Unexpected radiographic lucency following grafting of bone defects with calcium sulfate/tricalcium phosphate bone substitute

Application of osteoinductive calcium phosphate ceramics in giant cell tumor of the sacrum: report of six cases

This study aimed at evaluating the possibility and effectiveness of osteoinductive bioceramics to fill the tumor cavity following the curettage of sacral giant cell tumor (GCT). Six patients (four females and two males, 25–45 years old) underwent nerve-sparing surgery, in which the tumor was treated by denosumab, preoperative arterial embolization and extensive curettage. The remaining cavity was filled with commercial osteoinductive calcium phosphate (CaP) bioceramics, whose excellent osteoinductivity was confirmed by intramuscular implantation in beagle canine. All patients were followed by computed tomography (CT) scans postoperatively. According to the modified Neer criterion, five cases obtained Type I healing status, and one case had Type II. At the latest follow-up, no graft-related complications and local recurrence were found. The CT scan indicated a median time of healing initiation of 3 months postoperatively, and the median time for relatively complete healing was 12 months. The excellent bone regenerative ability of the ceramics was also confirmed by increased CT attenuation value, blurred boundary and cortical rim rebuilding. In conclusion, osteoinductive CaP bioceramics could be an ideal biomaterial to treat the large remaining cavity following extensive curettage of sacral GCT. However, further investigation with more cases and longer follow-up was required to confirm the final clinical effect.

Transforming the Degradation Rate of β-tricalcium Phosphate Bone Replacement Using 3-Dimensional Printing

BACKGROUND

β-Tricalcium phosphate (β-TCP) is one of the most common synthetic bone grafting materials utilized in craniofacial reconstruction; however, it is limited by a slow degradation rate. The aim of this study was to leverage 3-dimensional (3D) printing in an effort to accelerate the degradation kinetics of β-TCP.

METHODS

Twenty-two 1-month-old New Zealand white rabbits underwent creation of calvarial and alveolar defects, repaired with 3D-printed β-TCP scaffolds coated with 1000 μM of osteogenic agent dipyridamole. Rabbits were euthanized after 2, 6, and 18 months after surgical intervention. Bone regeneration, scaffold degradation, and bone mechanical properties were quantified.

RESULTS

Histological analysis confirmed the generation of vascularized and organized bone. Microcomputed tomography analysis from 2 to 18 months demonstrated decreased scaffold volume within calvarial (23.6% ± 2.5%, 5.1% ± 2.2%; P < 0.001) and alveolar (21.5% ± 2.2%, 0.2% ± 1.9%; P < 0.001) defects, with degradation rates of 54.6%/year and 90.5%/year, respectively. Scaffold-inducted bone generation within the defect was volumetrically similar to native bone in the calvarium (55.7% ± 6.9% vs 46.7% ± 6.8%; P = 0.064) and alveolus (31.4% ± 7.1% vs 33.8% ± 3.7%; P = 0.337). Mechanical properties between regenerated and native bone were similar.

CONCLUSIONS

Our study demonstrates an improved degradation profile and replacement of absorbed β-TCP with vascularized, organized bone through 3D printing and addition of an osteogenic agent. This novel additive manufacturing and tissue engineering protocol has implications to the future of craniofacial skeletal reconstruction as a safe and efficacious bone tissue engineering method.

Progressive Osteolysis After Use of Synthetic Bone Graft Substitute

Benign bone tumors are commonly treated with intralesional curettage and bone graft, with autogenous bone graft being the gold standard. However, autogenous bone graft has its limitation, and artificial bone graft substitutes were developed as an alternative. PRO-DENSE™ (Wright Medical Technology, Arlington, Tennessee) is a calcium sulfate and calcium phosphate mixed bone graft substitute that is biodegradable and osteoconductive, which has made them a popular choice among surgeons. However, long-term studies of this treatment method for benign tumors are still limited.

In this report, we present a case of progressive femoral neck osteolysis caused by an inflammatory reaction to PRO-DENSE™ two years after intralesional curettage and bone grafting of a benign bone tumor. 

A twenty-one-year-old female with fibrous dysplasia underwent intralesional curettage with the use of PRO-DENSE™ bone substitute to fill the cavitary defect. She developed an inflammatory reaction to the bone graft substitute leading to increasing pain and osteolysis requiring a reoperation.

Bone graft substitute has many advantages; however, they should be used with discretion due to many unknown regarding their safety and long-term outcomes.

