Percutaneous autologous bone marrow injection in the treatment of distal meta-diaphyseal tibial nonunions and delayed unions

Bone marrow aspirate and bone marrow aspirate concentrate: Does the literature support use in long-bone nonunion and provide new insights into mechanism of action?

PURPOSE

To assess the use of bone marrow aspirate (BM) and bone marrow aspirate concentrate (BMAC) in the treatment of long-bone nonunion and to understand mechanism of action.

METHODS

A systematic review of PubMed and EBSCOHost was completed to identify studies that investigated the use of BM or BMAC for the diagnosis of delayed union and/or nonunion of long-bone fractures. Studies of isolated bone marrow-mesenchymal stem cells (BM-MSCs) and use in non-long-bone fractures were excluded. Statistical analysis was confounded by heterogeneous fracture fixation methods, treatment history, and scaffold use.

RESULTS

Our initial search yielded 430 publications, which was screened down to 25 studies. Successful treatment in aseptic nonunion was reported at 79-100% (BM) and 50-100% (BMAC). Septic nonunion rates were slightly better at 73-100% (BM) and 83.3-100% (BMAC). 18/24 studies report union rates > 80%. One study reports successful treatment of septic nonunion with BMAC and no antibiotics. A separate study reported a significant reduction in autograft reinfection rate when combined with BMAC (P = 0.009). Major adverse events include two deep infections at injection site and one case of heterotopic ossification. Most studies note transient mild donor site discomfort and potential injection site discomfort attributed to needle size.

CONCLUSION

The current literature pertaining to use of BM/BMAC for nonunion is extremely heterogeneous in terms of patient population and concomitant treatment modalities. While results are promising for use of BM/BMAC with other gold standard treatment methodologies, the literature requires additional Level I data to clarify the impact of role BM/BMAC in treating nonunion when used alone and in combination with other modalities.

LEVEL OF EVIDENCE

Level III.

Comparison of reamer irrigator aspirator (RIA) suspension versus bone marrow aspirate concentrate (BMC) for percutaneous treatment of long bone nonunions-A preclinical canine model

OBJECTIVE

To compare the bone healing effects of percutaneously delivered bone marrow aspirate concentrate (BMC) versus reamer irrigator aspirator (RIA) suspension in a validated preclinical canine ulnar nonunion model. We hypothesized that BMC would be superior to RIA in inducing bone formation across a nonunion site after percutaneous application. The null hypothesis was that BMC and RIA would be equivalent.

METHODS

A bilateral ulnar nonunion model (n= 6; 3 matched pairs) was created. Eight weeks after segmental ulnar ostectomy, RIA from the ipsilateral femur and BMC from the proximal humerus were harvested and percutaneously administered into either the left or right ulnar defect. The same volume (3 ml) of RIA suspension and BMC were applied on each side. Eight weeks after treatment, the dogs were euthanized, and the nonunions were evaluated using radiographic, biomechanical, and histologic assessments.

RESULTS

All dogs survived for the intended study duration, formed radiographic nonunions 8 weeks after segmental ulnar ostectomy, and underwent the assigned percutaneous treatment. Radiographic and macroscopic assessments of bone healing at the defect sites revealed superior bridging-callous formation in BMC-treated nonunions. Histologic analyses revealed greater amount of bony bridging and callous formation in the BMC group. Biomechanical testing of the treated nonunions did not reveal any significant differences.

CONCLUSION

Bone marrow aspirate concentrate (BMC) had important advantages over Reamer Irrigator Aspirator (RIA) suspension for percutaneous augmentation of bone healing in a validated preclinical canine ulnar nonunion model based on clinically relevant radiographic and histologic measures of bone formation.

Biomaterials for bone defect repair: Types, mechanisms and effects

Bone defects or bone discontinuities caused by trauma, infection, tumours and other diseases have led to an increasing demand for bone grafts and biomaterials. Autologous bone grafts, bone grafts with vascular tips, anastomosed vascular bone grafts and autologous bone marrow components are all commonly used in clinical practice, while oversized bone defects require the use of bone tissue engineering-related biomaterials to repair bone defects and promote bone regeneration. Currently, inorganic components such as polysaccharides and bioceramics, as well as a variety of bioactive proteins, metal ions and stem cells can be loaded into hydrogels or 3D printed scaffold materials to achieve better therapeutic results. In this review, we provide an overview of the types of materials, applications, potential mechanisms and current developments in the repair of bone defects.

Gender-Specific Differences in Human Vertebral Bone Marrow Clot

Recently, our group described the application of vertebral bone marrow (vBMA) clot as a cell therapy strategy for spinal fusion. Its beneficial effects were confirmed in aging-associated processes, but the influence of gender is unknown. In this study, we compared the biological properties of vBMA clots and derived vertebral mesenchymal stem cells (MSCs) from female and male patients undergoing spinal fusion procedures and treated with vBMA clot. We analyzed the expression of growth factors (GFs) in vBMA clots and MSCs as well as morphology, viability, doubling time, markers expression, clonogenicity, differentiation ability, senescence factors, Klotho expression, and HOX and TALE gene profiles from female and male donors. Our findings indicate that vBMA clots and derived MSCs from males had higher expression of GFs and greater osteogenic and chondrogenic potential compared to female patients. Additionally, vBMA-clot-derived MSCs from female and male donors exhibited distinct levels of HOX and TALE gene expression. Specifically, HOXA1, HOXB8, HOXD9, HOXA11, and PBX1 genes were upregulated in MSCs derived from clotted vBMA from male donors. These results demonstrate that vBMA clots can be effectively used for spinal fusion procedures; however, gender-related differences should be taken into consideration when utilizing vBMA-clot-based studies to optimize the design and implementation of this cell therapy strategy in clinical trials.

