Dr. Andreas Gomoll is an orthopedic surgeon in Manhattan, an attending surgeon at Hospital for Special Surgery (HSS) — ranked the #1 orthopedic hospital in the US by U.S. News & World Report for 15 consecutive years — and a Professor of Clinical Orthopedic Surgery at Weill Cornell Medical College, specializing in cartilage repair and joint preservation. He grew up in Munich, Germany — the son of a pilot and engineer — and originally planned to build airplanes himself before a high school biology class redirected him toward the human body. He came to the US in the late 1990s intending to stay three months; he ended up doing two years of research at Harvard Medical School and Brigham and Women's Hospital, followed by a fellowship in Chicago, and never left.
Key Takeaways
- Dr. Gomoll's focus is joint preservation — cartilage repair, meniscus repair, and osteotomy aimed at helping younger patients avoid or delay a total knee replacement, which he reserves for when it "makes sense."
- Stem cell and PRP injections available today reduce pain and inflammation but do not regrow cartilage — a limitation he was direct about, distinguishing current practice from ongoing research.
- Only autologous stem cells (a patient's own, from bone marrow or fat) are used in compliant US orthopedic practice — used same-day, never cultured or stored.
- Birth-tissue products like amniotic membrane and umbilical cord blood were largely pulled from the US market around 2018 pending FDA trials; he expects amniotic membrane back on the market soon, and is preparing to join a trial using umbilical cord blood-derived stem cells to regrow cartilage surgically.
- His research found a patient's psychological outlook predicts cartilage transplant outcomes more strongly than the physical size of the joint damage — patients on antidepressants, for instance, tend to have better surgical outcomes because they feel better and engage more fully in recovery.
- His most common patient: someone in their late 20s or early 30s with a failed ACL reconstruction from their teenage years, lost meniscus, and early arthritis — too young, in his assessment, for a standard total knee replacement.
From Engineering to Joint Preservation
Dr. Gomoll traces his path to orthopedics back to two mentors in Boston. Tom Thornhill, who trained first as a rheumatologist before becoming an orthopedic surgeon, had treated patients in the era before modern rheumatoid arthritis therapy — patients with crippled hands in their 40s and 50s who needed every joint in their body replaced. "You don't see that anymore," Dr. Gomoll said. "Medicine has almost solved that problem." What stuck with him was that Thornhill had decades-long relationships with those patients, who were now bringing in their own kids.
The second mentor, Tom Minas, was one of the first surgeons to bring cartilage regeneration to the United States, building on technique developed in Sweden more than 40 years earlier by Lars Peterson — culturing a patient's own cartilage cells and reimplanting them to regrow damaged tissue. Watching Minas work convinced Dr. Gomoll that a total knee replacement didn't have to be the only endpoint for a damaged joint.
"Here is this whole different world of regenerating cartilage, preserving your own stuff, if you will, so that you have all these options."
— Dr. Andreas GomollDo Stem Cells Actually Regrow Cartilage?
Asked directly, Dr. Gomoll didn't hedge: available stem cell and PRP treatments make patients feel better — reducing pain and inflammation, and possibly slowing degeneration — but they are not yet regrowing cartilage, meniscus, or other tissue. "They may slow down things a little," he said, "but the science is not fully decided yet on that. They're not regrowing anything yet." He was careful to separate marketing from evidence: "I know there's a lot of advertising and hype out there, but at least what's established — we're not talking about trials — someone can take your own stem cells, spin them down, inject them into your knee, and you'll feel better. But it's not regrowing anything, unfortunately. That's where we're heading to."
What's Legally Allowed: FDA Rules on Orthopedic Stem Cells
In the US, Dr. Gomoll explained, the only stem cells considered fully compliant in orthopedic practice are autologous — drawn from a patient's own bone marrow or fat, concentrated, and reinjected in the same procedure without being cultured or stored. Birth-tissue products — umbilical cord blood, placenta, amniotic membrane — were widely available until around 2018, when the FDA began requiring the kind of formal trials already required for drugs like aspirin or blood pressure medication. Most of that material came off the market as a result, though Dr. Gomoll expects amniotic membrane, in particular, to return "hopefully this year or next," as trials demonstrating its effectiveness against inflammation complete.
He's preparing to participate in a coming trial of his own: a Korean company's banked umbilical cord blood-derived mesenchymal stem cells, surgically implanted to fill cartilage defects. Unlike a patient's own harvested cells, donor-derived cord blood cells are "immunoprivileged," meaning patients don't need immunosuppressive medication to receive them — and, notably, this treatment is aimed at patients with moderate arthritis who are too advanced for standard cartilage transplants but not yet candidates for replacement. It remains available only through the trial for now, not at a standard clinic visit.
