Bone-O₂ bio-adhesive: redefining the future of fracture fixation

Dear Editor,

Bone fractures caused by trauma, tumors, or orthopedic procedures remain a major clinical challenge, impacting the health of tens of millions of people worldwide^[1]. Majority of these cases are addressed with conventional methods like metallic device fixation. However, such methods are associated with notable limitations, including extended operative time and increased risk of postoperative infection^[2]. Given these challenges, bone adhesives have emerged as a new class of bio-compatible materials capable of providing stable bone-to-bone or bone-to-implant fixation under wet physiological conditions. They form strong, durable, and load-bearing bonds that gradually degrade into non-toxic byproducts^[3].

Recently, scientists in China have unveiled a revolutionary bio-adhesive, known as Bone-O₂ that is capable of repairing fractures within minutes. The project was led by Dr. Lin Xianfeng, Associate Chief Orthopedic Surgeon at Sir Run Run Shaw Hospital, who drew inspiration from oysters’ remarkable ability to adhere firmly to wet and moving surfaces^[4–7]. Structurally, the adhesive represents an organic-inorganic hybrid, characterized by an alternating CaCO₃ crystal phase, a cross-linked organic matrix, and a high protein content^[8]. Bone-O₂ has demonstrated remarkable mechanical strength, withstanding tensile loads exceeding 400 pounds, along with a shear strength of 0.5 MPa and compressive strength close to 10 MPa^[5,6,9,10].

Clinical trials have been performed on more than 150 patients in China. In one documented case, a complex wrist fracture treated with Bone-O₂ achieved rapid fixation within 3 minutes using a 2–3 cm incision, avoiding traditional metal implants. Follow-up at three months confirmed full recovery, demonstrating excellent clinical outcomes^[4,6,7,9]. Moreover, its biodegradable nature allows Bone-O₂ to be gradually absorbed as the bone heals, eliminating the need for a second surgery and significantly reducing the postoperative infection risks^[4–7,10].

While traditional methods of bone fixation are the current standard of treatment, bone-02 offers a shift in paradigm with multiple advantages over the existing methods. Conventionally, majority of the cases of fractures are addressed through metallic device fixation including plates and screws; however, this approach requires extensive dissection, periosteal stripping, and precise drilling/tapping, leading to longer operative times and greater soft tissue damage. Bone-02 on the other hand is minimally invasive (applied via 2–3 cm incision) and achieves fixation within minutes. This reduces the surgical trauma and blood loss and post-operative complications^[2]. Furthermore, metallic implants used for fixation are bio-inert but not bioactive or biodegradable requiring a second surgery for removal in most of the cases which increases the risk for a life-long infection, irritation or hardware failure. Bone-02, made from biodegradable material, is naturally absorbed after approximately 6 months as the bone heals, eliminating the need for secondary surgeries previously required in conventional treatments^[9].

Despite the promising early results of bone-02, there is still a need for more robust clinical evidence for its incorporation in clinical settings. Trials of bone-02 have been run for almost 150 patients representing a relative small cohort, and no long-term outcomes (1–2 years) have been reported on these patients yet, indicating the lack of large-scale multicenter Randomized Controlled Trials (RCTs) directly comparing Bone-02 to standard fixation methods^[5]. Moreover, the current evidence focuses on smaller and relatively uncomplicated fractures, including certain wrist fractures only. The efficacy of bone-02 in highly comminuted fractures, intra-articular fractures or long bone fractures under high loading is yet unproven and requires further clinical testing^[7].

In order to transition Bone-02 from an innovation to a clinical tool actively used in hospital settings, targeted future research is imperative. First and foremost, large, prospective and multicenter RCTs should be conducted comparing standard fixation methods with Bone-02 for specific and defined fracture types with the primary endpoints being functional outcomes, time-to-union, complication rates, and patient-reported satisfaction at 1, 2, and 5 years. Future studies should also systematically evaluate the use of Bone-02 in more challenging scenarios like osteoporotic fractures, peri-prosthetic fractures and as an adjunct to spinal or craniofacial surgeries. In addition, research should focus on incorporating osteo-inductive factors like BMPs to actively stimulate bone growth alongside the healing process^[11].

This letter to the editor adheres to the Transparency in the Reporting of Artificial Intelligence in Research (TITAN) guideline^[12].

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The authors received no specific funding for this work.

Author contributions

All authors contributed equally. All authors reviewed and approved the final version and agree to be accountable for all aspects of the work.

Conflicts of interest disclosure

The authors declare that they have no conflicts of interest.

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Guarantor

Raghabendra Kumar Mahato.

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Not applicable.

Data availability statement

Data are available on request from the authors.