Autologous bone graft: when shall we add growth factors?

Functional and Radiological Outcome Analysis of Osteoperiosteal Decortication Flap in Nonunion of Tibia

Introduction

The treatment of long bone shaft nonunions is challenging. The technique of osteoperiosteal decortications flap for approaching the nonunion site coupled with fixation modalities was first described by Judet in 1963. Despite promising clinical and radiological union, this technique is not popular among orthopaedic surgeons. Our study aimed to evaluate the radiological union and functional results of shaft tibia nonunions treated by the osteoperiosteal decortication approach.

Methods

This retrospective study included all the cases with established tibial shaft nonunion following stringent inclusion and exclusion criteria and operated upon by following the principle of osteoperiosteal flap technique from April 2015 to July 2019. Further subgroups were made based on nonunions complexity based on nonunion scoring system (NUSS) score. The outcome measures included radiological union scale in tibial fractures (RUST) and lower extremity functional scale (LEFS). The preoperative scores for union and function were recorded, and the subsequent scores were obtained at three, six, and nine months and one year. Appropriate statistical analysis of the data was done.

Results

Thirty-four cases were shortlisted for analysis, fulfilling our inclusion and exclusion criteria. There were 22 males (64.7%) and 12 females (35.3%) with a mean age of 34.17 ± 10.3 years. Subgroup analysis based on the complexity of nonunion (NUSS score) revealed 14 cases in group A, 10 cases in group B, 10 cases in group C, and 0 cases in group D. The average time from fracture to surgery in these cases was 14.6 months. The average time to achieve union was 9.6 months, with patients in groups A, B, and C, having a mean duration of 9, 10.5, and 12 months, respectively. Statistically, significant improvement was seen in both RUST scores and LEFS score. Complications included infection in seven cases, wound dehiscence in two cases, and four cases of persistent nonunion.

Conclusion

Osteoperiosteal decortication remains a highly effective surgical technique in the management of nonunion of long bones. NUSS scoring is an essential tool for prognosticating nonunion cases. This score is inversely related to the radiological union (RUST score) of the bone and functional recovery (LEFS score) of the patient.

Platelet-Rich Plasma Combined With Autologous Grafting in the Treatment of Long Bone Delayed Union or Non-union: A Meta-Analysis

Background: Platelet-rich plasma (PRP) has been suggested as an emerging treatment for bone defects. However, whether PRP could enhance the therapeutic efficacy of autologous bone grafting for long bone delayed union or non-union remains unknown. A meta-analysis of randomized and non-randomized controlled trials (RCT and NRCT) was performed to summarize current evidence. Methods: Relevant RCTs and NRCTs comparing the influences of autologous bone grafting on healing of long bone delayed union or non-union with and without PRP were obtained by searching PubMed, Embase, Cochrane's Library, China National Knowledge Infrastructure, and WanFang databases from inception to September 10, 2020. A random-effect model was applied to pool the results with the incorporation of the potential heterogeneity. Subgroup analysis according to study design was also performed. Results: Six RCTs and two NRCTs with 420 patients were included. Compared to patients allocated to autologous bone grafting alone, those allocated to combined treatment with PRP and autologous bone grafting were not associated with higher rates of radiographic bone healing [risk ratio (RR): 1.06, 95% confidence interval (CI): 0.99-1.13, P = 0.09; I ² = 24%] or excellent/good posttreatment limb function (RR: 1.14, 95% CI: 0.95-1.37, P = 0.37; I ² = 0%) but was associated with a shorter healing time (mean difference: -1.35 months, 95% CI: -1.86 to -0.84, P < 0.001; I ² = 58%). Subgroup analysis according to study design showed similar results for the above outcomes (P-values for subgroup difference all >0.10). Conclusions: Combined treatment with PRP and autologous bone grafting may be effective to accelerate the healing of long bone delayed union or non-union compared to autologous bone grafting alone.

Wrapping grafting for congenital pseudarthrosis of the tibia: A preliminary report

OBJECTIVE

Treatment of congenital pseudarthrosis of the tibia (CPT) remains a challenge. The autogenic iliac bone graft is important consistent of treatment for CPT. The purpose of this study was to investigate the role of wrapping autogenic iliac bone graft in improvement of the curing opportunities of CPT.

METHODS

We combined Ilizarov fixator with intramedullary rodding of the tibia and wrapping autogenic iliac bone graft for treatment 51 cases of CPT between 2007 and 2010. The mean age is 3.2 years at index operation, of which 31 patients (61%) were below 3 years old. According to Crawford classification, 5 tibia had type-II morphology; 3, type-III; 43, type-IV.

RESULTS

In the postoperative follow-up of 3.5 months (range from 3 to 4.5 months), all cases were found that the bone graft sites of pseudarthrosis of the tibia showed a significant augmentation and spindle-shaped expansion as obvious change. All cases of this series have been followed-up, average followed-up time were 1.6 years (range from 7 to 3.1 years), of which 19 cases were more than 2 years. The average time of removed the Ilizarov ring fixator was 3.5 months (range from 3 to 4.5 months). According to Johnston Clinical evaluation system, 26 cases had grade I, 21 cases, grade II, 4 cases, grade III. Following the Ohnishi X-ray evaluation criteria, union of pseudarthrosis of the tibia were 42 cases, delayed union 5 cases, nonunion 4 cases.

