Patient-specific titanium-reinforced calcium phosphate implant for the repair and healing of complex cranial defects

Kihlström Burenstam Linder L et al. 2018
Link to full article (World Neurosurgery)

Background 
The reconstruction of complex cranial defects is challenging and is associated with a high complication rate. The development of a patient-specific, titanium-reinforced, calcium phosphate-based (CaP-Ti) implant with bone regenerative properties has previously been described in 2 case studies with the hypothesis that the implant may improve clinical outcome.
Objective
To identify whether the introduction of CaP-Ti implant has the potential to improve clinical outcome.
Methods
A retrospective review of all patients having undergone CaP-Ti cranioplasty was conducted. Comprehensive clinical data were collected from the hospital computer database and patient records. Bone formation and osseointegration were analyzed in a single retrieval specimen.
Results
Fifty patients, with 52 cranial defects, met the inclusion criteria. The patient cohort displayed a previous failure rate of 64% (32/50) with autologous bone, alloplastic materials, or both. At a median follow-up time of 25 months, the explantation rate due to either early postoperative infection or persistent wound dehiscence was 1.9% (1/53) or 3.8% (2/53), respectively. Surgical intervention with local wound revision was required in 2 patients without the need of implant removal. One patient had a brain tumor recurrence, and the implant was explanted 31 months after implantation. Histologic examination showed that the entire implant was partly yet evenly transformed into vascularized compact bone.
Conclusions
In the present study the CaP-Ti implant appears to have improved the clinical outcomes in a cohort of patients with a high rate of previous cranioplasty failures. The bone regenerative effect may in particular have an impact on the long-term success rate of the implant.



Improving outcomes in cranioplasty - clinical results from 1055 patients treated with ossdsign cranial Psi

OssDsign post-market surveillance data
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Abstract 
Reconstruction of cranial defects can be a complex surgical procedure associated with an underestimated morbidity. This report describes the outcome of 1055 cranioplasties using OssDsign Cranial PSI, a patient-specific implant made from a calcium phosphate material reinforced with 3D printed titanium. All data was collected as part of post-market surveillance following introduction of the product in Europe, US and selected Asian markets in compliance with MEDDEV 2.7/1 rev.4 and MDR 2017/745. At a median follow up time of 21 months (range, 0-70 months) 44 implants (4.2%) had been explanted; whereof 22 (2.1%) of the implants were explanted due to early postoperative infections, 13 (1.2%) due to persistent wound dehiscence, 1 (0.1%) due to unsatisfactory aesthetical outcome and 8 (0.8%) due to other reasons, such as tumor recurrence. Histological analysis of several implants explanted ≥ 9 months following surgery revealed bony integration between the implant and the native bone, as well as new bone formation within and around the remaining calcium phosphate material.

Histological evidence 31 months post implantation

Figure 1. Histological evidence 31 months post implantation. Paragon stained sectioning of OssDsign Cranial PSI shows bony integration between the implant and the recipient bone (rb) as well as new bone formation (nb) within, and around the remaining calcium phosphate material (CaP) and supporting titanium structure (Ti).