Device and method for treating conditions of a joint

Abstract

A therapeutically effective compound is locally administered by associating the compound with a piece of orthopedic hardware that is implanted at an appropriate site within a body. The compound is adapted, such as through a sustained release device, to administer an effective dosage continuously over an extended period of time. The compound may be administered, for example, to a joint of a mammal by intraarticularly implanting a sustained release device to deliver the therapeutically effective compound within a synovial capsule of the joint, such that synovial fluid concentration of the compound is greater than plasma concentration of the compound. A wide range of orthopedic hardware, such as bone screws and staples, may be adapted to use in the systems described herein to provide treatment for a variety of medical conditions.

Description

FIELD OF THE INVENTION The present invention relates to the delivery of therapeutic compounds using orthopedic hardware. BACKGROUND OF THE INVENTION Pain, in and of itself, constitutes a sufficient impetus for remedial action. Moreover, otherwise productive Individuals lose more time due to pains, particularly in the joints, than to any other cause. Civilization and technological advances have ushered in a relatively sedentary existence, both as to work environment and leisure activities, which increases the likelihood of such pain-causing ailments. Although the term is applied to a wide variety of disorders, arthritis generally denotes the inflammation of a joint whether as a result of a disease, an infection, a genetic defect or some other cause. The long term effects of arthritis range from chronic pain to crippling disability. Osteoarthritis is a disease that attacks cartilage. Surfaces of joint cartilage and underlying bone compress and become irregular, leading to pain, inf...

AI Technical Summary

Problems solved by technology

Moreover, otherwise productive Individuals lose more time due to pains, particularly in the joints, than to any other cause.

Civilization and technological advances have ushered in a relatively sedentary existence, both as to work environment and leisure activities, which increases the likelihood of such pain-causing ailments.

Surfaces of joint cartilage and underlying bone compress and become irregular, leading to pain, inflammation, bone spurs and limited movement.

As osteoarthritis progresses, serious joint damage and chronic pain can result.

Treatment alternatives are limited and, in many cases, ineffective.

Aside from weight reduction and avoiding excessive stress on the joint cartilage, there is currently no specific treatment to halt cartilage degeneration or to repair damaged cartilage caused by osteoarthritis.

The effectiveness of these treatments decreases as the disease progresses.

Sometimes surgery is forestalled with injections of steroids into the affected joint, but the delivery of drugs in this manner is painful, and the drugs themselves provide decreasing effectiveness and wear off after several weeks.

Severe arthritis involves a serious auto-immune reaction for which steroids theoretically provide treatment but their efficacy is compromised by the systemic toxicity resulting from the dosage required to penetrate the natural barriers of the joints and the need for repeated treatments due to the chronic nature of the disease.

Unfortunately, steroid injections are a procedure that must be administered by a medical doctor, they are sometimes accompanied by an anesthetic to numb the area to be injected, and the effects of a steriod injection typically last for about only several months before a second injection is required.

Furthermore, the injected area may become more painful over the first 24 hours after the local anaesthetic wears off, requiring application of a cold compress or taking painkillers.

The injection becomes progressively less effective however as the steroid clears the joint.

Repeated injections to maintain therapeutic drug concentrations are not clinically acceptable, yet high initial doses carry a risk of toxicity.

It is difficult to maintain therapeutic drug concentrations.

Common side effects associated with steroid treatment include weight gain, thinning of the bones (osteoporosis), easy bruising, indigestion, mood changes, rises in blood sugar and blood pressure, and increased likelihood of developing infections.

Furthermore, severe rebound follows the withdrawal of corticosteroids in active diseases, in part due to the down regulation of naturally occurring glucocorticoid steroids.

The soluble 21-phosphate preparations of prednisolone or dexamethasone are not recommended because of rapid clearance from the joint and very short duration of action.

However, the effects of a steroid injection to the knee typically is limited to several months before another injection is required.

Also, injections provide an initial level of steroid that is greater than therapeutically required and which rapidly declines beneath therapeutic levels.

Yet, major side effects can occur, including liver disease, pneumonitis, and bone marrow suppression.

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