Enhancing bone healing during distraction osteogenesis with platelet-rich plasma

Versatility of Transport Distraction Osteogenesis for Reconstruction of Lateral Mandibular Ablative Defects

Introduction

The reconstitution of form and function after maxillofacial tumor resection or traumatic bony defects is a challenge when considering reconstructive options. The reconstructive options will depend upon whether the tissues to be replaced included bone alone or both bone and soft tissue (composite resection).

Methodology

This study was carried out on nine patients who with benign tumors or cysts of the mandible that required segmental resection. Mandibular reconstruction using mandibular transport distraction osteogenesis was performed for all the cases. Depending on whether the condyle was spared or sacrificed, the type of mandibular transport distractor either fixed on the remnant condyle-ramus unit or had a condylar component replacing the resected condyles. Depending on the location of the defect, transport distraction was carried our anterior to posterior or posterior to anterior.

Results

A total of nine cases of benign mandibular pathologies were operated. Segmental resection with condylar preservation was carried out in seven cases, segmental resection with condylar resection was carried out in two cases. In cases with condylar resection, the reconstruction plate of the distractor device had a condylar component. Anterior to posterior transport distraction was carried out in seven cases, and posterior to anterior transport distraction carried out in two cases. The amount of distracted bone ranged from 38 to 46 mm.

Conclusion

Mandibular transport distraction osteogenesis offers a modality of reconstruction where the patient's native host bone is osteotomized and gradually distracted to induce the formation of regenerated osseous structure and soft tissue. Being cost-effective, not requiring a steep learning curve/long operative time, and not technically demanding as vascularized bone grafts/flaps, it is feasible in the Indian setup as a practical reconstructive option for benign jaw tumors.

Clinical outcomes of autologous platelet-rich plasma and bone marrow mononuclear cells grafting combined with core decompression for Association Research Circulation Osseous II-IIIA stage non-traumatic osteonecrosis of the femoral head

PURPOSE

This study aimed to investigate the efficacy and safety of autologous platelet-rich plasma (PRP) and bone marrow mononuclear cells (BMMCs) grafting combined with core decompression (CD) in the treatment of Association Research Circulation Osseous (ARCO) II-IIIA stage non-traumatic osteonecrosis of the femoral head (ONFH).

METHODS

The clinical data of 44 patients (44 hips) with non-traumatic ONFH from December 2018 to December 2019 were retrospectively reviewed. Twenty-four patients underwent CD combined with autologous PRP and BMMCs grafting (PRP+BMMCs group), and 20 patients underwent core decompression alone (CD group). During a minimum follow-up of 36 months, radiographic outcomes were evaluated using X-ray, radiographic failure rates were compared, and Harris hip score (HHS) and visual analog scale (VAS) were selected to evaluate clinical outcomes. The percentage of patients with minimal clinically important difference (MCID) in both groups was analyzed. Clinical failure was defined as further total hip arthroplasty (THA) with Kaplan-Meier survival analysis. Surgical complications were recorded.

RESULTS

All patients had well healed wounds, and no complications such as infection and thrombosis occurred. HHS and VAS scores in both the PRP+BMMCs and CD groups were better than those preoperatively (P<0.05). At the last follow-up, the HHS and VAS scores of the PRP+BMMCs group were significantly better than those of the CD group (P<0.05). In ARCO II-IIIA stage, 66.7% of the PRP+BMMCs group and 30.0% of the CD group achieved the MCID (P<0.05). The clinical and imaging failure rates in the PRP+BMMCs group were 12.5% and 20.8%, respectively, compared with 40.0% and 50.0% in the CD group (P<0.05). In ARCO II stage, the MCID, clinical and imaging failure rates of PRP+BMMCs group and CD group were 66.7% and 33.3% (P<0.05), 4.8% and 33.3% (P<0.05), 14.3% and 44.4% (P<0.05), respectively. The PRP+BMMCs group had better hip survival rate compared with CD group (P<0.05).

CONCLUSION

CD combined with autologous PRP and BMMCs grafting is a safe and effective method for the treatment of ARCO II-IIIA stage non-traumatic ONFH, especially for ARCO II stage, effectively reducing the collapse rate of the femoral head and delaying or even avoiding THA.

Effect of Mechanical Stimulation Combined With Platelet-Rich Plasma on Healing of the Rotator Cuff in a Murine Model

BACKGROUND

Mechanical stimulation and platelet-rich plasma (PRP) have been shown to be beneficial for healing of the bone-tendon interface (BTI), but few studies have explored the efficacy of a combination of these applications. We investigated the effect of mechanical stimulation combined with PRP on rotator cuff repair in mice.

HYPOTHESIS

Mechanical stimulation combined with PRP can enhance BTI healing in a murine model of rotator cuff repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 160 C57BL/6 mice were used. Overall, 40 mice were used to prepare PRP, while 120 mice underwent acute supraspinatus tendon (SST) repair. The animals were randomly assigned to 4 groups: control group, mechanical stimulation group, PRP group, and mechanical stimulation combined with PRP group (combination group). At 4 and 8 weeks postoperatively, animals were sacrificed, the eyeballs were removed to collect blood, and the SST-humeral complexes were collected. Histological, biomechanical, immunological, and bone morphometric tests were performed.

