SVF Therapy: Can it Revolutionize Knee Osteoarthritis Treatment?
Adipose tissue is a valuable source of Mesenchymal Stem Cells (MSCs) and can be easily obtained through liposuction. To extract stem cells from this liposuctioned adipose tissue, referred to as lipoaspirates, it is typically subjected to a brief incubation with collagenase at human body temperature. Given that adipose tissue primarily comprises adipocytes and an extracellular matrix (ECM) housing various blood vessels, the result of incubating lipoaspirates with collagenase is known as the Stromal Vascular Fraction (SVF). These adipose SVFs contain a variety of components, including MSCs, Red Blood Cells (RBCs), White Blood Cells (WBCs), and fibrous ECM tissue. These MSCs obtained from adipose tissue, termed adipose tissue-derived stem cells (ADSCs or ASCs), have displayed the ability to regenerate cartilage in vitro. Moreover, ECM is known to serve as a scaffold and can enhance the attachment of stem cells to cartilage lesions. ECM is also known to release various growth factors that can bolster the survival and growth of injected stem cells. Therefore, autologous adipose SVF, encompassing both stem cells and ECM, holds promise as an effective agent for cartilage regeneration.
Presently, numerous techniques are employed to process autologous adipose tissue to obtain SVF. While most of these methods involve collagenase incubation, subtle differences exist, including variations in the type and quantity of collagenase, incubation duration, temperature, centrifugation forces, and time to remove residual collagenase. These distinctions in processing autologous adipose tissue for generating adipose SVF may influence its regenerative potential, leading to variable outcomes. Differences in the process can affect the quantity and quality of ADSCs and ECM produced, which, in turn, impact stem cell viability, adherence, and growth. Furthermore, none of these methods involve homogenization of the lipoaspirates, resulting in uneven effects of collagenase, with small lipoaspirates being digested effectively and larger ones not. Such non-uniform breakdown of the lipoaspirate matrix can produce large-sized fibrous tissue that may lead to unpredictable responses when injected into a joint and even obstruct syringes and needles, increasing the risk of bacterial contamination. Additionally, there is considerable individual variation in the content of adipose SVF. Regrettably, none of the reported methods for autologous adipose tissue involve homogenization for human patients.
In South Korea, adipose tissue SVF has been used for many years by plastic surgeons as a semi-permanent volume expander. In June 2009, the Korean Food and Drug Administration (KFDA) authorized the use of adipose SVF as a medical procedure when obtained and processed within the same medical facility with minimal manipulation. Subsequently, autologous adipose SVF has been successfully applied in the field of orthopedics as a potential solution for regenerating cartilage in human patients. In 2011, Pak demonstrated that ADSCs within adipose SVF, when combined with platelet-rich plasma (PRP), could regenerate cartilage-like tissue in patients with osteoarthritis. Numerous other studies have since affirmed that autologous ADSCs in human adipose SVF can regenerate cartilage in osteoarthritis patients.
In this study, an effort was made to reduce the variability in the contents of autologous adipose SVF and mitigate the potential issues associated with large-sized fibrous tissue. This was achieved by homogenizing the lipoaspirates, which allowed for a more uniform effect of collagenase in breaking down the matrix during incubation, theoretically leading to more even release of stem cells compared to non-homogenized adipose tissue. Homogenization also reduced the problem of clogging by cutting the fibrous ECM tissue into smaller pieces.
The study utilized platelet-rich plasma (PRP) as a source of growth factors and a differentiation agent for the injected ADSCs. PRP contains a variety of growth factors known to positively influence the growth and differentiation of various stem cells into chondrocytes. Hyaluronic acid (HA) was employed as a scaffold to enhance the penetration of stem cells into the cartilage matrix. Additionally, for the first time, the study demonstrated the positive effects of autologous lipoaspirates containing both ADSCs and homogenized ECM in terms of pain reduction (measured by the visual analog scale or VAS), improved physical therapy parameters, and provided magnetic resonance imaging (MRI) evidence of cartilage-like tissue regeneration in human knee osteoarthritis (OA) patients after 3 months of treatment.
