Microparticulate cortical allograft: an alternative to autograft in the treatment of osseous defects

How successful is synthetic graft treatment for children with pathological hip fractures?

PURPOSE

To determine whether synthetic grafts are a satisfactory treatment option for pathological proximal femoral fractures in children.

METHODS

Paediatric patients treated for pathological fractures of the proximal femur between 2013 and 2020 were evaluated retrospectively. 17 patients with a mean age of 10.7 years (range 6-16 years) were assessed. The definitive histopathological diagnoses were SBC (simple bone cyst) (12) and ABC (aneurysmal bone cyst) (5). The median duration of follow-up was 37 months (range 12-70 months).

RESULTS

All patients returned to their normal daily routine within 3-8 months following surgery. The mean post-op recovery time was 3.2 months (range 3-6 months). Graft was incorporated at approximately 12 months. No significant radiographic healing was observed in 2 patients. In the remaining 15 patients, the mean duration of healing was 14 months (range 8-24 months).

CONCLUSION

Synthetic grafts are a satisfactory treatment option for pathological proximal femoral fractures in children.

Allografts: expanding the surgeon's armamentarium

In Germany, bone allografts are widely used and their application in clinics has increased over the years. Successful use of allografts depends on many factors such as the procurement, processing, sterilization and the surgeon's surgical experience. Tissue banks have provided safe and sterile allografts for decades ranging from hard to soft tissue. Allografts are obtained from various tissues such as bone, tendon, amniotic membrane, meniscus and skin. An advantage of allografts is their wide applicability that has never been limited by indication restrictions thus providing a huge benefit for surgeon's. The use of the correct allograft in different indications is extremely important. Thereby surgeons have access to various allograft forms such as mineralized, demineralized, freeze-dried, paste, powder, chips strips and putty. The vast options of allografts allow surgeon's to use allografts in indications they deem fit. Currently, the application of allografts is at the discretion of the expert surgeon. However, regulations are often changed locally or internationally and may impact/limit allograft use to certain indications. Here, we report the different indications where our peracetic acid (PAA) sterilised bone allografts were used as well as general literature on bone allograft use in other indications.

Regenerative medicine: characterization of human bone matrix gelatin (BMG) and folded platelet-rich fibrin (F-PRF) membranes alone and in combination (sticky bone)

During the last two decades autologous platelet and leukocyte rich products (PRP; PRF), opened new perspectives in regenerative medicine. In particular regenerative dentistry played a pioneer role in the application of these products in bone regenerative cases. Many aspects of cytokines, such as, growth factor release, blood cell content and its characterization were reported, but some practical questions are still unanswered in the preparation of PRF membranes and sticky bones. A new folding technique was introduced that created a good quality, pliable, and strong F-PRF membrane with a dense fibrin network and more homogenous blood cell distribution. F-PRF produced a very promising sticky bone combined with human freeze-dried cortical bone matrix gelatin (BMG). There hasn’t been much focus on the quality and character of the applied bone and the optimal membrane/bone particle ratio has not been reported. A 0.125 g BMG/ml plasma (1 g/8 ml) seems like the ideal combination with maximal BMG adhesion capacity of the membrane. Particle distribution of BMG showed that 3/4 of the particles ranged between 300–1000 µ, the remnant 1/4 was smaller than 300 µ. The whole F-PRF membrane and its parts were compared with conventional A-PRF membrane concerning their resistance against proteolytic digestion. The F-PRF was superior to A-PRF, which dissolved within 4–5 days, while F-PRF was destroyed only after 11 days, so this provides a better chance for local bone morphogenesis. The F-PRF pieces had similar resistance to the whole intact one, so they can be ideal for surgical procedures without risk of fast disintegration.

Long-term Follow-up of the Use of a Synthetic Bone Graft Composite in the Surgical Management of Primary Bone Tumors

