologous CD34 + cell transplantation to accelerate fracture nonunion repair

BACKGROUND

We previously demonstrated that CD34 + cell transplantation in animals healed intractable fractures via osteogenesis and vasculogenesis; we also demonstrated the safety and efficacy of this cell therapy in an earlier phase I/II clinical trial conducted on seven patients with fracture nonunion. Herein, we present the results of a phase III clinical trial conducted to confirm the results of the previous phase studies using a larger cohort of patients.

METHODS

CD34 + cells were mobilized via administration of granulocyte colony-stimulating factor, harvested using leukapheresis, and isolated using magnetic cell sorting. Autologous CD34 + cells were transplanted in 15 patients with tibia nonunion and 10 patients with femur nonunion, who were followed up for 52 weeks post transplantation. The main outcome was a reduction in time to heal the tibia in nonunion patients compared with that in historical control patients. We calculated the required number of patients as 15 based on the results of the phase I/II study. An independent data monitoring committee performed the radiographic assessments. Adverse events and medical device failures were recorded.

RESULTS

All fractures healed during the study period. The time to radiological fracture healing was 2.8 times shorter in patients with CD34 + cell transplantation than in the historical control group (hazard ratio: 2.81 and 95% confidence interval 1.16-6.85); moreover, no safety concerns were observed.

CONCLUSIONS

Our findings strongly suggest that autologous CD34 + cell transplantation is a novel treatment option for fracture nonunion.

TRIAL REGISTRATION

UMIN-CTR, UMIN000022814. Registered on 22 June 2016.

Advances in Microgravity Directed Tissue Engineering

Tissue engineering aims to generate functional biological substitutes to repair, sustain, improve, or replace tissue function affected by disease. With the rapid development of space science, the application of simulated microgravity has become an active topic in the field of tissue engineering. There is a growing body of evidence demonstrating that microgravity offers excellent advantages for tissue engineering by modulating cellular morphology, metabolism, secretion, proliferation, and stem cell differentiation. To date, there have been many achievements in constructing bioartificial spheroids, organoids, or tissue analogs with or without scaffolds in vitro under simulated microgravity conditions. Herein, the current status, recent advances, challenges, and prospects of microgravity related to tissue engineering are reviewed. Current simulated-microgravity devices and cutting-edge advances of microgravity for biomaterials-dependent or biomaterials-independent tissue engineering to offer a reference for guiding further exploration of simulated microgravity strategies to produce engineered tissues are summarized and discussed.

Recombinant human bone morphogenetic protein is a valid alternative to autologous bone graft for long bone non-unions: a systematic review and meta-analysis

OBJECTIVE

To compare the efficacy of recombinant human bone morphogenetic proteins (rhBMPs) and autologous bone graft (ABG) on the healing of long bone non-union.

METHODS

A systematic literature search was conducted on PubMed, Web of Science, Cochrane Library, and CNKI up to December 2021. Two authors independently screened the studies, extracted data, and assessed the quality of the trials. A Meta-analysis was performed using state software (version 12.0).

RESULTS

A total of 14 studies were included in this meta-analysis. Overall, there was no significant difference between the rhBMPs group and the ABG group in terms of healing rate (RR = 1.04, 95% CI = 0.96-1.12, p = 0.365) and healing time (SMD = -0.31, 95% CI = -0.76-0.14, p = 0.175). Subgroup analysis showed rhBMPs lead to higher healing rates (RR = 1.35, 95% CI = 1.17-1.56, p < 0.001), and shorter healing time (SMD = -0.65, 95% CI = -1.08 to -0.22, p = 0.003) in the subgroup of moderate-quality studies. Sensitivity analysis proved that our conclusions were relatively robust. No significant publication bias was recognized in all studies (Begg's test, p = 0.193; Egger's test, p = 0.307).

CONCLUSIONS

RhBMPs or combined with allografts bone, inorganic bone was a valid alternative to ABG for the treatment of long bone non-union.

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.