Outcomes and Complications After Bone Marrow Aspirate Harvest From the Calcaneus

Background

Bone marrow aspirate (BMA) is used with the putative goal of enhancing healing of injured tissue. The most common sites to harvest BMA are the iliac crest, the tibia, and the calcaneus. Investigators have found that the tibia and calcaneus have fewer progenitor cells than the iliac crest. This retrospective review evaluates the efficacy and safety profile of harvesting BMA from the calcaneus bone. We hypothesized that harvesting BMA from the calcaneus will have high efficacy and safety profile with low complication rates.

Methods

A retrospective chart review of patients undergoing bone marrow aspiration from the calcaneus bone from January 2019 to October 2022 was performed. The main data points evaluated were patient satisfaction and pain level, follow-up times, quantity of BMA harvested, fusion rates, and complications including nerve damage, infections, and nonunions.

Results

There were 45 (34 female and 11 male) patients who underwent 45 procedures. The average age, BMI, and amount of BMA were 45.1 years (range 23-79), 33.1 (range 19.2-61.3), and 10.3 mL (range 2-40), respectively. There was no pain reported at the final follow-up in 32 patients (71.1%), and there was minimal to no pain in the area of surgery in the remaining 13 patients (28.9%). The 10 cases of fusion successfully healed with combined use of allograft and BMA. The average follow-up time was 12.3 months (range 2.4-33.7). There were no infections, wound complications, or nerve injuries.

Conclusion

Harvesting BMA from the calcaneus bone is a safe procedure. In this heterogenous series where BMA augmented other surgical strategies, patients had little to no pain and there were no cases of wound complication or iatrogenic neuropraxia after undergoing bone marrow harvest from the calcaneus.

Level of Evidence

Level IV, case series.

Review: cellularity in bone marrow autografts for bone and fracture healing

The use of autografts, as primary cell and tissue source, is the current gold standard approach to treat critical size bone defects and nonunion defects. The unique mixture of the autografts, containing bony compartments and bone marrow (BM), delivers promising results. Although BM mesenchymal stromal cells (BM-MSCs) still represent a major target for various healing approaches in current preclinical research and respective clinical trials, their occurrence in the human BM is typically low. In vitro expansion of this cell type is regulatory challenging as well as time and cost intensive. Compared with marginal percentages of resident BM-MSCs in BM, BM mononuclear cells (BM-MNCs) contained in BM aspirates, concentrates, and bone autografts represent a readily available abundant cell source, applicable within hours during surgical procedures without the need for time-consuming and regulatory challenging cell expansion. This benefit is one reason why autografting has become a clinical standard procedure. However, the exact anatomy and cellularity of BM-MNCs in humans, which is strongly correlated to their unique mode of action and wide application range remains to be elucidated. The aim of this review was to present an overview of the current knowledge on these specific cell types found in human BM, emphasize the contribution of BM-MNCs in bone healing, highlight donor site dependence, and discuss limitations in the current isolation and subsequent characterization procedures. Hereby, the most recent and relevant examples of human BM-MNC cell characterization, flow cytometric analyses, and findings are summarized, with a strong focus on bone therapy.

Current Trends in Orthobiologics: An 11-Year Review of the Orthopaedic Literature

BACKGROUND

The use of "orthobiologics" or regenerative therapies in orthopaedic surgery has grown in recent years. Particular interest has been raised with regard to platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells. Although studies have analyzed outcomes after orthobiologic treatment, no study has analyzed how the literature as a whole has evolved.

PURPOSE

To evaluate trends in platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cell publications and to assess how these might inform efforts to establish minimum reporting standards and forecast future use.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A database was compiled systematically using PubMed to identify articles published between 2009 and 2019 within 9 prominent orthopaedic journals and pertaining to the use of platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells in the treatment of musculoskeletal conditions. Included articles were classified as clinical, nonclinical (translational or basic science), or review, and a variety of study parameters were recorded for each. Additional queries were performed to identify articles that utilized minimum reporting standards.

RESULTS

A total of 474 articles (132 clinical, 271 nonclinical, 71 review) were included, consisting of 244 (51.5%) platelet-rich plasma, 146 (30.8%) bone marrow aspirate, 72 (15.2%) adipose-derived cells, and 12 (2.5%) amniotic cells. The greatest annual increase in publications for each orthobiologic topic was from 2018 to 2019. The American Journal of Sports Medicine demonstrated the highest number of overall (34.2%) and clinical (50.0%) publications, and accounted for 44.3% of all platelet-rich plasma publications. The Journal of Orthopaedic Research accounted for the second highest overall number of publications (24.9%) and highest nonclinical publications (41.0%). Platelet-rich plasma accounted for 91.5% of all level 1 clinical studies, while much greater than half of bone marrow aspirate, adipose-derived cells, and amniotic cell publications were level 3 or lower. Out of the 207 articles that used some form of reporting protocol, 59 (28.5%) used an established algorithm and 125 (60.4%) used their own.

