Illustration of bone marrow lesion treatment with calcium phosphate.

Hitting the Mark: Can Calcium Phosphate Injections Ease Knee Bone Marrow Lesions?

Nico Varela in Health & Wellness December 2025 • 4 min read.

"A comprehensive approach to using calcium phosphate injections to treat bone marrow lesions, potentially offering pain relief and promoting bone repair."

Osteoarthritis can cause increased pressure in the knee joint, leading to bone injuries and bone marrow lesions (BMLs). These lesions, characterized by marrow edema, contribute to persistent pain and disability.

While options for treating these osteoarthritis-related BMLs have been limited, recent advancements in injectable calcium phosphate show promise in alleviating pain and supporting the body's own repair mechanisms.

This article explores a comprehensive surgical technique that uses injectable calcium phosphate to target BMLs in the proximal tibia and distal femur. It highlights key considerations, including the use of magnetic resonance imaging (MRI) and fluoroscopy for precise targeting, controlled delivery of the calcium phosphate, and post-injection arthroscopy to prevent complications.

Why Calcium Phosphate for Bone Marrow Lesions?

Illustration of bone marrow lesion treatment with calcium phosphate.

Bone marrow lesions (BMLs) in the knee can indicate underlying damage to the bone's structure and are linked to various painful conditions. Magnetic resonance imaging (MRI) helps identify these lesions, appearing as fluid-sensitive areas when fat suppression is used.

In osteoarthritis, chronic overload contributes to BMLs, causing increased pain and impaired function. Although BMLs can vary, most tend to persist or worsen over time, potentially leading to the need for total knee replacement.

Provides Mechanical Support: Calcium phosphate acts as a scaffold to stabilize the damaged area.
Stimulates Bone Remodeling: It encourages the body to rebuild bone at the injury site.
Offers Early Pain Relief: The injection can quickly reduce pain associated with BMLs.

Emerging as a treatment, calcium phosphate injections, known as subchondroplasty, aim to address osteoarthritis-related BMLs by providing structural support and stimulating bone repair. Studies suggest that this method improves clinical outcomes, with a significant percentage of patients avoiding joint replacement. While promising, detailed techniques and combined approaches are essential to maximize the benefits of this procedure.

A Promising Path Forward

This article highlights the use of calcium phosphate injections as a comprehensive surgical approach for treating osteoarthritis-related BMLs.

By carefully targeting the affected area and using post-injection arthroscopy, surgeons aim to reduce pain, promote bone repair, and improve patient outcomes. Further studies are still needed to determine long-term efficacy.

As research evolves, calcium phosphate injections present a promising option for individuals seeking relief from knee pain associated with bone marrow lesions, potentially delaying or even preventing the need for more invasive procedures like total knee replacement.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.eats.2018.06.006, Alternate LINK

Title: Hitting The Mark: Optimizing The Use Of Calcium Phosphate Injections For The Treatment Of Bone Marrow Lesions Of The Proximal Tibia And Distal Femur

Subject: Orthopedics and Sports Medicine

Journal: Arthroscopy Techniques

Publisher: Elsevier BV

Authors: Brian J. Rebolledo, Kevin M. Smith, Jason L. Dragoo

Published: 2018-10-01

Everything You Need To Know

What exactly are bone marrow lesions (BMLs) in the knee, and how do they relate to osteoarthritis?

Bone marrow lesions (BMLs) are areas of damage within the bone, often found in the knee. In osteoarthritis, increased pressure and wear can lead to these lesions, which are identified using magnetic resonance imaging (MRI). They appear as fluid-sensitive areas indicating swelling or edema within the bone marrow. These lesions contribute to pain and reduced function in the knee. Over time, if left untreated, BMLs can worsen and may eventually lead to the need for total knee replacement.

How does injectable calcium phosphate work to treat bone marrow lesions in the knee?

Injectable calcium phosphate addresses bone marrow lesions by providing mechanical support, stimulating bone remodeling, and offering early pain relief. Acting as a scaffold, calcium phosphate stabilizes the damaged area and encourages the body to rebuild bone at the injury site. The injection can quickly reduce pain associated with BMLs. This approach, known as subchondroplasty, aims to treat osteoarthritis-related BMLs and improve clinical outcomes, potentially avoiding joint replacement.

What does the surgical procedure for calcium phosphate injections involve, and what makes it a comprehensive approach?

The comprehensive surgical technique involves precise targeting of the bone marrow lesions (BMLs) in the proximal tibia and distal femur using magnetic resonance imaging (MRI) and fluoroscopy. Calcium phosphate is then carefully delivered into the lesion. Post-injection arthroscopy is performed to prevent complications. This meticulous approach ensures that the calcium phosphate is accurately placed to provide optimal support and stimulate bone repair.

Why is magnetic resonance imaging (MRI) so important in the diagnosis and treatment of bone marrow lesions?

Magnetic resonance imaging (MRI) is crucial for identifying bone marrow lesions (BMLs) in the knee. MRI scans reveal these lesions as areas of marrow edema, appearing as fluid-sensitive regions when fat suppression is used. This imaging technique allows healthcare providers to visualize the extent and location of the lesions, guiding the targeted delivery of calcium phosphate during the injection procedure. MRI helps in assessing the effectiveness of the treatment post-injection as well.

What are the long-term implications of using calcium phosphate injections for bone marrow lesions, and does it cure osteoarthritis?

While calcium phosphate injections show promise in treating bone marrow lesions (BMLs) related to osteoarthritis, it's essential to understand that this approach primarily addresses the symptoms and supports bone repair. It doesn't directly cure the underlying osteoarthritis, which may continue to progress. Therefore, combining calcium phosphate injections with other treatments like physical therapy, weight management, and medications may be necessary for comprehensive management of osteoarthritis. Additionally, long-term studies are ongoing to fully evaluate the durability and effectiveness of calcium phosphate injections in preventing or delaying the need for total knee replacement.