Strategies for inclusion of growth factors into 3D printed bone grafts

There remains a critical need to develop new technologies and materials that can meet the demands of treating large bone defects. The advancement of 3-dimensional (3D) printing technologies has allowed the creation of personalized and customized bone grafts, with specific control in both macro- and micro-architecture, and desired mechanical properties. Nevertheless, the biomaterials used for the production of these bone grafts often possess poor biological properties. The incorporation of growth factors (GFs), which are the natural orchestrators of the physiological healing process, into 3D printed bone grafts, represents a promising strategy to achieve the bioactivity required to enhance bone regeneration. In this review, the possible strategies used to incorporate GFs to 3D printed constructs are presented with a specific focus on bone regeneration. In particular, the strengths and limitations of different methods, such as physical and chemical cross-linking, which are currently used to incorporate GFs to the engineered constructs are critically reviewed. Different strategies used to present one or more GFs to achieve simultaneous angiogenesis and vasculogenesis for enhanced bone regeneration are also covered in this review. In addition, the possibility of combining several manufacturing approaches to fabricate hybrid constructs, which better mimic the complexity of biological niches, is presented. Finally, the clinical relevance of these approaches and the future steps that should be taken are discussed.

The biology and treatment of acute long-bones diaphyseal fractures: Overview of the current options for bone healing enhancement

Diaphyseal fractures represent a complex biological entity that could often end into impaired bone-healing, with delayed union and non-union occurring up to 10% of cases. The role of the modern orthopaedic surgeon is to optimize the fracture healing environment, recognize and eliminate possible interfering factors, and choose the best suited surgical fixation technique. The impaired reparative process after surgical intervention can be modulated with different surgical techniques, such as dynamization or exchange nailing after failed intramedullary nailing. Moreover, the mechanical stability of a nail can be improved through augmentation plating, bone grafting or external fixation techniques with satisfactory results. According to the "diamond concept", local therapies, such as osteoconductive scaffolds, bone growth factors, and osteogenic cells can be successfully applied in "polytherapy" for the enhancement of delayed union and non-union of long bones diaphyseal fractures. Moreover, systemic anti-osteoporosis anabolic drugs, such as teriparatide, have been proposed as off-label treatment for bone healing enhancement both in fresh complex shaft fractures and impaired unions, especially for fragility fractures. The article aims to review the biological and mechanical principles of failed reparative osteogenesis of diaphyseal fractures after surgical treatment. Moreover, the evidence about the modern non-surgical and pharmacological options for bone healing enhancement will discussed.

The Treatment of Acute Diaphyseal Long-bones Fractures with Orthobiologics and Pharmacological Interventions for Bone Healing Enhancement: A Systematic Review of Clinical Evidence

BACKGROUND

The healing of long bones diaphyseal fractures can be often impaired and eventually end into delayed union and non-union. A number of therapeutic strategies have been proposed in combination with surgical treatment in order to enhance the healing process, such as scaffolds, growth factors, cell therapies and systemic pharmacological treatments. Our aim was to investigate the current evidence of bone healing enhancement of acute long bone diaphyseal fractures.

METHODS

A systematic review was conducted by using Pubmed/MEDLINE; Embase and Ovid databases. The combination of the search terms "long-bones; diaphyseal fracture; bone healing; growth factors; cell therapies; scaffolds; graft; bone substitutes; orthobiologics; teriparatide".

RESULTS

The initial search resulted in 4156 articles of which 37 papers fulfilled the inclusion criteria and were the subject of this review. The studies included 1350 patients (837 males and 513 females) with a mean age of 65.3 years old.

CONCLUSIONS

General lack of high-quality studies exists on the use of adjuvant strategies for bone healing enhancement in acute shaft fractures. Strong evidence supports the use of bone grafts, while only moderate evidence demineralized bone matrix and synthetic ceramics. Conflicting results partially supported the use of growth factors and cell therapies in acute fractures. Teriparatide showed promising results, particularly for atypical femoral fractures and periprosthetic femoral fractures.

