The recycling of autoclaved autografts in mandibular reconstruction: case report and review of literature

Osteoformation potential of an allogenic partially demineralized bone matrix in critical-size defects in the rat calvarium

Allogenic demineralized bone matrix has been developed as a reliable alternative to the autologous bone graft. In the present study, we assessed the osteoformation potential of a partially demineralized bone matrix (PDBM) in a paste form obtained without an added carrier. This formulation included the preparation of cancelous bone from femoral heads after decellularision, delipidation, demineralization in HCl and autoclaving at 121 °C. Structural and biochemical characteristics of PDBM were determined using FTIR (Fourier transform infrared spectroscopy), hydroxyproline, DNA content assays, and optical ellipsometry. The osteoformation potential was evaluated in 8-, 6-, and 4-mm-diameter rat-calvarial bone defects by in vivo micro-CT analysis, performed immediately after surgery on days 0, 15, 30, 45, and 60. Moreover, histological and histomorphometric analyses were done on day 60. PDBM was compared to cancelous bone powder (BP) before its partial demineralization. The expression levels of selected inflammation-, angiogenesis-, and bone-related genes were also investigated by RT-PCR, 3, 7, and 14 days after surgery. Compared to the control group, the PDBM group exhibited a significant increase (p < 0.05) in radiopacity in 8-mm- and 6-mm-diameter defects at all time points tested. On day 60, the amount of newly-formed bone was greater (16 and 1.6 folds; p < 0.001; respectively) compared to that in control defects. No bone formation was observed in defects filled with BP regardeless of the size. In 8-mm-diameter defect, PDBM was effective enough to induce the upregulation of genes pertinent to inflammation (i.e., TNFα, IL-6, and IL-8), angiogenesis (i.e., VEGF, VWF), and osteogenesis (ALP, RUNX2, BGLAP, SP7) by day 3 after surgery. This study showed that the tested PDBM deeply influences the early critical events involved in bone regeneration and exhibits efficient osteoformation capacity, making it an attractive graft option for treating defects in periodontal and maxillofacial areas.

Efficacy of immediate replacement of cranial bone graft following drainage of intracranial empyema

OBJECTIVE Intracranial empyema is a life-threatening condition associated with a high mortality rate and residual deleterious neurological effects if not diagnosed and managed promptly. The authors present their institutional experience with immediate reimplantation of the craniotomy flap and clarify the success of this method in terms of cranial integrity, risk of recurrent infection, and need for secondary procedures. METHODS A retrospective analysis of patients admitted for management of intracranial empyema during a 19-year period (1997-2016) identified 33 patients who underwent emergency drainage and decompression with a follow-up duration longer than 6 months, 23 of whom received immediate bone replacement. Medical records were analyzed for demographic information, extent and location of the infection, bone flap size, fixation method, need for further operative intervention, and duration of intravenous antibiotics. RESULTS The mean patient age at surgery was 8.7 ± 5.7 years and the infections were largely secondary to sinusitis (52.8%), with the most common location being the frontal/temporal region (61.3%). Operative intervention involved removal of a total of 31 bone flaps with a mean surface area of 22.8 ± 26.9 cm². Nearly all (96.8%) of the bone flaps replaced at the time of the initial surgery were viable over the long term. Eighteen patients (78.3%) required a single craniotomy in conjunction with antibiotic therapy to address the infection, whereas the remaining 21.7% required more than 1 surgery. Partial bone flap resorption was noted in only 1 (3.2%) of the 31 successfully replaced bone flaps. This patient eventually had his bone flap removed and received a split-calvaria bone graft. Twenty-one patients (91.3%) received postoperative CT scans to evaluate bone integrity. The mean follow-up duration of the cohort was 43.9 ± 54.0 months. CONCLUSIONS The results of our investigation suggest that immediate replacement and stabilization of the bone flap after craniectomy for drainage of intracranial empyemas has a low risk of recurrent infection and is a safe and effective way to restore bone integrity in most patients.

Clinical and histological evaluation of increase in the residual ridge width using mineralized corticocancellous block allografts: A pilot study

Background. Lateral ridge augmentation is conventionally accomplished by means of autogenous bone grafts. However, due to its complications, the application of autogenous bone graft substitutes, e.g. mineralized corticocancellous allograft, is ecommended. Methods. In the present study, twelve patients were included, with insufficient alveolar ridge widths in the designated sites for dental implant placement. During the primary surgery, mineralized corticocancellous block allografts were fixed in deficient sites with titanium screws and resorbable collagen membranes were used to cover the blocks. After a period of six months, a flap was raised and variations in ridge width values was measured. Finally, a micro-biopsy was obtained from the sites for histologic investigation prior to preparing them for subsequent implant placement. Results. All the applied blocks were incorporated into the underlying bone except for one. A statistically significant difference was seen between the average ridge widths before placing the allografts compared with that of implant placement stage (2.62±1.02 mm vs. 7.75±1.63 mm, respectively). Vital bone tissue was detected in all the histological specimens obtained from the interface of blocks and the underlying bone. Conclusion. The results suggest that mineralized corticocancellous block allografts might be used as scaffolds for bone growth and ridge width augmentation.