RESULTS

Histologically, at 4 and 8 weeks after surgery, the area of the fibrocartilage layer at the BTI in the combination group was larger than in the other groups. The content and distribution of proteoglycans in this layer in the combination group were significantly greater than in the other groups. At 8 weeks postoperatively, trabecular number, and trabecular bone thickness of the subchondral bone area of interest at the BTI of the combination group were greater than those of the other groups, bone volume fraction of the combination group was greater than the control group. On biomechanical testing at 4 and 8 weeks after surgery, the failure load and ultimate strength of the SST-humeral complex in the combination group were higher than in the other groups. Enzyme-linked immunosorbent assay results showed that, at 4 weeks postoperatively, the serum concentrations of transforming growth factor beta 1 and platelet-derived growth factor (PDGF) in the combination group were significantly higher than in the other groups; at 8 weeks, the PDGF-AB concentration in the combination group was higher than in the control and mechanical stimulation groups.

CONCLUSION

Mechanical stimulation combined with PRP can effectively promote the early stage of healing after a rotator cuff injury.

CLINICAL RELEVANCE

These findings imply that mechanical stimulation combined with PRP can serve as a potential therapeutic strategy for rotator cuff healing.

Combined use of calcium phosphate cement, mesenchymal stem cells and platelet-rich plasma for bone regeneration in critical-size defect of the femoral condyle in mini-pigs

Aim: To investigate the outcome of autologous bone marrow mesenchymal stem cells (BMMSCs) and platelet-rich plasma in combination with calcium phosphate cement (CPC) scaffold to reconstruct femoral critical bone defects in mini-pigs. Materials & methods: Scanning electron microscopy, micro-computed tomography evaluation and quantitative histological assessment were used. Results & conclusion: BMMSCs were attached to the CPC scaffold after 7 days of culture and decreased the residual CPC material in each group at 12 weeks compared with 6 weeks. The newly formed bone area was higher in the CPC+SC+P group than in the CPC group at each time point (all p < 0.05). The strategy of CPC combined with BMMSCs and platelet-rich plasma might be an effective method to repair bone defects.

Platet Rich Plasma or Hyperbaric Oxygen Therapy as callus accellerator in aseptic tibial non union. Evaluate of outcomes

Background and aim of the work:

The incidence of long bone non-unions has been estimated to range between 5-10%. Nonunion of fracture is a delayed complication of fracture. A large bone resection, associated with Ilizarov’s osteo-distraction technique, is commonly used in these cases. The war experience was very important for dealing with these injuries. The purpose of this study is to report whether the use of Platelet Rich of Plasma(PRP) or Hyperbric Oxygen Therapy(HOT) as an adjuvant to the osteogenic distraction of Ilizarov with respect to the classical method has advantages.

Methods:

From 183 tibial non union, we enrolled 50 patients suffering by Type B according ASAMI non union classification. We divided the patients into two groups. The first group was a retrospective group of patient treated by Ilizarov Tecnique plus PRP. Instead the second group, patients were treated by Ilizarov Tecnique associated with HOT. The chosen criteria to evaluate the two groups during the clinical and radiological follow-up were: the complication after the surgery in the two groups; the duration of surgery; the objective quality Bone results and functional results were evaluated according to ASAMI classification while the subjective quality of life correlated with Ilizarov frame function by the Short Form 12 Health Survey (SF-12); The correlation between bone regenerate/bone healing and X-rays. The evaluation endpoint was set at 12 months from the remotion of Ilizarov’s frame for both groups.

Results:

In comparing the complications of the two populations, there were a significant statistically difference(p<0.05) in the local skin inflammation and Dockin Point Skin retraction for HOT group while in refracture p<0.05 was for group PRP. From the SF-12 we discovered not statistically differences p<0.05. The average correlation between Bone Regenerate-Bone Healing/ X-rays is absolutely in the PRP as in the HOT, p>0.05. The average Time for remove Ilizarov’s Frame in months was 15.37(±7.34; range 9–32) in PRP while in HOT was15.22(± 7.83; range 9–31), p>0.05.