The surgical management of benign and benign aggressive bone tumors typically involves intralesional curettage and reconstruction of the resulting defect with cement or bone graft material. At the authors' institution, an injectable synthetic calcium sulfate-calcium phosphate composite is now the standard graft material for these cases. This study reports the long-term follow-up, specifically the stability of bone regeneration, for the use of the synthetic graft material for oncologic reconstruction. Fourteen patients who underwent intralesional curettage of a primary bone tumor followed by cavitary reconstruction with synthetic graft material who had at least 4-year follow-up were identified from an institutional orthopedic oncology database. Clinical outcome data, focusing on long-term clinical and radiographic features of the reconstruction, were extracted from electronic and paper medical records. Seven females and 7 males were included (mean age at surgery, 28.1 years; range, 13-64 years). Follow-up ranged from 50 to 105 months (mean, 68 months). Most surgical reconstructions were done for the lower limb (n=11), and giant cell tumor of bone was the most common tumor treated. The mean amount of synthetic graft material used was 18.6 cm³. Complete radiographic resorption and new bone incorporation was observed within the first year, and bone remodeling was complete in all patients. Bone remodeling remained stable throughout the longer-term follow-up (ie, up to 9 years). The use of an injectable synthetic calcium sulfate-calcium phosphate composite is a viable option in the reconstruction of cavitary bone defects following intralesional curettage of primary benign bone tumors. This reconstruction technique was safe, with no long-term complications, and led to complete radiographic resorption and new bone incorporation with long-lasting stability. [Orthopedics. 2018; 41(6):e868-e875.].

Transforaminal Lumbar Interbody Fusion With Viable Allograft: 75 Consecutive Cases at 12-Month Follow-up

Background

When conservative treatments fail to alleviate the discomfort of abnormal motion, spinal fusion has been shown to provide symptomatic treatment for spinal instability, stenosis, spondylolisthesis, and symptomatic degenerative disc disease. The trend and rates of fusion over the past few years have been dramatic in the United States. Accompanying that higher incidence has been the shifting from traditional open surgery to minimally invasive techniques to reduce scar tissue formation, extent of muscle stripping, and muscle retraction which all have been shown to adversely affect outcomes. Other reasons supporting the widespread transition to minimally invasive surgical (MIS) techniques include decreased postoperative pain, decreased intraoperative blood loss, shorter postoperative hospital stay, faster return to normal activity, and reduced reoperation rates. Spinal fusion procedures rely on a bony fusion substrate in addition to fixation hardware. While available grafting options include autogenous, allogeneic, and synthetic materials, recent interest in viable allograft material with living cells has drawn attention and attraction for incorporating a biologic basis for regenerative consideration. A recent viable allograft, complete with cellular and designated bone carrier (VIA Graft, Vivex Biomedical, Marietta, Georgia) has been developed. This study represents a retrospective review of a single-practice, single-surgeon evaluation of the product in 75 consecutive patients for fusion by computed tomography (CT) and radiographic evaluation at 12 months in conjunction with a MIS approach. Viable allograft was used to fill the peri-implant space, and central implant lumen was filled with a cancellous bone sponge soaked in perivertebral bone marrow. Posterolateral supplementation was attained with beta-tricalcium phosphate as a bulking agent.

Methods

A retrospective review identified patients treated for both primary and revision surgery who received VIA Graft cellular bone matrix material in minimally invasive interbody fusion (MIS-TLIF) with a minimum of 12-month follow up. The patient diagnoses included radiculopathy in all instances and varied collateral indications such as foraminal collapse, recurrent disc herniation, and spondylolisthesis to which pain and morbidity had been unresolved by conservative treatment. Adverse events including infection, revisions, and evidence of immune response were evaluated and patient comorbidities defined for the entire population of patients. Patient fusion status was assessed using thin slice CT by 2 independent radiologists separate from the surgeon. There were 75 consecutive adult patients with degenerative conditions of the lumbar spine who underwent MIS-TLIF surgery of which 40 (53%) were male and 35 (47%) were female. Mean age, height, and weight were 58 years, 170.18 cm (67 in), and 88.45 kg (195 lbs), respectively. The mean body mass index was 30. There were 16 patients (21%) who smoked and 12 (16%) with a history of diabetes. Independent blinded review of fusion was obtained by a board certified musculoskeletal radiologist and an experienced board certified orthopaedic surgeon to assess patient fusion status. Spinal segments were deemed fused if 12-month CT scans demonstrated evidence of bridging bone at the fusion site without observed motion on flexion-extension radiographs. Findings such as osteolysis around the implant or pedicle screws, extensive endplate cystic changes, or linear defects parallel to the endplates through intradiscal new bone formation were interpreted as signs of pseudarthrosis. Interobserver and intraobserver error and κ assessments were analyzed to assure agreement in the CT outcomes assessment where interpretation of κ were as follows: <0.00 = poor agreement, 0.00-0.20 = slight agreement, 0.21-0.40 = fair agreement, 0.41-0.60 = moderate agreement, 0.61-0.80 = substantial agreement, and 0.81-1.00 = almost perfect agreement. Differences were resolved by consensus amongst the observers.