CONCLUSION

Interest in orthobiologics continues to grow, as evidenced by an increasing trend in publications over an 11-year period. However, current reporting on orthobiologic formulations is largely heterogeneous, emphasizing the need for minimum reporting standards and higher-quality studies.

Injectable Bacteria-Sensitive Hydrogel Promotes Repair of Infected Fractures via Sustained Release of miRNA Antagonist

Fracture nonunion can result in considerable physical harm and limitation of quality of life in patients, exerting an extensive economic burden to the society. Nonunion largely results from unresolved inflammation and impaired osteogenesis. Despite advancements in surgical techniques, the indispensable treatment for nonunion is robust anti-inflammation therapy and the promotion of osteogenic differentiation. Herein, we report that plasma exosomes derived from infected fracture nonunion patients (Non-Exos) delayed fracture repair in mice by inhibiting the osteogenic differentiation of bone marrow stromal cells in vivo and in vitro. Unique molecular identifier microRNA-sequencing (UID miRNA-seq) suggested that microRNA-708-5p (miR-708-5p) was overexpressed in Non-Exos. Mechanistically, miR-708-5p targeted structure-specific recognition protein 1, thereby suppressing the Wnt/β-catenin signaling pathway, which, in turn, impaired osteogenic differentiation. AntagomicroRNA-708-5p (antagomiR-708-5p) could partly reverse the above process. A bacteria-sensitive natural polymer hyaluronic-acid-based hydrogel (HA hydrogel) loaded with antagomiR-708-5p exhibited promising effects in an in vivo study through antibacterial and pro-osteogenic differentiation functions in infected fractures. Overall, the effectiveness and reliability of an injectable bacteria-sensitive hydrogel with sustained release of agents represent a promising approach for infected fractures.

Current Modalities for Fracture Healing Enhancement

Previously, most fractures have been treated through bone reduction and immobilization. With an increase in the patients' need for an early return to their normal function, development in surgical techniques and materials have accelerated. However, delayed union or non-union of the fracture site sometimes inhibits immediate return to normal life. To enhance fracture healing, diverse materials and methods have been developed. This is a review on the current modalities of fracture healing enhancement, which aims to provide a comprehensive knowledge regarding fracture healing for researchers and health practitioners.

Bone Marrow Aspirate Concentrate as a Reliable Adjunct in Tibiotalocalcanal Fusion: A Radiographic Modified RUST Score Analysis

BACKGROUND

Tibiotalar and subtalar arthritis requiring tibiotalocalcaneal (TTC) fusion can be technically challenging and is dependent on reliable fusion for a good clinical outcome. Initial data regarding bone marrow aspirate concentrate (BMAC) has shown promise in use as an aide in both fracture and fusion healing. The purpose of this study is to determine the outcomes in TTC fusion when utilizing BMAC as an adjunct.

METHODS

Twenty consecutive patients who underwent TTC fusion with BMAC adjunct between March 2013 and November 2017 were retrospectively screened for inclusion. Patients were included regardless of comorbidities or risk factors for non-union, and only excluded if they did not have a minimum of 12 months of clinical and/or radiographic chart data. Follow-up was obtained at regular intervals of 6 weeks, 3 months, 6 months and 1 year. Modified RUST scores were applied to grade bony union in a blinded fashion by two orthopedic trauma fellowship-trained surgeons and agreement was assessed via intraclass correlation coefficient (ICC).

RESULTS

Twenty patients were screened and 12 met inclusion criteria for analysis. Majority were male (66.6%) at a mean age of 55.4 years and they were all treated via TTC fusion for a diagnosis of tibiotalar and subtalar arthritis. There were no postoperative complications and no reoperations in this cohort; no donor site morbidity was associated with BMAC. By the 3-month follow-up timepoint, all but one patient received a minimum modified RUST score of 10 indicating bony union (ICC 0.91); by the 6-month time point (ICC 0.94), all 12 patients were deemed united.

CONCLUSION

BMAC as an adjunct in the setting of TTC fusion is a safe treatment option that can promote reliable, consistent bony fusion with minimal complications.

Characteristics, Treatments, and Outcomes of Tibial Plateau Nonunions: A Systematic Review

BACKGROUND

Due to the rare incidence of tibial plateau nonunions, current studies are limited to small sample sizes and patient demographics. The aim of this systematic review is to quantify and report patient and fracture traits, possible risk factors, and treatment outcomes of tibial plateau nonunions.

METHODS

PubMed, Clinical Key, and MEDLINE were searched for articles published prior to August 2020 in accordance to the preferred reporting items for systematic reviews and meta-analyses (PRISMA). The authors used varying combinations of the following terms to identify relevant articles: "tibial," "plateau," "nonunion," "non-union." Studies were assessed for patient demographics, pre-revision nonunion characteristics, treatment, and post-revision outcomes.

