The restoration of normal knee joint motion and function without the need for replacement is accomplished through various joint care methods, collectively referred to as “knee joint preservation.” This preservation approach enables orthopedic surgeons to address knee joint issues while maintaining the natural architecture of the affected joints. Techniques aimed at preserving the knee joint are primarily employed for individuals with defects in the articular cartilage of the knee. 

Injuries to the cartilage can serve as precursors to arthritic conditions and may present as knee pain. The symptoms and severity associated with knee joint defects can differ significantly among individuals. Damage to the articular cartilage, often resulting from traumatic injuries or age-related degeneration, can lead to pain, stiffness, and a restricted range of motion.

Given that articular cartilage lacks the ability to regenerate or heal independently, surgical intervention is frequently necessary to promote or stimulate the growth of new cartilage. The restoration of articular cartilage alleviates pain, enhances normal function, and, in certain instances, may delay or prevent the development of arthritis in the knee joint.

Knee joint preservation vs. replacement, what are the indications for knee preservation?

Joint preservation is typically the preferred approach for physicians aiming to restore the normal functionality of the knee joint. However, several factors must be taken into account when deciding between knee joint preservation and knee replacement. Among these factors influencing the decision are:

• Age of the individual: It is commonly observed that preservation methods yield more favorable results in younger individuals; however, these methods may also be favored by older individuals who are not suitable candidates for extensive surgical procedures.
• Weight of the individual: The stress exerted on a joint correlates directly with an individual’s weight. A reduction of even one kilogram in body weight can alleviate the pressure on knee joints by approximately three to five kilograms. For individuals with obesity, weight loss is a key strategy for joint preservation.
• Muscle strength and conditioning: The muscles of an individual are crucial not only for joint movement but also serve as protectors by absorbing impact. Regular physical activity is essential for maintaining and enhancing muscle strength, which in turn diminishes stress and discomfort in the joints.
• Extent of cartilage damage: Cartilage functions as a cushion between the bones in the knee joint. Minor thinning or erosion of cartilage can often be effectively treated with minimally invasive joint restoration techniques. Conversely, significant cartilage loss results in direct bone contact, leading to friction that accelerates deterioration. Such conditions are typically more appropriate for joint replacement surgery.

The following knee conditions are potential indications for joint preservation:

• Injuries to ligaments and articular cartilage can result from either traumatic events or the gradual degeneration associated with wear and tear.
• A meniscus tear takes place in the flexible cartilage of the knee, which serves to absorb shock between the shinbone and the thighbone.
• Osteoarthritis is characterized by inflammation affecting the bones and joints.
• Osteochondritis dissecans refers to the presence of fissures in the articular cartilage as well as in the underlying bone.
• Patellar instability arises when the kneecap dislocates from the groove located at the distal end of the femur.
• Synovial chondromatosis of the knee is a benign tumor that develops within the synovial membrane of the joint.
• Valgus or Varus malalignment, a knee deformity.

Steps Involved in Knee Preservation

Knee preservation aims to sustain and rehabilitate the natural knee joint, thereby postponing or averting the necessity for surgical replacement. The following are the essential steps involved:

• Precise Diagnosis: Determining the underlying cause of knee pain or dysfunction through advanced imaging modalities such as X-rays, MRIs, or CT scans.
• Rehabilitation Therapy: Enhancing the strength of the muscles surrounding the knee to improve joint stability, alleviate stress on the knee, and increase the range of motion.
• Pharmaceuticals and Injections: Administering anti-inflammatory drugs, hyaluronic acid, or platelet-rich plasma (PRP) injections to mitigate inflammation and facilitate healing.
• Minimally Invasive Techniques: Procedures such as arthroscopy may be employed to remove damaged cartilage, repair ligaments, or eliminate loose fragments.
• Osteotomy: Adjusting the alignment of the knee bones to relieve stress from affected areas, especially in instances of misalignment.
• Cartilage Regeneration Methods: Techniques including microfracture, cartilage grafting, or autologous chondrocyte implantation (ACI) aimed at regenerating or replacing damaged cartilage.

Postoperative Rehabilitation After Knee Joint Preservation

Following knee joint preservation surgery, adhering to a well-organized rehabilitation program is crucial for effective recovery and restoring functionality to your knee. The typical recovery process generally includes the following steps:

Phase 1: Right After Surgery (0 -2 weeks)

• Pain Management: Use medication and ice packs to reduce discomfort and swelling.
• Ensuring Safety: Use crutches or a walker to avoid weight-bearing on the knee.
• Gentle Movement: Perform simple exercises to maintain mobility and prevent stiffness.
• Wound Care: Keep the surgical incision clean and dry to prevent infection.

Phase 2: Early Recovery (2-6 weeks)

• Enhancing Strength: Gradually increase weight-bearing on the knee.
• Developing Muscle: Start light exercises to strengthen surrounding muscles.
• Improving Balance: Incorporate exercises to boost balance and knee awareness.
• Maintaining Flexibility: Add stretches to improve knee flexibility.

Phase 3: Mid-Recovery (6-12 weeks)

• Building Strength: Progress to more challenging muscle-strengthening exercises.
• Functional Movements: Practice activities like walking and stair climbing.
• Cardio Conditioning: Begin low-impact activities like cycling or swimming.
• Joint Mobility: Use stretches and drills to enhance knee movement.

Phase 4: Final Recovery (12 weeks and beyond)

• Athletic Prep: Gradually return to sports with professional guidance.
• Enhancing Agility: Focus on exercises for jumping and quick movements.
• Structured Program: Follow a tailored plan for safe activity resumption.
• Consistency: Maintain regular exercise, strength training, and stretching to ensure long-term knee health.

Long-term outcomes

Approximately 80-90% of patients who undergo knee preservation surgery do not require knee replacement surgery within a decade. Various factors influence the probability of ultimately needing knee replacement, including the specific type of knee preservation procedure performed, the patient’s body weight, overall health, and age.