Conclusions:

From our study we can conclude that the association of HOT and PRP with the Ilizarov technique does not improve the functional outcomes but allows a more rapid healing of the regenerated bone and therefore an early removal of the device and a corresponding improvement in the quality of life. (www.actabiomedica.it)

Relevant advances in bone lengthening research: a bibliometric analysis of the 100 most-cited articles published from 2001 to 2017

This study aimed to assess the scientific production of bone lengthening research by identifying the most-cited papers. All articles including the term 'bone lengthening' published between 2001 and 2017 were retrieved through the Web of Science database. The 100 most-cited articles on bone lengthening included a total of 4244 citations, with 414 (9.7%) citations in 2017. There was an average of 249.6 citations per year. The articles predominantly addressed biomechanics and bone formation (38). Different surgical techniques, including intramedullary nail (14), Ilizarov (nine), intramedullary skeletal kinetic distractor (ISKD) (six), Taylor spatial frame (6), the PRECICE device (three), and lengthening and submuscular locking plate (three), were the second most-studied topic. Most studies were therapeutic (58), whereas 30 studies were experimental investigations using animal models. Among the clinical studies, case series were predominant (level of evidence IV) (57). This study presents the first bibliometric analysis of the most relevant articles on bone lengthening. The list is relatively comprehensive in terms of identifying the top issues in this field. However, the most influential clinical studies have a poor level of evidence, although a slight tendency toward a better level of evidence has been observed in more recent years.

Low-intensity pulsed ultrasound enhances callus consolidation in distraction osteogenesis of the tibia by the technique of lengthening over the nail procedure

BACKGROUND

Low-intensity pulsed ultrasound (LIPUS) has been widely accepted in promoting the fracture healing process. However, there have been limited clinical trials focused on the efficacy of LIPUS during distraction osteogenesis (DO) by the technique of lengthening over the nail procedure. The purpose of the current study was to evaluate the efficacy of LIPUS during DO.

METHODS

We retrospectively evaluated 30 patients (60 segments) who underwent simultaneous bilateral tibial lengthening over the nail. The patients were grouped into the LIPUS group and the control group based on LIPUS stimulation. The two patient groups were compared for demographic data (sex, age at operation, preoperative height, BMI, and smoking history), qualitative assessments of the callus (callus shape and type), external fixation index, and four cortical healing indexes.

RESULTS

Fifteen patients (30 segments) were classified as the LIPUS group, and another 15 patients (30 segments) were classified as the control group. No significant differences were found in the assessed demographic data between the groups. LIPUS stimulated a more cylindrical, more homogenous, and denser type of callus formation at the end of the distraction phase. The two groups exhibited equivalent outcomes in terms of external fixation index (p = 0.579). However, significant differences were found in healing indexes of the anterior and medial cortices (p <  0.001 and p = 0.002, respectively). The healing indexes of those cortices in the LIPUS group (mean of 36.6 days/cm and 32.5 days/cm, respectively) reflected their significantly faster healing compared to the control group (mean HI of 57.5 days/cm and 44.2 days/cm, respectively). There were no LIPUS-related complications.

CONCLUSIONS

LIPUS is a noninvasive and effective adjuvant therapy to enhance callus maturation during DO. It enhances callus consolidation and may have a positive effect on the appropriate callus shape and type.

Sclerostin antibody enhances bone formation in a rat model of distraction osteogenesis

Neutralizing monoclonal sclerostin antibodies are effective in promoting bone formation at a systemic level and in orthopedic scenarios including closed fracture repair. In this study we examined the effects of sclerostin antibody (Scl-Ab) treatment on regenerate volume, density, and strength in a rat model of distraction osteogenesis. Surgical osteotomy was performed on 179 Sprague Dawley rats. After 1 week, rats underwent distraction for 2 weeks, followed by 6 weeks for consolidation. Two treatment groups received biweekly subcutaneous Scl-AbIII (a rodent form of Scl-Ab; 25 mg/kg), either from the start of distraction onward or restricted to the consolidation phase. These groups were compared to controls receiving saline. Measurement modalities included longitudinal DXA, ex vivo QCT, and microCT, tissue histology, and biomechanical four-point bending tests. Bone volume was increased in both Scl-Ab treatments regimens by the end of consolidation (+26-38%, p < 0.05), as assessed by microCT. This was associated with increased mineral apposition. Importantly, Scl-Ab led to increased strength in united bones, and this reached statistical significance in animals receiving Scl-Ab during consolidation only (+177%, p < 0.01, maximum load to failure). These data demonstrate that Scl-Ab treatment increases bone formation, leading to regenerates with higher bone volume and improved strength. Our data also suggest that the optimal effects of Scl-Ab treatment are achieved in the latter stages of distraction osteogenesis. These findings support further investigation into the potential clinical application of sclerostin antibody to augment bone distraction, such as limb lengthening, particularly in the prevention of refracture. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1106-1113, 2018.

Progress of Regenerative Therapy in Orthopedics

PURPOSE OF REVIEW

To conduct a thorough appraisal of recent and inventive advances in the field of bone tissue engineering using biomaterials, cell-based research, along with the incorporation of biomimetic properties using surface modification of scaffolds.

RECENT FINDINGS

This paper will provide an overview on different biomaterials and emerging techniques involved in the fabrication of scaffolds, brief description of signaling pathways involved in osteogenesis, and the effect of surface modification on the fate of progenitor cells. The current strategies used for regenerative medicine like cell therapy, gene transfer, and tissue engineering have opened numerous therapeutic avenues for the treatment of various disabling orthopedic disorders. Precise strategy utilized for the reconstruction, restoration, or repair of the bone-related tissues exploits cells, biomaterials, morphogenetic signals, and appropriate mechanical environment to provide the basic constituents required for creating new tissue. Combining all the above strategies in clinical trials would pave the way for successful "bench to bedside" transformation in bone healing.

