Allograft Bone Use in Pediatric Subaxial Cervical Spine Fusions

Autologous rib grafts for craniocervical junction surgery in children: a clinical application

OBJECTIVE

Autologous iliac bone is commonly used as a bone graft material to achieve solid fusion in craniocervical junction (CVJ) surgery. However, the developing iliac bone of children is less than ideal as a bone graft material. The matured rib bone of children presents a potential substitute material for iliac bone. The aim of this study was to evaluate the efficacy of autologous rib grafts for craniocervical junction surgery in children.

METHODS

The outcomes of 10 children with abnormalities of the craniocervical junction who underwent craniocervical junction surgery between January 2020 and December 2022 were retrospectively reviewed. All patients underwent posterior fusion and internal fixation surgery with autologous rib grafts. Pre- and post-operative images were obtained and clinical follow-ups were conducted to evaluate neurological function, pain level, donor site complications, and bone fusion rates.

RESULTS

All surgeries were successful. During the 8- to 24-month follow-up period, all patients achieved satisfactory clinical results. Computed tomography at 3-6 months confirmed successful bone fusion and regeneration of the rib defect in all patients with no neurological or donor site complications.

CONCLUSION

Autologous rib bone is a safe and effective material for bone grafting in craniocervical junction fusion surgery for children that can reduce the risks of donor site complications and increase the amount of bone graft, thereby achieving a higher bone fusion rate.

Novelties for increased safety in cranio-vertebral surgery: a review

The cranio-vertebral junction (CVJ) was formerly considered a surgical "no man's land" due to its complex anatomical and biomechanical features. Surgical approaches and hardware instrumentation have had to be tailored in order to achieve successful outcomes. Nowadays, thanks to the ongoing development of new technologies and surgical techniques, CVJ surgery has come to be widely performed in many spine centers. Accordingly, there is a drive to explore novel solutions and technological nuances that make CVJ surgery safer, faster, and more precise. Improved outcome in CVJ surgery has been achieved thanks to increased safety allowing for reduction in complication rates. The Authors present the latest technological advancements in CVJ surgery in terms of imaging, biomaterials, navigation, robotics, customized implants, 3D-printed technology, video-assisted approaches and neuromonitoring.

Advances in the Study of Bionic Mineralized Collagen, PLGA, Magnesium Ionomer Materials, and Their Composite Scaffolds for Bone Defect Treatment

The healing of bone defects after a fracture remains a key issue to be addressed. Globally, more than 20 million patients experience bone defects annually. Among all artificial bone repair materials that can aid healing, implantable scaffolds made from a mineralized collagen (MC) base have the strongest bionic properties. The MC/PLGA scaffold, created by adding Poly (lactic-co-glycolic acid) copolymer (PLGA) and magnesium metal to the MC substrate, plays a powerful role in promoting fracture healing because, on the one hand, it has good biocompatibility similar to that of MC; on the other hand, the addition of PLGA provides the scaffold with an interconnected porous structure, and the addition of magnesium allows the scaffold to perform anti-inflammatory, osteogenic, and angiogenic activities. Using the latest 3D printing technology for scaffold fabrication, it is possible to model the scaffold in advance according to the requirement and produce a therapeutic scaffold suitable for various bone-defect shapes with less time and effort, which can promote bone tissue healing and regeneration to the maximum extent. This study reviews the material selection and technical preparation of MC/PLGA scaffolds, and the progress of their research on bone defect treatment.

Comparison of structural occipital and iliac bone grafts for instrumented atlantoaxial fusions in pediatric patients: Radiologic research and clinical outcomes

Background

Structural autografts harvested from the iliac bone have been used in atlantoaxial fusion; they have been the gold standard for years. However, emerging occipital bone grafts have the advantage of avoiding donor-site morbidity and complications. Thus, we compared the clinical outcomes of structural autografts from the occipital bone or iliac crest and discussed the clinical significance of occipital bone grafts in pediatric patients.