RESULTS

Eight studies were included, yielding 31 tibial plateau nonunions (21 males, 10 females). The majority of nonunions were associated with high energy trauma (52.2%) and were Schatzker class VI (54.8%). Schatzker class I and II nonunions were not attributed to neglect, contradicting previous suggestions. Time to union was 4.0 months, the most common treatments being autologous bone grafting (76.7%) and revision plating (63.3%).

CONCLUSION

This study demonstrates the effectiveness of autologous bone grafts and revision plating for tibial plateau nonunions. Physicians may use these findings to guide decision making in the event of high energy plateau nonunions. Lastly, various limitations exist within the current literature, emphasizing the need for standardized reporting measures.

[Effectiveness of percutaneous injection of autologous concentrated bone marrow aspirate combined with platelet-rich plasma in treatment of delayed fracture healing]

OBJECTIVE

To analyze the effectiveness of percutaneous injection of autologous concentrated bone marrow aspirate (cBMA) combined with platelet-rich plasma (PRP) in the treatment of delayed fracture healing.

METHODS

A prospective, randomized, controlled, single-blind case study was conducted. Between March 2016 and July 2018, 66 patients who met the inclusion and exclusion criteria for delayed fracture healing but had solid internal fixation of the fracture end were randomly divided into control group (31 cases, treated with percutaneous autogenous bone marrow blood injection) and study group (35 cases, treated with percutaneous autogenous cBMA+PRP injection). General data such as gender, age, body mass index, site of delayed fracture healing, length of bone defect at fracture end, and preoperative radiographic union score for tibia (RUST) showed no significant difference between the two groups ( P>0.05). Before injection, Kirschner wire was used in both groups to stimulate the fracture end and cause minor injury. The fracture healing time, treatment cost, and adverse reactions were recorded and compared between the two groups. Visual analogue scale (VAS) score was used to evaluate pain improvement. The tibial RUST score was extended to the tubular bone healing evaluation.

RESULTS

No infection of bone marrow puncture needle eyes occurred in both groups. In the control group, local swelling was obvious in 5 cases and pain was aggravated at 1 day after operation in 11 cases. In the study group, postoperative swelling and pain were not obvious, but 2 cases presented local swelling and pain. All of them relieved after symptomatic treatment. Patients in both groups were followed up, the follow-up time of the control group was 16-36 months (mean, 21.8 months), and the study group lasted 14-33 months (mean, 23.2 months). The amount of bone marrow blood was significantly lower in the study group than in the control group ( t=4.610, P=0.000). The degree of postoperative pain in the study group was less than that in the control group, and the treatment cost was higher than that in the control group. But the differences between the two groups in VAS score at 1 day after operation and treatment cost were not significant ( P>0.05). Fracture healing was achieved in 19 cases (61.3%) in the control group and 30 cases (85.7%) in the study group. The difference in fracture healing rate between the two groups was significant ( χ 2=5.128, P=0.024). Fracture healing time and RUST score at last follow-up were significantly better in the study group than in the control group ( P<0.05). At last follow-up, RUST scores in both groups were significantly improved when compared with those before operation ( P<0.05).

CONCLUSION

Autogenous cBMA combined with PRP percutaneous injection can provide high concentration of BMSCs and growth factors, and can improve the fracture healing rate and shorten the fracture healing time better than autogenous bone marrow blood injection.

The top three unanswered questions in the management of open fractures

Despite improvements in treatment strategies and emphasis on preventative measures, the management of open fractures continues to be a challenging endeavor for orthopaedic surgeons. Deep infections, delayed healing, and nonunion continue to be problematic complications associated with these devastating injuries. There remain many unanswered clinical questions regarding the management of these injuries and how the various aspects of care can be further optimized. There continues to be a paucity of evidence regarding how infection can best be treated and prevented, how to reliability predict bone healing/nonunion, and how bone healing can be best augmented in the setting of open fractures and their potential nonunions. This review aims to assess the current literature on these top unanswered questions and discuss the gaps in evidence that may be filled with future studies.

Does bone marrow aspirate help enhance the integration of gamma irradiated allograft bone?

Bone allografts donated by other individuals offer a viable alternative to autograft. Risks of disease transmission are overcome by sterilizing the bone; unfortunately sterilization methods generally affect bone functional properties including osteogenic potential and biomechanical integrity. This study aimed to determine any enhancement effect when gamma sterilised allografts was impregnated with autologous bone marrow in improving the rate and quality of integration in metaphyseal-tibial defects of rabbits. Almost all subjects showed 50% of the defect being covered by new bones by the third week and smaller residual defect size in the treated group at the fifth week. Hounsfield units at the defect site showed increasing healing in all samples, with the treated group having an apparent advantage although insignificant (p > 0.05). In the histopathological score evaluating healing over cortical and cancellous bone at the fracture site showed only slight variations between the groups (p > 0.05). Therefore no enhanced healing by the autologous bone marrow was observed when added to the bone allografts in treating the unicortical defects.

