About

Andrew F. Kuntz, MD, is an Associate Professor of Orthopaedic Surgery at the Hospital of the University of Pennsylvania and serves as the Director of the Shoulder Study Group. His clinical expertise focuses on shoulder treatment, encompassing all aspects of shoulder surgery from arthroscopy to joint replacement surgery. Dr. Kuntz is a Penn Medicine physician with hospital privileges at the Hospital of the University of Pennsylvania, Pennsylvania Hospital, and Penn Presbyterian Medical Center. He has completed his medical education at the University of Virginia, followed by residency at the University of Pennsylvania Health System, and fellowship training at both the University of Pennsylvania Health System and Thomas Jefferson University Hospital. His professional memberships include the American Academy of Orthopaedic Surgeons, American Orthopaedic Association, American Shoulder and Elbow Surgeons, and several regional and national orthopaedic societies. His research interests involve musculoskeletal conditions and treatments related to shoulder injuries and disorders, contributing to advancements in shoulder surgery techniques and understanding of shoulder pathology.

Research topics

• Medicine
• Surgery
• Anatomy
• Biomedical engineering
• Chemistry

Selected publications

• Return to sport after shoulder arthroplasty: an ASES multicenter analysis of sport-specific predictors of performance in reverse shoulder arthroplasty and total shoulder arthroplasty

  Journal of Shoulder and Elbow Surgery · 2026-04-01

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• Localized Delivery of a Small Molecule Hedgehog Agonist via Poly(ε‐caprolactone) Scaffolds Enhances Tendon‐to‐Bone Integration

  Journal of Orthopaedic Research® · 2026-03-30

  articleOpen access

  Tendon and ligament injuries often require surgery, with successful recovery, whether direct repair of a torn tendon to bone or reconstruction of ligaments, requiring effective tendon-to-bone integration. Unfortunately, re-tear rates can be high, demonstrating the need for improved treatment strategies. The Hedgehog (Hh) pathway is critical to fibrocartilage formation at tendon and ligament insertion sites during development, and recent studies indicate that it promotes tendon-to-bone integration post-surgery. However, systemic delivery of Hh signaling agonists can result in off-target effects. In this study, we developed a scaffold system for local delivery of a Hh signaling agonist (SAG) to promote tendon-to-bone integration. We fabricated aligned electrospun scaffolds loaded with four concentrations of SAG and quantified the fiber alignment and diameter, which were not different between the different concentrations. We then measured the in vitro release profile and found a dose-dependent release of SAG from the scaffolds, as measured by expression of the downstream Hh target gene, Gli1, in bone marrow stromal cell cultures that received conditioned media. Finally, we combined the scaffolds with tendon grafts and inserted them into bone tunnels created in the proximal tibiae of mice. SAG released from the scaffolds did not affect cell infiltration in the graft or scaffold, but increased expression of Gli1 by cells in the bone tunnels while also increasing mineralized fibrocartilage formation in a dose-dependent manner. These findings indicate that scaffold-mediated local delivery of SAG can effectively enhance tendon-to-bone integration, offering a promising strategy for treating tendon and ligament injuries.

  PublisherDOI

• Return to Golf After Shoulder Arthroplasty: An ASES Multicenter Study Predicting Performance after rTSA and aTSA

  Journal of Shoulder and Elbow Surgery · 2026-04-01

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• Return to weightlifting after shoulder arthroplasty: an ASES multicenter study predicting performance after reverse shoulder arthroplasty and anatomic shoulder arthroplasty

  Journal of Shoulder and Elbow Surgery · 2026-02-01

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• Developmental, but not Homeostatic, Collagen V Expression Regulates Mature Murine Supraspinatus Tendon Structure, Function, and Gene Expression