On stem cell tourism specifically, his advice was blunt: "A lot of people travel abroad, they get all sorts of stem cells. I would be really careful where you go, because you don't know what you get."
What Does "MSC" Actually Mean?
The term "mesenchymal stem cell" (MSC) is common in stem cell marketing, but Dr. Gomoll pointed out it's slightly misleading. The original theory held that an MSC would sense what tissue was needed and transform directly into it — becoming cartilage, bone, or ligament as required. Research has since shown that isn't really what happens: these cells mostly send chemical signals that prompt the body's own existing cells to do the repair work, rather than transforming into new tissue themselves. Regenerative medicine pioneer Arnold Caplan — credited with coining the original term — later proposed keeping the same MSC acronym but redefining what it stands for: "medicinal signaling cells," a name Dr. Gomoll said better reflects how these cells actually work.
Who's a Real Candidate for Joint Preservation?
Dr. Gomoll's most frequent patient profile: someone in their late 20s or early 30s who tore an ACL as a teenager, lost some meniscus along the way, and is now dealing with a failed ACL reconstruction and early arthritis — "and you've been told, take an apple and come back when you're old enough to have a total knee." He also treats much younger patients; the youngest he mentioned was 12, with a congenital cartilage problem. For patients who are already bone-on-bone with advanced arthritis, he was equally direct that a knee replacement is still usually the right call — the goal isn't to avoid replacement altogether, but to delay it until it's the appropriate step, since every replacement eventually wears out and each revision costs the patient more of their own bone.
He offered a concrete example from his own practice: a femoral osteotomy he performed a decade ago on a then-21-year-old with significant wear on one side of the knee. "We bought him 10 years," he said — the patient, now 31, is only just starting to feel aching again, and will need a new MRI to figure out the next step. It's an honest picture of what joint preservation offers: not a permanent fix, but meaningful time gained before more invasive treatment becomes necessary.
The Overlooked Factor: Mindset and Surgical Outcomes
One of the more striking points in the conversation: Dr. Gomoll's research has tied cartilage transplant outcomes to a patient's psychological profile — measured through standard patient-reported outcome questionnaires — more strongly than to the physical size of the cartilage defect being treated. Patients who are more resilient, or simply more optimistic, tend to do better. He cited data showing that patients started on an antidepressant around the time of surgery often have better surgical outcomes, not because the medication changes the joint, but because patients who feel better engage more fully with the hard work of recovery.
His Advice on Getting a Second Opinion
For patients who've been told to simply live with pain, Dr. Gomoll's advice was measured: a second or third opinion is worth getting, but there's a point of diminishing returns. "Once you've hit like three people who seem qualified and they say the same thing, then maybe that is the answer," he said — cautioning against becoming, as he put it, someone's tenth opinion. He also pointed out that recovery is rarely passive: physical therapy, weight management, and simply doing the unglamorous rehab work often go further than any single procedure, stem cell or otherwise.
Credentials & Training
- MD, Ludwig-Maximilians-Universität, Munich, Germany
- Harvard Combined Orthopaedic Residency Program — Massachusetts General Hospital, Brigham and Women's Hospital, and Boston Children's Hospital
- Fellowship in Orthopaedic Sports Medicine, Rush University Medical Center, Chicago
- Board Certified, American Board of Orthopaedic Surgery — Orthopaedic Surgery & Sports Medicine subspecialty
- 170+ peer-reviewed publications; co-author of 6 medical textbooks on cartilage restoration and joint preservation
- Named among "Top 1% Academic Orthopedic Surgeons"
About Dr. Gomoll's Practice
- Attending orthopedic surgeon, Hospital for Special Surgery (HSS), New York City
- Professor of Clinical Orthopedic Surgery, Weill Cornell Medical College
- Practice focus: knee and shoulder surgery, cartilage repair and transplantation, ACL reconstruction (allograft, autograft, and revision), meniscal procedures and transplantation, rotator cuff repair, shoulder instability reconstruction, osteotomy, and joint preservation
- New York office: 523 East 72nd Street, 2nd Floor, New York, NY 10021 · (646) 917-7441
- Office hours: Monday–Friday 8:00am–5:00pm, Saturday by appointment, closed Sunday
Schedule a consultation or learn more: andreasgomollmd.com · LinkedIn