CONCLUSION

Autogenic iliac bone graft is able to offer the activity of osteoblasts and osteogenesis induced by bone morphogenetic protein (BMP) and glycoprotein, meanwhile enclosing bone graft could help keep cancellous bone fragments in close contact around pseudarthrosis of the tibia, allowing the formation of high concentration of glycoprotein and BMP induced by chemical factors because of established the sealing environment in location, all of which could enhance the healing of pseudarthrosis of the tibia.

Effect of Choukroun Platelet-Rich Fibrin Combined With Autologous Micro-Morselized Bone on the Repair of Mandibular Defects in Rabbits

PURPOSE

The aim of this study was to explore the effect of Choukroun platelet-rich fibrin (PRF) combined with autologous micro-morselized bone on the repair of mandibular defects in rabbits.

MATERIALS AND METHODS

Thirty-six healthy New Zealand rabbits were selected for the present study. After models of mandibular defects were established, rabbits were randomly divided into Choukroun PRF, autologous micro-morselized bone (autologous), Choukroun PRF combined with autologous bone (combined) and model groups. After the rabbits were sacrificed at 2, 8, and 12 weeks postoperatively, their bone formation was assessed by x-ray and scanning electron microscopy, and the histologic changes of the mandibular defect area were detected by hematoxylin and eosin staining. Cone-beam computed tomography was used to observe the size of the change of the mandibular defect area. Bone mineral density (BMD) was analyzed by dual-energy x-ray absorptiometry.

RESULTS

The bone defect in the combined group showed better repair, increased bone mineral content, and denser callus than the other groups, and the defect area was filled with mature trabecular bone. In the Choukroun PRF and autologous groups, the defect area was smaller and filled with osteoporotic trabecular bone. A clear mandibular defect area was still observed in the model group. Compared with the other groups, the combined group showed more bone regeneration, more fibrous tissue regeneration, and greater bone maturity at all time points. The combined group had the highest BMD, there was no relevant difference in BMD between the Choukroun PRF and autologous groups, and the model group had the lowest BMD. BMD in all 4 groups increased with time.

CONCLUSION

These findings indicate that Choukroun PRF combined with autologous micro-morselized bone can substantially improve the repair of mandibular defects in rabbits, and the effect is superior to Choukroun PRF or autologous micro-morselized bone alone.

A new animal model for delayed osseous union secondary to osteitis

Background

The treatment of infection-related delayed bone unions is still very challenging for the orthopedic surgeon. The prevalence of such infection-related types of osteitis is high in complex fractures, particularly in open fractures with extensive soft-tissue damage. The aim of this study was to develop a new animal model for delayed union due to osteitis.

Methods

After randomization to infected or non-infected groups 20 Sprague–Dawley rats underwent a transverse fracture of the midshaft tibia. After intramedullary inoculation with staphylococcus aureus (10³ CFU) fracture stabilization was done by intramedullary titanium K-wires. After 5 weeks all rats were euthanized and underwent biomechanical testing to evaluate bone consolidation or delayed union, respectively. Micro-CT scans were additionally used to quantitatively evaluate the callus formation by the score of Lane and Sandhu. Blood samples were taken to analyze infectious disease markers (day 1, 14 and 35).

Results

Biomechanical testing showed a significant higher maximum torque in the non-infected group 5 weeks postoperatively compared with the infected group (p < 0.001). According to the Lane and Sandhu score a significantly higher callus formation was found in the non-infected group (p < 0.001). Similarly, the leucocyte count in the infected group was significantly higher than in the non-infected group (p < 0.05).

Conclusions

Here we have established a new animal model for delayed osseous union secondary to osteitis. The animal model appears to be appropriate for future experimental studies to test new therapeutic strategies in these difficult to treat bone healing complications.

Effect of Emdogain enamel matrix derivative and BMP-2 on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells

The objective of this study was to evaluate the effect of Emdogain (Enamel Matrix Derivative, EMD) and Bone Morphogenetic Protein-2 (BMP-2), either solely or in combination, on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells. Stem/progenitor cells were isolated from human alveolar bone proper, magnetically sorted using STRO-1 antibodies, characterized flowcytometrically for their surface markers' expression, and examined for colony formation and multilineage differentiation potential. Subsequently, cells were treated over three weeks with 100 μg/ml Emdogain (EMD-Group), or 100 ng/ml BMP-2 (BMP-Group), or a combination of 100 ng/ml BMP-2 and 100 μg/ml Emdogain (BMP/EMD-Group). Unstimulated stem/progenitor cells (MACS(+)-Group) and osteoblasts (OB-Group) served as controls. Osteogenic gene expression was analyzed using RTq-PCR after 1, 2 and 3 weeks (N = 3/group). Mineralized nodule formation was evaluated by Alizarin-Red staining. BMP and EMD up-regulated the osteogenic gene expression. The BMP Group showed significantly higher expression of Collagen-I, III, and V, Alkaline phosphatase and Osteonectin compared to MACS(+)- and OB-Group (p < 0.05; Two-way ANOVA/Bonferroni) with no mineralized nodule formation. Under in-vitro conditions, Emdogain and BMP-2 up-regulate the osteogenic gene expression of stem/progenitor cells. The combination of BMP-2 and Emdogain showed no additive effect and would not be recommended for a combined clinical stimulation.