Physical Health and Psychological Outcomes in Adult Patients with Long-bone Fracture Non-unions: Evidence Today

Background: Research has suggested that bone fractures can hinder the health status of patients’ life. However, limited research has examined the impact that the healing process of a fracture has on the physical health and psychological state of individuals, particularly in considering the short- and long-term impact of having a fracture that fails to heal and drops into a non-union. The aim of this systematic review is to better understand the impact of fracture non-union to physical health and to respective psychological outcomes. Methods: Electronic databases ‘PubMed’, ‘Cochrane’, ‘PsycInfo’, ‘Medline’, ‘Embase’, ‘Web of Science’, and ‘CINAHL’ were used. Search terms used were nonunion OR non-union OR “non union” OR “long bone” OR “delayed union” AND “quality of life” OR qol OR depression OR anxiety OR psycholog* OR PTSD OR “post-traumatic stress disorder”. Studies published in the years 1995 to 2018 were included. Two independent reviewers carried out screening and data extraction. Studies were included if (1) participants were adult (human) patients with a traumatic non-union secondary to fracture/s; (2) outcomes measured included physical health and psychological wellbeing (e.g., PTSD, psychological trauma, depression, anxiety, etc.). Studies received emphasis if they compared those outcomes between: (1) The “non-union” group to a normative, matched population and (2) the “non-union group” to the same group after union was achieved. However, studies that did not use comparison groups were also included. Results: Out of the 1896 papers identified from our thorough literature search, 13 met the inclusion criteria. Quality assessment was done by the Methodological Index for Non-Randomized Studies (MINORS). Findings suggested that non-unions had a detrimental impact on physical health, and psychological difficulties often after recovery. Conclusions: Patients who experience a long bone non-union are at risk of greater psychological distress and lower physical health status. There is a need for early identification of psychological distress in patients with fracture non-unions and psychological provision should become part of the available treatment.

Multidirectional percutaneous drilling and autologous bone marrow injection for the treatment of femoral diaphyseal nonunions: a prospective interventional study

Background

To examine the outcomes of multidirectional percutaneous drilling and autologous concentrated bone marrow (BM) transplantation for atrophic femoral diaphyseal nonunion characterized by intact hardware and mechanical stability at the nonunion site.

Methods

Fourteen patients (22–63 years of age) were admitted to our hospital with atrophic femoral diaphyseal nonunion. All patients were treated with a combination of multidirectional percutaneous drilling and autologous concentrated BM transplantation. Radiographic evaluation was conducted every month after transplantation until bone healing was achieved.

Results

Bony union was achieved in 13 of the 14 patients (92.9%) after an average of 3.9 months (range: 2.5–6 months). The average radiographic union scale in tibial (RUST) scale score improved significantly from the preoperative period (6.15±1.21) to follow-up (11.23±0.73; P<0.05). The mean follow-up after transplantation was 31.4±9.5 months (range: 18–50 months). At the final follow-up, the quality of function had improved significantly, allowing a return to normal activities.

Conclusion

Combined multidirectional percutaneous drilling and autologous concentrated BM transplantation is an easy, safe, inexpensive, and efficacious method to treat atrophic femoral diaphyseal nonunion characterized by intact hardware and mechanical stability at the nonunion site.

Trial registration number: ISRCTN29808592

Ex vivo gene therapy using human bone marrow cells overexpressing BMP-2: "Next-day" gene therapy versus standard "two-step" approach

Traditionally, ex vivo gene therapy involves a two-step approach, with culture expansion of cells prior to transduction and implantation. We have tried to simplify this strategy and eliminate the time and cost associated with culture expansion, by introducing "next-day" regional gene therapy using human bone marrow cells. The purpose of this study was to determine whether a lentiviral vector (LV) carrying the cDNA for BMP-2 can transduce freshly isolated human BM cells, leading to abundant BMP production and bone formation in vivo, and evaluate the in vivo osteoinductive potential of "next-day" gene therapy and the standard "two-step" tissue culture expansion approach. To this end, human bone marrow cells (HBMC) from patients undergoing total hip arthroplasty were harvested, transduced with a BMP-2-expressing LV either overnight ("next day" gene therapy; ND) or after culture expansion (cultured "two-step" approach; C) and then implanted into a rat critical-sized femoral defect. The animals were randomly assigned to one of the following groups: I; ND-HBMC transduced with LV-TSTA BMP-2, II; ND-HBMC transduced with LV-TSTA GFP, III; non-transduced ND-HBMC; IV; C-HBMC transduced with LV-TSTA BMP-2, V; C-HBMC transduced with LV-TSTA-GFP, VI; non-transduced C-HBMC. Treatment with either "next-day" or cultured HBMC demonstrated a significant increase in new bone formation compared with all negative control groups as seen in plain radiographs, microCT and histologic/histomorphometric analysis. At 12 weeks post-op, complete defect union on plain X-rays occurred in 7/14 animals in the ND-HBMC/BMP-2 group and 12/14 in the C-HBMC/BMP-2 treated rats. The two-step approach was associated with more consistent results, a higher union rate, and superiority with regards to all of the studied bone healing parameters. In this study we demonstrate proof of concept that BMP-2-transduced human bone marrow cells can be used to enhance bone healing in segmental bone defects, and that regional gene therapy using lentiviral transduction has the osteoinductive potential to heal large bone defects in clinical settings.

