Absorbable Skull Device Could Replace Traditional Metal Implants Used After Brain Surgery

Closing the skull safely after neurosurgery remains a major clinical challenge, as traditional metal or semi-absorbable fixation devices can interfere with imaging, degrade unpredictably, or persist long after healing. These issues may delay recovery or increase complications. To address these limitations, researchers have developed a fully degradable cranial flap fixation system made from high-purity poly-L-lactic acid (PLLA), designed to maintain strength as the skull heals and then disappear completely.

The device, developed by researchers at Central South University (Hunan, China), in collaboration with MedArt Technology (Chengdu, China), uses high-purity PLLA to achieve strong, stable fixation while degrading slowly and evenly. In a study, published online in Chinese Neurosurgical Journal, the researchers compared the PLLA-based MedArt device with the established Aesculap CranioFix system through laboratory testing and a multicenter clinical trial involving 90 patients across four hospitals.

Laboratory tests showed that the MedArt system maintained fixation strength for twice as long as CranioFix, reaching its test endpoint at 14 days versus 7 days for the control system. Its gradual breakdown also avoided sudden lactic-acid release, a known cause of tissue irritation. The design includes a threaded connecting rod and adjustable locking discs that allow repositioning or tightening during surgery, adapting to skull curvature and distributing pressure evenly.

Clinical trial findings further validated its performance. Using 3D CT reconstruction, researchers found that the average bone gap in MedArt-treated patients was 0.58 mm, compared with 0.80 mm using CranioFix. The new system achieved a 100% success rate in maintaining bone-flap position and showed no device-related complications. Bone healing was typically completed within one year, matching the system’s full resorption timeline. Only one possible device-related issue—minor incision healing—occurred with CranioFix, with none reported in the MedArt group.

Blood tests and imaging confirmed that both systems were safe, but the MedArt implant demonstrated superior biocompatibility and fewer postoperative concerns. Practical advantages also emerged during surgery. The ability to adjust the fixation assembly enables precise placement and reduces operating time, and the flexible structure helps prevent localized pressure or stress. These features, combined with complete biodegradability, may make the system especially suitable for children or trauma patients who benefit from implants that leave no long-term residue.

“Our goal was to create a device that’s strong, safe, and leaves nothing behind,” said Dr. Siyi Wanggou, who led the research team. “This is an important step toward safer, more patient-friendly neurosurgery. We’ve shown that strength and biodegradability can go hand in hand.”