Methods

Pediatric patients who underwent posterior fusion using occipital bone grafts (OBG) or iliac bone grafts (IBG) between 2017 and 2021 were included in this study. Data on clinical outcomes, including operation time, estimated blood loss, length of hospitalization, complications, fusion rate, and fusion time, were collected and analyzed. Additionally, 300 pediatric patients who underwent cranial computed tomography scans were included in the bone thickness evaluation procedure. The central and edge thicknesses of the harvested areas were recorded and analyzed.

Results

Thirty-nine patients were included in this study. There were no significant differences in patient characteristics between the OBG and IBG groups. Patients in both groups achieved a 100% fusion rate; however, the fusion time in the OBG group was significantly longer than that in the IBG group. Estimated blood loss, operation time, and length of hospitalization were significantly lower in the OBG group than those in the IBG group. The surgery-related complication rate was lower, but not significantly, in the OBG group than that in the IBG group. For occipital bone thickness evaluation, a significant difference in the central part of the harvesting area was found between the young and old groups, with no significant sex differences.

Conclusion

The use of OBG for atlantoaxial fusion is acceptable for pediatric patients with atlantoaxial dislocation, avoiding donor-site morbidity and complications.

Pediatric Spine Trauma: A Brief Review

Pediatric spinal trauma is a broad topic with nuances specific to each anatomic region of the spinal column. The purpose of this report is to provide a brief review highlighting the most important and common clinical issues regarding the diagnosis and management of pediatric spine trauma. Detailed descriptions of imaging findings along with specific operative and nonoperative management of each fracture and dislocation type are beyond the scope of this review.

Treatment of chronic bilateral facet dislocation in a 6-year-old: A case report

Objectives:

Spine injuries seldom affect the subaxial spine in children less than 9 years of age. We describe the management of a chronic paediatric bilateral facet dislocation.

Methods:

Case report and literature review. A 6-year-old boy presented 10 weeks after a motor vehicle collision with bilateral C4–C5 malunited facet dislocation. He had an incomplete spinal cord injury; right brown sequard hemiplegia, Frankel grade D.

Results:

Surgical management was through posterior–anterior–posterior approach without preoperative skull traction. Two years postoperatively, the child was asymptomatic, ambulating and functioning well. The injury had healed in radiographs.

Conclusion:

A combined approach for chronic bilateral facet dislocation applies to the paediatric age group to realign the spine.

Vertebroplasty Using Allograft Bone Chips with Posterior Instrumented Fusion in the Treatment of Osteoporotic Vertebral Fractures with Neurological Deficits

Introduction

In general, osteoporotic vertebral fractures with neurological deficits require surgery. However, the ideal surgical method remains controversial. We evaluated the efficacy of combining posterior instrumented fusion and vertebroplasty using allograft bone chips.

Methods

Twelve patients (five men, seven women; age 68-84 years, mean age 75.9 years) with osteoporotic vertebral fractures with neurological deficits were reviewed retrospectively. They underwent posterior instrumented fusion and vertebroplasty, using allograft bone, at our institution between January 2007 and June 2016. We assessed the surgical results, radiologically and neurologically, after a mean follow-up of 37.3 months.

Results

The mean local kyphosis angle was 10° before surgery, −3.3° immediately after surgery, and 4.4° at follow-up. The average spinal canal compromise was 26.9% before surgery and 19.5% at follow-up. All patients achieved bony fusion and none needed additional surgery. All patients improved by at least one grade on the modified Frankel grading system.

Conclusions

Combining vertebroplasty, using allograft bone chips, and posterior instrumented fusion appears to be an effective option for osteoporotic vertebral fractures with neurological deficits.

Orthobiologics in Pediatric Orthopedics

Orthobiologics are biologic devices or products used in orthopedic surgery to augment or enhance bone formation. The use of orthobiologics in pediatric orthopedics is less frequent than in other orthopedic subspecialties, mainly due to the naturally abundant healing potential and bone formation in children compared with adults. However, orthobiologics are used in certain situations in pediatric orthopedics, particularly in spine and foot surgery. Other uses have been reported in conjunction with specific procedures involving the tibia and pelvis. The use of bioabsorable implants to stabilize children's fractures is an emerging concept but has limited supporting data.

