Cartilage Regeneration (Cartistem Surgery)

Overview

This cartilage is prone to regular wear and strain and may be injured as a result of injury, resulting in discomfort and decreased function. Articular cartilage injuries are caused by mechanical destruction of the cartilage, such as a traumatic injury or a direct hit, or by gradual degeneration, such as wear and strain. The cartilage cells can repair, but it is dependent on the amount of the damage and the location of the injury. However, because to a lack of blood flow, the healing potential is relatively limited.

Because cartilage tissue lacks blood veins, its capacity to repair itself is severely reduced, and bleeding is required for healing. A surgeon performs cartilage regeneration by creating tiny wounds beneath a broken cartilage in the bone, with the hope that the resulting blood stimulates cartilage cell development.

 

What is Osteoarthritis (OA)?

It is estimated that 10% of the world's population aged 60 and more has major clinical difficulties that can be linked to osteoarthritis (OA). Because this condition gradually affects the aging population, the healthcare impact of OA on society is substantial. Furthermore, the ever-changing demographics of the population raise the expense of healthcare to society while adding suffering and impairment to a substantial part of the population.

Among the major aetiological reasons of OA include trauma, degenerative joint illnesses, metabolic variables such as obesity, and mechanical ones such as joint instability. There are currently no pharmacological medications available for the prevention or treatment of OA; the sole medical option for OA is pain management.

In this context, cartilage tissue engineering has not delivered on the high expectations of OA treatment, and the potential for cartilage regeneration via stem cell therapy has not yet realized. As a result, complete joint replacement, despite its high cost, is regarded as the last resort for reducing pain and restoring function in OA patients.

Articular cartilage is regarded to have a restricted capacity for regeneration. However, clinical pain alleviation and cartilage repair have been documented in OA joints that have been surgically torn apart or distracted for extended periods of time. This might have been a hint that cartilage regeneration in OA joints is conceivable. 

The mechanism(s) via which cartilage formation may proceed in the distracted joint area, however, remain unclear. In this context, we examine the biological components of cartilage formation, such as damage and growth, and provide a conceptual framework for cartilage regeneration in distracted OA joints. As a result, a unique paradigm is suggested for the nonsurgical treatment of OA joint distraction.

 

What is Articular Cartilage?

Articular cartilage is a special tissue that exists between the ends of bones in joints and aids in load bearing and lubrication. It is densely packed with extracellular matrix and dotted with chondrocytes. Adult cartilage is divided into three zones: superficial, medium, and deep. The biochemical makeup of the matrix, cell density and shape, cell metabolism, and the pericellular matrix (PCM) differ across these zones. The superficial zone accounts for 10-20% of the articular cartilage's total thickness.

Chondrocytes in this zone are elongated, flattened, and orientated parallel to the cartilage surface, surrounded by tightly packed collagen fibrils with low aggrecan levels but greater decorin and biglycan concentrations. The Prg4 gene encodes superficial zone proteins homologous to proteoglycan 4, which provide lubrication and a load-bearing surface for the articular cartilage. The transitory zone accounts for 40-60% of cartilage thickness.

Chondrocytes in this intermediate zone are surrounded by collagen type II fibrils that are irregularly arranged and contain high quantities of aggrecan, hyaluronic acid, and dermatan sulfate. Chondrocytes in the deep zone, on the other hand, are ellipsoid and stacked in cell columns surrounded by a specific PCM and interspersed with a radially oriented collagen matrix. The tidemark is a specialized amorphous substance resembling a foundation membrane that exists between the deep zone of cartilage and the calcific cartilage in adults.

 

What is Cartilage regeneration?

Cartilage regeneration is a novel technique for replacing injured or worn-down cartilage in the knee. The method, known as autologous chondrocyte implantation (ACI), involves extracting healthy cartilage cells from the injured knee, cultivating them in a lab for four to six weeks, and then injecting the new cells into the damaged joint to regenerate with the surrounding cartilage. Some individuals with one or two sites of isolated cartilage degeneration that develops over time may benefit from this minimally invasive surgery. Patients with more severe injuries may require knee replacement.

 

Diagnosis and treatment options

Following a comprehensive examination of your knee, your consultant will obtain a complete history of your symptoms. You may require some further tests:

• X-ray
• Magnetic resonance imaging (MRI) scan

Cartilage repair surgery tries to rebuild damaged cartilage using a variety of procedures ranging from microfracture (a basic keyhole procedure) to chondrocyte transplantation, which uses your own cells to heal the damaged joint surface. Keyhole surgery is used to extract a sample of your cartilage, which is then developed and extended in the laboratory. These cells are then re-implanted in the region that has been injured.

Cartilage regeneration surgery is often performed as an outpatient treatment, but it takes around six weeks on crutches after surgery to allow the new joint surface to integrate.

 

Why might I need a cartilage regeneration?

Patients requiring cartilage regeneration often require the treatment owing to a lack of blood arteries in the cartilage tissue, which means it is unable to mend itself. As a result, bleeding is required as part of the healing process.

Regeneration surgery is not for everyone, and it is more successful in individuals who have had discomfort for months rather than years, do not have knee stability or alignment issues, experience pain when resting, or have localized cartilage destruction (no more than two isolated cartilage lesions). It is not usually suggested that patients with extensive cartilage injury undergo cartilage regeneration.

 

Progress with Cartilage Regeneration

Several approaches for cartilage regeneration have been established, indicating progress.