Bone marrow aspirate concentrate with cancellous allograft versus iliac crest bone graft in the treatment of long bone nonunions

Objectives:

The purpose of this study was to compare bone marrow aspirate concentrate (BMAC) with cancellous allograft to iliac crest bone graft (ICBG) in the treatment of long bone nonunions.

Design:

Retrospective cohort study.

Setting:

A single level I trauma center.

Patients:

26 patients with long bone diaphyseal or metaphyseal nonunions with defects >2 mm and treated with open repair and BMAC, compared to 25 patients with long bone diaphyseal or metaphyseal nonunions with defects >2 mm and treated with open repair and ICBG.

Intervention:

Open repair of long bone nonunion using either autologous ICBG or BMAC with cancellous allograft.

Main outcome measure:

Nonunion healing, radiographically measured by the modified Radiographic Union Score for Tibia (mRUST) score. Secondary outcomes included risk factors associated with failed repair.

Results:

The union rates for the BMAC and ICBG cohorts were 75% and 78%, respectively (P = .8). Infection was the only risk factor of statistical significance for failure.

Conclusion:

In this study, we found no significant difference in union rate for long bone nonunions treated with ICBG or BMAC with allograft. BMAC and allograft led to 75% successful healing in this series. Given the heterogeneity of the control group and loss to follow-up, further prospective investigation should be conducted to more rigorously compare BMAC to ICBG for nonunion treatment.

Level of evidence:

III, retrospective cohort.

Intraoperative Construct Preparation: A Practical Route for Cell-Based Bone Regeneration

Stem cell-based bone tissue engineering based on the combination of a scaffold and expanded autologous mesenchymal stem cells (MSCs) represents the current state-of-the-art treatment for bone defects and fractures. However, the procedure of such construct preparation requires extensive ex vivo manipulation of patient's cells to achieve enough stem cells. Therefore, it is impractical and not cost-effective compared to other therapeutic interventions. For these reasons, a more practical strategy circumventing any ex vivo manipulation and an additional surgery for the patient would be advantageous. Intraoperative concept-based bone tissue engineering, where constructs are prepared with easily accessible autologous cells within the same surgical procedure, allows for such a simplification. In this study, we discuss the concept of intraoperative construct preparation for bone tissue engineering and summarize the available cellular options for intraoperative preparation. Furthermore, we propose methods to prepare intraoperative constructs, and review data of currently available preclinical and clinical studies using intraoperatively prepared constructs for bone regenerative applications. We identify several obstacles hampering the application of this emerging approach and highlight perspectives of technological innovations to advance the future developments of intraoperative construct preparation.

Cellular therapies and stem cell applications in trauma

BACKGROUND

As the leading cause of mortality in the United States, trauma management have improved drastically over the past few decades with improved resuscitation and hemorrhage control. Stem cells are being used in an attempt to augment healing from trauma.

DATA SOURCES

PubMed and ClinicalTrials.gov were searched for published and registered pre-clinical and clinical trials for the application of stem cells to AKI, ARDS, shock, infection, TBI, wound healing, and bone healing.

CONCLUSIONS

Stem cell therapy for augmentation of healing traumatic injuries appears safe, as demonstrated by completed phase I/II trials. Further large scale studies are needed to assess the clinical efficacy.

Percutaneous autologous bone marrow transplantation for the treatment of delayed union of limb bone in children

Background and purpose

Percutaneous autologous bone marrow transplantation (PABMT) is a minimally invasive therapeutic strategy for the treatment of delayed bone union in adults, which has been confirmed by many studies. However, there is no report on PABMT application in pediatric orthopedic surgery. The aim of this article was to analyze the therapeutic effect of PABMT in children with delayed union of limb bone and its influence in relation to delayed bone union therapy, transplantation period, patients’ sex, fracture location, and fracture fixation.

Methods

In this study, 53 patients (aged 3–16 years, with an average age of 6.7 years) with delayed union of long bone (20 femurs, 12 tibiae, 10 humeri, 5 radiuses, 5 ulnas, and 1 fibula) were treated using PABMT. Clinical examination and X-ray were integrated to evaluate the therapeutic effect.

Results

All 53 patients were followed up for 2–6 years (average time, 3.5 years). Of the 53 patients, 47 (88.7%) were healed, whereas the other 6 (11.3%) were not, and were subsequently treated by autologous bone grafting. In 30 patients who received their first PABMT treatment 6–8 months after fixation, the clinical cure rate, operation times, and healing time were 83.3%, 5.8±0.5 months, and 2.5±0.6, respectively. In the other 23 patients, whose first PABMT treatments were started within 4 to 6 months after fixation, the clinical cure rate, operation times, and healing time were 95.7% (P=0.167), 3.2±0.3 months (P=0.001), and 1.3±0.6 (P=0.001), respectively. The patients’ sex, fracture location, and fracture fixation did not have statistical influence on the clinical efficacy.

Conclusion

PABMT is a minimally invasive and effective strategy for the treatment of delayed union of limb bone in children. The early surgical treatment facilitates the fracture healing, reduces the number of transplantation, and shortens the course of treatment.