  Journal of Orthopaedic Research® · 2026-02-01

  articleOpen access

  The development of tendon hierarchical structure is dependent on collagen I assembly into fibrils and higher-order assemblies, a process regulated by interactions involving collagen V, a quantitatively minor yet essential component of the tendon extracellular matrix. Collagen V critically regulates fibrillogenesis and is expressed throughout tendon development and maturation. Clinically, deficiency of collagen V manifests as classic Ehlers-Danlos syndrome (cEDS), a disorder characterized by hyperextensible skin, joint hypermobility and instability, and impaired wound healing. Recent studies in mouse supraspinatus tendons-which experience complex, region-dependent loading environments at insertion and midsubstance-demonstrate that developmental collagen V deficiency results in altered tendon structure and biomechanical function. However, differences in structure, mechanics, and gene expression resulting from reduced collagen V expression from embryonic development versus reduction during homeostasis have not been clearly delineated in mature tendons. To address this gap, this study elucidated the role of collagen V on region-specific tendon structural, functional, and compositional properties in mature, day 150 supraspinatus tendons. Tendon-targeted Col5a1 deficiency from embryonic development resulted in substantial structural, mechanical, and transcriptional alterations, including disrupted fibril organization, compromised mechanical properties, and altered gene expression profiles. Conversely, acute deficiency and knockdown of Col5a1 in mature tendons resulted in relatively minimal changes. Collectively, these findings identify a distinct and critical role for collagen V during tendon development, rather than homeostasis, in establishing region-specific multiscale structural, mechanical, and molecular properties essential for mature supraspinatus tendon function.

  PublisherDOI

• National opioid prescription decline across outpatient specialty surgeries: A claims database study

  Journal of the American Academy of Dermatology · 2025-04-14 · 2 citations

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• Mature murine supraspinatus tendons demonstrate regional differences in multiscale structure, function and gene expression

  PLoS ONE · 2025-02-20 · 5 citations

  articleOpen accessCorresponding

  The hierarchical structure of tendon dictates its ability to effectively transmit loads from muscle to bone. Tendon- and site-specific differences in mechanical loading result in the establishment and remodeling of structure, as well as associated changes in composition throughout development and healing. Previous work has demonstrated region-specific differences in the response of collagen fibrils to mechanical loading within the insertion region and midsubstance regions of mouse supraspinatus tendons using atomic force microscopy. However, multiscale structure, function, and gene expression differences between the insertion and midsubstance of the supraspinatus tendon have not yet been linked together in a comprehensive study. Therefore, the purpose of this study was to elucidate site-specific hierarchical structure, function, and gene expression differences in mouse supraspinatus tendons. Supraspinatus tendons from day 150 wild-type C57BL/6 mice were harvested for regional mechanics, histology, transmission electron microscopy (TEM), and quantitative polymerase chain reaction (qPCR). Mechanical testing revealed that the midsubstance region demonstrated a greater modulus and increased collagen fiber realignment compared to the insertion region. Histological scoring demonstrated greater cellularity and more rounded cells in the insertion region. TEM analysis showed differences in collagen fibril diameter distributions between the two regions, with a shift towards smaller diameters observed at the insertion region. Gene expression analysis identified several genes that were differentially expressed between regions, with principal component analysis revealing distinct clustering based on region. These findings provide insight into the regional heterogeneity of the supraspinatus tendon and underscore the importance of considering these differences in the context of tendon injury and repair, contributing to a better understanding of tendon structure-function and guiding future studies aimed at elucidating the mechanisms underlying tendon pathology.

  PublisherDOI

• Murine Supraspinatus Tendons Demonstrate Aging‐Related Changes in Multiscale Mechanics, Structure, and Gene Expression