Gene activated adipose tissue fragments as advanced autologous biomaterials for bone regeneration: osteogenic differentiation within the tissue and implications for clinical translation

Cost-effective, expedited approaches for bone regeneration are urgently needed in an ageing population. Bone Morphogenetic Proteins (BMPs) stimulate osteogenesis but their efficacy is impeded by their short half-life. Delivery by genetically modified cells can overcome this problem. However, cell isolation and propagation represent significant obstacles for the translation into the clinic. Instead, complete gene activated fragments of adipose tissue hold great potential for bone repair. Here, using an in-vitro culture system, we investigated whether adenoviral transduction with human BMP-2 can promote osteogenic differentiation within adipose tissue fragments. Osteoinduction in adipose tissue fragments was evaluated by quantitative reverse transcriptase polymerase chain reaction, immunohistology and histomorphometry. BMP-2 transduced adipose tissue synthesized BMP-2 protein over 30 days peaking by day six, which significantly promoted osteogenic differentiation as indicated by increased calcium depositions, up-regulation of bone marker genes, and bone-related protein expression. Our results demonstrate that cells within adipose tissue fragments can differentiate osteogenically after BMP-2 transduction of cells on the surface of the adipose tissue. BMP-2 gene activated adipose tissue represents an advanced osteo-regenerative biomaterial that can actively contribute to osteogenesis and potentially enable the development of a novel, cost-effective, one-step surgical approach to bone repair without the need for cell isolation.

Comparison of the clinical effectiveness of Bone Morphogenic Protein (BMP) -2 and -7 in the adjunct treatment of lower limb nonunions

BACKGROUND

Substantial evidence exists demonstrating the individual effectiveness of both rhBMP-2 and -7 in the treatment of nonunions, data comparing the clinical effectiveness of adjunct rhBMP-2 and -7 remains scarce. Therefore, we examined our large single-center case series to compare the clinical effectiveness of both rhBMP-2 and -7 in non-union therapy aiming to answer: - Does a certain type of BMP have an advantageous effect on radiological outcome of applied lower limb non-union therapy? - Does application of a certain type of BMP have an advantageous effect on radiological outcome of infected lower limb nonunions? - Are there any additional risk factors associated with inferior outcome in context with an adjunct BMP treatment?

HYPOTHESIS

Both BMPs have the same effect on the radiological outcome of surgically treated lower limb nonunions.

PATIENTS AND METHODS

Single-center retrospective database analysis of a case series of patients with lower limb long bone nonunions receiving either a one- or two-stage (Masquelet-) procedure based on the "diamond concept" with application of rhBMP-2 or -7. The "diamond concept" summarizes core factors that need to be present to achieve bone healing. In particular, these factors relate to the optimization of the mechanical (stability) and biological environment (sufficient osteogenic and angiogenic cells, osteoconductive scaffolds and growth factors). All medical data from patients that received surgical treatment between 01/01/2010 and 31/12/2016 were assessed. In total, 356 patients were treated with BMPs and 156 patients 18 years or older with non-union of their tibia or femur having a follow-up of at least 1 year were included. Consolidation in context with type of rhBMP was compared and the influence of relevant risk factors assessed.

RESULTS

Consolidation rate was significantly higher in patients treated with rhBMP-2 (rhBMP-2: 42/46 (91%) vs. rhBMP-7: 64/110 (58%); p<0.001). In particular, application of rhBMP-2 increased the likelihood of consolidation for tibial nonunions (OR 32.744; 95%CI: 2.909-368.544; p=0.005) and when used in two-stage therapy (OR 12.095; 95% CI: 2.744-53.314; p=0.001). Furthermore, regression modeling revealed a higher correlation between application of rhBMP-2 and osseous consolidation in infected nonunions (OR 61.062; 95% CI: 2.208-1688.475; p=0.015) than in aseptic nonunions (OR 4.787; 95% CI: 1.321-17.351; p=0.017). Risk factors negatively influencing the outcome of non-union treatment in context with rhBMPs were identified as active smoking (OR 0.357; 95% CI: 0.138-0.927; p=0.024), atrophic nonunion (OR 0.23; 95% CI: 0.061-0.869; p=0.030), higher BMI (OR 0.919; 95% CI: 0.846-0.998; p=0.046) and a larger defect size (OR 0.877; 95% CI: 0.784-0.98; p=0.021).

