Traumatic fracture of a polymethyl methacrylate patient-specific cranioplasty implant.
OBJECTIVE
To present a case of a traumatic fracture of a polymethyl methacrylate (PMMA) patient-specific implant (PSI) for cranioplasty.


METHODS
A 14-year-old boy with a history of right decompressive hemicraniectomy and reconstructive cranioplasty with a PMMA PSI presented after an unhelmeted bicycle accident with somnolence, confusion, seizures, left hemiparesis, and an obviously deformed cranium.


RESULTS
Computed tomography scan showed a comminuted, depressed fracture of the implant and cerebral contusions. The implant was seen to be shattered, resulting in displaced, overriding fragments and significant damage to underlying brain. The patient remained neurologically stable. To minimize the number of operations, intervention was delayed while a polyetheretherketone PSI was fabricated. During surgery, it was noted that the fractured pieces of the implant had caused dural lacerations, and some pieces were embedded in brain parenchyma. The fractured PMMA was removed, and the new implant was placed. The patient remained hemiparetic and was later transferred to an inpatient rehabilitation facility.


CONCLUSIONS
PMMA PSIs are commonly used for large defects and generally have good outcomes with low rates of revision. The case report described involves a shattered PMMA PSI after a traumatic impact, which resulted in hemiparesis. The question arises if this type of complication can be easily avoided with the addition of titanium onlay to restrict displacement in the event of fracture. This onlay represents a minor change of technique that could prevent migration of fracture fragments.
Department of Neurological Surgery, University of Washington, Seattle, Washington, USA.
Andrew L
AL
Ko
Department of Neurological Surgery, University of Washington, Seattle, Washington, USA. Electronic address: jdnerva@uw.edu.
John D
JD
Nerva
Department of Neurological Surgery, University of Washington, Seattle, Washington, USA.
Jason J J
JJ
Chang
Department of Neurological Surgery, University of Washington, Seattle, Washington, USA.
Randall M
RM
Chesnut
D000293:Adolescent; D001642:Bicycling / Q000293:injuries; D001843:Bone Cements; D056424:Decompressive Craniectomy; D006801:Humans; D008297:Male; D009422:Nervous System Diseases / Q000209:etiology; D010291:Paresis / Q000209:etiology; D019904:Polymethyl Methacrylate; D011183:Postoperative Complications / Q000601:surgery; D019736:Prostheses and Implants; D012887:Skull Fractures / Q000150:complications / Q000601:surgery*
D001843:Bone Cements; D019904:Polymethyl Methacrylate
Cranioplasty fracture; Patient-specific implants; Pediatric neurosurgery; Synthetic cranioplasty; Traumatic brain injury