Stone Research Foundation

Our Research

Our team, alongside our collaborative network, is advancing breakthroughs that will transform the treatment, prevention, and recovery of osteoarthritis. Discover how below.

Read our 2025 Annual Report to see what we achieved last year

Our Focus

Our research pipeline spans five key areas. Explore each one below to learn more about the research, techniques, and clinical significance shaping our work.

Articular Cartilage

Regenerating damaged articular cartilage to restore healthy and smooth joint surfaces, treating and preventing osteoarthritis.

Explore Articular Cartilage Research

Meniscus

Advancing meniscus allograft transplantation, replacing the knee’s shock absorber to preserve function and delay joint replacement.

Explore Meniscus Research

Ligament

ACL reconstruction techniques for improved outcomes.

Explore Ligament Research

Orthobiologic Injections

Expanding regenerative, non-operative treatments with studies on growth factors, PRP, and other orthobiologics to accelerate healing and relieve joint pain.

Explore Injections Research

Veterinary

Advancing regenerative treatments for humans and animals alike.

Explore Veterinary Research

Landmark Findings

Research that has changed how we approach biologic joint repair.

PASTE GRAFT OUTCOMES

19.1 Years

Longest follow-up study demonstrating sustained benefit of articular cartilage paste grafting for knee arthritis.

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MENISCUS SURVIVAL

89.4%

Meniscus allograft transplant survival rate at minimum 2-year follow-up, restoring knee function.

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XENOGRAFT ACL

20 Years

First proof that processed porcine tissue can successfully reconstruct human ACL ligaments.

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Global Collaboration with Field Leaders

The scientific and clinical leaders guiding this work from lab to clinic. Stone Research Foundation partners with internationally recognized pioneers in orthopaedic science, tissue engineering, and regenerative medicine to translate breakthrough ideas from discovery into real-world therapies.

Explore Our Research Partners

Active Studies

Current Research Projects

Our ongoing research initiatives focused on advancing regenerative orthopaedics and developing new treatments for arthritis.

Results Pending2023 - Present

ArtCart+ Characterization and Optimization Studies

Enhancing the Articular Cartilage Paste Graft (ArtCart) surgical technique, with support from the California Institute for Regenerative Medicine (CIRM), to improve graft fixation, cell viability, and cartilage regeneration with the goal of developing a one-step, affordable, and accessible OA treatment.

Active2024 - Present

ArtCart+ Equine Study: Candidate Selection Phase

Evaluating an enhanced version of the Articular Cartilage Paste Graft (ArtCart) surgical technique in an equine joint model to improve cartilage regeneration and graft fixation, advance treatment for veterinary patients, and generate essential evidence for future human clinical improvements.

In Development2022 - Present

Characterization of Orthobiologic Injections

Comparing leading orthobiologic injections for joint pain and inflammation to determine which therapies provide the safest, most effective, and longest-lasting outcomes for patients with sports injuries and arthritis.

Active2022 - Present

Articular Cartilage Paste Graft (ArtCart) Augmentation with Alpha-Gal Nanoparticles

Investigating whether adding the Alpha-Gal carbohydrate to augment the Articular Cartilage Paste Graft (ArtCart) procedure can stimulate a stronger healing response and produce more effective cartilage regeneration in arthritic joints through a novel molecular approach.

In Development2024 - Present

Use of Testosterone to Reduce Post-Surgical Muscle Loss: Clinical Trial

Building on a completed 15-patient pilot demonstrating feasibility and safety, this study will test whether short-term, long-acting injectable testosterone can protect against muscle loss after knee surgery. MuscleSound, Inc. technology will provide detailed ultrasound assessments of muscle mass and health.

Active2022-Present

Longitudinal Patient Outcomes

Tracking long-term patient-reported outcomes across a range of orthopaedic procedures to understand how patients recover over time. This data has already led to peer-reviewed publications while helping SRF identify patterns, evaluate treatment results, and generate evidence to guide future research and improve patient care.

Published Research Library

Showing 15 of 15 studies

Articular Cartilage Knee 1997

Surgical Technique for Articular Cartilage Transplantation to Full-Thickness Cartilage Defects in the Knee Joint

Kevin R. Stone, Ann Walgenbach

Research Question: How can full-thickness cartilage defects be repaired in a single procedure?

Arthroscopic articular cartilage and cancellous bone grafting into full-thickness knee chondral defects resulted in consistent lesion repair and meaningful short-term improvements in patient pain, function, and activity. OR Description of the Articular Cartilage Paste Graft Procedure

Key Finding: Articular cartilage paste grafting offers a feasible method of lesion repair and meaningful short-term improvements in patient pain, function, and activity.

Operative Techniques in Orthopaedics View Publication

Meniscus Cartilage Knee 2003

Meniscal Allografting: The Three-Tunnel Technique

Kevin R. Stone, Ann W. Walgenbach

Research Question: How can arthroscopic meniscal allografting be refined?