Treatment of aseptic tibial shaft non-union without bone defect

Non-union is incomplete consolidation of a fracture, without effective formation of a uniting callus. Despite better understanding of the physiology of bone consolidation, management of tibial non-union remains a challenge for orthopedic surgeons. Several treatments have been developed in recent decades, and we now have a range of techniques, with indications based on type of non-union, prior treatments, available equipment, and the surgeon's experience. Firstly, there are surgical techniques such as osteo-periosteal decortication, cancellous iliac graft, or inter-tibiofibular graft. The decision to fix the non-union (or revise existing fixation) and choice of type of internal fixation depend on the stability of the fracture site. There are also non-operative biological and biochemical consolidation stimulation techniques: local injection of bone-marrow, platelet-rich plasma (PRP) or bone morphogenetic protein (BMP). Stimulation can also be physical, applying ultrasound or an electromagnetic field to the non-union site. Each technique may be used in isolation or association.

Biological Facet of Segmental Bone Loss Reconstruction

The management of long bone defects continues to be associated with significant challenges for optimum and timely bone repair. When bone grafting is needed, essential parameters to be addressed include adequate volume, optimum density, and structural capacity as well as potent biological properties. Although the autologous iliac crest bone graft remains the gold standard, its reduced availability and donor site morbidity have made the clinicians to seek for other alternative options. Reamer irrigator aspirator graft with materials used as graft expanders along with inductive molecules and cellular augmentation constitute the current trend for optimum bone regeneration. This article presents the contemporary thinking of the biological facet of segmental bone loss reconstruction.

Role of Bone Marrow Aspirate in Orthopedic Trauma

Bone marrow aspirate grafting entails mesenchymal stem cell-containing bone marrow harvesting and injection into a fracture site to promote bone formation. Although the use of bone marrow aspirate in orthopedic trauma is not widespread, an increasing number of studies are reporting clinical success. Advantages of using bone marrow aspirate are that it is readily obtainable, has low harvest morbidity, and can be easily and quickly injected. However, no universally accepted role for its use exists. Future studies directly comparing bone marrow aspirate with conventional techniques are needed to define its role in the treatment of orthopedic trauma patients.

Osseous Healing in Foot and Ankle Surgery with Autograft, Allograft, and Other Orthobiologics

In the surgical treatment of foot and ankle abnormality, many problems require bone grafting for successful osseous union. Nonunion, reconstruction, and arthrodesis procedures pose specific challenges due to bony defects secondary to trauma, malunions, or previous surgery. Nonunion in foot and ankle arthrodesis is a significant risk and is well documented in recent literature. This article is a review of the recent literature regarding the use of bone graft and orthobiologics in foot and ankle surgery.

Comparison of intramedullary nail, plate, and external fixation in the treatment of distal tibia nonunions

PURPOSE

The purpose of this study was to examine time to union of extra-articular distal tibia nonunions based on fracture type and fixation methods: intramedullary nail (IMN), plate osteosynthesis (PO), and external fixation (EF).

METHODS

This retrospective chart review included all patients who presented at a Level I trauma center with AO/OTA 43A & distal third 42A-C fracture nonunions between 2008 and 2014. Fixation methods were recorded and patient course was followed until nonunion had healed clinically.

RESULTS

Thirty-three distal tibia nonunions were included, and 29 reached eventual union (88%). Five AO/OTA fracture types were present. Mean times to union from nonunion diagnosis between original fracture types were compared (p = 0.203). Comminuted fracture types had longer times to union from nonunion diagnosis compared to simple fracture types (78 vs. 46 weeks, p = 0.051) and more revision fixations (1.5 vs. 0.5, p = 0.037). Mean time to union from nonunion diagnosis was shorter when no revision fixation was done compared to revisions (15 vs. 42 weeks, p = 0.102). Times to union from nonunion diagnosis without revision fixation were: IMN (12 weeks), PO (27 weeks), and EF (13 weeks) (p = 0.202). Times to union from definitive revision fixation were: IMN (17 weeks), PO (21 weeks), and EF (66 weeks) (p = 0.009), with EF taking significantly longer than both other methods. 21 patients (64%) underwent revision fixation. Revision fail rates were: IMN (0/6, 0%), PO (2/8, 25%), and EF (15/21, 71%). Time to union was longer in revisions that changed fixation method compared to revisions that used the same method (51 vs. 18 weeks, p = 0.030). Deep infections were also associated with longer union times (81 vs. 47 weeks, p = 0.040).

CONCLUSIONS

In this nonunion population, comminuted fracture types needed more time and revisions to reach union. Time to union was only clinically shorter when revision fixation was not performed, but IMN and PO were both successful fixation options with significantly shorter times to union than EF. Mean time to union increased even more when revision of fixation method was performed vs. exchange revision, as did nonunions with deep infections.

Management of Aseptic Tibial and Femoral Diaphyseal Nonunions Without Bony Defects

An evidence-based description of aseptic tibial and femoral diaphyseal nonunions without segmental defects is based on a systematic search of MEDLINE. Aseptic nonunion of the femoral or tibial diaphysis without segmental defects and with an in situ nail, treated with reamed exchange nailing or augmentative plating and bone grafting, has consistently high union rates. Aseptic nonunion without segmental defects and with in situ plate and screw fixation is best managed with revision plate and screw fixation and autogenous bone graft. Various techniques and methods of biological stimulation have relatively high union rates.