Structural Allograft versus Autograft for Instrumented Atlantoaxial Fusions in Pediatric Patients: Radiologic and Clinical Outcomes in Series of 32 Patients

BACKGROUND

Allograft with wire techniques showed a low fusion rate in pediatric atlantoaxial fusions (AAFs) in early studies. Using allograft in pediatric AAFs with screw/rod constructs has not been reported. Thus we compared the fusion rate and clinical outcomes in pediatric patients who underwent AAFs with screw/rod constructs using either a structural autograft or allograft.

METHODS

Pediatric patients (aged ≤12 years) who underwent AAFs between 2007 and 2015 were retrospectively evaluated. Patients were divided into 2 groups (allograft or autograft). Clinical and radiographic results were collected from hospital records and compared.

RESULTS

A total of 32 patients were included (18 allograft, 14 autograft). There were no significant group differences in age, sex, weight, diagnosis, or duration of follow-up. A similar fusion rate was achieved (allograft: 94%, 17/18; autograft: 100%, 14/14); however, the average fusion time was 3 months longer in the allograft group. Blood loss was significantly lower in the allograft group (68 ± 8.5 mL) than the autograft group (116 ± 12.5 mL). Operating time and length of hospitalization were slightly (nonsignificantly) shorter for the allograft group. A significantly higher overall incidence of surgery-related complications was seen in the autograft group, including a 16.7% (2/14) rate of donor-site-related complications.

CONCLUSIONS

The use of allograft for AAF was safe and efficacious when combined with rigid screw/rod constructs in pediatric patients, with a similar fusion rate to autografts and an acceptable complication rate. Furthermore, blood loss was less when using allograft and donor-site morbidity was eliminated; however, the fusion time was increased.

Bone substitutes and expanders in Spine Surgery: A review of their fusion efficacies

STUDY DESIGN

A narrative review of literature.

OBJECTIVE

This manuscript intends to provide a review of clinically relevant bone substitutes and bone expanders for spinal surgery in terms of efficacy and associated clinical outcomes, as reported in contemporary spine literature.

SUMMARY OF BACKGROUND DATA

Ever since the introduction of allograft as a substitute for autologous bone in spinal surgery, a sea of literature has surfaced, evaluating both established and newly emerging fusion alternatives. An understanding of the available fusion options and an organized evidence-based approach to their use in spine surgery is essential for achieving optimal results.

METHODS

A Medline search of English language literature published through March 2016 discussing bone graft substitutes and fusion extenders was performed. All clinical studies reporting radiological and/or patient outcomes following the use of bone substitutes were reviewed under the broad categories of Allografts, Demineralized Bone Matrices (DBM), Ceramics, Bone Morphogenic proteins (BMPs), Autologous growth factors (AGFs), Stem cell products and Synthetic Peptides. These were further grouped depending on their application in lumbar and cervical spine surgeries, deformity correction or other miscellaneous procedures viz. trauma, infection or tumors; wherever data was forthcoming. Studies in animal populations and experimental in vitro studies were excluded. Primary endpoints were radiological fusion rates and successful clinical outcomes.

RESULTS

A total of 181 clinical studies were found suitable to be included in the review. More than a third of the published articles (62 studies, 34.25%) focused on BMP. Ceramics (40 studies) and Allografts (39 studies) were the other two highly published groups of bone substitutes. Highest radiographic fusion rates were observed with BMPs, followed by allograft and DBM. There were no significant differences in the reported clinical outcomes across all classes of bone substitutes.

CONCLUSIONS

There is a clear publication bias in the literature, mostly favoring BMP. Based on the available data, BMP is however associated with the highest radiographic fusion rate. Allograft is also very well corroborated in the literature. The use of DBM as a bone expander to augment autograft is supported, especially in the lumbar spine. Ceramics are also utilized as bone graft extenders and results are generally supportive, although limited. The use of autologous growth factors is not substantiated at this time. Cell matrix or stem cell-based products and the synthetic peptides have inadequate data. More comparative studies are needed to evaluate the efficacy of bone graft substitutes overall.