Paul Gerdhem

Paul Gerdhem

Affiliated to Research | Docent
Visiting address: Hälsovägen, Enheten för ortopedi och teknologi K54, 14186 Stockholm
Postal address: H9 Klinisk vetenskap, intervention och teknik, H9 CLINTEC Ortopedi och bioteknologi, 141 52 Huddinge
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About me

  • Paul Gerdhem became specialist in Orthopaedics 2000. He defended his thesis
    titled "Risc factors for falls and fractures in elderly women" 2004 and
    became associate professor 2005, and adjunct professor in 2019 to 2022. From 2023 Paul Gerdhem is professor in Orthopaedics at Uppsala University. Paul Gerdhem is still affiliated to Karolinska Institutet. 
    His clinical work concerns spinal disorders with a special interest in spinal
    deformities.
    He is the principal investigator of three national multicenter studies; on
    scoliosis and genetics, on conservative treatment for scoliosis, and on
    thoracolumbar burst fractures. He is a member of the steering committees of
    the national quality registers Swespine and the Swedish Fracture Register.
    He is the former President of the Swedish Society of Spinal Surgeons and the
    former President of the Nordic Spinal Deformities Society.
    Awards
    ASBMR Young Investigator Award (first author of abstract) (American Society
    for Bone and Mineral Research), September, 2003, in Minneapolis, USA
    John Sevastik Award for best abstract in the category etiology and genetics
    at the ”International Research Society of Spinal Deformities” in
    Montreal, Canada, 1-3 juli, 2010 (senior author of abstract)
    Best abstract / Highest ranked abstract among 800 submissions during
    Eurospine/Spineweek 2012 (senior and presenting author).
    Nominated to best abstract, Nordic SpinalDeformity Society, Oslo 26-28 Aug,
    2014 (first and presenting author).
    Best podium presentation / Highest ranked abstract among more than 1000
    submissions during Eurospine, Berlin, 5-7 Oct, 2016 (senior author of
    abstract)
    Nominated to Best abstract presentation during Eurospine, Barcelona, 19-21
    Sep, 2018 (as 7 out of more than 1000 submitted abstracts nominated) (senior
    and presenting author of abstract).
    Co-author of the book “Ortopedi-patofysiologi, sjukdomar och trauma hos
    barn och vuxna” which was acknowledged as the best textbook 2018 by the
    publisher “Studentlitteratur”
    Hibbs basic science award at the Scoliosis Research Society, Montreal,
    Canada, 18-21 Sep, 2019 (co-author of abstract).
    /Positions of trust and honor (selected)/
    Appointed member of the Doctoral Dissertation committee at the Karolinska
    Institutet (2010-2016).
    Elected Scientific Secretary of the Swedish Society of Spine Surgeons
    (2006-2008).
    Elected Vice President of the Swedish Society of Spine Surgeons
    (2010-2012).
    Elected President of the Swedish Society of Spine Surgeons (2012-2014)
    Member of the steering committee of the Swedish Spine Register
    (2014-ongoing)
    Member of the steering committee of the Swedish Fracture Register
    (2014-ongoing)
    Secretary of the Swedish Study Group on Early Onset Scoliosis (2014-
    ongoing)
    Appointed member of the committee for academic evaluation of physicians
    applying for a position at the Karolinska University Hospital (2007-2017)
    President of the Nordic Spinal Deformities Society (2017-2019)
    *Teaching interests*
    Orthopaedics, osteoporosis, spinal disorders.
    Teaching includes supervision of students during theses projects (15-30
    credits) and lectures. Paul Gerdhem is the course leader of courses in spinal
    disorders and basic orthopaedic skills for residents with about 2 courses per
    year.

