Introduction
Osteoarthritis (OA) stands as one of the most prevalent medical conditions globally, and its incidence is expected to rise with the increasing age of the general population. While both oral medications, such as NSAIDs (non-steroidal anti-inflammatory drugs), and surgical interventions have traditionally been employed in OA management, they come with their own set of limitations. Consequently, there is a growing demand for minimally invasive approaches, including intra-articular injections and percutaneous interventions, either as stand-alone treatments or in combination with oral medications and surgery. Over the past two decades, there has been a rapid expansion in the development of both pharmacologic and non-pharmacologic minimally invasive treatments for OA. These procedures often incorporate image guidance techniques using fluoroscopy, CT (computed tomography) scans, or ultrasound to ensure precise targeting and maximize therapeutic effectiveness.
What Are the Benefits of Interventional Radiology in Osteoarthritis Management?
Interventional radiology is a medical subspecialty that uses minimally invasive procedures and imaging guidance to diagnose and treat various medical conditions.
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IR procedures are minimally invasive, requiring only small incisions or needle insertions. This reduces the risk of complications, infection, and scarring compared to traditional open surgery.
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IR techniques are guided by advanced imaging modalities like fluoroscopy and ultrasound, ensuring precise targeting of the affected area, leading to improved outcomes.
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Patients typically experience faster recovery times after IR procedures, allowing them to return to their daily activities sooner than with surgery.
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IR interventions can reduce the need for long-term use of pain medications, which may have adverse side effects and risks of dependence.
What Are the Commonly Used IR Techniques in the Management of OA?
Managing osteoarthritis (OA) through interventional radiology (IR) techniques offers patients minimally invasive options for pain relief and improved joint function. Here, we'll discuss several IR techniques commonly used in OA management, providing a detailed overview of each:
1. Viscosupplementation -
Viscosupplementation involves injecting hyaluronic acid (HA) directly into the affected joint, typically the knee. HA is a naturally occurring substance that provides lubrication and cushioning to the joint. HA injections aim to restore the lubricating properties of the synovial fluid, reducing friction and pain in the joint. Viscosupplementation is often used for knee OA, and it can provide temporary pain relief and improve joint mobility. It is minimally invasive, and many patients experience relief with minimal side effects.
2. Corticosteroid Injections -
Corticosteroids, such as Triamcinolone acetonide, are injected directly into the affected joint to reduce inflammation and relieve pain. Corticosteroids suppress inflammation and immune responses in the joint, providing rapid pain relief. These injections are used for various joints affected by OA, including the knee, hip, and shoulder. Corticosteroid injections offer quick relief and can be performed with precision under imaging guidance.
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Triamcinolone Acetonide Extended-Release Injectable Suspension (TA-ER): This innovative formulation is based on microspheres designed to release triamcinolone acetonide gradually. This extended-release mechanism allows for several advantages compared to traditional triamcinolone acetonide preparations. By gradually releasing the drug from the microspheres, TA-ER can potentially offer enhanced effects within the joint space while reducing systemic absorption, thus minimizing systemic side effects.
3. Genicular Nerve Ablation (GNA) -
GNA is primarily used for knee OA. It involves the application of heat or cold to the genicular nerves responsible for transmitting pain signals from the knee joint. GNA disrupts the pain signals, providing long-lasting pain relief. Knee osteoarthritis patients who have not responded well to other treatments may benefit from GNA. This technique is a minimally invasive alternative to surgical options, offering durable pain relief.
4. Radiofrequency Ablation (RFA) -
RFA is used to treat OA-related pain in various joints, including the spine, hip, and knee. RFA uses radiofrequency energy to target and ablate the nerves, transmitting pain signals, leading to prolonged pain relief. Patients with OA experiencing chronic pain in different joints may be candidates for RFA. RFA provides lasting pain relief with minimal invasiveness and a shorter recovery period compared to surgery. Radiofrequency ablation (RFA) of nerves can be administered through various techniques, which include standard RFA, cooled RFA, and bipolar RFA.
