Processed versus fresh frozen bone for impaction bone grafting in revision hip arthroplasty

Revision of Total Hip Arthroplasty with Acetabular Bone Defects: Are Biological Grafts Really Better than Synthetic Bone Graft Substitutes?

BACKGROUND

Acetabular aseptic loosening due to bone defect in total hip arthroplasty revisions is a great challenge and several solutions have been proposed, but a broadly accepted consensus in the literature has not been reached yet. The aim of this study is to compare the clinical and radiographic results of acetabular bone defects treatment with biological-only graft or with a mixture of bone graft substitute and biological graft.

METHODS

33 patients had revision hip arthroplasty using impaction grafting with biological-only graft (21 patients, Group A) or a 1/3 mixture of allograft and tricalcium phosphate bone graft substitute (12 patients, Group B). Patients were reassessed at a minimum of one year after surgery with new x-rays and the Harris Hip Score (HHS).

RESULTS

Survivorship of bone graft was 86% in Group A and 100% in Group B at a mean follow-up of 35 months. No statistical difference between the two groups was found in terms of implants survivorship (P=0.28), clinical (P=0.08) or radiographic (P=0.27) outcomes.

CONCLUSION

In our experience the use of tricalcium phosphate bone graft substitutes in combination with allo and autograft provides good outcomes, low risk of failure and great clinical and radiographic results. Further investigations on larger samples are needed to impact clinical practice.

Clinical trial and in-vitro study comparing the efficacy of treating bony lesions with allografts versus synthetic or highly-processed xenogeneic bone grafts

Background

Our study aim was to compare allogeneic cancellous bone (ACB) and synthetic or highly-processed xenogeneic bone substitutes (SBS) in the treatment of skeletal defects in orthopedic surgery.

Methods

232 patients treated for bony lesions with ACB (n = 116) or SBS (n = 116) within a 10-year time period were included in this case–control study. Furthermore, both materials were seeded with human osteoblasts (hOB, n = 10) and analyzed by histology, for viability (AlamarBlue®) and protein expression activity (Luminex®).

Results

The complication rate was 14.2 %, proportion of defects without bony healing 3.6 %; neither outcome parameter differed comparing the intervention groups. Failed consolidation correlated with an increase in complications (p < 0.03). The rate of complications was further highly significant in association with the location of use (p < 0.001), but did not depend on age, ASA risk classification, BMI, smoking behavior or type of insurance. However, those factors did significantly influence the bony healing rate (p < 0.02). Complication and consolidation rates were independent of gender and the filling substances employed within the different locations. Histological examination revealed similar bone structures, whereas cell remnants were apparent only in the allografts. Both materials were biocompatible in-vitro, and seeded with human osteoblasts. The cells remained vital over the 3-week culture period and produced microscopically typical bone matrix. We observed initially increased expression of osteocalcin, osteopontin, and osteoprotegerin as well as leptin and adiponectin secretion declining after 1 week, especially in the ACB group.

Conclusion

Although both investigated materials appeared to be similarly suitable for the treatment of skeletal lesions in-vivo and in-vitro, outcome was decisively influenced by other factors such as the site of use or epidemiological parameters.

Horizontal Resorption of Fresh-Frozen Corticocancellous Bone Blocks in the Reconstruction of the Atrophic Maxilla at 5 Months

Background

Reliable implant-supported rehabilitation of an alveolar ridge needs sufficient volume of bone. In order to achieve a prosthetic-driven positioning, bone graft techniques may be required.

Purpose

This prospective cohort study aims to clinically evaluate the amount of resorption of corticocancellous fresh-frozen allografts bone blocks used in the reconstruction of the severe atrophic maxilla.

Materials and Methods

Twenty-two partial and totally edentulous patients underwent bone augmentation procedures with fresh-frozen allogenous blocks from the iliac crest under local anesthesia. Implants were inserted into the grafted sites after a healing period of 5 months. Final fixed prosthesis was delivered ± 4 months later. Ridge width analysis and measurements were performed with a caliper before and after grafting and at implant insertion. Bone biopsies were performed in 16 patients.

