Early experience and results of bone graft enriched with autologous platelet gel for recalcitrant nonunions of lower extremity

Orthobiologics in delayed union and non-union of adult long bones fractures: A systematic review

Background

Fracture healing poses a significant challenge in orthopedics. Successful regeneration of bone is provided by mechanical stability and a favorable biological microenvironment. This systematic review aims to explore the clinical application of orthobiologics in treating aseptic delayed union and non-union of long bones in adults.

Methods

A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Three databases were explored, with no date restrictions, using keywords related to orthobiologics and delayed union and non-union. Eligible studies included human clinical studies in English, with available full texts, examining orthobiologics such as platelet-rich plasma (PRP), mesenchymal stem cells (MSCs), and bone morphogenetic protein (BMPs) for treating aseptic delayed unions and non-unions in adults. Animal studies, in vitro research, and studies on non-unions due to congenital defects, tumors or infections were excluded.

Results

The initial search identified 9417 studies, with 20 ultimately included in the review. These studies involved 493 patients affected by non-union and 256 patients affected by delayed union, with an average age respectively of 40.62 years and 41.7 years. The mean follow-up period was 15.55 months for non-unions and 8.07 months for delayed unions. PRP was the most used orthobiologic, and outcomes were evaluated through time to union, functional scores, and clinical examinations. The results indicated that orthobiologics, especially PRP, tended to yield better outcomes compared to surgical procedures without biological factors.

Conclusion

This systematic review suggests that orthobiologics, such as PRP, BMPs, and MSCs, can be effective and safe in the management of delayed union and non-union fractures. These biological treatments have the potential to improve union rates, reduce healing times, and enhance functional outcomes in patients with non-union fractures. Further research is essential to refine treatment protocols and determine the most suitable orthobiologic for specific patient populations and fracture types.

Advances with Platelet-Rich Plasma for Bone Healing

Despite significant advances in the understanding and delivery of osteosynthesis, fracture non-union remains a challenging clinical problem in orthopaedic surgery. To bridge the gap, basic science characterization of fracture healing provides a platform to identify and target biological strategies to enhance fracture healing. Of immense interest, Platelet-rich plasma (PRP) is a point of care orthobiologic that has been extensively studied in bone and soft tissue healing given its relative ease of translation from the benchtop to the clinic. The aim of this narrative review is to describe and relate pre-clinical in-vitro and in-vivo findings to clinical observations investigating the efficacy of PRP to enhance bone healing for primary fracture management and non-union treatment. A particular emphasis is placed on the heterogeneity of PRP preparation techniques, composition, activation strategies, and delivery. In the context of existing data, the routine use of PRP to enhance primary fracture healing and non-union management cannot be supported. However, it is acknowledged that extensive heterogeneity of PRP treatments in clinical studies adds obscurity; ultimately, refinement (and consensus) of PRP treatments for specific clinical indications, including repetition studies are warranted.

Treatment Effect of Platelet Gel on Reconstructing Bone Defects and Nonunions: A Review of In Vivo Human Studies

In ideal circumstances, a fractured bone can heal properly by itself or with the aid of clinical interventions. However, around 5% to 10% of bone fractures fail to heal properly within the expected time even with the aid of clinical interventions, resulting in nonunions. Platelet gel is a blood-derived biomaterial used in regenerative medicine aiming to promote wound healing and regeneration of damaged tissues. The purpose of this paper is to review relevant articles in an attempt to explore the current consensus on the treatment effect of platelet gel on reconstructing bone defects and nonunions, hoping to provide a valuable reference for clinicians to make treatment decisions in clinical practice. Based on the present review, most of the studies applied the combination of platelet gel and bone graft to reconstruct bone defects and nonunions, and most of the results were positive, suggesting that this treatment strategy could promote successful reconstruction of bone defects and nonunions. Only two studies tried to apply platelet gel alone to reconstruct bone defects and nonunions, therefore a convincing conclusion could not be made yet regarding the treatment effect of platelet gel alone on reconstructing bone defects and nonunions. Only one study applied platelet gel combined with extracorporeal shock wave therapy to reconstruct nonunions, and the results were positive; the hypothetical mechanism of this treatment strategy is reasonable and sound, and more future clinical studies are encouraged to further justify the effectiveness of this promising treatment strategy. In conclusion, the application of platelet gel could be a promising and useful treatment method for reconstructing bone defects and nonunions, and more future clinical studies are encouraged to further investigate the effectiveness of this promising treatment method.