DISCUSSION

Patients who received rhBMP-2 for the treatment of tibial nonunions and as part of the two-stage treatment had a significantly higher rate of healing compared to patients treated with rhBMP-7 regardless of infection.

LEVEL OF EVIDENCE

III, retrospective case-control study.

Current perspectives on biological approaches for osteoarthritis

Musculoskeletal injuries that disrupt the structure and function of diarthrodial joints can cause permanent biomechanical alterations and lead to a more severe, chronic condition. Despite advancements that have been made to restore tissue function and delay the need for joint replacement, there are currently no disease-modifying therapies for osteoarthritis (OA). To reduce the risk of OA, innovative preventive medicine approaches have been developed over the last decade to treat the underlying pathology. Several biological approaches are promising treatment modalities for various stages of OA owing to their minimally invasive nature and actively dynamic physiological mechanisms that attenuate tissue degradation and inflammatory responses. Individualized growth factor and cytokine therapies, tissue-engineered biomaterials, and cell-based therapies have revolutionary potential for orthopedic applications; however, the paucity of standardization and categorization of biological components and their counterparts has made it difficult to determine their clinical and biological efficacy. Cell-based therapies and tissue-engineered biologics have become lucrative in sports medicine and orthopedics; nonetheless, there is a continued effort to produce a biological treatment modality tailored to target intra-articular structures that recapitulates tissue function. Advanced development of these biological treatment modalities will potentially optimize tissue healing, regeneration, and joint preservation strategies. Therefore, the purpose of this paper is to review current concepts on several biological treatment approaches for OA.

Non-unions

Non-union of long bones is a significant consequence of fracture treatment. Bone regeneration is a complex physiological process of bone formation which can be seen during normal fracture healing. An improved understanding of the molecular and cellular events that occur during bone repair and remodelling has led to the development of biologic agents that can augment the biological microenvironment and enhance bone repair. Currently, there are different strategies to augment the impaired or "insufficient" bone-regeneration process, including the "gold standard" autologous bone graft, free fibula vascularised graft, allograft implantation, and use of growth factors, osteoconductive scaffolds, osteoprogenitor cells and distraction osteogenesis. A lack of standardized outcome measures for comparison of biologic agents in clinical fracture repair trials, frequent off-label use and a limited understanding of the biological activity of these agents at the bone repair site have limited their efficacy in clinical applications.

Clavicle aseptic nonunion: is there a place for cortical allogenic strut graft?

We investigated functional and radiological outcome in 57 cases of midshaft clavicle nonunion treated with open reduction and internal fixation with plate and screws over a 13 year-period. Intercalary bone graft was used in 42 patients; opposite autologous strut graft was used in 31 cases to provide mechanical support to the host bone. Patients were analysed using chart and radiological review and assessed with DASH questionnaire obtained at the latest follow-up. 37 patients were male while 20 were females, with a mean age of 35 years (63-17). All cases were of nonunion, 35 atrophic and 22 hypertrophic. The dominant side was injured in 32 cases and the non dominant in 25 cases. Primarily, 43 cases were treated conservatively with a figure of eight bandage. Time between fracture and our operative treatment was on average 44 months (13-72 months). Only those patients who were symptomatic were included in this study. We used straight reconstruction LCP and low profile precontoured plates. By reviewing patients charts all the cases but one of nonunion progressed to osseous healing at a mean time of 14 weeks (range 12-16). The patient with non-union refused further surgery. 49 patients were available for a final follow up. DASH score was 16.7 at an average of 42 months. Open surgery and internal fixation, using plate and screws in a compression construct is the treatment of choice for symptomatic clavicular non-unions. Intercalary autologous or allograft bone graft should be used especially in patient with significant bone loss; autologous cortical strut graft provides optimum mechanical stability, thus assuring optimal screw purchase and allowing immediate limb movement.

