gms | German Medical Science

63rd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Japanese Neurosurgical Society (JNS)

German Society of Neurosurgery (DGNC)

13 - 16 June 2012, Leipzig

Aseptic bone resorption after autologous bone flap reinsertion following decompressive craniotomy – Risk factors for bone flap necrosis

Meeting Abstract

  • P. Duenisch - Klinik für Neurochirurgie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena
  • J. Walter - Klinik für Neurochirurgie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena
  • P. Schmidt - Sektion für Neuroradiologie des Instituts für diagnostische und interventionelle Radiologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena
  • Y. Sakr - Klinik für Anästhesie und Intensivmedizin, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena
  • R. Kalff - Klinik für Neurochirurgie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena
  • C. Ewald - Klinik für Neurochirurgie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS). Leipzig, 13.-16.06.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. DocFR.13.01

doi: 10.3205/12dgnc277, urn:nbn:de:0183-12dgnc2771

Published: June 4, 2012

© 2012 Duenisch et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: After consolidation of the cerebral situation, the autologous bone flap reinsertion becomes necessary. However, aseptic resorption of the bone flap remains a matter of concern. The aim of our study was to report possible perioperative complications in patients undergoing autologous bone flap reinsertion and to identify the risk factors that may predispose to bone flap resorption in these patients.

Methods: We included all adult patients admitted to our neurosurgical department between 09/1994 and 06/2011 in whom we reinserted a cryoconservated bone flap. Clinical and radiological findings were retrieved retrospectively. The grade of the lysis was classified into two types depending on the extent of the osseous changes. Bone necrosis was defined as aseptic resorption with circumscribed or complete lysis of the tabula interna and externa and loss of the bony protection of the brain. To identify the factors predisposing to bone flap necrosis, we performed a multivariate analysis with bone necrosis as the dependent variable.

Results: In a series of 372 patients (mean age: 48.6 ±18.4 years; 57.4% males), who received 414 bone flaps during the observation period, 134 (36.0%) had diffuse traumatic brain injury; 69 (18.5%) subarachnoidal haemorrhage; 58 (15.6%) cerebral infarction; 56 (15.1%) extraaxial bleeding; 43 (11.6%) intracerebral bleeding and 12 (3.2%) had a neoplasm. Bone flap necrosis as long-term complication rate occurred in 85 patients (22.8%) and 91 bone flaps, after a median time of 15 months (interquartile range: 15 [10–33]). In a multivariate analysis with bone flap necrosis as the dependent variable, bone flap fragmentation with two (Odds ratio (OR) = 3.35, 95% confidence interval (CI): 1.59–7.01, p < 0.002) or more fragments (OR = 24.00, 95% CI: 10.13–56.84, p < 0.001), shunt dependent hydrocephalus (OR = 1.76, 95% CI: 0.99–3.12, p = 0.04) and a younger age (OR = 0.98, 95% CI: 0.96–0.99, p = 0.004) were associated with a higher risk for the development of an aseptic necrosis in these patients.

Conclusions: In patients undergoing bone flap reinsertion after craniotomy, aseptic bone necrosis seems to be an underestimated problem during long-term follow-up. Especially in younger patients with an estimated good neurological recovery and a fragmented bone flap, an initial allograft should be considered.