Comparison of bone dust with other types of bone grafts for cranioplasty

Autologous Cranioplasty Using a Dental SafeScraper Device

SUMMARY

Conventional methods to reconstruct cortical bone defects introduced by pediatric cranial vault remodeling (CVR) procedures have shortcomings. Use of bone burr shavings as graft material leads to variable ossification, and harvesting split-thickness cortical grafts is time-intensive and often not possible in thin infant calvaria. Since 2013, the authors' team has used the SafeScraper, originally developed as a dental instrument, to harvest cortical and cancellous bone grafts during CVR. The authors assessed the effectiveness of this technique by analyzing postoperative ossification using computed tomography scans of 52 patients, comparing cohorts treated with the SafeScraper versus those who received conventional methods of cranioplasty during fronto-orbital advancement. The SafeScraper cohort had a greater reduction in total surface area of all defects (-83.1% ± 14.9 versus -68.9% ± 29.8; P = 0.034), demonstrating a greater and more consistent degree of cranial defect ossification compared with conventional methods of cranioplasty, suggesting potential adaptability of this tool. This is the first study that describes the technique and efficacy of the SafeScraper in reducing cranial defects in CVR.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Long-term follow-up for ossification of autologous bone plug and skin sinking after periosteum-preserved burr hole surgery

Background:

The demand of a burr hole surgery for chronic subdural hematoma (CSDH) is increasing in the global aging society. Burr hole-derived autologous bone dusts are not associated with extra costs compared with other commonly used synthetic materials. In addition, postoperative calvarium ossification requires periosteum-mediated blood supply, which is lacking after using avascular synthetic materials. Based on these findings, we hypothesized that the combination of the bone plugs and the preserved periosteum during burr hole surgeries for CSDH would induce efficient calvarium ossification.

Methods:

We evaluated the long-term effects of bone plugs on the degree of ossification and cosmetic appearance of the skin covering the burr hole sites. We included 8 patients (9 burr holes) who received the autologous bone dust derived from burr holes. As the control group, 9 burr holes that did not receive any burr hole plugs were retrospectively selected. These burr holes were evaluated by computed tomography (CT) scan for the calvarium defect ratios, CT value-based ossification, and the degree of skin sinking.

Results:

Ossification was observed in all the bone plugs by the bone density CT scans; they maintained their volume at 12 months after the surgeries. The calvarium defect ratios (volume ratios of the unossified parts in the burr holes) gradually increased during the first 6 months and reached 0.44 at 12 months. The mean CT values also increased from 527 HU to 750 HU for the first 6 months and reached 905 HU at 12 months. The degrees of skin sinking at the burr hole sites with the bone plugs were 1.24 mm whereas those without the bone plugs were 2.69 mm (P = 0.004).

Conclusion:

Application of burr hole-derived autologous bone dust is associated with better ossification and objective cosmetic result following burr hole surgery after CSDH.

The Efficacy of Local Autologous Bone Dust: A Systematic Review

STUDY DESIGN

A systematic review of bone dust as an autologous bone graft to encourage osseous fusion.

OBJECTIVE

To identify and review studies that report on the therapeutic potential of bone dust. The research question was structured as follows: populations-animal and human sources of bone dust harvested using burrs; interventions-autologous bone dust compared with other clinically utilized bone graft options; outcomes assessed-(1) in vitro cell viability, cell differentiation, and osteogenic potential and (2) clinical efficacy in the form of fusion rates as assessed using plain radiographs; study designs-in vitro, preclinical in vivo and clinical studies investigating the therapeutic potential of bone dust, harvested by burring, are included in this systematic review.

SUMMARY OF BACKGROUND DATA

Little is known about the efficacy of bone dust, generated during burring of local bone in spine surgery, as a bone graft to encourage osseous union.

METHODS

A systematic search was conducted in Medline, PubMed, OVID, Scopus, and Cochrane library. The following key words were used: bone dust, bone burring, bone paste, bone pate.

RESULTS

A total of 285 studies were reviewed. Fourteen articles were identified as relevant for inclusion in this systematic review. Current evidence suggests that bone dust retains osteogenic properties, but limited information is available regarding the osteoinductive potential of bone dust.

CONCLUSION

Bone dust represents a free source of autologous bone, which can be easily collected during the time of surgery and used as an augment to aid osseous fusion. Further research is required to evaluate the osteoinductive potential of bone dust. The retained growth factors in bone dust may potentially induce local osteoprogenitor cells to proliferate and mineralize to form new bone.

Advantages of Calvarial Vault Distraction for the Late Treatment of Cephalocranial Disproportion

PURPOSE

Cephalocranial disproportion is a symptomatic condition related to a volume discrepancy between the calvarial vault and the brain. Traditional expansion techniques are unfavorable in older children due to inadequate dural ossification, lack of bone pliability, and limited future growth potential. The authors review their experience using distraction to close bone defects in this setting.

METHODS

A retrospective analysis was performed of all patients treated using distraction in this setting by a single surgeon. Demographic and outcomes data were collected. The efficacy of ossification of bone defects after expansion by distraction was measured using volume analysis of three-dimensional computed tomography (CT) scans. This required a CT scan at the completion of device activation and a follow-up CT scan 6 months or more beyond activation.

RESULTS

Sixteen patients (17 distractions) met the imaging-based inclusion criteria. The average age at surgery was 3.97 (2.14-6.89) years. The mean initial bone defect volume after asymmetric transverse distraction was 7.26 (5.45-13.73) mL. The mean final defect volume was 2.18 (0.00-5.90) mL with a mean change of 5.08 (1.21-12.79) mL and mean interval time of 27.85 (7.13-56.39) months. This represents a mean percent defect closure of 72.30 (20.38-100.00).

CONCLUSION

Distraction osteogenesis is a very effective tool for treating the older child with cephalocranial disproportion. The ability to ossify the bone defects without a donor site provides a considerable advantage in these patients.