Recalcitrant aseptic atrophic non-union of the shaft of the humerus after failure of surgical treatment: management by excision of non-union, bone grafting and stabilization by LCP in different modes

Non-union of the humeral shaft is infrequently noticed after surgical fixation. Sixty eight patients whose osteosynthesis of humeral shaft had failed leading to non-union were identified over a duration of 10 years from (January 2006 to December 2015). Clinical and radiographical follow-up was available for 64 patients (4 patients were lost for follow-up), with a mean age of 58 years (range 25-78 years). All patients had aseptic atrophic non-union of either: proximal shaft (n=12), mid shaft (n=38), and lower shaft (n=14). All these patients had failure of primary fixation, with a minimum duration from 36 to 110 weeks. Non-unions were operated by excision of non-union, autogenous bone grafting and osteosynthesis by locking compression plating. Adequate fixation of non-union with bone grafting was achieved in all patients. All non-unions healed well at an average of 16 weeks (range 6-36 weeks). The mean length of follow-up was 120 weeks (range 60-250 weeks). The mean range of movements following healing of non-union was forward flexion of 140°, external rotation and internal rotation of 30° at shoulder and average fixed flexion deformity of 10° and flexion of 130° at elbow. Two patients had postoperative radial nerve palsy because of neuropraxia, which recovered in eight weeks. Three patient developed superficial infections at the iliac crest, which settled with antibiotics, dressings in 3 weeks time and two patients had some discomfort over the fibular graft harvest site. In all patients complete clinical and radiological union was achieved with satisfactory outcome in terms of relief of symptoms and functional improvement in the range of movements. The main points in surgical treatment were complete excision of non-union, correction of deformity, use of plenty of corticocancellous graft, furthermore the use of intramedullary fibula and osteosynthesis by long locking compression plating in different modes of fixation provided good to excellent results and clinical outcome.

Management of resistant distal femur non-unions with allograft strut and autografts combined with osteosynthesis in a series of 22 patients

INTRODUCTION AND PURPOSE

Challenges to the surgeon in managing cases of resistant non-union of the distal femur include poor bone stock, disuse osteopenia and joint contractures. Procedures varying from simple bone grafting to megaprosthesis revision have been described. We successfully managed such cases using our technique of combining cortical allograft struts to augment the defect in the femoral condyle coupled with autogenous iliac crest bone grafting and locking plate osteosynthesis.

MATERIALS AND METHODS

Between April 2012 and May 2014, 22 patients who presented with resistant nonunions of the distal femur following initial surgery were managed using this technique. Cortical allograft struts were taken from the tissue bank of our institution. All patients were followed up post operatively and their time to union was noted. Functional outcome was calculated using LEFS (Lower extremity functional score). The average follow up of all our patients was 24 months.

RESULTS

All patients went on to achieve complete bony union. The average union time was 6.2 months (5 to 8 months). One patient who was a diabetic had superficial infection post operatively which was treated successfully with IV antibiotics. Average knee flexion was 110 degrees (80 to 130 degrees). The mean LEFS score was 72 (59 to 79).

CONCLUSION

Combing a locking plate fixation with the bone grafting technique of using an allograft strut to support the metaphyseal medial bone defect and autografts gives a good union and a good functional outcome in the management of resistant non-unions of the distal femur by enhancing the biology and providing a good structural support to the distal femur.

Effectiveness of exchange K-nail and augmented plating in aseptic femoral diaphyseal non-union

BACKGROUND

Femoral diaphyseal non-unions present difficult scenario to manage. There are multiple options but most of them still report varying incidences of failure. We combined the principles of augmented plating and exchange nailing and aim to study the effectiveness of this technique.