Analysis of cytokine profile and growth factors in platelet-rich plasma obtained by open systems and commercial columns

Objective:

To evaluate growth factors and cytokines in samples of platelet-rich plasma obtained by three different centrifugation methods.

Methods:

Peripheral blood of six individuals with no hematological diseases, aged 18 to 68 years, was drawn to obtain platelet-rich plasma, using the open method and commercial columns by Medtronic and Biomet. The products obtained with the different types of centrifugation were submitted to laboratory analysis, including pro-inflammatory cytokines and chemokines by flow cytometry assays, the concentration of fibroblast growth factors-2 (FGF-2) and transforming growth factor-beta1 (TGF-β1).

Results:

The diverse separation methods generated systematically different profiles regarding number of platelets and leukocytes. The Medtronic system yielded a product with the highest concentration of platelets, and the open method, with the lowest concentration of platelets. The results of cytokine analysis showed that the different types of centrifugation yielded products with high concentrations of interleukin 8, interleukin 1β. The open system resulted in a product with high levels of interleukin 6. Other cytokines and chemokines measured were similar between systems. The product obtained with the open method showed higher levels of TGF-β1 in relation to other systems and low FGF-2 levels.

Conclusion:

The formed elements, growth factors and cytokines in samples of platelet-rich plasma varied according to the centrifugation technique used.

Objetivo:

Avaliar fatores de crescimento e citocinas em amostras de plasma rico em plaquetas obtidas por três diferentes métodos de centrifugação.

Métodos:

Foi coletado sangue periférico de seis indivíduos, sem doença hematológica, com idades entre 18 e 68 anos, para obtenção de plasma rico em plaquetas, utilizando o método aberto e sistemas comerciais das empresas Medtronic e Biomet. Os produtos obtidos com os diferentes tipos de centrifugação foram submetidos às análises laboratoriais, incluindo citocinas próinflamatórias e quimiocinas, por meio de ensaios de citometria de fluxo, concentração do fator de crescimento fibroblástico-2 (FGF-2) e fator de crescimento transformador-beta1 (TGF-β1).

Resultados:

As diferentes centrifugações geraram perfis sistematicamente diferentes referentes ao número de plaquetas e de leucócitos. O sistema da Medtronic originou produto com a maior concentração de plaquetas, e o método aberto com a menor concentração de plaquetas. Os resultados da análise de citocinas demonstraram que os diferentes tipos de centrifugação originaram produtos com elevadas concentrações de interleucina 8 e interleucina 1β. O sistema aberto resultou em produto com elevados níveis de interleucina 6. As demais citocinas e quimiocinas mensuradas foram similares entre os sistemas. O produto obtido com o método aberto apresentou níveis superiores de TGF-β1 em relação aos demais sistemas e reduzidos níveis de FGF-2.

Conclusão:

Os elementos figurados, fatores de crescimento e citocinas, em amostras de plasma rico em plaquetas, variaram conforme a técnica de centrifugação utilizada.

PRECICE® magnetically-driven, telescopic, intramedullary lengthening nail: pre-clinical testing and first 30 patients

Introduction: Femoral/tibial lengthening with a telescopic, magnetically-powered, intramedullary nail is an alternative to lengthening with external fixation.

Methods: Pre-clinical testing was conducted of the PRECICE in a human cadaver. A retrospective review of the first 30 consecutive patients who underwent unilateral lengthening was also conducted. Nail accuracy was obtained by comparing the amount of nail distraction to the final bone length achieved at the end of the distraction process. Relative standard deviation of accuracy was used to calculate nail precision.

Results: Devices performed successfully in a human cadaver. Thirty consecutive patients (10 females, 20 males; mean age, 23 years) with limb length discrepancy (LLD) were followed an average of 19 months (range, 12–24 months). Etiology included congenital shortening (14), posttraumatic deformities (7), Ollier disease (3), osteosarcoma resection (1), prior clubfoot (2), hip dysplasia (1), post-septic growth arrest of knee (1), and LLD after hip arthroplasty (1). Twenty-four femoral and eight tibial nails were implanted. Mean preoperative lengthening goal was 4.4 cm (range, 2–6.5 cm); mean postoperative length achieved was 4.3 cm (range, 1.5–6.5 cm). Average consolidation index was 36.4 days/cm (range, 12.8–113 days/cm). Mean nail accuracy was 97.3% with a precision of 92.4%. Average preoperative and 12-month postoperative Enneking scores were 21.5 and 25.3 (p < 0.001), respectively. The preoperative and 12-month postoperative SF-12 physical and mental component scores were not statistically different. Nine complications (nine limb segments) resolved: two partial femoral unions, two suspected deep vein thrombosis (DVT), one delayed tibial union, one fibular nonunion, one peroneal nerve irritation, one knee joint subluxation, and one confirmed DVT. Twenty-nine (91%) of 32 limb segments achieved successful bone healing without revision surgery.

