Titanium mesh cranioplasty in pediatric patients after decompressive craniectomy: Appropriate timing for pre-schoolers and early school age children

Spontaneous fracture of a titanium mesh cranioplasty implant in a child: A case report

BACKGROUND

Titanium mesh cranioplasty is often performed after decompressive craniectomy. Spontaneous fracture of the titanium prosthesis is an extremely rare postoperative complication. Here, we report a 10-year-old boy who presented with a spontaneous fracture of titanium mesh without antecedent head trauma.

CASE SUMMARY

A 10-year-old boy presented with a 1-wk history of a tender bulge over the left temporo-parieto-occipital scalp. He had undergone a temporo-parieto-occipital titanium mesh cranioplasty 26 mo previously. He denied antecedent head trauma. Computerized tomography disclosed a perpendicular fissure in the titanium mesh, suggesting a diagnosis of spontaneous titanium mesh fracture. He underwent a second temporo-parieto-occipital cranioplasty and made an uneventful recovery. Three-dimensional modeling and finite element analyses were used to explore potential risk factors of titanium mesh fracture.

CONCLUSION

We report a case of spontaneous fracture of a titanium mesh cranioplasty implant. The current case and literature review indicate that titanium mesh implants should be well-anchored to the base of bony defects to prevent fatigue-induced fractures.

How Partial Skull Defect Affects Vulnerability of the Skull in Traumatic Situations: A Biomechanical Study

BACKGROUND

Part of the skull can be lost due to neurosurgical diseases or trauma. Skulls with partial defects can develop different fracture patterns from those of intact skulls. This study aims to clarify the differences.

METHODS

A 3-dimensional skull model was produced by referring to the computer-tomography data of a 23-year-old intact male volunteer. We defined the model as Intact Model. Another model was produced by removing part of the frontal bone, which was defined as Defect Model. Dynamic simulations of impacts were performed varying the site and direction of impact. Fracture patterns caused by the impacts were calculated using dynamic analysis software (LS-DYNA; Livermore Software Technology Corp.) and were compared between the intact model and defect model.

RESULTS

When Defect Model was impacted, fracture involved wider areas than when Intact Model was impacted. This finding was observed not only when Defect Model was impacted on its defect side but also when it was impacted on its intact side.

CONCLUSIONS

When a skull carrying a defect on one side is impacted, serious fracture occurs even when the non-defect side is impacted, meaning that a skull with a defect is vulnerable to impacts on the non-defect side. This finding should be taken into consideration in deciding indications of skull defect reconstruction.

Biphasic mineralized collagen based composite scaffold for cranial bone regeneration in developing sheep

Appropriate mechanical support and excellent osteogenic capability are two essential prerequisites of customized implants for regenerating large-sized cranial bone defect. Although porous bone scaffolds have been widely proven to promote bone regeneration, their weak mechanical properties limit the clinical applications in cranioplasty. Herein, we applied two previously developed mineralized collagen-based bone scaffolds (MC), porous MC (pMC) and compact MC (cMC) to construct a biphasic MC composite bone scaffold (bMC) to repair the large-sized cranial bone defect in developing sheep. A supporting frame composed of cMC phase in the shape of tic–tac–toe structure was fabricated first and then embedded in pMC phase. The two phases had good interfacial bond, attributing to the formation of an interfacial zone. The in vivo performance of the bMC scaffold was evaluated by using a cranial bone defect model in 1-month-old sheep. The computed tomography imaging, X-ray scanning and histological evaluation showed that the pMC phase in the bMC scaffold, similar to the pMC scaffold, was gradually replaced by the regenerative bone tissues with comprehensively increased bone mineral density and complete connection of bone bridge in the whole region. The cMC frame promoted new bone formation beneath the frame without obvious degradation, thus providing appropriate mechanical protection and ensuring the structural integrity of the implant. In general, the sheep with bMC implantation exhibited the best status of survival, growth and the repair effect. The biphasic structural design may be a prospective strategy for developing new generation of cranioplasty materials to regenerate cranial bone defect in clinic.

Therapeutic strategies for retention of cranioplasty titanium mesh after mesh exposure

BACKGROUND

Titanium mesh exposure after cranioplasty is a possible complication and is usually managed by mesh removal and flap transfer, but the advantages of the rigid prosthesis are then lost. This study aimed to present our experience with negative pressure wound therapy combined with soft tissue dilation for retaining the titanium mesh in patients with mesh exposure after cranioplasty.

