Ivo Jajià(2 July 1932 â 10 June 2010) was a Croatian rheumatologist, university professor and full member of the Croatian Academy of Medical Sciences. He was a pioneer in the development of rheumatology in Croatia, where he significantly advanced the clinical practice, research, and education in the field. Jajiàauthored over 700 scientific publications and several firsts foundational textbooks in Croatian rheumatology, establishedàand led key national institutions, registries, professional and patient societies, and Croatian medical journals. He was internationally recognized for his contributions to rheumatic disease research and diagnostic imaging, education in rheumatology and application of clinical rheumatology.
JajiÃÂ graduated from the University of Zagreb School of Medicine in 1960. He specialized in physical medicine and rehabilitation in 1965 and earned his doctorateÃÂ at the University of Zagreb School of Medicine in 1972 with a topic on extravertebral changes in ankylosing spondylitis. He became the second physician in Croatia with a doctoral degree in rheumatology.
His early clinical work coincided with emerging interest in rheumatic diseases, and due to the lack of organized rheumatology education in Croatia at the time, he undertook advanced clinical and research training at internationally renowned institutions. These included Westminster Hospital, GuyâÂÂs Hospital and MiddlesexàHospital in London, Hospital Cochin in Paris, Karolinska University Hospital in Stockholm, Institute of Rheumatism in Moscow, as well as hospitals and institutions in Oslo, Budapest, Riga, Warsaw, Vilnius, Prague, Bucharest, Heinola, Pieà ¡à ¥any, Manchester, Leeds, and the NIH in Bethesda, Maryland. These international experiences influenced his approach to clinical rheumatology, with an emphasis on interdisciplinary collaboration, immunogenetics of rheumatic diseases, diagnostic imaging, and early intervention.:
Jajiàwas appointed tenured professor at the University of Zagreb School of Medicine in 1981. In 1988, at the same School he founded and led the Postgraduate Specialist Study in Physical Medicine and Rehabilitation (1988âÂÂ2001), which featured many rheumatology-focused modules, beingàinstrumental in shaping the study in rheumatology and treatment of rheumatic diseases in Croatia.
In parallel with his academic career, he played a role in expanding rheumatology services within the Croatian healthcare system.
He was founder and head (1985âÂÂ2001) of the University of Zagreb School of Medicine new teaching base -àDepartment of Rheumatology, Physical Medicine, and Rehabilitation at the Sestre Milosrdnice University Hospital Center in Zagreb, which became a leading national center for clinical practice, education, and research in rheumatology.
In 1999, he established the Croatian Reference Centre for Inflammatory Rheumatic Diseases under the Ministry of Health. This institution served as a national hub for complex rheumatologic cases, interdisciplinary research, and postgraduate training.
JajiÃÂ remained active in medical education andÃÂ international collaborationÃÂ throughout his life, and became internationally recognized rheumatologist.
He organized numerous international and national rheumatology congresses, including the Ninth Congress of Rheumatologists of Yugoslavia (1984), the First European Conference on Epidemiology of Rheumatic Diseases (1990), the Eighteenth European Osteoarthrology Symposium (1990), the First and Second Hypertrophic Osteoarthropatic Symposium (1992, 1995),ÃÂ Rheumatology Congress of Mediterranean Countries (1992, cancelled due to the Homeland war in Croatia), and Second Croatian Rheumatology CongressÃÂ (1997). He regularly participated in over 200 international scientific meetings as an invited lecturer and active delegate. He was a member of theÃÂ organizing committee of several Congresses of Rheumatologists of Mediterranean Countries and Central European Countries.
He also led numerous domestic symposia and educational events, such as the Symposium on Psoriatic Arthritis (1966), Symposium on HLA Antigens in Rheumatology (1981),ÃÂ SymposiumÃÂ on Lumbar Pain Syndrome (1984), New Discoveries in Diagnosis of Rheumatic Diseases (1993), Most Common Rheumatic Diseases (1995), New Discoveries in Treatment of Rheumatic Diseases (1995), and other events addressing rheumatic diseases and war injury rehabilitation.
In 1980, he established the Registry for Rheumatic Diseases in Croatia under the Institute of Public Health.
