A rare case of psammomatoid ossifying fibroma in the sphenoid bone reconstructed using autologous particulate exchange cranioplasty

Giant fronto-spheno-orbitary juvenile psammomatoid ossifying fibroma: Case report and literature review

Juvenile psammomatoid ossifying fibroma (JPOF) is an osteofibrous neoplasm that originates in the craniofacial skeleton typically during the first three decades of life. JPOFs usually involve the orbit, paranasal sinuses or the jaws. Extensive involvement of the anterior cranial base with compromised visual function is a rare phenomenon. In such clinical context, a definite diagnosis can only be made on the basis of histopathological findings, given the absence of pathognomonic radiological features. Despite being considered a benign entity, JPOFs present a locally aggressive behavior. Therefore, these neoplasms must be included in the differential diagnosis in every patient harboring a skull base osteofibrous lesion, and, once diagnosed, gross total surgical removal should be attempted. In this study, we present our experience in the diagnosis and treatment of a patient diagnosed with a giant JPOF involving the cranial base.

Spheno-orbital juvenile psammomatoid ossifying fibroma: a case report and literature review

Ossifying fibroma (OF) is an uncommon benign fibro-osseous lesion. Based on its clinical, morphological, and radiological features, OF is further divided into cemento-ossifying fibroma (COF), juvenile psammomatoid ossifying fibroma (JPOF), and juvenile trabecular ossifying fibroma (JTOF). JPOF rarely involves the cranial base, with limited reports published on spheno-orbital JPOF. In this paper, we report a case of JPOF of the greater wing of the sphenoid bone and lateral orbital wall in an 11-year-old child and show a surgical video. Although rare, JPOF should be considered in the differential diagnosis of fibro-osseous lesions of the spheno-orbital region.

An Experimental Study of Particulate Bone Graft for Secondary Inlay Cranioplasty Over Scarred Dura

BACKGROUND

Inlay cranioplasty in children is challenging because autologous bone is limited. Cranial particulate bone graft effectively closes defects when placed over normal dura. The purpose of this study was to determine if particulate bone graft will ossify when used for secondary cranioplasty over scarred dura.

METHODS

A 17 × 17-mm critical-sized defect was made in the parietal bone of 16 rabbits. Four animals had no implant (group 1). Twelve animals had the defect remade 16 weeks postoperatively, which was managed in 2 ways: group 2 (no implant; n = 6) and group 4 (particulate bone graft; n = 6). Particulate graft was obtained using a brace and bit from the frontal bone. Computed tomography was used to determine the area of ossification and thickness of the healed graft. Eight animals previously managed with particulate bone graft over normal dura were used as an additional control (group 3).

RESULTS

Critical-sized defects filled with particulate bone graft over scarred dura (group 4) exhibited superior healing of the area (83.8%; range, 73.0%-90.6%) compared to control defects over normal dura (group 1: 62.9%; range, 56.5%-73.4%) or scarred dura (group 2: 56.9%; range, 40.0%-68.3%) (P = 0.0004). Particulate bone on scarred dura exhibited less ossified area (P = 0.002), and thinner bone (0.95 mm, range, 0.71-1.32 mm) compared to defects in which graft was placed over normal dura (group 3: area, 99.2%; range, 96.8%-100%; thickness, 1.9 mm, range; 1.1-3.1 mm) (P = 0.04).

CONCLUSIONS

Particulate bone graft ossifies inlay cranial defects over scarred dura although inferior to placement over normal dura. Clinically, particulate bone graft may be used for secondary inlay cranioplasty.

Experimental Comparison of Cranial Particulate Bone Graft, rhBMP-2, and Split Cranial Bone Graft for Inlay Cranioplasty

Background

Particulate bone graft and recombinant human bone morphogenetic protein-2 (rhBMP-2) are options for inlay cranioplasty in children who have not developed a diploic space. The purpose of this study was to determine whether particulate bone graft or rhBMP-2 has superior efficacy for inlay cranioplasty and to compare these substances to split cranial bone.

Methods

A 17 mm × 17 mm critical-sized defect was made in the parietal bones of 22 rabbits and managed in four ways: Group I (no implant; n=5), Group II (particulate bone graft; n=5), Group III (rhBMP-2; n=7), and Group IV (split cranial bone graft; n=5). Animals underwent microcomputed tomography and histologic analysis 16 weeks after cranioplasty.

Results

Defects without an implant (Group I) demonstrated inferior ossification (41.4%; interquartile range [IQR], 28.9% to 42.5%) compared to those treated with particulate bone graft (Group II: 99.5%; IQR, 97.8% to 100%), rhBMP-2 (Group III: 99.6%; IQR, 99.5% to 100%), or split cranial bone (Group IV: 100%) ( P < .0001). There was no difference between Groups II, III, and IV ( P = .1). Defects treated with rhBMP-2 exhibited thinner bone (0.90 mm; IQR, 0.64 to 0.98) than particulate bone graft (1.95 mm; IQR, 1.09 to 2.83) or split cranial bone (1.72 mm; IQR, 1.54 to 1.88) ( P = .006); particulate and split cranial bone grafted defects had a similar thicknesses ( P = .6).

Conclusions

Particulate bone graft, rhBMP-2, and split cranial bone close inlay calvarial defect areas equally, although the thickness of bone healed with rhBMP-2 is inferior. Clinically, particulate bone graft or split cranial bone graft may be superior to rhBMP-2 for inlay cranioplasty.