Robert Kollmorgen
Associate Professor
Orthosurgery - Fresno
School of Medicine

He earned his medical degree from Ohio University College of Osteopathic Medicine. He completed his residency in orthopaedic surgery at Midwestern University and his fellowship in hip preservation at Duke University.

Dr. Kollmorgen previously practiced as an orthopaedic surgeon specializing in sports medicine and instructed as an Associate Professor at Ohio University. He also served as a Lieutenant Commander in the United States Navy, caring for active-duty soldiers at Camp Pendleton.

He was awarded the Navy and Marine Corps Commendation Medal for creating the hip preservation and hip arthroscopy program at Naval Hospital Camp Pendleton. He also twice received the Ohio University Fellows Award for Sports Medicine Educator of the Year.

Dr. Kollmorgen is dedicated to providing compassionate and effective care. He believes that excellent health begins with education and prevention and has made it his mission to enlighten patients on ways they can take greater control over their own health.

His hobbies include fitness and spending time with family.

• Multiligament Knee Reconstruction of the ACL, PLC, and ALL in a Floating Knee: A Case Report.
  Journal of orthopaedic case reports 2023 Kollmorgen R, Singleton A, Eaddy S, Phillips S
• Claw Toe Deformity After Revision Hip Arthroscopy with Concomitant Periacetabular Osteotomy: A Case Report.
  JBJS case connector 2023 Wilson H, Kollmorgen R
• Comparison of the PROMIS and iHOT-12 in Determining Satisfaction Levels After Hip Arthroscopy for FAIS.
  Orthopaedic journal of sports medicine 2023 Martin RL, Harris JD, Ellis T, Kollmorgen R
• Addition of Pericapsular Nerve Group and Transversus Abdominis Plane Blocks Significantly Reduces Opioid Use in Patients Undergoing Concomitant Hip Arthroscopy and Periacetabular Osteotomy.
  Cureus 2023 Ellis S, Harris JD, Flemming DP, Ellis TJ, Kollmorgen RC
• Editorial Commentary: Excessive Femoral Retroversion and Increased Femoral Anteversion Has a Negative Effect on Hip Arthroscopy Outcomes: Symptomatic Extremes of Version Require an Osteotomy.
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2023 Kollmorgen R
• Editorial Commentary: Degeneration of Acetabular Cartilage of any Degree Is a Predictor of Worse Outcome After Hip Arthroscopy for Labral Repair and Femoroacetabular Impingement Syndrome: The Greater the Damage, the Worse the Outcome.
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2022 Kollmorgen R
• Computer Navigation vs. Conventional Overlay Methods in Direct Anterior Total Hip Arthroplasty: A Single Surgeon Experience.
  Cureus 2022 Goodell P, Ellis S, Kokobun B, Wilson H, Kollmorgen RC
• Preoperative Pericapsular Nerve Group Block Results in Less Pain, Decreased Narcotic Use, and Quicker Discharge Time Than No Block in Patients Who Were Surgically Treated for Femoroacetabular Impingement Syndrome.
  Arthroscopy, sports medicine, and rehabilitation 2022 Kollmorgen R, Umerani M, Gollon J, Fleming D, Lewis B, Harris J, Ellis T
• Post-Related Complications in Hip Arthroscopy Are Reported Significantly Greater in Prospective Versus Retrospective Literature: A Systematic Review.
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2021 Wininger AE, Mei-Dan O, Ellis TJ, Lewis BD, Kollmorgen RC, Echo A, Harris JD
• Arthroscopic and Endoscopic Treatment of Proximal Rectus Femoris Avulsion.
  Orthopedics 2021 Salazar E, Kollmorgen RC
• Editorial Commentary: Post-Free Arthroscopy Reduces Complications and Pain: To Post or Not to Post? Is That Still a Question?
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2021 Kollmorgen R
• Mandatory Nicotine Cessation for Elective Orthopedic Hip Procedures Results in Reduction in Postoperative Nicotine Use.
  Cureus 2020 Rao BM, Moylan DD, Sochacki KR, Kollmorgen RC, Atwal L, Ellis TJ
• Editorial Commentary: Patient-Reported Outcomes Measurement Information System (PROMIS) Has Decreased Disease-Specific Responsiveness More Than Legacy Outcome Measures, But PROMIS and Legacy Measures Do Correlate: You Can't Have Your Cake and Eat It Too.
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2020 Kollmorgen R
• A Novel Radiographic Finding of Intracapsular Heterotopic Ossification: A Report of Two Cases.
  Cureus 2020 Wilson HJ, Goodell PB, Kollmorgen RC
• A comparison of leg length discrepancy between direct anterior and anterolateral approaches in total hip arthroplasty.
  Arthroplasty (London, England) 2020 Dunn H, Rohlfing G, Kollmorgen R
• Editorial Commentary: Hip Hypotrophic Labrum Should Not Change Our Treatment Algorithm: Welcome to the Augmented Reality of the Hip-Preservation Zone.
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2020 Kollmorgen R
• Validation of Self-Reported Smoking Status Among Orthopedic Hip Surgery Patients.
  Cureus 2020 Ellis ST, Rao BM, Kohlrieser D, Kollmorgen RC, Sochacki KR
• Editorial Commentary: Quantifying Patient Satisfaction After Hip Arthroscopy: I Cannot Deactivate Until You Are Satisfied With Your Care.
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2020 Kollmorgen R
• Pseudotumor Caused by a Retained Intra-articular Bullet: A Case Report.
  JBJS case connector 2020 Rohlfing G, Refaat M, Kollmorgen R
• Achieving Post-Free Distraction in Hip Arthroscopy With a Pink Pad Patient Positioning Device Using Standard Hip Distraction Tables.
  Arthroscopy techniques 2019 Kollmorgen RC, Ellis T, Lewis BD, Harris JD
• Editorial Commentary: Single Versus Double-Row Abductor Tendon Repair: Is the Juice Worth the Squeeze?
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2019 Kollmorgen R
• Relationship Between PROMIS Computer Adaptive Tests and Legacy Hip Measures Among Patients Presenting to a Tertiary Care Hip Preservation Center.
  The American journal of sports medicine 2019 Kollmorgen RC, Hutyra CA, Green C, Lewis B, Olson SA, Mather RC
• Editorial Commentary: You Cannot Choose the Hip….It Chooses You!! Big Database Versus Private Database Complication Reporting.
  Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2018 Kollmorgen R
• A Novel All-Inside Arthroscopic Technique for Radial-Sided Triangular Fibrocartilage Complex Tears: A Case Report and Review of Literature.
  Hand (New York, N.Y.) 2017 Edgerton MT, Kollmorgen RC
• Current Concepts in Labral Repair and Refixation: Anatomical Approach to Labral Management.
  American journal of orthopedics (Belle Mead, N.J.) 2017 Kollmorgen R, Mather R