JajiÃÂ led scientific projects in rheumatology under the Ministry of Health and participated in several international collaborative studies, including:
He was alsoÃÂ involved in multiple international clinical trials related to disease-modifying antirheumatic drugs (DMARDs) and biologic therapies in rheumatic diseases.
He published original research on clinical tests, including the development of JajiÃÂâÂÂs Heel-Knee Test, a diagnostic maneuver used to identify sacroiliitis (1999), a hallmark of spondyloarthropathies. (e.g., JajiÃÂâÂÂs Heel-Knee Test),àradiological changes, and immunogenetics of rheumatic diseases. He described clinical observations such as the "Blue Skin" Sign (2000) in psoriatic arthritis, "Diastasis of the Rectus Abdominis Muscle" Sign (1999) and âÂÂUmbilical extrusionâ Sign (1998) in ankylosing spondylitis.
In 1968, he published radiological changes in the sacroiliac joints and spine inÃÂ psoriatic arthritis, considered one of the first contributions to this clinical issue, and continues to be cited in the literature. His early radiological research was included in the textbook "Seronegative Polyarthritis" by Wright V. and Moll J.M.H. in 1976.
His immunogenetic research on rheumatic diseases, published in 1975 and 1977, were amongÃÂ theÃÂ first studies on histocompatibility antigens in ankylosing spondylitis and psoriatic arhritis.
JajiÃÂÃÂ co-authored an international consensus on hypertrophic osteoarthropathy (1993), and was the first to describe radiological changes in flat bones associated with this condition (1998).
JajiÃÂ authoredÃÂ over 700 publications, including academic papers with research spanningÃÂ clinical rheumatology, immunogenetics, diagnostic radiology and treatment of rheumatic diseases, and around 100 books, book chapters and several firsts foundational textbooks in Croatian rheumatology. Most notable include
He also contributed to the Croatian Medical Encyclopaedia. and authored numerous patient manuals promoting health literacy and awareness of chronic rheumatic conditions published by the Croatian League Against Rheumatism.
As of 2025, his works had been cited over 4,600 times according to the Web of Science, and over 5,180 times according to Scopus, with an h-index of 32. His publications have also been cited more than 50 times in international rheumatology textbooks.
A complete list of his publications is available through the Croatian Scientific Bibliography (CroRIS â CROSBI)
Jajiàchaired the Association of Rheumatologists of Yugoslavia (1982âÂÂ1986) and led various Croatian Medical Association sections.àHe was founding memberàand president of the Croatian Society of Vertebrology (1986-1989) and àpresident of àthe Croatian Rheumatology Society (1996-1998), both under the Croatian Medical Association.
He founded the Croatian Society of Rheumatic Patients (1982), focused on patient education and support, and was the founder and president of the Croatian League against Rheumatism (1992-2001) aimed at public health advocacy.
He initiated and edited the leading national journal in the field Fizikalna medicina i rehabilitacija] (1984), the Croatian Rheumatology Society journal Reumatizam (1991-1998), and the Croatian League Against Rheumatism journal ReumatiÃÂar / Reuma (1989), aimed at patients promoting awareness of chronic rheumatic conditions.
He was a member of the editorial board of several international journals, including Clinical Rheumatology, New European Rheumatology, and Acta Clinica Croatica.
JajiÃÂ was a member or honorary member of numerous international and domestic scientific and professional organizations. Internationally, he was affiliated with:
He was also an honorary member of national rheumatology societies in:
Domestically, he was:
Sources:
Since 1959, he had been married to Ivanka Jajià(née DevÃÂiÃÂ; 1931âÂÂ1996), a physician who graduated from the University of Zagreb School of Medicine and specialized in school medicine. During the Croatian War of Independence, although retired, she was actively involved in humanitarian and organizational work within wartime healthcare.
The couple had two daughters, both physicians. Zrinka is a specialist in rheumatology, a full professor at the University of Zagreb School of Medicine and was head of the Clinical Ward for Rheumatic Diseases at the Department for Rheumatology of the University of Zagreb School of Medicine at the Sestre Milosrdnice University Hospital Center. Ines holds a PhD in microbiology and is the head of the Department of Microbiology at the same hospital.