Implantable polymer for bone and vascular lesions

Abstract

A solidifying implant composition of a polymer mixed with a bioabsorbable solvent. A method of treating a patient, by implanting the solidifying implant composition into bone, and solidifying the implant composition. A method of improving bone structure in patients by applying the solidifying implant composition to bone, shoring up bone structure, and improving load bearing capacity and aiding healing of microfractures. A method of fixing an implant, by applying the solidifying implant composition to an implant, and shoring up the implant. A method of devascularizing and treating a tumor or vascular lesion. A method of treating a vascular disease. A method of treating aneurysms / pseudoaneurysms.

Description

BACKGROUND OF THE INVENTION[0001]1. Technical Field[0002]The present invention relates to compositions and methods of treating bone fractures. In particular, the present invention relates to compositions made of polymers and ceramics for treating bone fractures, lesions, voids, and temporary or permanent fixation of implants. Additionally, the present invention relates to compositions made of polymers for treating vascular lesions and visceral fistulas.[0003]2. Background Art[0004]Progressive loss of bone density or thinning of bone tissue are characteristics of osteoporosis, the most common type of bone disease affecting 10 million Americans. Although regular exercise with daily intake of vitamin and mineral supplements can help alleviate the symptoms of osteoporosis, they do not provide wholesome treatment to those experiencing osteoporosis-induced fractures. The early stages of this disease yield little to no symptoms; however, as the disease progresses to late stage, patients be...

AI Technical Summary

Benefits of technology

[0023]The present invention provides for a method of improving bone structure in patients by applying the solidifying implant composition of a polymer mixed with a biocompatible solvent to bone, shoring up bone structure, and improving load bearing capacity and aiding healing of microfractures.

Problems solved by technology

Although regular exercise with daily intake of vitamin and mineral supplements can help alleviate the symptoms of osteoporosis, they do not provide wholesome treatment to those experiencing osteoporosis-induced fractures.

Although these medications and routine changes can help prevent fractures, it cannot reverse pre-collapsed vertebrae, or regenerate large quantity bone defects created by trauma, infection, skeletal abnormalities or tumor resection.

Although these clinical procedures allow the patient to regain functional abilities without pain, they carry various risks with them as well, including: risk of infection, risk of orthopedic cement leakage out of vertebral body that can cause pulmonary edema if cement migrated to the lungs, secondary fracture of the adjacent vertebra if cement leaks into the disk space, and neurological symptoms if cement leaks onto spinal nerves.

The most common problem that arises from osteoporosis-induced fractures is failure of fixation of the aforementioned screws, metal plate, or rod due to the decreased bone density in the osteoporotic patient.

The disadvantage of current PMMA based bone cements is their physical properties, lack of osteoconductivity, and resorption.

This prevents the PMMA from being properly integrated into the bone, and instead, the PMMA is encapsulated by a connective tissue layer.

When the natural bone stops receiving mechanical signals from daily movement by the patient, bone remodeling comes to a standstill and worsens osteoporotic weakening of the bone.

This can lead to a revision surgery.

The difficulty and length of the revision surgery is increase by the difficulty in removing current bone cements.

The disadvantage of PMMA infused with various salt additives has similar disadvantages as aforementioned for sole PMMA based bone cements.

The disadvantages of calcium phosphate based bone substitute include, but are not limited to, large pore size, and low Young's modulus.

Furthermore, large pore sizes within calcium phosphate based bone substitute yield poor compressive strength, and therefore, low Young's modulus.

This poor compressive strength will not adequately stabilize bone or implants in loadbearing applications, and therefore would lead to failure because these bone substitutes are not load-bearing prior to bone regeneration.

The disadvantage of bioactive glass substitutes includes, but is not limited to, poor resorption in natural bone.

Although bioactive glass substitutes possess superior mechanical strength, varying pore sizes between 50-150 microns, and high connectivity between pores, the substitute has a poor resorption rate, and therefore, the natural bone has hindered growth.

There are several challenges with current liquid embolic technologies.

Currently, there are not effective treatments available or available treatments options are dangerous, painful, and debilitating.

The available methods for endovascular treatment of vascular lesions are often ineffective and require numerous re-treatments.

The buildup of radiopaque material from multiple injections, large injections, or subsequent embolization procedures makes imaging and safely navigating the vascular lesion more difficult, takes longer, and limits the imaging options.

Difficulty visualizing the vascular lesion leads to increased procedural times, radiation dose to the patient and surgical staff, and treatment cost.

Patients frequently get radiation burns and lose hair from the prolonged exposure.

Current devices approved for treatment and / or occlusion of venous varices, vascular tumors, and traumatic vessel injury are awkward, lack control, and are often incomplete or require multiple treatments.

More invasive and dangerous treatment with open neurovascular surgery or single, high dose stereotactic radiation (which may be incompletely effective, or require a significant therapeutic interval during which the patient is not protected from cerebral hemorrhage) can be required for these patient who cannot be completely and durably treated by minimally invasive methodologies.

Endovascular devices and surgical repair of aneurysms may not completely and durably occlude certain lesions and may require retreatment.

The solvent volume used in current liquid embolic agents is not safe or compatible for many procedures.

This was demonstrated when Onyx did not meet the FDA requirement of a USP 7-day muscle implant evaluation because implantation resulted in an acute tissue response.

Making visualization difficult for the surgeon and causing pain for the patient.

These procedures are converted to an intubated procedure increasing the risk and cost of the treatment.

DMSO ability to lower the vagal threshold could be a cause of the bradycardia seen when using Onyx near the valgus nerve.

Open surgical treatment is dangerous, debilitating and more costly.

Currently, no optimal and safe device exists for endovascular treatment for many arteriovenous malformations, arteriovenous fistulae, or visceral and / or viscerocutaneous fistulae.

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