METHODS

This retrospective study included patients treated between 01/2016 and 05/2019 at the Jiangyin Hospital Affiliated to Southeast University School of Medicine. The wound was cleaned, and a cystic space was created for the tissue dilator, which was used with a self-designed negative pressure dressing. After the target dilation was achieved, the repair was conducted while retaining the titanium mesh.

RESULTS

Eight patients were included (seven males and one female; 53.6 ± 8.8 (range, 43-65) years of age). The exposed mesh area ranged from 1 × 1 to 4 × 5.5 cm. The thinning scalp area around the exposed mesh ranged from 3.6 × 3.8 to 4 × 5.5 cm. Five patients had positive wound cultures and received sensitive antibiotics. The dilator embedding time was 20-28 days. The time of negative pressure wound therapy was 25-33 days. The hospital stay was 30-41 days. Primary wound healing was achieved in all eight patients. There were no signs of recurrence after 6-18 months of follow-up. The cranial CT scans were unremarkable.

CONCLUSIONS

Negative pressure wound therapy combined with soft tissue dilation for exposed titanium mesh after cranioplasty might help retain the titanium mesh.

A novel prefabricated patient-specific titanium cranioplasty: reconsideration from a traditional approach

OBJECTIVE

Patient-specific implants (PSI) for cranioplasty are expensive, and cost remains the limiting factor in low- to middle-income countries. The authors describe a novel, reproducible and cost-effective method of designing prefabricated titanium PSI cranioplasty.

METHODS

Ten patients from June 2018 to December 2020 were included in this retrospective study. A three-dimensional stereolithography model was made on a custom-built 3D printer with variable layer heights to produce efficient and accurate details. A certain amount of defect in the temporal region was left uncovered to avoid complications related to temporalis muscle dissection. The stereolithography model with a cranial defect was reconstructed with modelling wax. The wax model was scanned with a blue light visible scanner. The digital data was transferred to the milling machine (Jayon Surgical®, Kerala, India), where a 1-mm-thick sheet of titanium was milled according to the specifications. RFCC scoring system was used for assessing cosmetic outcome.

RESULTS

The mean duration of the surgery was 56.50 min, SD = 14.916 min (range 45-75 min). In 9/10 patients, the RFCC score was 4 points. No other complications were found at a minimum follow-up of 18 months in all patients. The cost per patient was approximately 30,000 INR or 400 US dollars. The average time required for us to get the PSI ready for surgery was about 15 days.

CONCLUSION

The authors demonstrate a novel, cost-effective and reproducible method of PSI using titanium for cranioplasty.

OssDsign cranioplasty in children: a single-centre experience

INTRODUCTION

OssDsign have developed a new type of cranioplasty plate, consisting of calcium phosphate reinforced with titanium. Currently, there is little known about the cosmetic outcomes and infection rate when OssDsign cranioplasty plates are implanted into paediatric patients.

METHODS

A retrospective case series was performed to include all paediatric patients who received an OssDsign cranioplasty at a single centre, Sheffield Children's Hospital. The cosmetic outcomes were subjectively reported by the parents of the children.

RESULTS

We identified seven paediatric patients where OssDsign cranioplasty was performed. This included two bifrontal and five hemicranioplasties. However, there was failure to implant an OssDsign hemicranioplasty in one patient where a titanium plate was subsequently used. The median duration of follow-up was 15 months. The infection rate was zero. The parents of the patients who successfully received OssDsign cranioplasties were pleased with the cosmetic outcomes. There were cosmetic complaints from the parents of the one patient who received a titanium plate.

CONCLUSION

Our early experience with OssDsign cranioplasty in paediatric patients indicates that it may potentially be associated with a low rate of infection and good cosmetic outcomes.

Exchange Cranioplasty Using Bioabsorbable Hydroxyapatite and Collagen Complex After Removal of an Extensive Frontal Bone Tumor in an Infant

BACKGROUND

Forehead reconstruction is challenging. Reconstruction of the innate curvature of the forehead is difficult, and the forehead is an esthetically important part of the face. Although synthetic implants and autologous split bone grafts are useful, these cannot be used in infants.

CASE DESCRIPTION

A 4-month-old girl was presented with a right frontal bone Ewing sarcoma. The tumor was removed, and the defect was reconstructed with an autologous contralateral parietal bone graft. The parietal bone defect was repaired with a bioabsorbable hydroxyapatite and collagen complex. Good reconstruction of the forehead and ossification of the donor site was achieved within 3 years after surgery.

CONCLUSIONS

After removal of an extensive frontal bone tumor in an infant, exchange cranioplasty with an autograft using a bioabsorbable hydroxyapatite and collagen complex at the donor site yielded good results.