• Debridement or abrasion: A surgeon arthroscopically removes loose cartilage, causing bleeding at the bone surface and the formation of fibrocartilage (fibrous cartilage or scar tissue). In rare circumstances, the fibrocartilage may be insufficient to preserve the joint.
• Microfracture: An arthroscopic procedure in which a surgeon clears the problematic region and produces numerous holes in the bone. This is intended to induce bleeding as well as the formation of fibrocartilage.
• Mosaicplasty, also known as osteochondral autograft transplantation, is a surgical procedure in which a physician takes a plug of bone with cartilage covering a healthy portion of the joint and transplants it to the injured area.
• Periosteal flap: A surgeon takes a part of the shin's periosteum (the connective tissue that covers all bones) and transplants it to the region of cartilage damage.
• Autologous Chondrocyte Implantation (ACI): An arthroscopic procedure is used to extract a tiny amount of cartilage from the knee. The tissue is then cultivated in a laboratory. A second procedure is necessary to implant the lab-grown cells at the location of the injured cartilage.
• Osteochondral allografts: A donor's bone is used to repair the damaged cartilage.
• Matrix Associated Chondrocyte Implantation (MACI): In 2017, the Food and Drug Administration authorized this surgery for persons under the age of 55 who have "focal chondral defects"—lesions that can progress to knee osteoarthritis. 4 It is similar to ACI in that the chondrocytes are transported back to the surgeon on a patch that functions as a scaffold over the injured region.

All of the techniques provide inconclusive findings. Many questions remain concerning attempts at cartilage regeneration. More clinical studies are required to establish conclusive answers and develop methods that ease arthritic symptoms while also producing a long-lasting substitute for damaged cartilage.

 

Knee Cartilage Repair

Special instruments can be used by a surgeon to remove frayed and shredded cartilage and smooth the remaining cartilage surface. This cartilage contouring lowers joint friction, which can lead to:

• Reduce knee pain
• Restore knee function
• Potentially slow down future cartilage degeneration

Knee chondroplasty is the medical name for surgery to restructure knee cartilage. The term "chondroplasty" refers to the formation or molding of cartilage. Chondroplasty can be done on the articular cartilage, the meniscus, or both.

• Knee debridement

Debridement is frequently performed in combination with knee chondroplasty. The surgeon removes possible irritants to the joint, such as loose fragments of cartilage, and flushes the joint with a saline solution during knee debridement (lavage).

• Knee Cartilage Regeneration

Because cartilage tissue lacks blood veins, its capacity to repair itself is severely reduced, and bleeding is required for healing. A surgeon can stimulate the formation of new cartilage by creating tiny incisions or abrasions in the bone beneath the torn cartilage. The goal is that the blood from the broken bone would stimulate the development of new cartilage cells.

Three typical knee cartilage regeneration procedures that involve bleeding to promote cartilage repair are:

• Knee microfracture, which necessitates the removal of all injured cartilage. The surgeon next pierces the bone using a pointed instrument known as an awl.

• Knee drilling is a procedure that employs a drill or wire to produce microscopic holes in the bone. There is some indication that the heat from the drill might cause unneeded damage to adjacent tissue, leading to bone cysts or other issues. 1 Knee abrasion arthroplasty, which necessitates the removal of all injured cartilage. The surgeon next scrapes and roughens the damaged bone's surface with a specific instrument.

These procedures are used to repair damaged articular cartilage. They cannot be used to repair a torn meniscus in the knee.

 

What can I expect from the procedure?

You will have the opportunity to discuss all elements of your surgery with your doctor prior to the treatment. Before you enter the operating room, an anesthesiologist will be there to discuss the appropriate form of anesthetic for your condition.

Microdrilling surgery is drilling microscopic holes into the bone at the site of cartilage injury. Through the mobilization of marrow-derived stem cells, it is intended to activate the marrow and provide an optimum environment for cartilage regeneration. The surgery is scheduled to last one to two hours.

 

Research Continues

Many academics are thinking about how to provide a better option for cartilage regeneration. New studies and methodologies are being developed all around the world to investigate this issue, and the preliminary results are encouraging. For example, bioengineers at Rice University discovered in 2008 that extreme pressure (similar to that found over half a mile below the ocean's surface) encourages cartilage cells to create new tissue.  This synthesized tissue has virtually all of the characteristics of normal cartilage.

The researchers believe this breakthrough has the potential to improve arthritis treatment. The primary researcher warned that it would be many years before the procedure was suitable for human clinical trials.

In 2017, stem cells were also employed to create new cartilage for arthritic hips in a process developed at Washington University School of Medicine. The researchers anticipate that by collaborating with Cytex Therapeutics, this will offer an option to hip replacement surgery.

This approach has the most potential for people under the age of 50. It relies on a "3-D, biodegradable synthetic scaffold" to rebuild the hip joint and alleviate discomfort. It might postpone, if not eliminate, the need for a replacement hip.

 

Conclusion 

Cartilage that has been injured by trauma has a restricted ability to repair. Current treatments for minor chondral defects include palliative arthroscopic débridement and lavage, reparative marrow-stimulation procedures (for example, microfracture), and restorative treatments such as osteochondral grafting and autologous chondrocyte implantation. Larger defects need osteochondral allograft or complete joint replacement. However, the future of cartilage defect management rests on offering biologic remedies via cartilage regeneration.