The Methods and Procedure
1. Before The Procedure
Regulatory Compliance and Informed Consent
The KFDA's new regulations have facilitated the use of autologous adipose tissue as a source of ADSCs in South Korea. Informed consent was obtained from each patient. The requirement for approval and consent to report individual cases was waived by the Myongji University Institutional Review Board committee (MJUIRB) for this case report.
Inclusion and Exclusion Criteria and Outcome Measures
- Patients with MRI-confirmed hip osteoarthritis (OA).
- Orthopedic evaluation with negative Apley and McMurray tests, indicating suitability for total knee replacement (TKR) surgery.
- Both male and female individuals aged 50 or older.
- Patients declining TKR.
- Unsuccessful outcomes with conservative management.
- Ongoing, incapacitating pain.
- Presence of an active inflammatory or connective tissue disease that may affect the pain condition (e.g., lupus, rheumatoid arthritis, fibromyalgia).
- Active endocrine disorders that might impact the pain condition (e.g., hypothyroidism, diabetes).
- Active neurological disorders that may impact the pain condition (e.g., peripheral neuropathy, multiple sclerosis).
- Active cardiac disease.
- Active pulmonary disease requiring medication usage.
- Assessment of pain levels using the Visual Analog Scale (VAS) before and after treatment.
- Evaluation of functional improvement through the Functional Rating Index (FRI).
- Measurement of the range of motion (ROM).
- Comparison of pre-treatment and post-treatment MRI findings conducted before the treatment and three months after the treatment.
Patients were advised not to take steroids, aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or Asian herbal medications for one week before the procedure.
2. During The Procedure
Liposuction and Preparation of ADSC/ECM Mixture
In the operating room, approximately 50 mL of packed adipose tissue was obtained through liposuction of the subcutaneous layer of the lower abdominal area using manual techniques. The lower abdominal area was anesthetized with tumescent solution, and adipose tissue was collected using a 3.0 cannula connected to a 60-mL Luer-Lock syringe. These lipoaspirates were then centrifuged at 1600 g for 5 minutes. Afterward, the adipose tissue was minced and filtered using a manual tissue homogenizer with blades, resulting in the removal of large fibrous tissue. The minced lipoaspirates were then mixed thoroughly with collagenase (0.07% type 1 collagenase; Adilase; Worthington, Lakewood, NJ) and incubated in a rotating incubator mixer at 37°C for 40 minutes. Following incubation, the SVF and collagenase mixture were centrifuged at 300 g to separate and remove collagenase. The top part of the solution was discarded, and the centrifuge syringe was filled with dextrose 5% in normal saline solution (D5NS; Baxter Healthcare Corp., Marion, NC) and centrifuged thrice. The final volume of the SVF, containing ADSCs, ECM, and other cellular components, was 7.5–8.5 mL.
While preparing the ADSCs and ECM, 30 mL of autologous blood was drawn, along with 2.5 mL of anticoagulant citrate dextrose solution (0.8% citric acid, 0.22% sodium citrate, and 0.223% dextrose; Baxter Healthcare Corp.). After centrifugation, 4.4 mL of PRP was obtained, and 3% (w/v) calcium chloride (0.1 mL; Choongwae Pharmaceutical Co., Gyeonggido, Korea) was added to activate the PRP. Additionally, 0.5% (w/v) HA (2 mL; Huons, Chungbuk, Korea) was included as a scaffold in this mixture. These ADSCs and ECM, combined with PRP activated by calcium chloride and HA, collectively formed the ADSC/ECM mixture.
ADSC/ECM Mixture-Based Treatment
The knee was cleaned with 5% povidone–iodine and anesthetized with 0.25% ropivacaine outside of the joint capsule. Inside the joint capsule, 0.125% lidocaine was used for anesthesia. On the same day as liposuction, approximately 14 mL of the ADSC/ECM mixture was injected into the medial inferior tibiofemoral joint of the knees using a 38-mm 18-gauge needle under ultrasound guidance. The patient was instructed to remain still for 60 minutes to allow for cell attachment. The patient was advised to limit activities for one week and returned for three additional injections of PRP activated by calcium chloride over three weeks.