METHOD

A retrospective study at a tertiary trauma centre was conducted. Seventy patients (60 men, 10 women), average age 40.7±15.27 years (range 18-81 years) with diaphyseal femoral fracture non-unions treated between July 2010 and January 2015 were reviewed. The average interval between first and the last surgery was 18.07±17.65 months (range 4-96 months). Forty six patients had hypertrophic non-union and 24 patients had atrophic non-union. Twenty one patients had undergone a prior surgery for non-union, 13 dynamisation, 4 bone grafting, 1 augmented plating and 3 exchange nailing. Non-unions were treated with implant removal, freshening of bone edges and exchange K-nailing and augmented plating. Autologous bone grafting and raising of osteoperiosteal flaps was done in all cases. Outcome measures were radiographic evidence of fracture union at minimum three out of four cortices, knee range of motion as compared to opposite knee, and study of complications.

RESULTS

All patients demonstrated radiographic evidence of fracture union with an average time of 16.77±2.38 weeks (range 12-26 weeks). Mean knee range of motion of unaffected limb was 126±9.76° (range 90-140°) while in operated limb it was 121.1±11.36° (range 80-140°), p>0.01. Patients with hypertrophic non-unions, prior surgery for non-union and supra- or infra-isthmal non-unions had shorter union time. Two patients had superficial infection which was managed by superficial debridement and two patients had pain at proximal nail tip site which was managed by anti-inflammatory medication. None of the patients required additional surgery for implant removal.

CONCLUSION

Exchange K nailing with Bone graft and additional plating technique for non-union diaphyseal femur fracture achieved good union rates with minimal complication. In our series none of the patient required revision and the technique probably will further minimise the revision rates compared to current options for non-union femur.

Damage control and intramedullary nailing for long bone fractures in polytrauma patients

The early fracture treatment in patients with multiple injuries should be focused on damage control. The fracture type and its location, local soft tissue condition as well as the patient's physiological condition shall determine the time and type of fracture treatment. Prevention of local and systemic complications must be immediately considered and included in the treatment planning. The use of external fixator (ExFix), which will be replaced by IM-implants in most cases at a later stage, provides adequate temporary fracture stabilization with less collateral damage. Good clinical results can be expected in patients with long bone fractures if the principles of damage control surgery are applied and local complications are prevented through proper reduction, firm fixation, early soft tissue reconstruction, and early rehabilitation.

Clinical application of bone morphogenetic proteins for bone healing: a systematic review

PURPOSE

This paper documents the existing evidence on bone morphogenetic proteins (BMPs) use for the treatment of bone fractures, non-union, and osteonecrosis, through a review of the clinical literature, underlying potential and limitations in terms of cost effectiveness and risk of complications.

METHODS

A systematic review was performed on the PubMed database using the following string: (bone morphogenetic proteins OR BMPs) and (bone repair OR bone regeneration) including papers from 2000 to 2016. The search focused on clinical trials dealing with BMPs application to favor bone regeneration in bone fractures, non-union, and osteonecrosis, in English language, with level of evidence I, II, III, and IV. Relevant data (type of study, number of patients, BMPs delivery material, dose, site, follow-up, outcome, and adverse events) were extracted and analyzed.

RESULTS

Forty-four articles met the inclusion criteria: 10 randomized controlled trials (RCTs), 7 comparative studies, 18 case series, and 9 case reports. rhBMP-2 was documented mainly for the treatment of fractures, and rhBMP-7 mainly for non-unions and osteonecrosis. Mixed results were found among RCTs and comparative papers: 11 reported positive results for BMPs augmentation, 3 obtained no significant effects, and 2 showed negative results. The only study comparing the two BMPs showed a better outcome with rhBMP-2 for non-union treatment.

CONCLUSION

Clinical evidence on BMPs use for the treatment of fractures, non-union, and osteonecrosis is still controversial, with the few available reports being mainly of low quality. While positive findings have been described in many studies, mixed results are still present in the literature in terms of efficacy and adverse events. The difficulties in drawing clear conclusions are also due to the studies heterogeneity, mainly in terms of different BMPs applied, with different concomitant treatments for each bone pathology. Therefore, further research with well-designed studies is needed in order to understand the real potential of this biological approach to favour bone healing.

