1. Field of the Disclosure
The disclosure is directed to devices and methods for dispensing biomaterials such as for injecting bone cement, also known as poly(methyl methacrylate) or PMMA. In particular, the disclosure is directed to a cement gun for injecting bone cement. Bone cement is often injected to secure prosthetic devices, such as, e.g., artificial joints and spinal fusion constructs, to natural bone.
2. Related Art
Many devices are available to assist a surgeon with injecting bone cement to secure a prosthesis. These devices, however, suffer from one or more flaws. For example, some devices are single-use and may not be re-sterilized, increasing surgical costs.
Some devices are incompatible with interchangeable syringe assemblies. If the surgeon uses all the cement in the device, she must halt the surgical procedure while she mixes additional cement. To avoid this, the surgeon may have a second device ready. Either solution increases surgical costs.
Moreover, some syringe assemblies may have inadequate configurations for securing the syringe assembly. When using these devices, the syringe assembly may unexpectedly fall out of the device, adding additional complications to an already difficult procedure.
Many devices lack mechanisms for relieving injection pressure in the syringe. When a device does have such a mechanism, it is usually difficult to operate. Quick relief of injection pressure is critical for safety during a surgical procedure. Bone cement hardens by a polymerization reaction that releases heat. Droplets of bone cement that contact soft tissue can result in burns and other injuries that may add additional complications to an invasive surgical procedure. Preventing stray droplets of bone cement may substantially reduce or eliminate the burn danger posed by bone cement. A surgeon may prevent stray droplets by reducing injection pressure in the syringe. If the mechanism for reducing injection pressure is clumsy or difficult to operate, the surgeon may not be able to prevent stray droplets of bone cement from falling onto soft tissues. Other complications, such as, e.g., over-filling a cavity or fracture, may also result from clumsy or complicated pressure-relief mechanisms. In contrast, a mechanism for quickly and easily reducing injection pressure may help the surgeon improve the safety of the procedure by, e.g., preventing stray droplets.
Accordingly, there is a need for a device that is compatible with an interchangeable syringe assembly and provides an easy-to-use mechanism for quickly relieving injection pressure in the syringe.