A 2016 study by Dr Jaewoo Pak titled Regeneration of Cartilage in Human Knee Osteoarthritis with Autologous Adipose Tissue-Derived Stem Cells and Autologous Extracellular Matrix has conducted a cross-case research to study 3 different patients with 3 different condition.
Patient Case #1
Patient #1 is an 87-year-old Korean female with a history of bilateral knee pain lasting over 20 years. Her left knee pain was more severe than her right, and it had recently escalated to the point of limiting her daily activities. She was diagnosed with stage 3 knee osteoarthritis (OA) and had previously undergone multiple injections of steroids and hyaluronic acid (HA) without experiencing permanent relief. She was advised to undergo total knee replacement (TKR) surgery but was hesitant due to potential side effects.
At the initial evaluation, she reported severe pain at rest (VAS score of 8) and increased pain (FRI: 37) during stair climbing. Physical examination revealed mild joint edema, decreased range of motion (ROM), and tenderness with flexion. A pretreatment MRI showed a decreased size and deformed contour of the left knee's medial meniscus due to maceration. She received the ADSC/ECM mixture-based treatment, and by the 16th week, her pain and ROM had significantly improved by more than 70%. Post-treatment MRI revealed increased thickness of cartilage-like tissue on the medial side of the knee.
Patient Case #2
Patient #2 is a 68-year-old Korean male who had been experiencing left knee pain for over two years. Initially diagnosed with knee OA and meniscus tear, he underwent left medial meniscus resection and debridement via arthroscopy, which did not alleviate his knee pain. Multiple injections of steroids and HA also provided no relief. Another orthopedic surgeon recommended TKR, but the patient was reluctant due to potential side effects.
At the initial evaluation, the patient reported severe pain at rest (VAS score: 7) and increased pain during stair climbing (FRI: 33). Physical examination revealed mild deformity and joint swelling, with decreased ROM. A pretreatment MRI confirmed stage 3 OA, showing a decreased size and deformed contour of the medial meniscus due to prior meniscectomy. The patient underwent the same ADSC/ECM mixture-based treatment, resulting in significant pain and ROM improvements by the 18th week. Repeated MRI revealed an increase in the height of cartilage-like tissue on the anterior medial side of the knee.
Patient Case #3
Patient #3 is a 60-year-old Korean female who had been suffering from left knee pain for over eight years due to stage 3 OA. She had undergone arthroscopic lavage/debridement and received multiple injections of steroids and HA, all without sustained improvement. TKR surgery was recommended by an orthopedic surgeon, but the patient was reluctant due to potential side effects.
At the initial evaluation, the patient reported severe pain at rest (VAS score: 8) and increased pain during walking (FRI: 36). Mild knee swelling and decreased ROM were observed during physical examination. A pretreatment MRI showed a decreased size and deformed contour of the left knee's medial meniscus due to maceration, along with cartilage thinning. Similar to the previous cases, the patient received the ADSC/ECM mixture-based treatment. By the 22nd week, her pain and ROM had significantly improved by over 80%. Repeated MRI revealed an increase in the height of the cartilage-like tissue on the medial side of the knee.
Regeneration of Cartilage in Human Knee Osteoarthritis with utologous Adipose Tissue-Derived Stem Cells and Autologous Extracellular Matrix (2016)
Understanding adipose-derived stromal vascular fraction (AD-SVF) cell biology and use on the basis of cellular, chemical, structural and paracrine components: a concise review (2012)
Human adipose tissue is a source of multipotent stem cells (2002)
Regeneration of human bones in hip osteonecrosis and human cartilage in knee osteoarthritis with adipose-tissue-derived stem cells (2011)
Cartilage regeneration in human with adipose tissue-derived stem cells: current status in clinical implications (2016)
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