Page 47 - Clinical relevance of current materials for cranial implants

Autologous bone is inferior to alloplastic cranioplasties
Study limitations
Virtually all currently available evidence on the safety of cranioplasty materials is
retrospective, limiting the amount of relevant data available for review. 2
Reliability of the reported infection rates in the included studies was questionable, because a significant number of studies synonymized infection and removal of the cranioplasty after infection or did not specify their definition of infection. Malcolm et al.5 already noted this wide range of definitions for infection. This was also true for the definition of resorption. Neurologic functioning and aesthetic outcome were often reported subjectively and were sometimes included as a complication.
HA likely was used in smaller and safer located defects resulting in skewed conclusions. It may also be prevalent in pediatric situations, to accommodate a growing skull; naturally, these patients have a greater capacity for recovery than elderly patients. This review did not correct for these parameters, and future studies should aim to verify these results.
In some studies, the amount of cranioplasties, whether it was unilateral or not, and the affected cranial bone was not reported. In these cases, we assumed the number of patients was equal to the amount of cranioplasties.
A number of the non-primary outcome complications could not be attributed to a material as only studies that did not report the primary outcomes per material were excluded.
CONCLUSION
Implications for practice
This systematic review of a substantial body of evidence offers insufficiently strong evidence to conduct a meta-analysis or support the use of any material over another for cranioplasty. However, available evidence does show a significantly lower removal rate for alloplastic materials for cranioplasty than for autologous bone. Hence, autologous bone is dissuaded for cranioplasty after decompressive craniectomy.
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