A technical note on the arthroscopic three-tunnel technique

Key Finding: The arthroscopic three tunnel technique for meniscal allografting enables accurate placement and stable fixation of medial and lateral allografts to the tibia at 3 sites.

Arthroscopy View Publication

Meniscus Cartilage Knee 2006

Meniscus Allograft Survival in Patients with Moderate to Severe Unicompartmental Arthritis: A 2- to 7-Year Follow-up

Kevin R. Stone, Ann W. Walgenbach, Thomas J. Turek, Abhi Freyer, Martin D. Hill

Research Question: Can meniscus allografts survive and provide clinical benefit in knees with moderate to severe unicompartmental arthritis?

2-7 Year Prospective Study of 45 Patients with Moderate to Severe Arthritis Receiving a Meniscus Allograft Transplant

Key Finding: Meniscus allograft transplantation can reliably survive and improve symptoms in knees with advanced unicompartmental arthritis.

Arthroscopy View Publication

Articular Cartilage Knee 2006

Articular Cartilage Paste Grafting to Full-Thickness Articular Cartilage Knee Joint Lesions: A 2- to 12-Year Follow-up

Kevin R. Stone, Ann W. Walgenbach, Abhi Freyer, Thomas J. Turek, Donald P. Speer

Research Question: Can articular cartilage paste grafting (ArtCart) provide durable pain relief, long-term functional improvement, and true cartilage repair for severe chondral lesions?

Case series report of validated pain and function assessments of 125 ArtCart patients and biopsy findings from 65 patients.

Key Finding: ArtCart resulted in significant improvements in patient pain, function, and activity with approximately 63.6% of patients experiencing restoration of the articular surface and 27.3% of patients regrowing normal hyaline cartilage.

Arthroscopy View Publication

Meniscus Cartilage Knee 2007

Meniscal Sizing Based on Gender, Height, and Weight

Kevin R. Stone, Abhi Freyer, Thomas J. Turek, Ann W. Walgenbach, Sonali Wadhwa, John V. Crues III

Research Question: Can demographic variables (i.e., height, weight, gender) serve as reliable, fast, and cost-effective predictors of meniscal dimensions for transplantation compared to traditional imaging-based sizing methods?

Pearson correlation between MRI-based meniscal sizing of 147 menisci in 111 patients to BMI and gender followed by a paired t test to stratify by BMI.

Key Finding: Height, weight, and gender are practical and easily obtained variables that correlate with tibial plateau width and meniscal size.

Arthroscopy View Publication

Meniscus Cartilage Knee 2008

Lessons Learned From Our First 100 Meniscus Allograft Transplants in Arthritic Knees

Kevin R. Stone, Ann W. Walgenbach, Abhi Freyer

Research Question: What lessons from the first 100 meniscus allograft transplants in arthritic knees can optimize patient outcomes and delay or avoid joint arthroplasty?

Book chapter detailing patient selection, surgical techniques, post-operative rehabilitation, and summary of published outcomes study results.

Key Finding: Meniscus allograft transplants can reliably survive and provide meaningful symptom improvement, even in arthritic joints.

Humana Press - Musculoskeletal Tissue Regeneration View Publication

Meniscus Cartilage Knee 2010

Meniscus Reconstruction: The New Field of Rebuilding Meniscus Cartilage

Kevin R. Stone, Johnathan R. Pelsis, Wendy S. Adelson, Ann W. Walgenbach

Research Question: Can collagen meniscus implants be used to reconstruct areas of torn or damaged meniscus?

Monograph detailing use of collagen meniscus implants to help repair meniscal tears and failed meniscectomies.

Key Finding: Collagen meniscus implantation is a means of biologic reconstruction of complex tears in the meniscus, demonstrating a method of functional joint preservation in patients with complex meniscus tears.

Knee Surgery, Arthroscopy, Sport Traumatology View Publication

Meniscus Cartilage Knee 2010

Long-term Survival of Concurrent Meniscus Allograft Transplantation and Articular Cartilage Repair

Kevin R. Stone, Wendy S. Adelson, Johnathan R. Pelsis, Ann W. Walgenbach, Thomas J. Turek

Research Question: What is the long-term survival and patient-reported outcomes of concomitant meniscal allograft transplantation performed with articular cartilage repair in knees with moderate to severe cartilage damage?

Prospective report of 119 meniscal allograft transplantations in 115 patients undergoing concomitant articular cartilage repair.

Key Finding: 79.9% of procedures were intact at a mean follow-up time of 5.8 years. Kaplan-Meier estimated mean survival time was 9.9 years in patients undergoing meniscal allograft transplantation with concomitant articular cartilage repair.

Journal of Bone and Joint Surgery (British) View Publication

Articular Cartilage Knee 2014

Osteochondral Grafting for Failed Knee Osteochondritis Dissecans Repairs

Kevin R. Stone, Johnathan R. Pelsis, John V. Crues III, Ann W. Walgenbach, Thomas J. Turek

Research Question: What treatment options exist for patients with osteochondritis dissecans (OCD) when prior repait procedures have failed?