The role of Platelet Rich Plasma and other orthobiologics in bone healing and fracture management: A systematic review

BACKGROUND

Treatment of large bone defects and fracture healing complications (delayed and non-union) presents a substantial challenge for orthopaedic surgeons. Given that bone healing requires mechanical stability as well as a favourable biological microenvironment, orthobiologics such as Platelet-Rich Plasma (PRP) may have a significant clinical role to play.

AIMS

To perform a systematic review of the available literature to assess the clinical effect of PRP, with or without other orthobiologics, on bone healing.

METHOD

Two independent reviewers performed the literature search based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Clinical studies of any evidence, assessing effect of PRP with or without other orthobiologics on bone healing, were included. A qualitative analysis was carried out on the clinical and radiological outcomes reported.

RESULT

27 articles with 1631 patients (mean age = 43.56, 57.1% male, mean follow-up = 17.27 months) were included in the qualitative. Of the 27 studies, 13 dealt with fracture complications (delayed or non-unions), 7 with acute fracture healing, 4 with tibial osteotomies and lengthening procedures and 3 with lumbar spine pathology. 18/27 studies showed a clinical benefit of PRP, 8/27 showed no significant effect, and 1/27 showed a worse outcome with PRP.

CONCLUSION

Our review suggests PRP may play a clinical role in bone healing but further randomised controlled trials (RCTs) using standardised outcomes should be performed to establish its efficacy.

The Use of Platelet-Rich Plasma (PRP) for the Management of Non-union Fractures

PURPOSE OF REVIEW

The treatment of non-union fractures represents a significant challenge for orthopaedic surgeons. In recent years, biologic agents have been investigated and utilised to support and improve bone healing. Among these agents, platelet-rich plasma (PRP) is an emerging strategy that is gaining popularity. The aim of this review is to evaluate the current literature regarding the application and clinical effectiveness of PRP injections, specifically for the treatment of non-union fractures.

RECENT FINDINGS

The majority of published studies reported that PRP accelerated fracture healing; however, this evidence was predominantly level IV. The lack of randomised, clinical trials (level I-II evidence) is currently hampering the successful clinical translation of PRP as a therapy for non-union fractures. This is despite the positive reports regarding its potential to heal non-union fractures, when used in isolation or in combination with other forms of treatment. Future recommendations to facilitate clinical translation and acceptance of PRP as a therapy include the need to investigate the effects of administering higher volumes of PRP (i.e. 5-20 mL) along with the requirement for more prolonged (> 11 months) randomised clinical trials.

The medial femoral condyle free corticoperiosteal flap versus traditional bone graft for treatment of nonunions of long bones: a retrospective comparative cohort study

Fracture healing is a complex process and many factors change the local biology of the fracture and reduce the physiologic repair process. Since 1991 the free vascularised corticoperiosteal graft has been proposed to treat nonunions. In this study we compare the healing rate and the healing time of the free vascularised corticoperiosteal graft harvested from medial femoral condyle versus the traditional cancellous bone graft from the iliac crest combined with other biologic or pharmacologic factors. We performed a retrospective cohort study. The main measures of outcomes were the rate of bone union and the mean healing time from surgery. The authors performed 10 free vascularised corticoperiosteal grafts in the cohort A and 10 patients received traditional cancellous bone graft plus other biologic or pharmacologic treatment in the same period in the cohort B. The mean follow up in cohort A was 18.6 months with a healing rate of 100% (10/10). In cohort B the mean follow up was 22.5 month with a healing rate of 90%. The mean time to obtain union (healing time) in the group that was treated with the free flap procedure was significantly shorter, 3.2 months versus a mean time of 8.8 months in the other group. Some studies describe a high healing rate of recalcitrant nonunions with treatments different from vascularized bone flaps: it is difficult to compare the results of vascularized bone transfers with the results of other case series. Our groups are very homogeneous even if it is difficult to define correct inclusion criteria because there is still no agreement about what is defined a recalcitrant or difficult nonunion, and the number of trials of previous surgery before to perform a vascularized free flap. Even if our study cohort is small, we have demonstrated that the MFCCF generally seems to give a better healing chance with a shorter healing time compared to other treatments.

Platelet-rich plasma for the treatment of bone defects: from pre-clinical rational to evidence in the clinical practice. A systematic review

PURPOSE

The treatment of large bone defects represents a significant challenge for orthopaedic surgeons. In recent years, biologic agents have also been used to further improve bone healing. Among these, platelet-rich plasma (PRP) is the most exploited strategy. The aim of the present study was to systematically review the available literature to identify: 1) preclinical in-vivo results supporting the rational of PRP use for bone healing; 2) evidence from the clinical practice on the actual clinical benefit of PRP for the treatment of fractures and complications such as delayed unions and non-unions.