Treatment of hypertrophic distal tibia nonunion and early malunion with callus distraction

BACKGROUND

Hypertrophic nonunions and early malunions of pilon and distal tibia fractures result in complex, challenging to treat deformities. Callus distraction histiogenesis is an option for their management, allowing for the simultaneous correction of multiplanar deformity and limb length discrepancy.

METHODS

A single-surgeon, retrospective case series was performed. Eight patients (6 males and 2 females) who were treated with callus distraction from 1991 to 2011 were reviewed. Six of 8 patients had varus deformities (range, 8-19 degrees) and 2 patients had valgus deformities (both 16 degrees) of the distal tibia metaphysis. Six of 8 had apex anterior deformities (range, 2-21 degrees) and 2 had apex posterior deformity (range, 9-20 degrees). An Ilizarov fixator or Taylor Spatial Frame (Smith & Nephew, Memphis, TN) was used to distract the nonunion or early malunion to correct alignment and shortening. Preoperative and postoperative radiographic outcomes, limb alignment, and ankle-hindfoot scores were reviewed.

RESULTS

Union was achieved in all patients at a mean of 5.8 months (range, 4.1-7.6 months). The 3 patients treated with an Ilizarov-type fixator had deformity correction to within 5 degrees of neutral in 1 plane and to within 10 degrees in the other plane. All 5 patients treated with a Taylor Spatial Frame had correction to within 5 degrees of neutral alignment in both coronal and sagittal planes. There were 2 complications requiring reoperation and 1 persistent limb length discrepancy (2 cm) after treatment. Median AOFAS ankle-hindfoot score was 82.5 (range, 53-90) at an average follow-up of 30.4 months (range, 8-92).

CONCLUSIONS

Callus distraction histiogenesis was a minimally invasive technique that can successfully treat patients with hypertrophic nonunion and early malunion of the distal tibia. We believe the application of a computer-assisted 6-axis frame to correct the deformity improved the correction of these multiplanar deformities.

LEVEL OF EVIDENCE

Level IV, case series.

Percutaneous grafting with bone marrow autologous concentrate for open tibia fractures: analysis of forty three cases and literature review

PURPOSE

Tibial fractures are the most common lower limb fractures. Some criteria such as open fractures and increasing open stage are known to be associated with high delayed union and pseudarthrosis rate. In cases of delayed or nonunion, classical treatment is autologous cancelous bone graft which is associated with high morbidity rate. The ideal treatment would be a percutaneous harvesting and grafting technique. As bone marrow autologous concentrate (BMAC) presents both advantages, we evaluated this technique from 2002 to 2007.

METHODS

This was a retrospective study of 43 cases of open tibial fractures with initial surgical treatment. The criteria of inclusion were open fracture and nonunion, delayed union or suspicion of delayed union.

RESULTS

In 23 cases (53.5 %) BMAC was successful. The success group had received significantly more CFU-F than the failure group (469 vs 153.10(3), p = 0.013). A threshold of 360.10(3) CFU-F grafted could be established over which there was 100 % success. BMAC done before 110 days after fracture had 47 % success and BMAC done since 110 days after fracture had 73 % success. BMAC success rate decreased with increasing initial fracture skin open stage. There was no BMAC success in cases of a fracture with a remaining gap of more than 4 mm. We had no complications with the technique at the iliac harvesting zone and tibia injection point.

CONCLUSION

BMAC is a technique that should be considered as one of the different alternatives for management of long-bone delayed and nonunion because of its effectiveness, low complication rate, preservation of bone stock and low cost.

Percutaneous autologous concentrated bone marrow grafting in the treatment for nonunion

The purpose of this study was to evaluate the clinical and radiographic treatment effects of percutaneous autologous concentrated bone marrow grafting in nonunion cases and to evaluate the effectiveness of this grafting procedure. We enrolled 17 cases those had atrophic changes due to continuous nonunion for over 9 months after injury and had undergone low-intensity pulsed ultrasound treatment for more than 3 months. The site of nonunion was the femur in 10 cases, the tibia in 5 cases, the humerus in 1 case, and the ulna in 1 case. They underwent percutaneous autologous concentrated bone marrow grafting and continued low-intensity pulsed ultrasound stimulation treatment after grafting. Patients were evaluated using the visual analogue scale for pain at immediately before the procedure, 3, 6, and 12 months after grafting. Plain radiographs of the affected site were taken and evaluated about the healing of the nonunion site at each clinical evaluation. As quantitative assessment, CT scans were undertaken before the procedure and 6 months after grafting. The visual analogue scale pain score was reduced consistently after grafting in all patients. About the healing at the nonunion site, 11 and 13 cases of bone union were observed at 6 and 12 months after grafting. The mean volume of callus formation based on CT images was 4,147 (262-27,392) mm3 total between grafting and 6 months. Percutaneous autologous concentrated bone marrow grafting is an effective procedure for the treatment of patients with nonunion.