Osteochondral grafting may be a viable treatment option for patients with knee OCD lesions after previous repair procedures have failed.

Key Finding: Patients with OCD treated with osteochondral graft were able to successfully regain knee function and experienced a reduction in pain.

The Knee View Publication

Cartilage and OA General 2016

Systematic Analysis of the Quality of Scientific Evidence and Conflicts of Interest in Osteoarthritis Guidelines

Joseph D. Feuerstein, Jonathan R. Pelsis, Samuel Lloyd, Adam S. Cheifetz, Kevin R. Stone

Research Question: Are hip and knee osteoarthritis (OA) treatment guidelines based on high-quality evidence and transparent conflict-of-interest reporting?

Hip and knee OA treatment guidelines often rely on evidence of variable quality and inconsistent conflict-of-interest reporting, highlighting the need for more rigorous and transparent guideline development.

Key Finding: 50% of hip/knee OA guideline reccommendations were based on low-quality evidence; 46% don't disclose conflicts of interest.

Seminars in Arthritis and Rheumatism View Publication

Articular Cartilage Knee 2016

Articular Cartilage Paste Graft for Severe Osteochondral Lesions of the Knee: A 10- to 23-Year Follow-up Study

Kevin R. Stone, Johnathan R. Pelsis, Kellan Na, Ann W. Walgenbach, Thomas J. Turek

Research Question: Is articular cartilage paste grafting a durable, long-term treatment for severe cartilage loss in the knee?

The Articular Cartilage Paste Graft procedure can successfully treat severe cartilage damage, reduce pain, and improve function while also delaying the need for an artificial joint replacement.

Key Finding: Median benefit time of 19.1 years; 90% reported good-excellent pain relief; delayed arthroplasty to mean age 60.2 years.

Knee Surgery, Sports Traumatology, Arthroscopy View Publication

Articular Cartilage Knee 2020

Osteochondral Autograft Plugs versus Paste Graft: Ex Vivo Morselization Increases Chondral Matrix Production

Daniel Grande, Todd Goldstein, Thomas J. Turek, Susan Hennessy, Ann W. Walgenbach, Le Hanh Dung Do, David Greene, Kevin R. Stone

Research Question: Does morselizing cartilage damage cells or actually stimulate regeneration?

Morselizing cartilage for paste graft preparation does not appear to compromise early cell viability and may instead stimulate chondrocyte proliferation and cartilage matrix production.

Key Finding: Morselization increases chondrocyte proliferation 34-80%; contradicting long-held beliefs that impaction trauma leads to cell death.

Cartilage View Publication

Ligaments & Tendons Knee 2023

Xenograft Bone-Patellar Tendon-Bone ACL Reconstruction: A Case Series at 20-Year Follow-up as Proof of Principle

Kevin R. Stone, Ann W. Walgenbach, Thomas J. Turek, John V. Crues, Uri Galili

Research Question: Can pig ligament tissue be "humanized" and successfully used for ACL reconstruction in humans?

The possibility of humanizing porcine tissue opens the door to unlimited clinical material for tissue reconstructions if supported by additional clinical trials.

Key Finding: First demonstration that "humanized" porcine ligament can remodel into functional autologous ACL over 20 years.

Journal of Experimental Orthopaedics View Publication

Ligaments & Tendons Knee 2024

Anterior Cruciate Ligament Reconstruction: 3-Incision Technique With Allograft Quad Tendon ACL Reconstruction

Kevin R. Stone

Research Question: How can ACL reconstruction be performed without harvesting tissue from the patient?

The 3-incision technique with allograft quadriceps tendon for ACL reconstruction is a reproducible surgical technique that avoids harvesting from the patient's own body.

Key Finding: The 3-incision allograft quadriceps tendon technique provides a reproducible approach for ACL reconstruction while avoiding tissue harvest from the patient's own patellar tendon or hamstrings.

Video Journal of Sports Medicine View Publication

Meniscus Cartilage Knee 2024

Meniscus Allograft Transplantation in Conjunction with Biologic Knee Restoration Delays Arthroplasty in Patients Older Than 50 Years

Kevin R. Stone, Ann W. Walgenbach, Shadera Slatter, Thomas J. Turek, Caroline Ferguson-Dryden, Marie Dicker, Emma Miltenberger, Haley Cowles, Vivian Liu, Stephanie Wu, Mani Vessal

Research Question: Can meniscus allograft transplantation delay or prevent knee replacement in older patients?

Meniscus allograft transplantation in conjunction with biologic knee restoration procedures can effectively delay or prevent the need for total knee replacement in patients older than 50 years.

Key Finding: Meniscus allograft transplantation with biologic knee restoration improved pain and function in patients over 50 years old. Patients who progressed to knee replacement delayed the need for one by a mean time of 8.64 years.

Arthroscopy View Publication