METHODS

A systematic review of the literature was performed on the application of PRP in bone healing, using the following inclusion criteria: pre-clinical and clinical reports of any level of evidence, written in English language, published in the last 20 years (1996-2016), on the use of PRP to stimulate long-bone defect treatment, with focus on fracture and delayed/non-unions healing.

RESULTS

The search in the Pubmed database identified 64 articles eligible for inclusion: 45 were preclinical in-vivo studies and 19 were clinical studies. Despite the fact that the overall pre-clinical results seem to support the benefit of PRP in 91.1 % of the studies, a more in depth analysis underlined a lower success rate, with a positive outcome of 84.4 % in terms of histological analysis, and even lower values considering radiological and biomechanical results (75.0 % and 72.7 % positive outcome respectively). This was also mirrored in the clinical literature, where the real benefit of PRP use to treat fractures and non-unions is still under debate.

CONCLUSION

Overall, the available literature presents major limitations in terms of low quality and extreme heterogeneity, which hamper the possibility to optimize PRP treatment and translate it into a real clinical benefit despite positive preclinical findings on its biological potential to favour bone healing.

Radiological assessment of the PRF/BMSC efficacy in the treatment of aseptic nonunions: A retrospective study on 90 subjects

BACKGROUND

Nonunion is a major orthopaedic concern because of treatment difficulty, high costs and devastating effects on the patients' life quality. Therefore, there is interest in the use of bone substitutes and cell-based strategies to augment fracture repair. We aimed to verify if Platelet Rich Fibrin (PRF) added with bone marrow stromal cells (BMSC) was able to improve the reparative process in the aseptic nonunion, and to establish whether it was worthwhile with atrophic nonunion. The primary outcome was radiological union. As secondary endpoint, the healing time was assessed, and the radiological consolidation grade at each follow-up.

METHODS

We identified 113 subjects with tibia or femur nonunion and retrospectively created two groups. Group A was constituted by 56 subjects who underwent the standard procedure, i.e. Judet decortication with/out internal fixation devices, and opposite cortical homoplastic stick. In 57 patients, the standard procedure was modified by adding PRF and BMSC carried by homologous lyophilised bone chips (group B). The same surgeon performed all the operations. To our knowledge, no data are reported in the literature about such application. Since a "gold standard" for healing quantification does not exist, a new scoring radiological system was applied, at 1.5, 3, 6, 12 and 24 months after treatment.

RESULTS

At the final 24-month follow-up, the radiological union percentage was 94,12 in group B and 95,12% in group A. A decreased healing time was demonstrated in the presence of PRF/BMSC in comparison with the standard procedure. When we compared the radiological scores at each follow-up, we found that the PRF/BMSC combination significantly improved the consolidation grade at 1.5-, 3- and 6-month follow-up in femurs and at 1.5-month follow-up in tibiae. Furthermore, an improved consolidation grade was demonstrated in the atrophic subjects treated with adjuvants compared to atrophic patients treated with the standard procedure at 1.5-month follow-up.

CONCLUSIONS

This study supports the concept that the use of PRF/BMSC, during the standard procedure, is effective in shortening nonunion healing time. It could allow an early mobilization of patients, minimizing suffering, and could be an effective tool to reduce the health-care costs resulting from this issue.

LEVEL OF EVIDENCE

Therapeutic level III.

Optimizing platelet-rich plasma gel formation by varying time and gravitational forces during centrifugation

Despite the increasing clinical use of topical platelet-rich plasma (PRP) to enhance tissue healing and regeneration, there is no properly standardized method of autologous PRP gel preparation. This study examined the effect of the centrifugation time and gravitational force (g) on the platelet recovery ratio of PRP and determined the most effective centrifugation conditions for preparing PRP. Two-step centrifugations for preparing PRP were used in 39 subjects who had consented prior to the study's start. The separating centrifugation (Step 1, used to separate whole blood into its two main components: red blood cells and plasma) was tested from 500g to 1900g at 200g increments for 5 minutes (min), and from 100g to 1300g at 200g increments for 10 minutes. After separating centrifugation, upper plasma layer was transferred to another plain tube for the condensation centrifugation and remaining lower cell layer was discarded. The condensation centrifugation (Step 2, used to condense the platelets in the separated plasma) was tested at 1000g for 15 min, 1500g for 15 min, 2000g for 5 min and 3000g for 5 min, additionally at 1000g for 10 min and 1500g for 10 min. Platelet gelation was induced by adding 10% calcium gluconate to final PRP with volume ratio of 1:10. The optimal separating centrifugation conditions were followed by 900g for 5 minutes and the condensation conditions were followed by 1500g for 15 minutes, of which recovery ratios were 92.0 ± 3.1% and 84.3 ± 10.0%, respectively.