Discussion: Limb lengthening with PRECICE is reliable, but larger trials with longer follow-up will reveal limitations. Implantable nails prevent problems associated with external fixation, such as muscle tethering and pin-site infections.

Bone Lengthening in the Pediatric Upper Extremity

➤Bone lengthening has been used successfully for several congenital and acquired conditions in the pediatric clavicle, humerus, radius, ulna, and phalanges.➤Common indications for bone lengthening include achondroplasia, radial longitudinal deficiency, multiple hereditary exostosis, brachymetacarpia, symbrachydactyly, and posttraumatic and postinfectious growth arrest.➤Most authors prefer distraction rates of <1 mm/day for each bone in the upper extremity except the humerus, which can safely be lengthened by 1 mm/day.➤Most authors define success by the amount of radiographic bone lengthening, joint motion after lengthening, and subjective patient satisfaction rather than validated patient-related outcome measures.➤Bone lengthening of the upper extremity is associated with a high complication rate, with complications including pin-track infections, fixation device failure, nerve lesions, nonunion, fracture of regenerate bone, and joint dislocations.

Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells with Platelet-Rich Plasma Accelerate Distraction Osteogenesis in A Canine Model

Objective

Distraction osteogenesis (DO) is a surgical procedure used to generate large volumes of new bone for limb lengthening.

Materials and Methods

In this animal experimental study, a 30% lengthening of the left tibia (mean distraction distance: 60.8 mm) was performed in ten adult male dogs by callus distraction after osteotomy and application of an Ilizarov fixator. Distraction was started on postoperative day seven with a distraction rate of 0.5 mm twice per day and carried out at a rate of 1.5 mm per day until the end of the study. Autologous bone marrow mesenchymal stem cells (BM-MSCs) and platelet-rich plasma (PRP) as the treatment group (n=5) or PRP alone (control group, n=5) were injected into the distracted callus at the middle and end of the distraction period. At the end of the consolidation period, the dogs were sacrificed after which computerized tomography (CT) and histomorphometric evaluations were performed.

Results

Radiographic evaluationsrevealed that the amount and quality of callus formations were significantly higher in the treatment group (P<0.05). As measured by CT scan, the healing parametersin dogs of the treatment group were significantly greater (P<0.05). New bone formation in the treatment group was significantly higher (P<0.05).

Conclusion

The present study showed that the transplantation of BM-MSCs positively affects early bony consolidation in DO. The use of MSCs might allow a shortened period of consolidation and therefore permit earlier device removal.

Platelet derived growth factor (PDGF) contained in Platelet Rich Plasma (PRP) stimulates migration of osteoblasts by reorganizing actin cytoskeleton

Platelet-rich plasma (PRP) is a platelet concentrate in a small volume of plasma. It is highly enriched in growth factors able to stimulate the migration and growth of bone-forming cells. PRP is often used in clinical applications, as dental surgery and fracture healing. Platelet derived growth factor (PDGF), is highly concentrated in PRP and it was shown in our previous studies to provide the chemotactic stimulus to SaOS-2 osteoblasts to move in a microchemotaxis assay. Aim of the present studies is to analyze the effects of a PRP pretreatment (short time course: 30-150 min) of SaOS-2 cells with PRP on the organization of actin cytoskeleton, the main effector of cell mobility. The results indicate that a pretreatment with PRP increases chemokinesis and chemotaxis and concomitantly induces the organization of actin microfilaments, visualized by immunocytochemistry, in a directionally elongated phenotype, which is characteristic of the cells able to move. PRP also produces a transient increase in the expression of PGDF α receptor. This reorganization is blocked by the immunoneutralization of PDGF demonstrating the responsibility of this growth factor in triggering the mechanisms responsible for cellular movements.

Bone Regeneration Is Promoted by Orally Administered Bovine Lactoferrin in a Rabbit Tibial Distraction Osteogenesis Model

BACKGROUND

Lactoferrin, an iron-binding glycoprotein which belongs to the transferrin family, has been shown to promote bone growth. However, reports regarding effects of lactoferrin on bone regeneration during distraction osteogenesis are limited. Our study was designed to investigate the effect of bovine lactoferrin treatment on bone formation of the distracted callus.

QUESTIONS/PURPOSES

We asked whether bovine lactoferrin enhances bone formation of the distraction callus as determined by (1) radiographic and histologic appearances; (2) dual-energy x-ray absorptiometry (DXA) analysis of bone mineral composition and bone mineral density; (3) micro-CT measures of trabecular architecture; and (4) biomechanical strength of the healing bone. Additionally, serology, reverse transcription (RT)-PCR, and immunohistochemistry were used to explore the possible mechanisms of bovine lactoferrin use on bone formation during distraction osteogenesis.