Results

In total, 96% of the 75 patients with a total of 85 levels (96.5% of levels treated) achieved a fusion at 12 months. There were no perioperative or latent complications and no transfusions in all 75 patients.

Conclusions

In this population, 96% of the patients treated achieved the surgical objective in 96.5% of the levels treated.

Level of Evidence

IV.

Clinical Relevance

The high rate of fusion, the lack of secondary morbidity with autologous bone harvest, and the clinical success account for the benefits of viable allograft matrix for MIS-TLIF use.

Orthobiologics in the Foot and Ankle

Many allogeneic biologic materials, by themselves or in combination with cells or cell products, may be transformative in healing or regeneration of musculoskeletal bone and soft tissues. By reconfiguring the size, shape, and methods of tissue preparation to improve deliverability and storage, unique iterations of traditional tissue scaffolds have emerged. These new iterations, combined with new cell technologies, have shaped an exciting platform of regenerative products that are effective and provide a bridge to newer and better methods of providing care for orthopedic foot and ankle patients.

Preparation and evaluation of an Arg-Gly-Asp-modified chitosan/hydroxyapatite scaffold for application in bone tissue engineering

Bone tissue engineering has become a promising method for the repair of bone defects, and the production of a scaffold with high cell affinity and osseointegrative properties is crucial for successful bone substitute. Chitosan (CS)/hydroxyapatite (HA) composite was prepared by in situ compositing combined with lyophilization, and further modified by arginine‑glycine‑aspartic acid (RGD) via physical adsorption. In order to evaluate the cell adhesion rate, viability, morphology, and alkaline phosphatase (ALP) activity, the RGD‑CS/HA scaffold was seeded with bone marrow stromal cells (BMSCs). The osseointegrative properties of the RGD‑CS/HA scaffold were evaluated by in vivo heterotopic ossification and in vivo bone defect repair. After 4 h culture with the RGD‑CS/HA scaffold, the adhesion rate of the BMSCs was 80.7%. After 3 days, BMSCs were fusiform in shape and evenly distributed on the RGD‑CS/HA scaffold. Formation of extracellular matrix and numerous cell‑cell interactions were observed after 48 h of culture, with an ALP content of 0.006 ± 0.0008 U/l/ng. Furthermore, the osseointegrative ability and biomechanical properties of the RGD‑CS/HA scaffold were comparable to that of normal bone tissue. The biocompatibility, cytocompatibility, histocompatibility and osseointegrative properties of the RGD‑CS/HA scaffold support its use in bone tissue engineering applications.

Posttreatment imaging of pediatric musculoskeletal tumors

Pediatric patients who are diagnosed with musculoskeletal tumors often require serial imaging both during and after treatment. Although many of the treatments used in adults overlap with those used in children and adolescents, the growing skeleton presents specific challenges that require a unique approach. Surgical treatment of benign osseous lesions typically requires only curettage and bone grafting, whereas that of osseous malignancies generally consists of wide excision and limb salvage, with either endoprosthetic or biologic reconstruction. Current conventional endoprostheses consist of modular components that allow intraoperative customization; however, if there is great potential for future growth, an expandable endoprosthesis may be required. Biologic reconstruction may consist of an allograft and/or autograft and, in some circumstances, can spare the growth plates in a child, thereby allowing normal growth. Expected posttreatment imaging findings in soft-tissue tumors may include muscle flaps and postoperative fluid collections. Medical treatment, including radiation therapy and chemotherapy, can have predictable imaging manifestations, including signal alterations in bone marrow, muscle, and subcutaneous fat. Finally, treatment complications may manifest with clinical symptoms and include infection or mechanical failure, although other complications such as local tumor recurrence may go clinically undetected until surveillance imaging. Familiarity with the expected posttreatment imaging findings in pediatric patients with musculoskeletal tumors can aid in the detection of complications.

Radiographical and clinical evaluation of critical size defects in rabbit calvaria filled with allograft and autograft: a pilot study

