Cartilage Damage

What is Knee Cartilage?

The knee joints are lined by extremely smooth tissue called “articular cartilage.”


The articular cartilage of the knee coats

  • the end of the femur (thigh bone),
  • the top surface of the tibia (shin bone) and
  • the back surface of the patella (kneecap)


It is a protective cushion, allowing smooth, low-friction movement of the joints as one bone end moves on the other. Cartilage tissue covers the adjacent bone surfaces of the knee.


What is Knee Cartilage Damage?

Knee Cartilage Damage can result from:

  • Degeneration from age
  • Repetitive wear and tear,
  • Twisting or jumping down, or
  • Trauma injuries such as a fall


Knee cartilage damage can also relate to a fracture or ligament injury in the knee.


How Does Knee Cartilage Damage Impact Your Anatomy and Health?

Meanwhile, cartilage damage does not always produce immediate secondary pain because there are no nerve endings in the cartilage. However, patients may experience swelling, stiffness, and mechanical-type symptoms such as locking and catching.


Pain, when it occurs, may be related to other injuries, such as fracture, ligamentous injury, bone bruise or severe articular cartilage injury where the injury is full-thickness and down to the nerve endings in the bone.


Cause and Risk Factors for Knee Cartilage Damage

Several factors can increase the risk of knee cartilage damage, and it's important to be aware of these risk factors:

  • Age: The risk of cartilage damage tends to increase with age. Older individuals are more prone to wear and tear on their knee cartilage.
  • Previous Injuries: If you've had knee injuries, such as a torn meniscus or ligament damage, it can predispose you to cartilage damage.
  • Sports and Physical Activity: Participation in high-impact sports or activities that involve repetitive knee movements, such as running or jumping, can increase the risk of cartilage damage.
  • Obesity: Being overweight or obese places extra stress on the knee joint, accelerating cartilage wear and tear.
  • Genetics: Some people may have a genetic predisposition to cartilage problems, making them more susceptible to damage.
  • Occupational Factors: Certain occupations that involve prolonged kneeling or squatting may increase the risk of knee cartilage damage.


Symptoms of Cartilage Damage

If the cartilage gets damaged by disease or injury, the tissues around the joint become inflamed, causing:

  • Pain
  • Swelling,
  • Stiffness,
  • Locking and
  • Limited Movement


Types of Knee Cartilage Damage:

  • Articular Cartilage Damage: This type of damage affects the smooth, white tissue covering the ends of bones in the knee joint. It can occur due to injury, overuse, or degenerative conditions like osteoarthritis.
  • Meniscus Tears: The menisci are C-shaped pieces of cartilage in the knee that act as shock absorbers. Tears in the meniscus can occur due to twisting or forceful movements and are a common form of cartilage damage.
  • Chondromalacia Patellae: This condition involves the softening and degeneration of the cartilage on the underside of the kneecap. It can result from improper tracking of the kneecap or overuse.
  • Osteoarthritis: While not a type of damage per se, osteoarthritis is a degenerative condition that can lead to the breakdown of cartilage in the knee joint over time.


Diagnosis of Cartilage Damage

Your doctor will need to diagnose the specific nature of your cartilage damage or the extent of any osteoarthritis in the knee joint.


Often, cartilage damage can be identified during a physical examination, and during this consultation, your doctor will:

  • Take a Medical History
  • Perform a Physical Examination
  • Assess The Joint’s Range of Motion


To clearly understand the nature of any loss of the joint space or bone spur formation, imaging scans are required:

  • X-rays do not show cartilage but are often normal as they can help rule out other problems with the knee that may have similar symptoms like fractures (broken bone) or ACL injury.
  • MRI can create detailed images of your knee's hard and soft tissues. An MRI can produce cross-sectional images of internal structures required if the diagnosis is unclear or other soft tissue injuries are suspected, such as ligament or articular cartilage injuries.


While not all of these tests are required to confirm the diagnosis, this diagnostic process will allow your doctor to review any possible risks or existing conditions that could interfere with the surgery or its outcome.


Treatments for Cartilage Damage

Conservative Management

  • Rest and Activity Modification: Reducing activities that exacerbate symptoms and giving the knee time to heal.
  • Physical Therapy: Targeted exercises to strengthen the muscles around the knee and improve joint stability.
  • Medications: Pain relievers and anti-inflammatory drugs to manage pain and inflammation.


Injections

  • Corticosteroid Injections: These can reduce inflammation and alleviate pain.  This is a powerful intervention though is often short lived.
  • Viscosupplementation: Injections of hyaluronic acid to lubricate the joint.  There are level 1 studies that show 70% of patients do have a benefit for 6 months or more.


Stem Cells and Tissue Engineering

Current research is focused on new ways to make the body grow healthy cartilage tissue. This is called tissue engineering. Growth factors that stimulate new tissue may be isolated and used to stimulate new cartilage formation.

The use of mesenchymal stem cells is also being investigated. Mesenchymal stem cells are basic human cells obtained from living human tissue, such as bone marrow. When stem cells are placed in a specific environment, they can give rise to cells that are similar to the host tissue. For example, if implanted in bone, they will stimulate the creation of bone cells.


The hope is that stem cells placed near a damaged joint surface will stimulate hyaline cartilage growth. Tissue engineering procedures are still at an experimental stage.  There is no good evidence at this stage that stem cell therapy can regrow cartilage in humans.



Surgical Interventions

  • Arthroscopic Chondroplasty Surgery: Used to repair minor cartilage tears or remove loose fragments.
  • Microfracture: A procedure to stimulate the growth of new cartilage.
  • Autologous Chondrocyte Implantation (ACI): A more advanced procedure where healthy cartilage cells are cultured and implanted into the damaged area.
  • Osteochondral Autograft or Allograft Transplantation:  This procedure involves taking bone and cartilage from the patients own knee (low demand area) or from donated tissue and inserting it into the area of deficiency.
  • Knee Replacement: In severe cases, when conservative and surgical treatments are ineffective, total or partial knee replacement may be necessary. In many cases with older patients, Knee Joint Replacement Surgery is the most appropriate course, but not always.


As cartilage cannot repair itself, most other treatments do not completely restore the cartilage to its original structure. Still, these procedures can relieve pain and allow better function.


These other surgical techniques have been developed to stimulate the growth of new cartilage. Current techniques can

  • Stimulate Cartilage Growth
  • Delay or Prevent The Onset of Arthritis


Surgical techniques to repair damaged cartilage are evolving; your doctor is experienced in these approaches.


Chondroplasty

This procedure involves

  • smoothing the roughened areas,
  • removing any loose fragments


In many cases, patients who have joint injuries, such as meniscal or ligament tears, will also have cartilage damage.


This involves smoothing out any unstable areas of cartilage by using fine mechanical shavers and thermal devices to stabilise loose areas of cartilage.


The benefits of Chondroplasty are that it is not invasive with quick recovery but does not stimulate cartilage regeneration.


Microfracture

The goal of microfracture is to stimulate the growth of fibrocartilage by creating a new blood supply. As with Chondroplasty, this procedure involves

  • Smoothing The Roughened Areas,
  • Removing Any Loose Fragments And
  • Scraping Any Exposed Bone to Stimulate Cartilage Recovery.


A tool makes multiple holes in the joint surface to promote a healing response. Stem cells from the underlying bone marrow create new fibrocartilage tissue.


This procedure is best for young patients with

  • A Single Lesion
  • Lesions Under 2cm
  • Healthy Subchondral Bone


The recovery is usually slower than a chondroplasty, as specific rehabilitation protocols are required to allow the new fibrocartilage to regenerate.


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