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In standard RFA, the tissues surrounding the electrode are heated to approximately 80 degree Celsius, with temperatures at the electrode-tissue interface reaching around 100 degrees Celsius.
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Cooled RFA employs a water cooling system to reduce the temperature at the interface between the electrode and tissues to approximately 80 degrees Celsius, while keeping the surrounding soft tissues at an approximately 60 degrees Celsius treatment temperature.
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Bipolar RFA offers an alternative approach. It involves the insertion of two electrodes into the treatment area, through which the electrical current flows exclusively between these two electrodes. This confined current flow ensures that there is no risk of skin burns or stimulation of implant devices, making bipolar RFA a safer option in certain cases.
5. Platelet-Rich Plasma (PRP) and Stem Cell Injections -
These therapies involve injecting concentrated platelets (PRP) or stem cells from the patient's own body into the affected joint to stimulate healing and reduce inflammation. PRP and stem cell injections promote tissue repair and regeneration, potentially slowing OA progression and providing pain relief. PRP and stem cell therapies are emerging as alternatives for OA patients seeking less invasive treatments. They offer a potential opportunity for tissue regeneration and reduced pain, but their long-term effectiveness is still under investigation.
6. Prolotherapy-
This therapy, also known as proliferative therapy, involves the injection of irritants and hyperosmolar solutions into a joint, creating controlled injury and inflammation. The primary objective of prolotherapy is to enhance blood flow and initiate the healing process, ultimately leading to collagen deposition and hypertrophy, thereby promoting joint regeneration. The most commonly used and extensively researched composition in prolotherapy is hypertonic dextrose (concentrations ranging from 12.5 to 25 percent). The recommended treatment schedule involves sessions approximately every 2 to 6 weeks, with a typical treatment series consisting of three to six injections.
7. Intraarticular Pulsed Radiofrequency Therapy -
This medical procedure involves using an electrode to generate intermittent radiofrequency pulses. The therapeutic benefits mainly stem from the electric field generated by the electrode, with the intermittent nature of the pulses helping to prevent excessive heating. Pulsed radiofrequency therapy has been applied to treat osteoarthritis (OA) in various joints, including but not limited to the shoulder, knee, and thumb.
8. Subchondroplasty -
This minimally invasive procedure is employed for the management of pain associated with bone marrow edema. This technique entails the injection of a flowable synthetic calcium phosphate filler into the bone, guided by fluoroscopy. Synthetic calcium phosphate serves as a supportive framework that facilitates the remodeling of bone by osteoblasts and osteoclasts. This formulation preserves the existing local bone structure while simultaneously acting as a scaffold that fosters the formation of new bone tissue.
9. Magnetic Resonance Imaging (MRI)-Guided Focused Ultrasound Therapy -
This therapy medical approach utilizes high-intensity focused ultrasound to precisely direct acoustic energy to a specific area of the body, allowing for localized tissue ablation. This technique can be combined with MRI imaging for precise targeting of tissues during therapy and real-time temperature monitoring in the treated area, all done in a non-invasive manner. While initially developed for tumor treatment in the field of oncology, MRI-guided focused ultrasound has more recently found applications in treating conditions such as neuropathic pain and osteoarthritis (OA).
Conclusion:
Currently, the most commonly employed minimally invasive treatments for osteoarthritis (OA) involve intra-articular corticosteroids and viscosupplements. Emerging research suggests that the intraarticular injection of biologic agents and prolotherapy also demonstrate effectiveness in OA management. Nonpharmacologic approaches such as nerve ablation and guided genicular artery embolization (GAE) present the potential to offer more sustained pain relief for OA when compared to the relief achieved through intra-articular injections. Additionally, there are other nonpharmacologic treatments like intraarticular pulsed radiofrequency therapy, subchondroplasty, and MRI-guided focused ultrasound therapy that exhibit promise in the treatment of OA. However, their effectiveness should be further explored through research, including comparative studies with other minimally invasive therapeutic options.