Core decompression and biotechnologies in the treatment of avascular necrosis of the femoral head

Avascular necrosis (AVN) of the femoral head (FH) causes 5% to 12% of total hip arthroplasties (THA). It especially affects active male adults between the third and fifth decades of life. The exact worldwide incidence is unknown. There are only few data related to each country, but most of it relates to the United States.Non-surgical management has a very limited role in the treatment of AVN of the FH and only in its earliest stages. Core decompression (CD) of the hip is the most common procedure used to treat the early stages of AVN of the FH. Recently, surgeons have considered combining CD with autologous bone-marrow cells, demineralised bone matrix or bone morphogenetic proteins or methods of angiogenic potential to enhance bone repair in the FH.Manuscripts were deemed eligible for our review if they evaluated treatment of early stage AVN of the FH with biotechnology implanted via CD. After application of eligibility criteria, we selected 19 reports for final analysis.The principal results showed that only by correctly mastering the therapeutic principles and adopting proper methods specifically oriented to different stages can the best therapeutic effect be achieved. Combining CD with biotechnology could result in a novel long-lasting hip- preserving treatment option.Furthermore, more refined clinical studies are needed to establish the effectiveness of biotechnology treatments in AVN of the FH. Cite this article: EFORT Open Rev 2017;2:41-50. DOI: 10.1302/2058-5241.2.150006.

Closing the gap: a novel technique for humeral shaft nonunions using cup and cone reamers

INTRODUCTION

Nonunion following closed treatment of humeral shaft fracture is estimated to be 5.5%. Many surgical techniques have been described to address humeral shaft nonunion including: open reduction, internal fixation (ORIF) with compression plating and bone graft, dual plating, cortical strut allograft and autograft, and adding biologic augmentation (BMP). The current standard of care includes ORIF with compression plating and bone grafting, but even this technique has an approximated 10% failure rate. We describe a novel surgical technique using cup and cone reamers, which were originally designed for metatarsophalangeal or metacarpalphalangeal arthrodesis. Cup and cone reamers are the appropriate size for mid-shaft, transverse humeral nonunions to ensure ideal apposition of healthy, bleeding bone.

METHODS AND PATIENTS

We retrospectively reviewed 3 patients with nonunion of the midshaft humerus which were treated with the cup and cone technique and a large fragment LCDC plate. An anterolateral approach was used in 2 cases and a posterior in the other. After exposure of fracture ends, 24-mm hemispherical convex and concave reamers were then used to ream the proximal and distal ends in order to create a "cup and cone" articulation of the fracture ends. All patients were followed for a minimum of 6 months with a mean follow-up of 12 months.

RESULTS

All patients treated with this technique achieved union, reported zero pain and full functional outcome. Specifically, patients had a mean age of 36.3 and the mean interval between injury and time to surgery was 11.5 months. Two of the patients presented with nonunions after attempted closed treatment and the other patient had 3 prior surgeries for infected nonunion. Union was achieved at a mean of 12 weeks.

CONCLUSION

To our knowledge, the use of cup and cone reamers for nonunion of the humerus has never been described. We describe a simple and effective technique for humeral shaft nonunions which has been successful in both septic and hypertrophic nonunions, as well as from multiple approaches-both anterolateral and posterior.

Treatment of recalcitrant atrophic non-union of the humeral shaft with BMP-7, autologous bone graft and hydroxyapatite pellets

Recalcitrant humeral non-union is a disabling condition that is extremely difficult to treat. The use of BMP-7 has been proposed to improve bone healing. This is a report of the results obtained in 12 patients with recalcitrant humeral non-union treated using stable fixation with a long locking compression plate and BMP-7, autologous bone graft and hydroxyapatite pellets applied at the non-union site. Patients had up to three surgical attempts at non-union healing prior to our treatment. The average time from the initial fracture to our surgery was 5.2 years. Average follow-up was 5.3 years. At follow-up, non-union had healed in all patients by an average of 7.3 months. All the patients were very satisfied with their final results, despite a restricted range of motion of the elbow and a moderate muscular atrophy, which was frequently observed. Our study shows that BMP-7 associated with autologous bone grafting and hydroxyapatite pellets after stable fixation is an effective adjuvant to stimulate bone healing in the treatment of recalcitrant humeral non-union.