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.

2023 - 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.

2024 - Present

ArtCart+ Equine Study: Definitive Efficacy 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. mass and health.

2022 - Present

Characterization of Orthobiologic Injections [SD2]

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. Presented at ORS 2025, ISAKOS 2025

2022 - Present

Alpha-Gal Nanoparticle Study at the University of Illinois, Urbana-Champaign (UIUC)

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.

2024 - 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.

Published Research Library

15 peer-reviewed studies spanning 27+ years of orthopaedic research in biologic joint repair.

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?

The mixture of articular cartilage and cancellous bone appears to provide a supportive matrix for cartilage formation. Pain relief is excellent if careful surgical technique and defined rehabilitation program is followed.

Key Finding: Original description of the paste graft surgical technique.

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 meniscus allograft fixation be improved?

An improved arthroscopic technique of meniscal transplantation that simplifies the surgical procedure and secures the allograft to the tibia at 3 sites.

Key Finding: Improved arthroscopic technique securing allograft to 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: Should patients with arthritis be excluded from meniscus transplantation?

Meniscus allografts can survive in a joint with arthrosis, challenging the contraindications of age and arthrosis severity.

Key Finding: 89.4% allograft survival rate in arthritic knees—challenging conventional contraindications of age and arthrosis.

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: Does paste grafting provide lasting relief for severe cartilage damage?

Paste grafting is a low-cost, 1-stage arthroscopic treatment for patients with Outerbridge classification grade IV arthritic chondral lesions offering excellent, long-lasting pain relief.

Key Finding: 85.6% success rate; 63.6% of biopsies showed strong cartilage regeneration evidence.

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: How can surgeons accurately match meniscus allografts to patients?

Height, weight, and gender should be considered by both tissue banks and surgeons as fast and cost-effective variables by which to predict meniscal dimensions.

Key Finding: Height, weight, and gender correlate with meniscal dimensions—simplifying tissue bank matching protocols.

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: Can meniscus transplants succeed in knees that already have arthritis?

Meniscus transplantation is a rewarding soft tissue reconstruction that can be useful for arthritic as well as pristine knees to alleviate pain, restore function, and ultimately, delay or avoid joint arthroplasty.

Key Finding: Comprehensive review demonstrating allografts can survive in arthritic knees and delay joint replacement.

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: Is it possible to rebuild meniscus cartilage that has been lost?

Meniscus reconstruction techniques offer new possibilities for rebuilding meniscus cartilage in patients who have lost this critical structure.

Key Finding: Meniscus reconstruction represents a new paradigm for rebuilding damaged meniscus cartilage.

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: Can meniscus transplant and cartilage repair be performed together successfully?

Combined meniscus allograft transplantation with articular cartilage repair procedures demonstrates excellent long-term survival and functional outcomes.

Key Finding: Concurrent meniscus allograft transplantation and articular cartilage repair provides long-term joint preservation.

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