METHODS

Unilateral tibial osteodistraction was performed on 80 New Zealand White rabbits with a distraction rate of 1 mm per day for 10 days. Animals then were divided randomly into two groups: (1) vehicle and (2) bovine lactoferrin. At 4 and 8 weeks after completion of distraction, the animals were sacrificed. Lengthened tibias and serum samples were obtained and subjected to radiologic, DXA, micro-CT, histologic, and biomechanical examinations, and serum, RT-PCR and immunohistochemical analyses.

RESULTS

Radiologic, DXA, micro-CT, histologic, and biomechanical examinations indicated that bovine lactoferrin treatment not only accelerated bone formation at early stages of distraction osteogenesis but also promoted bone consolidation at late stages. The ultimate force of the distracted calluses was increased by 37% (118.8 ± 6.65 N in the lactoferrin group and 86.5 ± 5.47 N in the vehicle group; p < 0.001) and 84% (384.8 ± 18.4 N in the lactoferrin group and 209.0 ± 15.2 N in the vehicle group; p < 0.001) at 4 and 8 weeks, respectively. Moreover, serum analysis showed that bovine lactoferrin treatment significantly increased serum levels of bone alkaline phosphatase and decreased serum levels of tartrate resistant acid phosphatase 5b. In addition, RT-PCR and immunohistochemical analyses suggested that bovine lactoferrin treatment induced a lower receptor activator of nuclear factor-kappaB (RANK) ligand/osteoprotegerin (RANKL/OPG) ratio in the distracted callus.

CONCLUSIONS

The results of our study suggest that bovine lactoferrin treatment could promote bone regeneration during distraction osteogenesis in the rabbit. The results indicate that the OPG/RANKL/RANK system might be a major mechanism for increased bone formation and decreased bone resorption in distraction osteogenesis with bovine lactoferrin treatment.

CLINICAL RELEVANCE

Oral administration of bovine lactoferrin may provide a feasible approach for promoting osteogenesis during distraction osteogenesis.

Bone marrow aspirate concentrate and platelet-rich plasma enhanced bone healing in distraction osteogenesis of the tibia

BACKGROUND

During lower limb lengthening, poor bone regeneration is a devastating complication. Several local or systemic applications have been used to promote osteogenesis, and biologic stimulations are gaining attention, but their utility has not been proven in this setting.

QUESTIONS/PURPOSES

In patients undergoing bilateral tibial lengthening, we compared those receiving an osteotomy site injection of autologous bone marrow aspirate concentrate (BMAC) plus platelet-rich plasma (PRP) with those not receiving such an injection in terms of external fixator index (time in external fixation divided by amount of lengthening), full weightbearing index (time until a patient was permitted to do full weightbearing divided by amount of lengthening), four cortical healing indexes (time until each cortical union divided by amount of lengthening), and callus shape and type.

METHODS

Twenty-two patients (44 tibias) undergoing bilateral tibial lengthening enrolled in this randomized trial. Two patients were excluded, one due to insufficient radiographic evaluation and one who was lost to followup, leaving 20 patients (40 segments) for inclusion. Ten patients (20 segments) received BMAC combined with PRP injection (treatment group) and 10 patients (20 segments) received no injection (control group). All patients underwent stature lengthening for familial short stature with the lengthening over nail technique. Autologous BMAC combined with PRP was injected at the tibial osteotomy site at the end of the index surgery. Mean distraction rates were similar between groups (0.75 mm/day in the treatment group versus 0.72 mm/day in the control group; p = 0.24). Full weightbearing was permitted when we observed radiographic evidence of healing at two cortices; this assessment was made by the surgeon who was blinded to the treatment each patient received. Minimum followup was 24 months (mean, 28 months; range, 24-34 months).

RESULTS

There was no difference in mean external fixator index between groups. However, mean cortical healing indexes (anterior/posterior/medial/lateral) were 1.14/0.81/0.96/0.88 months/cm in the treatment group and 1.47/1.26/1.42/1.22 months/cm in the control group (all p < 0.001), showing faster healing in the treatment group at each cortex. Full weightbearing was permitted earlier in the treatment group than in the control group (index: 0.99 months/cm and 1.38 months/cm, respectively, p < 0.001). Callus shape and type were not different between groups.

CONCLUSIONS

Autologous BMAC combined with PRP injection at the osteotomy site helped improve bone healing in distraction osteogenesis of the tibia, although the effect size was small.

LEVEL OF EVIDENCE

Level I, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Construction of tissue-engineered bone using a bioreactor and platelet-rich plasma

The aim of the present study was to construct tissue-engineered bone using a bioreactor and platelet-rich plasma (PRP). Bone marrow mesenchymal stem cells (BMSCs) and β-tricalcium phosphate (β-TCP) were cultured in a perfusion bioreactor with PRP-containing medium for 21 days to form a BMSC-TCP composite. Rabbits were then implanted with the BMSC-TCP composite. The morphology of the implanted BMSC-TCP composite was observed three months after surgery by scanning electron microscopy and hematoxylin and eosin (H&E) staining. In addition, the expression of cluster of differentiation (CD)31 and von Willebrand factor (WF) in the implanted BMSC-TCP composite was detected using immunohistochemistry. Bone formation was determined by comprehensive testing Following culture in a perfusion bioreactor and PRP, the BMSCs adhered to the β-TCP scaffold and the secretion of extracellular matrix was observed. The spreading and proliferation of cells was found to be enhanced on the scaffold. Furthermore, the vascular endothelial cell markers CD31 and VEF, were positively expressed. Therefore, these results suggest that tissue-engineered bone may be constructed using a bioreactor and PRP. PRP, which contains multiple growth factors, may promote vascularization of tissue-engineered bone.