Regeneration of resorbed edentulous sites can be induced by bone grafts from the subject himself and/or by the use of biomaterials. At present, there has been an extensive search for biomaterials that are evaluated by artificially creating one or more critical defects. The aim of this work was to clinically and radiographically analyze bone formation by the use of some biomaterials in artificially created defects in the parietal bone of rabbits. Six rabbits were used, creating defects of 8 mm in diameter in parietal bones. One defect was maintained with coagulum only, and in others, freeze-dried bone allograft (FDBA), autologous bone, and a combination of autologous bone with FDBA respectively, were added. Animals were sacrificed at 15-90 days with 2 weeks interval each, and calvaria were analyzed macroscopically, measuring by digital caliper the lack of filling at the surface of defects, identifying limits at anteroposterior and coronal view, realizing a digital photograph register of their external surfaces. This was subsequently evaluated radiographically by occlusal film radiography used to quantify its density through software. In conclusion, autologous bone showed the best behavior, clinically as well as radiographically. However, FDBA is a good option as an alternative to autologous bone as its behavior was slightly lower over time. The combination of autologous bone and FDBA in the same defect showed results considerably inferior to grafts used separately. Low radiopacity and clear limits were observed through time for the control coagulum filled defect.

Use of a calcium sulfate-calcium phosphate synthetic bone graft composite in the surgical management of primary bone tumors

Benign primary bone tumors are commonly treated with intralesional curettage with or without the use of surgical adjuvants. The reconstructive approach to the resulting contained bone defects is controversial, and clinical practice is varied. Synthetic bone substitutes may provide early mechanical support while minimizing the risks of disease transmission, nonunion, infection, and donor-site morbidity. Limited data exists regarding the use of calcium sulfate-calcium phosphate composite bone substitute for this purpose. The authors retrospectively reviewed the clinical outcomes of 24 patients with benign primary bone tumors who underwent intralesional curettage followed by reconstruction with a calcium sulfate-calcium phosphate composite bone substitute. Mean follow-up was 23 months. The most common diagnosis was giant cell tumor of bone. Six patients had upper-extremity tumors and 18 had lower-extremity tumors. Mean preoperative radiographic tumor volume was 41.0 cm(3). Mean volume of PRO-DENSE (Wright Medical Technology, Arlington, Tennessee) used in each patient was 15.6 cm(3). Mean time to full weight bearing for all patients was 7.3 weeks. Two patients sustained local tumor recurrences. No postoperative fractures occurred, and no complications occurred related to the use of the calcium sulfate-calcium phosphate composite. One case of deep infection occurred secondary to wound breakdown. The use of a calcium sulfate-calcium phosphate composite was associated with rapid biological integration and an early return to activities of daily living, with no composite-related complications. This technique is a viable option in the reconstruction of cavitary bone defects following intralesional curettage of primary benign bone tumors.

Efficacy of injectable demineralized bone matrix as graft material during sinus elevation surgery with simultaneous implant placement in the posterior maxilla: clinical evaluation of 49 sinuses

PURPOSE

The purpose of the present retrospective investigation was to evaluate the survivability and success of single implants placed simultaneously during direct sinus lifts with allograft forms of bone and to investigate the effect demineralized bone matrix paste has on time management and membrane integrity during these procedures.

MATERIALS AND METHODS

The charts of 49 consecutively treated nonsmoking patients who had met the inclusion criteria were examined. All the patients had undergone unilateral direct sinus augmentation using the lateral window technique, during which only 1 implant (minimum 10 mm in length) was placed in the premolar or molar maxillary region. All implants were submerged using a 2-stage technique and with at least 3 mm of residual sinus floor bone height. The control group of 27 patients had received particulate allograft bone as the graft material, and the 22 test patients had received allograft bone in a paste form (DynaBlast). No implants were loaded before a minimum of 6 months from the date of fixture placement. All implant-supported single crowns in the present study had been functioning for at least 12 months. All patients were seen immediately after placement of the final crown and were requested to return to the surgeon's practice for 1 annual radiographic follow-up examination. The range of follow-up for these patients was 12 to 24 months based entirely on patient compliance. This interval constituted the loading time. The patients were not seen by the specialist in between the "final crown" appointment (original radiograph) and the "annual" follow-up evaluation (final radiograph). No patients experienced complications that required surgical re-entry. The average loading time for the control group was 13.62 months and was 18.77 months for the test group. The survivability and success of the implants were studied, along with the operative time, between the 2 groups. Statistical analysis was performed for various comparisons in the present study.

RESULTS

None of the fixtures placed in these patients failed. The success and survivability criteria as stated were met for all 49 implants, regardless of the allograft formulation used. The average operative time in the control group was 70.11 minutes and was 62.36 minutes in the test group. This difference was statistically significant (P < .05).

CONCLUSIONS

Using an injectable formulation of allograft material during simultaneous direct sinus lift and implant placement seems to be an acceptable alternative to particulate forms of allograft bone. In addition, when using the injectable graft evaluated in our study, a statistically significant 11% decrease in the operative time resulted.