Effect of hyperbaric oxygen therapy combined with autologous platelet concentrate applied in rabbit fibula fraction healing

OBJECTIVES

The purpose is to study the effects of hyperbaric oxygen therapy and autologous platelet concentrates in healing the fibula bone of rabbits after induced fractures.

METHODS

A total of 128 male New Zealand albino rabbits, between 6-8 months old, were subjected to a total osteotomy of the proximal portion of the right fibula. After surgery, the animals were divided into four groups (n = 32 each): control group, in which animals were subjected to osteotomy; autologous platelet concentrate group, in which animals were subjected to osteotomy and autologous platelet concentrate applied at the fracture site; hyperbaric oxygen group, in which animals were subjected to osteotomy and 9 consecutive daily hyperbaric oxygen therapy sessions; and autologous platelet concentrate and hyperbaric oxygen group, in which animals were subjected to osteotomy, autologous platelet concentrate applied at the fracture site, and 9 consecutive daily hyperbaric oxygen therapy sessions. Each group was divided into 4 subgroups according to a pre-determined euthanasia time points: 2, 4, 6, and 8 weeks postoperative. After euthanasia at a specific time point, the fibula containing the osseous callus was prepared histologically and stained with hematoxylin and eosin or picrosirius red.

RESULTS

Autologous platelet concentrates and hyperbaric oxygen therapy, applied together or separately, increased the rate of bone healing compared with the control group.

CONCLUSION

Hyperbaric oxygen therapy and autologous platelet concentrate combined increased the rate of bone healing in this experimental model.

Intraoperative platelet rich plasma usage in total knee arthroplasty: does it help?

Autologous platelet rich plasma preparations, commonly referred to as platelet gel, have been reported to have benefits when used in total knee replacement of less blood loss and better motion, with few reported complications. This retrospective review of 268 consecutive primary total knee arthroplasty cases compares postsurgical range of motion at 2, 8, and 12 weeks, knee manipulation rates, change in hemoglobin, and complications between one group receiving a platelet gel preparation (135 cases), and an equivalent group receiving no platelet gel preparation (133 control cases). No difference was found between groups in manipulation rates, knee range of motion, or changes in hemoglobin (P > 0.05). The use of platelet gel in this study did not have a significant effect on hemoglobin at 72 hours postoperatively, knee range of motion, or manipulation rates up to 3 months post-op in this patient cohort.

Platelet lysate coating on scaffolds directly and indirectly enhances cell migration, improving bone and blood vessel formation

Suitable colonization and vascularization of tissue-engineered constructs after transplantation represent critical steps for the success of bone repair. Human platelet lysate (hPL) is composed of numerous growth factors known for their proliferative, differentiative and chemo-attractant effects on various cells involved in wound healing and bone growth. The aim of this study was to determine whether the delivery of human mesenchymal stromal cells (hMSC) seeded on hPL-coated hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) scaffolds could enhance vascularization and bone formation, as well as to investigate the mechanisms by which hMSC participate in tissue regeneration. Our study demonstrates that hPL can be coated on HA/β-TCP scaffolds, which play direct and indirect effects on implanted and/or resident stem cells. Effectively, we show that hPL coating directly increases chemo-attraction to and adhesion of hMSC and endothelial cells on the scaffold. Moreover, we show that hPL coating induces hMSC to produce and secrete pro-angiogenic proteins (placental growth factor and vascular endothelial growth factor) which allow the proliferation and specific chemo-attraction of endothelial cells in vitro, thus improving in vivo neovascularization and new bone formation. This study highlights the potential of functionalizing biomaterials with hPL and shows that this growth factor combination can have synergistic effects leading to enhanced bone and blood vessel formation.

Diagnostic and treatment modalities in nonunions of the femoral shaft: a review

Nonunions of the femoral shaft represent a treatment challenge for the orthopaedic surgeon and a serious socioeconomic problem for the patient. Inadequate fracture stability, insufficient blood supply, bone loss or presence of infection are the main reasons for the development of a nonunion. Careful classification and exclusion of infection are crucial for the choice of the proper treatment alternative. Nail dynamization, primary intramedullary nailing or nail exchange, plate osteosynthesis and external fixation along with bone grafting, usage of bone substitutes and electrical stimulation can stimulate osseous union. A review of the aetiology, classification and treatment should prove helpful managing this serious complication.