The Molecular and Cellular Events That Take Place during Craniofacial Distraction Osteogenesis

Summary:

Gradual bone lengthening using distraction osteogenesis principles is the gold standard for the treatment of hypoplastic facial bones. However, the long treatment time is a major disadvantage of the lengthening procedures. The aim of this study is to review the current literature and summarize the cellular and molecular events occurring during membranous craniofacial distraction osteogenesis. Mechanical stimulation by distraction induces biological responses of skeletal regeneration that is accomplished by a cascade of biological processes that may include differentiation of pluripotential tissue, angiogenesis, osteogenesis, mineralization, and remodeling. There are complex interactions between bone-forming osteoblasts and other cells present within the bone microenvironment, particularly vascular endothelial cells that may be pivotal members of a complex interactive communication network in bone. Studies have implicated number of cytokines that are intimately involved in the regulation of bone synthesis and turnover. The gene regulation of numerous cytokines (transforming growth factor-β, bone morphogenetic proteins, insulin-like growth factor-1, and fibroblast growth factor-2) and extracellular matrix proteins (osteonectin, osteopontin) during distraction osteogenesis has been best characterized and discussed. Understanding the biomolecular mechanisms that mediate membranous distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone regeneration that may lead to shorten the treatment duration.

Effect of administration of platelet-rich plasma in early phases of distraction osteogenesis: an experimental study in an ovine femur model

BACKGROUND

It has been suggested that platelet-rich plasma (PRP) might enhance bone formation. The aim of this study was to quantify the effect of PRP administered in the early phases of distraction osteogenesis in an ovine femur model.

METHODS

Twenty sheep aged 4 months underwent osteotomy of the femoral diaphysis followed by distraction osteogenesis. The sheep were divided into two groups of 10. One group received three injections of PRP on days 0, 10, and 20 of the procedure (PRP group) and the other received no additional treatment (control group). The results were evaluated by computed tomography (CT) and histology on completion of distraction osteogenesis (day 40). CT evaluation included measurement of the callus and bone density. Femur size was also measured proximally and distally. Histological evaluation was used to quantify osteoblasts, osteoclasts, vascular lumens, and trabecular maturity by zones and to calculate trabecular bone, fibrous tissue, and cartilage ratios.

RESULTS

Radiological and histological evaluation of the regenerate bone showed no significant differences between the PRP group and the control group for any of the variables analysed. The only significant difference detected was a wider femur (increased diaphyseal thickness) at the proximal and distal levels in the PRP group.

CONCLUSION

We found no radiological or histological evidence that the administration of PRP in the early phases of distraction osteogenesis enhances bone formation.

Genetic predisposition to non-union: evidence today

Atrophic non-union represents a complex clinical condition and research is ongoing in an effort to elucidate its pathophysiology and to offer new and more efficient treatment modalities. Differences seen in fracture healing responses and final outcome may be attributed among other factors to biological variations between patients resulting in a "disturbed" signalling pathway and an "inert or deficient local biology with reduced potentials for bone regeneration". The genetic contribution with or without the interaction of other exogenous factors in cases of impaired fracture healing, is yet to be elucidated. However, preliminary animal and human studies demonstrate the molecular basis of fracture non-unions and correlate genetic variants of the molecules regulating fracture healing and their expression patterns with impaired bone healing and fracture non-union. Further research is needed to clarify the genetic component and its role and interaction with other risk factors that may result in increased susceptibility of a patient to develop this complication.

A novel hypothesis: the application of platelet-rich plasma can promote the clinical healing of white-white meniscal tears

The white-white tears (meniscus lesion completely in the avascular zone) are without blood supply and theoretically cannot heal. Basal research has demonstrated that menisci are unquestionably important in load bearing, load redistribution, shock absorption, joint lubrication and the stabilization of the knee joint. It has been proven that partial or all-meniscusectomy results in an accelerated degeneration of cartilage and an increased rate of early osteoarthritis. Knee surgeons must face the difficult decision of removing or, if possible, retaining the meniscus; if it is possible to retain the meniscus, surgeons must address the difficulties of meniscal healing. Some preliminary approaches have progressed to improve meniscal healing. However, the problem of promoting meniscal healing in the avascular area has not yet been resolved. The demanding nature of the approach as well as its low utility and efficacy has impeded the progress of these enhancement techniques. Platelet-rich plasma (PRP) is a platelet concentration derived from autologous blood. In recent years, PRP has been used widely in preclinical and clinical applications for bone regeneration and wound healing. Therefore, we hypothesize that the application of platelet-rich plasma for white-white meniscal tears will be a simple and novel technique of high utility in knee surgery.