Bone Healing and Regeneration Potential in Rabbit Cortical Defects Using an Innovative Bioceramic Bone Graft Substitute

This study aimed to elucidate the local effect and micro-computed tomographic (μ-CT) assessment following bone implantation of an innovative bioceramic (α-calcium sulfate hemihydrate; α-CSH) on femur lateral condyle cortical bone of rabbit models. The innovative α-CSH bioceramic was synthesized through a green processing technology (microwave irradiation treatment). The bilateral implantation model was performed among 24 New Zealand White rabbits which were divided into three groups based on the type of filling materials: α-CSH, control, and blank. Treatments were performed in defects with 6 mm diameter and 7 mm depth and observed after 2, 4, 8, and 12 weeks. Material reaction and bone formation after implantation were evaluated radiographically and histopathologically. The μ-CT analysis results showed that the degradation of α-CSH and control material was similar at 4 and 8 weeks. The bone volume in the defects indicated the α-CSH increased most in 8 weeks. In histopathological evaluation, the α-CSH group was repaired with lamellar bone and well-grown bone marrow infiltration similar to the control material. Moreover, the α-CSH revealed a faster degradation rate and better healing progress than the control material under the same conditions. Therefore, the α-CSH was confirmed to be useful in promoting osteoconduction and in controlling the resorption rate in bone defects. Further, the innovative α-CSH could be considered as a promising bone substitute for utilization in bone reconstructive therapy in dental and orthopedic fields.

Early postoperative compilations of bone filling in curettage defects

Background

Curettage is widely used in orthopedic oncology; the defect created frequently requires filling for mechanical and functional stability for the bones and adjacent joint. Allograft, bone graft substitute, and polymethyl methacrylate (PMMA) are the most common substances used each with their benefits and drawbacks. The aim of the study is to show that good functional result can be achieved with curettage and bone filler, regardless of type.

Methods

A series of 267 cases were reviewed between 1994 and 2015 who received curettage treatment and placement of a bone filler. Endpoints included fracture, infection, cellulitis, pulmonary embolism, and paresthesia. Complication rates at our single institution were compared against literature values for three study cohorts: allograft, bone graft substitute, and PMMA bone fillers. Friedman test, Wilcoxon test, and Z-score for two populations were used to compare our subset against literature values and between different bone filling types.

Results

Our cases included 18 autografts, 74 allografts, 121 bone graft substitute, and 54 PMMA of which the bulk of complications occurred. Our overall complication rate was 3.37%. Allograft has a complication rate of 1.35%, bone graft substitute of 4.13%, and PMMA of 5.56%. Other techniques did not yield any complications. Combination filling techniques PMMA + allograft and PMMA + bone graft substitute had sample sizes too small for statistical comparison. Statistical comparison yielded no significant difference between complications in any of the filling groups (P = 0.411).

Conclusions

Some has even argued that bone defects following curettage do not require bone filling for good outcome. However, many structural or biologic benefits that aid in earlier return to functionality can be conferred by filling large bone defects. There was no significant difference in postoperative complication rates between allograft, bone graft substitute, and PMMA when compared at our institution and with literature values. Nevertheless, one complication with a large defect filled with allograft, requiring a subsequent reconstruction using vascularized fibular graft. Taking everything into account, we see bone graft substitute as a suitable alternative to other bone filling modalities.

Sinus Tract Formation with Chronic Inflammatory Cystic Mass after Beta Tricalcium Phosphate Insertion

Beta tricalcium phosphate (β-TCP) is one of allogenic bone substitute which is known to have interconnected pores that draws cell and nutrients for bone generation. It has been resulted in good outcomes for bone defect coverage or augmentation. However, several studies have also reported negative outcomes and associated complications including unexpected formation of cystic mass, continuous pain and secretion. We present the case of a 36-year-old man with a right cheek cystic mass who had a history of right zygomaticomaxillary (ZM) complex fracture and surgical correction with β-TCP powder insertion to ZM bone defect. Excisional biopsy under local anesthesia revealed calcified mass in a sinus tract which was found to be connected to the ZM bone defect site in postoperative computed tomography image. Further excision under general anesthesia was performed to remove the sinus tract and fine granules which filled the original defect site. Pathologic report revealed bony spicules and calcification materials with chronic foreign body reaction. Postoperative complications and recurrence were not reported.