Results

A total of 98 onlay block allografts were used in 22 patients with an initial mean alveolar ridge width of 3.41 ± 1.36 mm. Early exposure of blocks was observed in four situations and one of these completely resorbed. Mean horizontal bone gain was 3.63 ± 1.28 mm (p < .01). Mean buccal bone resorption between allograph placement and the reopening stage was 0.49 ± 0.54 mm, meaning approximately 7.1% (95% confidence interval: [5.6%, 8.6%]) of total ridge width loss during the integration period. One hundred thirty dental implants were placed with good primary stability (≥ 30 Ncm). Four implants presented early failure before the prosthetic delivery (96.7% implant survival). All patients were successfully rehabilitated. Histomorphometric analysis revealed 20.9 ± 5.8% of vital bone in close contact to the remaining grafted bone. A positive strong correlation (adjusted R² = 0.44, p = .003) was found between healing time and vital bone percentage.

Conclusions

Augmentation procedures performed using fresh-frozen allografts from the iliac crest are a suitable alternative in the reconstruction of the atrophic maxilla with low resorption rate at 5 months, allowing proper stability of dental implants followed by fixed prosthetic rehabilitation.

The pyrolytic profile of lyophilized and deep-frozen compact part of the human bone

Background. Bone grafts are used in the treatment of nonunion of fractures, bone tumors and in arthroplasty. Tissues preserved by lyophilization or deep freezing are used as implants nowadays. Lyophilized grafts are utilized in the therapy of birth defects and bone benign tumors, while deep-frozen ones are applied in orthopedics. The aim of the study was to compare the pyrolytic pattern, as an indirect means of the analysis of organic composition of deep-frozen and lyophilized compact part of the human bone. Methods. Samples of preserved bone tissue were subjected to thermolysis and tetrahydroammonium-hydroxide- (TMAH-) associated thermochemolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS). Results. Derivatives of benzene, pyridine, pyrrole, phenol, sulfur compounds, nitriles, saturated and unsaturated aliphatic hydrocarbons, and fatty acids (C12–C20) were identified in the pyrolytic pattern. The pyrolyzates were the most abundant in derivatives of pyrrole and nitriles originated from proteins. The predominant product in pyrolytic pattern of the investigated bone was pyrrolo[1,2-α]piperazine-3,6-dione derived from collagen. The content of this compound significantly differentiated the lyophilized graft from the deep-frozen one. Oleic and palmitic acid were predominant among fatty acids of the investigated samples. The deep-frozen implants were characterized by higher percentage of long-chain fatty acids than lyophilized grafts.

Secondary bone grafting for alveolar cleft in children with cleft lip or cleft lip and palate

BACKGROUND

Secondary alveolar bone grafting has been widely used to reconstruct alveolar cleft. However, there is still some controversy.

OBJECTIVES

To compare the effectiveness and safety of different secondary bone grafting methods.

SEARCH STRATEGY

The final electronic and handsearches were carried out on 11 February 2011, and included the Cochrane Oral Health Group's Trials Register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Chinese Biomedical Literature Database and WHO International Clinical Trials Registry Platform. All the Chinese professional journals in the oral and dental field were handsearched and conference proceedings consulted. There was no language or time restriction.

SELECTION CRITERIA

Only randomized clinical trials were selected. Patients with the diagnosis of cleft lip and alveolar process only, unilateral cleft lip and palate and bilateral cleft lip and palate involving the alveolar process and greater than 5 years of age were included.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and assessed the quality of included studies independently. Disagreement between the two review authors was resolved by discussion in the review team. The first authors of the included studies were contacted for additional information, if necessary.

MAIN RESULTS

Two of 582 potential studies met the inclusion criteria and were included. One trial compared alveolar bone grafting using artificial materials (InFuse bone graft substitute impregnated with BMP-2) with a traditional iliac graft. The other trial investigated the application of fibrin glue to the bone graft. Both trials were small with 21 and 27 patients and were assessed as being at high risk of bias. Any apparent differences between the interventions for outcomes in either study must therefore be treated with great caution and are not highlighted here.

AUTHORS' CONCLUSIONS

Due to the high level of risk of bias in the two included trials there is insufficient evidence to conclude that one intervention is superior to another.