Does short-term application of an Ilizarov frame with transfixion pins correct relapsed clubfoot in children?

BACKGROUND

Treatment of relapsed clubfoot after soft tissue release in children is difficult because of the high recurrence rate and related complications. Even though the Ilizarov method is used for soft tissue distraction, there is a high incidence of recurrence after removal of the Ilizarov frame owing to previous contracture of soft tissue and a skin scar.

QUESTIONS/PURPOSES

We asked (1) whether transfixation of midfoot joints by temporary K wires during the consolidation stage after short-term application of an Ilizarov frame would maintain correction of the relapsed clubfoot clinicoradiologically and (2) whether this method would reduce the rate of recurrence and related complications in patients with a skin scar from previous surgery.

METHODS

We retrospectively reviewed 18 patients (19 feet) with relapsed clubfeet who underwent correction by soft tissue distraction using an Ilizarov ring fixator, between March 2005 and June 2008. The mean age of the patients was 8 ± 2 years (range, 4-15 years). K wire fixation for the midfoot joints combined with a below-knee cast were used during the consolidation stage. The minimum followup was 2 years (mean, 4.5 years; range, 2-6 years).

RESULTS

The average duration of frame application was 5 weeks; the mean duration of treatment was 11 weeks. At last followup, 16 of 19 feet were painless and plantigrade and only three of 19 feet had recurrence. The mean preoperative clinical American Foot and Ankle Society (AOFAS) score had increased at last followup (57 versus 81). The values of the AP talocalcaneal, AP talo-first metatarsal, and lateral calcaneo-first metatarsal angles improved after treatment. The three recurrent clubfeet were treated by corrective osteotomies and Ilizarov frame application.

CONCLUSION

This method could maintain the correction of relapsed clubfoot in children and reduce the recurrence rate and complications regardless of the presence of a skin scar owing to previous surgery.

Transport distraction osteogenesis for maxillomandibular reconstruction: current concepts and applications

Reconstruction of the facial skeleton remains a herculean task for a reconstructive surgeon, even with the availability of ample reconstructive options. Transport distraction osteogenesis is a novel reconstructive modality in the armamentarium of a maxillofacial reconstructive surgeon with obvious advantages of osteogenesis and histogenesis from the residual host tissues after tumor ablative surgeries or trauma and also, precludes donor site morbidity. This paper reviews the current concepts, principles involved and applications of transport distraction osteogenesis in maxillomandibular reconstruction.

Tissue engineered strategies for skeletal muscle injury

Skeletal muscle injuries are common in athletes, occurring with direct and indirect mechanisms and marked residual effects, such as severe long-term pain and physical disability. Current therapy consists of conservative management including RICE protocol (rest, ice, compression and elevation), nonsteroidal anti-inflammatory drugs, and intramuscular corticosteroids. However, current management of muscle injuries often does not provide optimal restoration to preinjury status. New biological therapies, such as injection of platelet-rich plasma and stem-cell-based therapy, are appealing. Although some studies support PRP application in muscle-injury management, reasons for concern persist, and further research is required for a standardized and safe use of PRP in clinical practice. The role of stem cells needs to be confirmed, as studies are still limited and inconsistent. Further research is needed to identify mechanisms involved in muscle regeneration and in survival, proliferation, and differentiation of stem cells.

Positive effect on bone fusion by the combination of platelet-rich plasma and a gelatin β-tricalcium phosphate sponge: a study using a posterolateral fusion model of lumbar vertebrae in rats

We developed a novel method for bone fusion by combining platelet-rich plasma (PRP) and a gelatin β-tricalcium phosphate (β-TCP) sponge. The PRP is an autologous concentration of platelets that includes several growth factors. The gelatin β-TCP sponge comprises gelatin and β-TCP, thus enabling the sustained release of growth factors and osteoconduction. To evaluate this method, we generated a posterolateral fusion model of lumbar vertebrae in rats and divided it into five groups by implanting the following materials between transverse processes of vertebrae, (1) the gelatin β-TCP sponge with PRP (PRP sponge), (2) the gelatin β-TCP sponge with platelet-poor plasma, (3) gelatin hydrogel with PRP, (4) autologous iliac bone (autograft), and (5) no material was implanted as a control. The assessment of bone fusion by a radiographic assessment, a biomechanical test, microcomputed tomography, and histological evaluations demonstrated that there were no significant differences between the PRP sponge and the autograft groups regarding the osteogenic effect. Subsequent examinations revealed that no significant differences existed between the PRP sponge and the autograft groups in either biomechanical stiffness or the bone volume over time; whereas the radiographic and histological composition underwent similar changes in the fusion process. These results indicate that the PRP sponge could, therefore, be potentially useful as an attractive and less invasive method for bone fusion.