Effect of bone morphogenetic protein-2 on tendon-bone integration in an in vitro cell culture

The goal of this study was to evaluate the influence of bone morphogenetic protein-2 (BMP-2) on tendon-bone integration in a bovine in vitro cell culture. Seventy-two bovine tendons were cultivated over 3 months. The effects of BMP-2 were evaluated by generation in 4 subgroups. The groups differed in 2 parameters: the application of BMP-2 and the application of primary bovine osteoblasts. Results were analyzed biochemically by determining alkaline phosphatase activity and histologic tendon calcification, both markers for graft incorporation. Histological analysis demonstrated a positive effect of BMP-2 on the production of extracellular matrix and therefore the induction of osteogenesis. In addition, the results showed a superior cell ingrowth on the tendon in the BMP-2-stimulated groups. Calcium carbonate-like structures and organized ossification zones could only be detected in the BMP-2-stimulated tendons. The histological results matched those of the biochemical alkaline phosphatase analysis. The highest alkaline phosphatase activity was detected using BMP-2 stimulation in the first month (P<.001). High alkaline phosphatase values suggest high osteoblast activity and a high potential for mineralization. Furthermore, a positive effect of BMP-2 on fibroblasts existed with regard to the overall integration process. These results confirm the positive influence and triggering effect of BMP-2 on the mineralization process. Bone morphogenetic protein-2 seems to accelerate and optimize tendon-bone integration in the early process of graft incorporation. Besides the influence of BMP-2 on bovine osteoblasts, an additional positive effect of BMP-2 on bovine fibroblasts was detected; therefore, graft incorporation may be carried out by osteoblasts and fibroblasts.

Use of the reamer–irrigator–aspirator technique to obtain autograft for ankle and hindfoot arthrodesis

The use of autograft bone is the best option when undertaking a procedure that requires bone graft because it is osteogenic, osteoconductive and osseo-inductive. Pain, morbidity and complications associated with harvesting iliac or non-iliac sites occur in between 6% and 30% of cases. An alternative source of graft with possibly a lower morbidity is the intramedullary canal. In this study, 28 patients undergoing 30 arthrodesis procedures on the hindfoot had a mean of 48 cm3 (43 to 50) of bone harvested locally from the hindfoot or the tibial shaft by antegrade or retrograde reaming. No patient sustained a fracture of the calcaneum, talus or tibia. There was no morbidity except for one complication when the reamer breached the medial tibial cortex. This healed uneventfully.

This method of using the reamer–irrigator–aspirator system is an extension of the standard technique of intramedullary reaming of the lower limb: it produces good-quality bone graft with viable growth factors consistent with that of the iliac crest, and donor site morbidity is low. This is an efficient method of obtaining autologous bone for use in arthrodesis of the ankle or hindfoot.

Reaming Irrigator Aspirator system: early experience of its multipurpose use

The evolution of contemporary intramedullary reaming systems has recently generated the Reamer Irrigator Aspirator system (RIA-Synthes®), which has progressively gained in popularity as well as in indications. The preliminary results of its use over the initial period of 18 months ata single tertiary referral centre were prospectively collected and are presented. The wide spectrum of RIA's indications have been exploited, including 7 patients with polytrauma that underwent acute femoral nailing, 8 with femoral intramedullary osteomyelitis, 9 with pathological lesions of the femoral shaft, as well as 18 patients where the RIA system has been used to harvest morselised autologous bone graft in the presence of recalcitrant atrophie non-unions and bone defects. Overall its use was proven safe and efficient, achieving aggressive medullary canal debridement, collection of adequate samples for further analysis in the infected and oncology cases, as well as impressive volumes of the osteoinductive and osteogenic reaming debris for grafting purposes. No pulmonary complications or evidence of the second hit sequelae were recorded in the polytrauma patient subgroup despite the presence of a high ISS Further controlled clinical studies should follow focused in all different applications of this reliable, user-friendly and impressively versatile system, to validate these preliminary results.

Growth factors and bone regeneration: how much bone can we expect?

A large body of research has investigated the use of growth factors for bone regeneration, as a potential alternative to autogenous bone grafting. The bone morphogenetic proteins (BMPs) represent the most extensively investigated growth factors to date, as potential therapeutic agents for bone regeneration. Despite decades of research, the ideal growth factor or combination of growth factors for bone regeneration remains undefined. This article reviews the current available evidence for the application of growth factors for bone regeneration, with a focus on the clinical evidence for BMP use. Emerging pre-clinical and clinical evidence for growth factors other than the BMPs is also discussed.