Bone Flap Resorption After Cranioplasty: Risk Factors and Proposal of the Flap Integrity Score.

BACKGROUND: Bone flap resorption is a known complication of postdecompressive autologous cranioplasty. Although several potential etiopathogenetic factors have been investigated, their role is still under discussion. To further complicate things, resorption is not an all-or-nothing event, patients frequently presenting with different degrees of flap remodeling. Focus of this paper was to describe the elaboration of a score quantifying bone resorption according to a set of clinical and radiological criteria, hopefully allowing prompt identification of patients needing resurgery before the development of adverse events. METHODS: In a 10-year period, 281 autologous cranioplasties were performed at our institution following decompressive craniectomy. Pertinent clinical and radiological information was registered. A set of 3 clinical and 3 radiological parameters was established to score the degree of resorption, identified under the acronym FIS (Flap Integrity Score). Three groups of patients emerged, respectively showing no (208), partial (32), and advanced (41) resorption. RESULTS: An overall 14.6% incidence of advanced bone resorption was found in our series. Younger age, bone multifragmentation, higher postcranioplasty Glasgow Outcome Scale scores, <2 cm distance of medial craniectomy border from the midline, and cause leading to decompressive craniectomy were associated to a statistically significant higher risk of developing a relevant bone flap resorption. The first three variables were confirmed as risk factors in multivariate analysis. Flap Integrity Score well discriminated the 3 different groups. CONCLUSIONS: Autologous bone repositioning is still a valuable, low-cost, cosmetically and functionally satisfactory procedure. Nonetheless, although resorption affects a minor percentage of patients, its early identification and treatment can improve long-term results.

An unusual instrumentation-related s1 radiculopathy in a patient treated for a primary vertebral (l3) lymphoma.

Paravertebral titanium rod migration represents an unusual and potentially fatal complication of vertebral stabilization surgical procedures. This condition, which requires a prompt and rapid diagnosis, is often mistaken for other more common diseases, or scotomized. We present a case of a 69 years old female affected by a non-Hodgkin lymphoma with evidence of migration of both rods five years after the posterior stabilization procedure for a pathological L3 fracture. Unusual clinical onset was represented by a left S1 radiculopathy without other symptoms. For several months, the symptoms were attributed to a possible radicular infiltration by the lymphoma. We conclude that paravertebral rod migration could happen not only within the spinal canal, but could also rarely damage blood vessels or parenchymal organs. This is generally a long-term complication, probably due to an insufficient fixation. Strict long-term follow-up monitoring is mandatory since this unusual complication can mimic other more common pathological conditions.