What happens if a cranioplasty fails?

Why a cranioplasty fails

Infection

About 8 in 100 cranioplasties develop an infection across published studies.² Not every infection means removal, but a deep infection of the implant often does. A review of patients after craniectomy found infection-related failure in 6.9% of own-bone cranioplasties and 8.3% of synthetic implants, a difference that was not statistically significant.³ The infection rates guide covers this in detail.

Bone flap resorption

When the surgeon puts back your own bone, the body sometimes breaks it down instead of healing it in place. If enough of it dissolves, the skull is weak or misshapen again and the bone may need to be replaced.

• In a review of bone flaps stored under the skin of the abdomen, about 1 in 5 showed resorption, and 17% of patients needed revision surgery.⁴
• Resorption was more likely when the bone flap was broken into more than two pieces, when the craniectomy followed a head injury, and in younger patients.⁵
• In children, resorption needing another operation approached 30% in a 2025 review, which is one reason pediatric cranioplasty is especially challenging.⁶

Synthetic implants don't resorb, which is one reason surgeons consider them when the risk of resorption is high.³

Wound breakdown and implant exposure

If the scalp over the implant wears thin or the incision opens, the implant can become visible. This is called exposure, and it usually needs surgery. Studies have reported it more often with titanium than with other materials.⁷ Scalp thickness, past radiation and earlier wound problems all matter here. See PEEK vs titanium for the comparison.

Fluid collections and other problems

Fluid or blood can collect under the scalp after surgery. In the 318-patient series, larger fluid collections on the post-surgery CT scan were linked to a higher chance of reoperation, while using a drain under the scalp was linked to a lower chance.¹

Who is more likely to need another operation?

In the 318-patient series, patients who needed reoperation more often had:¹

• a shorter wait between craniectomy and cranioplasty (median 86 vs 140 days)
• a shunt to drain fluid from the brain (26% vs 13%)
• a synthetic implant rather than their own bone

Other studies point in different directions. A review of head injury patients found that own-bone cranioplasty carried a higher reoperation risk after head injury, while synthetic implants did not.¹⁰ These are mostly single-hospital, backward-looking studies, so no single factor decides your risk. Your surgeon can explain how these factors apply to you.

What happens next

1. Diagnosis. Your team will usually use an exam, blood tests and a CT scan to work out what is wrong.
2. Treating infection first. If the bone or implant is infected, it is often removed and you receive antibiotics. For infected bone flaps after craniotomy, a 2026 review found that leaving the flap in place with antibiotics failed more often (16%) than removing it and placing mesh right away (5%), although each approach suits different patients.¹¹
3. Protecting your head. While the skull is open again, you may need a protective helmet.
4. Revision cranioplasty. Once healed, the skull is rebuilt again. In one series of 15 revisions, the average wait between implant removal and the new cranioplasty was about 300 days.⁹

Revisions are often done with a custom implant made from a new CT scan. Small published series have reported results with custom titanium (43 patients, 5 with wound breakdown afterward)⁸ and with titanium-reinforced calcium phosphate (15 patients, 73% success over two years).⁹ Surgeons may also use tissue expanders or a plastic surgeon's help when the scalp is thin.⁹

The cost of a second operation

A repeat operation is one of the biggest drivers of total cranioplasty cost. In one German study, patients whose own bone failed and was replaced had the highest overall cost of any group.¹² See how much a cranioplasty costs.

Questions to ask your surgeon

1. How often do your patients need a second operation, and for what reasons?
2. Is my own bone a good option, or is it likely to resorb?
3. What signs should make me call you right away?
4. If this cranioplasty fails, what would the plan be?
5. If I need a revision, which material would you use, and why?

Sources

1. Hafazalla K, et al. Reoperation risk factors for cranioplasty surgery. Neurosurgery. 2026. doi:10.1227/neu.0000000000003976
2. Henry J, et al. Complications of cranioplasty in relation to material: systematic review, network meta-analysis and meta-regression. Neurosurgery. 2021;89(3):383-394. doi:10.1093/neuros/nyab180
3. Cerveau T, et al. Infection-related failure of autologous versus allogenic cranioplasty after decompressive hemicraniectomy: a systematic review and meta-analysis. Brain Spine. 2023;3:101760. doi:10.1016/j.bas.2023.101760
4. Al-Salihi MM, et al. Subcutaneous preservation versus cryopreservation of autologous bone grafts for cranioplasty: a systematic review and meta-analysis. J Clin Neurosci. 2024;122:1-9. doi:10.1016/j.jocn.2024.02.025
5. Signorelli F, et al. A systematic review and meta-analysis of factors involved in bone flap resorption after decompressive craniectomy. Neurosurg Rev. 2022;45(3):1915-1922. doi:10.1007/s10143-022-01737-z
6. Shabo E, et al. Beyond decompression: predictors of cranioplasty failure in pediatric patients, a meta-analysis. Acta Neurochir. 2025;167(1):222. doi:10.1007/s00701-025-06637-x
7. Zhu S, et al. Complications following titanium cranioplasty compared with nontitanium implants cranioplasty: a systematic review and meta-analysis. J Clin Neurosci. 2021;84:66-74. doi:10.1016/j.jocn.2020.12.009
8. Kayhan S, et al. Revision cranioplasty with three-dimensional custom-made titanium implants in patients with failed cranioplasty. World Neurosurg. 2024;191:e465-e472. doi:10.1016/j.wneu.2024.08.154
9. Naser PV, et al. Patient-specific titanium-reinforced calcium-phosphate (CaP:Ti) implants for revision cranioplasty. Brain Spine. 2025;5:104213. doi:10.1016/j.bas.2025.104213
10. Henry J, et al. Complications of cranioplasty following decompressive craniectomy for traumatic brain injury: systematic review and meta-analysis. Acta Neurochir. 2021;163(5):1423-1435. doi:10.1007/s00701-021-04809-z
11. Musmar B, et al. Bone flap preservation versus removal with immediate mesh cranioplasty for post-craniotomy infections: a systematic review and meta-analysis. Neurosurg Rev. 2026;49(1). doi:10.1007/s10143-026-04206-z
12. Lethaus B, et al. Interval cranioplasty with patient-specific implants and autogenous bone grafts: success and cost analysis. J Craniomaxillofac Surg. 2014;42(8):1948-1951. doi:10.1016/j.jcms.2014.08.006