Resynthesis of sternal dehiscence with autologous bone graft and autologous platelet gel

Postoperative management of sternal dehiscence requires the organised effort of a multidisciplinary medical team, including orthopaedic surgeons, plastic surgeons, microbiologists, critical care nurses and rehabilitation experts. Clinical care of this complication impacts heavily on health-care costs, length of hospital stay, and the time to full recovery and return to regular work activity. There are various surgical approaches to sternal resynthesis, but they are often unsuccessful. In this paper, we describe the case of a 67-year-old male complaining of chronic pain due to sternal dehiscence after coronary artery bypass grafting surgery. We first report a technique for sternal resynthesis, performed in the cardiac surgery setting, using a combination of autologous bone graft and autologous platelet-derived gel (APG), and describe its postoperative management and outcome. The four-month follow-up was uneventful and a CT scan confirmed full healing of the nonunion site with solid bridging bone.

The aseptic femoral and tibial shaft non-union in healthy patients - an analysis of the health-related quality of life and the socioeconomic outcome

Long bone non-unions may lead to recurrent surgical procedures and in-hospital stays. Thus, restrictions of the health-related quality of life and of socioeconomic parameters might be expected. Knowledge of the impact on several parameters of professional life is sparse. Therefore, we analyzed the outcome in patients following non-unions of the tibial and femoral shaft after fracture compared to patients with uneventful healing.

MATERIAL AND METHODOLOGY

51 patients following non-unions of the the femoral (FNU) or tibial shaft (TNU) were compared to 51 patients (groups FH and TH) with uneventful fracture healing. Physical and mental health was assessed using the Short-Form Health Survey (SF-12), Hospital Anxiety and Depression Scale (HADS) and the Impact of Event Scale (IES). We also analyzed employment status and the usage of medical aids.

RESULTS

Scores of the SF-12 physical and psychological were lower in group TNU compared to group TH, the score of SF-12 physical but not psychological was significantly lower in group FNU compared to FH. Compared to uneventful healing, a significantly more frequent usage of medical aids was found in both non-union groups. A higher incidence of early retirement and unemployment was found in group FNU but not in group TNU.

CONCLUSIONS

There is a profound influence on the quality of life following femoral or tibial non-unions after trauma. Compared to patients with uneventful fracture healing, patients with tibial and even more so femoral non-union show worse scores of the SF-12. Medical aids are frequently used following both, femoral and tibial non-unions. Not tibial, but femoral non-unions frequently lead to severe restrictions in professional life such as early retirement and unemployment.

Decreased osteogenesis, increased cell senescence and elevated Dickkopf-1 secretion in human fracture non union stromal cells

The delicately orchestrated process of bone fracture healing is not always successful and long term non union of fractured bone occurs in 5-20% of all cases. Atrophic fracture non unions have been described as the most difficult to treat and this is thought to arise through a cellular and local failure of osteogenesis. However, little is known about the presence and osteogenic proficiency of cells in the local area of non union tissue. We have examined the growth and differentiation potential of cells isolated from human non union tissues compared with normal human bone marrow mesenchymal stromal cells (BMSC). We report the isolation and culture expansion of a population of non union stromal cells (NUSC) which have a CD profile similar to that of BMSC, i.e. CD34-ve, CD45-ve and CD105+ve. The NUSC demonstrated multipotentiality and differentiated to some extent along chondrogenic, adipogenic and osteogenic lineages. However, and importantly, the NUSC showed significantly reduced osteogenic differentiation and mineralization in vitro compared to BMSC. We also found increased levels of cell senescence in NUSC compared to BMSC based on culture growth kinetics and cell positivity for senescence associated beta galactosidase (SA-beta-Gal) activity. The reduced capacity of NUSC to form osteoblasts was associated with significantly elevated secretion of Dickkopf-1 (Dkk-1) which is an important inhibitor of Wnt signalling during osteogenesis, compared to BMSC. Conversely, treating BMSC with levels of rhDkk-1 that were equivalent to those levels secreted by NUSC inhibited the capacity of BMSC to undergo osteogenesis. Treating BMSC with NUSC conditioned medium also inhibited the capacity of the BMSC to undergo osteogenic differentiation when compared to their treatment with BMSC conditioned medium. Our results suggest that the development of fracture non union is linked with a localised reduced capacity of cells to undergo osteogenesis, which in turn is associated with increased cell senescence and Dkk-1 secretion.