Non-surgical treatments for knee pain: Effective options according to pain medicine.

Introduction

Knee pain is one of the leading causes of disability worldwide and a frequent reason for consultation in pain medicine. It is estimated that approximately 25% of the adult population experiences knee pain at some point in their lives, with a higher prevalence in people over 50 years of age. Knee osteoarthritis, the most common cause of this pain, affects more than 30% of adults over 65 years of age and its incidence continues to increase due to the aging population and the increase in risk factors such as obesity and sedentary lifestyles.

From a pain medicine perspective, treatment strategies that avoid or delay surgery, improve patients’ quality of life, and reduce the economic burden on healthcare systems are essential. This brief addresses the main pathologies that cause knee pain, the diagnostic protocol from pain medicine, nonsurgical interventional treatment options, and the importance of a multidisciplinary approach in the management of this condition.

Knee Pathology Causing Pain

Knee pain can be caused by various pathologies, the most frequent being:

• Osteoarthritis: This is the most common cause of chronic knee pain and is characterized by progressive degeneration of the articular cartilage, resulting in inflammation, pain and loss of function.
• Patellofemoral syndrome: It is associated with patellar malalignment and mainly affects young people and athletes, causing pain in the anterior part of the knee.
• Meniscal injuries: Meniscal tears can be traumatic or degenerative and present with pain, joint effusion and mechanical blockage of the knee.
• Patellar tendinopathy: Common in athletes, this pathology is the result of overuse and generates pain in the anterior part of the knee, just below the kneecap.
• Bursitis: Inflammation of the periarticular bursae, generally caused by repetitive trauma or mechanical overload.
• Iliotibial band syndrome: It occurs in runners and cyclists due to friction of the iliotibial band on the lateral femoral condyle.

Diagnostic Protocol from a Pain Medicine Point of View

Accurate diagnosis of knee pain is essential to select the appropriate treatment. From pain medicine, the diagnostic protocol includes:

1. Complete medical history: Pain characteristics (onset, duration, location, aggravating and extenuating factors), medical history and previous treatments are evaluated.
2. Physical examination: joint mobility, stability, presence of effusion, patellar alignment and specific pain points are assessed.
3. Pain and Functionality Scales: Tools such as the Visual Analog Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) are used to assess the impact of pain on quality of life.
4. Imaging studies: X-rays, MRI and ultrasound allow identification of structural lesions and guide treatment.
5. Diagnostic blocks: Infiltrations with local anesthetics in specific structures (geniculate nerves, joint compartments) help to determine the source of pain and to plan interventional treatments.

Non-surgical interventional treatments available

The non-surgical interventional treatment of knee pain allows to relieve those patients who suffer pain in this joint. Depending on the triggering cause of the pain, the type of treatment will differ, however interventional treatments are focused on those patients in whom pharmacological treatments have not been sufficiently satisfactory and who are not candidates for surgical treatment or who prefer to opt for less invasive alternatives. In this context, pain medicine offers various non-surgical interventional options focused on each patient profile and that seek to modulate the perception of pain allowing to reduce inflammation and thus improve joint function without the need for major surgical procedures.

1. Intra-articular infiltrations

They are a very effective alternative for patients suffering from meniscus injuries (without surgical criteria), patello-femoral injuries or incipient stages of osteoarthritis.

Inside the joint there are various compounds that can be used to reduce pain and thus improve joint function.

Corticosteroid infiltrations are widely used to reduce inflammation and pain in the knee, especially in patients with osteoarthritis. However, their use should be limited due to possible adverse effects on cartilage.

Hyaluronic acid is a synthetic compound that acts as a lubricant that improves joint mobility, reduces inflammation and promotes a regenerative state, relieving pain in patients with mild to moderate joint wear and tear or meniscal pathology.

Another alternative increasingly used are growth factors such as platelet-rich plasma (PRP), this autologous therapy (from the patient himself) injected into the joint at the right time favor the regeneration of joint and tendon tissues that may suffer wear. This therapy shows promising results especially in patients suffering from osteoarthritis and meniscus pathology, although more evidence on its long-term effectiveness is still needed.

2. Nerve Blocks and Radiofrequency

Nerve blocks consist of the infiltration of local anesthetics and anti-inflammatory drugs in the nerves responsible for picking up the sensitivity of the knee (and which are called geniculate). Thanks to this treatment we manage to temporarily block the transmission of pain. If these blocks are effective, radiofrequency of the geniculate nerves can be considered, which is a procedure in which controlled heat is applied to desensitize these structures and provide long-term pain relief.

Radiofrequency has become a key option for patients with advanced osteoarthritis who do not respond to conventional treatments and wish to avoid or delay joint replacement surgery. Its effectiveness has been demonstrated in multiple studies, with pain reduction lasting from six months to several years. Our group has pioneered these research studies.

3. Regenerative Therapy and Other Options

Regenerative medicine, including the use of mesenchymal stem cells, represents one of the most innovative options in the treatment of knee pain. Its aim is to promote the repair of damaged cartilage and improve joint function, although its application is still in the research phase and needs further studies to establish which pathologies and at what stage are most suitable to be subjected to this treatment.

Advantages of Multidisciplinary Treatment

The multidisciplinary approach is key in the treatment of knee pain, as it allows combining different therapeutic strategies to improve the patient’s quality of life. Some advantages of this approach include:

• Better pain control: The combination of interventional treatments with physiotherapy, pharmacological management and psychological support improves pain relief compared to a single therapeutic approach.
• Preservation of joint function: Muscle strengthening, manual therapy and patient education help reduce the load on the joint and improve mobility.
• Reducing the need for surgery: By offering effective alternatives for pain management, unnecessary surgical procedures can be avoided or the progression of degenerative diseases such as osteoarthritis can be delayed.
• Optimizing emotional well-being: Psychotherapy, cognitive-behavioral therapy and mindfulness help patients cope better with chronic pain and improve their quality of life.
• Personalized approach: Pain medicine allows tailoring treatments to the patient’s individual needs, ensuring comprehensive and effective care.

Conclusion

Knee pain management from pain medicine offers multiple non-surgical options that can significantly improve the quality of life of patients. Through proper diagnosis, the application of interventional treatments and a multidisciplinary approach, it is possible to control pain, preserve joint function and avoid the need for surgery in many cases. The combination of these strategies represents an effective and less invasive alternative for the treatment of chronic knee pain.