  Journal of Orthopaedic Research® · 2025-06-27 · 4 citations

  articleOpen access

  Rotator cuff disorders are common in the aging population, often leading to pain, disability, and reduced quality of life. Age-associated changes can occur disproportionately in regions of high mechanical stress, such as the insertion site of the supraspinatus tendon, leading to increased injury rates and tendinopathies. We previously demonstrated site-specific differences in structure, function, and gene expression between the insertion and midsubstance regions of supraspinatus tendons in mature, Day 150 mice. However, a comprehensive study examining the role of aging on site-specific supraspinatus tendon multiscale structure, function, and gene expression is needed. Therefore, our objective was to elucidate the role of aging on supraspinatus tendon multiscale structure, function, and gene expression. Whole-tissue and regional mechanics, as well as regional fibril response to load, cellularity and cell shape, collagen fibril morphology, and gene expression were evaluated in supraspinatus tendons of Day 300 and Day 570 mice. Aging resulted in decreased stiffness, dynamic modulus, and decreased midsubstance modulus. Collagen fibril morphology analysis revealed a more noticeable shift toward smaller fibril diameters with aging in the midsubstance region. Histological evaluation demonstrated reduced cellularity and a transition to more elongated cell morphology in aged tendons. Gene expression profiling highlighted upregulation of pro-inflammatory and catabolic markers and downregulation of major collagens in Day 570 tendons relative to Day 300 tendons. Understanding the effects of aging on tendon structure, function and gene expression provides critical insights into the mechanisms underlying aging-related injury and tendinopathy.

  PublisherOA PDFDOI

• Knockout of collagen V in development, but not in skeletal maturity, leads to long-term deficits in supraspinatus tendon mechanics in mice

  Journal of Biomechanics · 2025-09-10 · 1 citations

  articleOpen access

  Collagen V is a key matrix protein involved in fibril nucleation and lateral fibril growth during extracellular matrix assembly. Genetic mouse models have been used to investigate the role of collagen V in tendon, which showed deficient mechanical properties and aberrant fibril structure in the absence of collagen V. However, the lasting effects of collagen V deficiency later into adulthood remain unknown, as well as the role of collagen V in maintaining a mature matrix. This study therefore investigated the long-term effects of collagen V reduction on tendon as well as its role in mature tendon matrix in adulthood. Tendon-targeted conditional Col5a1 knockout, which excises Col5a1 alleles early in development, had long-term impact on tendon structure and function in 300-day old mice. Gene expression was altered with differential expression of primarily matrix and matrix remodeling genes. Regional changes in cellular shape and density were consistent with typical behavior in tendinopathy. Fibril diameters were increased due to dysregulated lateral growth. Deficits in mechanical properties indicate a weaker tendon matrix after knockout, although deformation patterns of collagen fibrils were not affected. In contrast, inducing collagen V knockdown in a mature tendon matrix at 120-days old did not cause substantial changes in any of the above-mentioned properties in 300-day old mice. In conclusion, these findings highlight the important function of collagen V in matrix assembly that has lasting effects into later ages, even though collagen V has little role in homeostatic maintenance of a mature tendon matrix.

  PublisherDOI

• A participatory photovoice investigation of community assets, barriers, and opportunities to curb the opioid epidemic

  Journal of Substance Use and Addiction Treatment · 2025-07-02 · 1 citations

  articleOpen access
  PublisherOA PDFDOI

Recent grants

• Improving tendon-to-bone repair with hedgehog signaling therapeutics

  NIH · $371k · 2021–2024

• Effect of Scaffold-delivery Growth Factors in Rotator Cuff Repair

  NIH · 2015–2018

Frequent coauthors

• Joseph A. Abboud

  Thomas Jefferson University Hospital

  44 shared

• Louis J. Soslowsky

  University of Pennsylvania

  40 shared

• Ibrahim J. Raphael

  37 shared

• Michael P. Dougherty

  Augusta University

  37 shared

• Julianne Huegel

  University of Central Florida

  20 shared

• Courtney A. Nuss

  University of Pennsylvania

  18 shared

• Robert L. Mauck

  Philadelphia VA Medical Center

  13 shared

• Dong Hwa Kim

  12 shared

Labs

• Andrew F. Kuntz LabPI

Education

• MD

  University of Virginia School of Medicine

  2005

• BS, Chemistry

  College of William and Mary School of Arts and Sciences

  2001

Awards & honors

• The 2024 Kappa Delta Young Investigator Award: Leveraging In…