Research

  • Our research group perform clinical and translational studies that cover
    fractures, osteoporosis, spinal deformity, degenerative spinal disorders, hip
    and pelvic disorders, and improvement in surgical techniques. Methodologies
    include clinical trials, register studies, genetics, bone metabolism, bone
    density measurements, imaging and navigation. I will here give a summary of
    my ongoing research.
    /Studies on scoliosis/
    Spinal deformity affects around 3% of children and adolescents. About one
    tenth gets an aggressive variant leading to a severe deformity of the spine
    and thorax. Severe scoliosis leads to pulmonary dysfunction and pain.
    Despite the frequent use of braces to prevent severe scoliosis, evidence for
    effectiveness of the brace is based on a few studies. Data is especially
    scarce for braces used only night time compared to full-time brace wear (>20
    hours per day). The former have proposed advantages such as better compliance
    and patient comfort. Postural retraining has been proposed as treatment for
    scoliosis, but higher quality evidence is lacking.
    Therefore, a randomised controlled trial is performed to compare the result
    from night time brace treatment, postural retraining and observation in
    patients with idiopathic scoliosis (clinicaltrials.gov: NCT01761305)18, and
    all 135 patients have been included into the study. The study is estimated to
    have come to its first final end-point in 2021.
    The only effective treatment to reduce a scoliotic curve is surgery. My
    research is also aimed at improving surgical positioning of implants and
    defining optimal number of implants in scoliosis surgery. We have performed a
    study with augmented reality navigation, and are now planning a randomized
    controlled trial. We also participate in another multicenter randomised
    controlled trial (clinicaltrials.gov: NCT03729947) on the use of
    postoperative drains in pediatric spine surgery (together with Turku
    university hospital, Finland).
    The hereditary component of idiopathic scoliosis is well known, but the
    pathogenesis of scoliosis is poorly understood and it is difficult to early
    identify those at risk of severe scoliosis. Our aim is to increase
    understanding of the genetic background in idiopathic scoliosis and to find
    prognostic markers for scoliosis progression by genetic studies in families,
    and by examining RNA expression from tissue samples collected from idiopathic
    scoliosis patients and controls. Significant genes and genetic pathways will
    be tested in a large already available cohort of patients and controls. New
    insights into the aetiology and treatments may give rise to new and more
    personalised treatment options. The results from the treatment studies and
    genetic studies could also lead to trials on patients with other causes of
    spinal deformity.
    /Spine fractures/
    The treatment of severe spinal fractures is part of the responsibility of the
    Karolinska University Hospital. These may occur as single fractures or as
    part of the injuries sustained during a multi-trauma. The Swedish Fracture
    register is a relatively new resource headed to improve fracture treatment at
    a large scale. A first study on the reliability of the spinal fracture
    classification in the register has been published. A comparative study on
    surgical techniques and a study on non-surgical treatment are ongoing, which
    include a comparison on complications of different fracture treatments.
    In a national group we aim to commence large observational and randomized
    controlled trials using the infrastructure of the Swedish Fracture register,
    with the aim to involve several of the hospitals now engaged in the Fracture
    register. Randomized controlled trials on fracture treatment are relatively
    sparse, especially regarding spinal fractures. Outcome will include patient
    reported outcome, postoperative wound healing/infection, postoperative
    thrombo-embolic complications and mortality. The results will improve
    treatment for patients with spinal trauma.
    In low energy fractures, one of the most important risk factors besides old
    age is low bone density. The gold standard for bone density measurement is
    dual energy X-ray absorptiometry (DXA). FRAX
    (https://www.sheffield.ac.uk/FRAX [1]) is an important and often used web
    based tool to assess fracture risk. However, it does not incorporate
    assessment of frailty, function and balance which are important independent
    risk factors, as shown by my research group. We are now also studying whether
    volumetric bone density will result in better assessment of fracture risk
    than the areal density provided by DXA in two longitudinal cohorts.
    /Sacro-iliac// (SI)// joint pain/
    Together with Oslo University hospital we have started a randomized
    sham-controlled trial on minimal invasive sacro-iliac joint stabilisation in
    the treatment of sacro-iliac joint pain, that will also study effects on the
    brain of pelvic pain and treatment (clinicaltrials.gov: NCT03507049).
    Sacro-iliac joint pain may be the result of pelvic trauma, pregnancy or
    degenerative conditions. In recent years, surgical treatment of the
    sacroiliac joint has again gained popularity. A majority of papers are case
    series mostly published by the industry or by authors with close connections
    to the industry, and therefore carrying a risk of being biased.
    The placebo effect after surgery has been shown to be an important factor in
    short-term efficacy. This has particularly been shown in trials where surgery
    is aimed at treating chronic pain. In fact, in a meta-analysis, surgery was
    not better than sham treatment in chronic pain conditions. Since invasive
    interventions are frequently associated with larger placebo-effects (compared
    to non-invasive treatments), there is a large risk that surgery trials give
    biased results unless they include a sham control comparison. Therefore, it
    is important to determine to what degree the positive effects are due to
    specific efficacy of the surgical intervention or to non-specific factors
    such as the placebo effect. Although surgical treatment of the SI- joint has
    been shown to have effect superior to conservative care, it is still unclear
    if these effects can be explained by placebo mechanisms. We are therefore
    undertaking a study that has a placebo comparison group. In total about 60
    individuals (30 at Karolinska) with SI-joint pain will be randomized to
    minimal invasive SI-joint stabilisation or sham surgery. Effects on the brain
    of pain and treatment are studied with functional MRI as well.
    /Studies on //degenerative disorders/
    Lumbar disc herniation is a common cause of low back and leg pain. When
    non-surgical treatment fails, surgery gives relief from symptoms for the
    majority, but as much as one fourth are reporting an unsatisfactory result.
    We look for the reason for this and study the long term prevalence of disc
    degeneration and additional surgery after disc herniation and compare our
    findings to controls. As in the study on sacro-iliac joint pain, functional
    brain MRI is performed to study long term effects of pain.
    The incidence of surgery for degenerative spinal disorders varies with
    country, also in the Western world. Between the Nordic countries there is a
    30-60% difference in surgical incidence. Using data in three Nordic national
    spine registers we are studying indications and patient reported outcome
    after surgery for different degenerative disorders. The variation in
    incidence seems not associated with outcome differences. In lumbar spinal
    stenosis a simpler technique generates the same outcome as a more costly and
    complicated technique. These findings are similar to others done in my
    research group; newer and more complicated techniques have difficulties
    showing an improved outcome.
    Osteoarthritis is a degenerative condition which affects both the spine and
    the hip. Most patients with osteoarthritis in the hip undergo non-surgical
    treatment. When non-surgical treatment is insufficient a total hip
    replacement can be performed. Concomitant low back pain is common, and about
    3% out of all patients who have undergone a total hip replacement also have
    spinal surgery. Previous reports have suggested poorer outcome (higher
    dislocation and revision rate) among patients with total hip replacement when
    both lumbar fusion and total hip replacement have been performed. Together
    with Ted Eneqvist, Södersjukhuset, Stockholm, data from both the Swedish
    spine register and hip register will be used to further expand the current
    knowledge of the hip-spine relationship.
    In an extension of the above project, we will study the relationship between
    the hip and spine in children with cerebral palsy, who often have hip and
    spinal deformity problems. Hip migration is seen in 30-60% of the children
    with more severe cerebral palsy. Whether hip migration/dislocation and spinal
    deformity are caused by one another or coexistent is debated. By use of the
    Swedish Spine register and the Cerebral palsy register/follow-up program we
    hope to disentangle this question.
    [1] https://www.sheffield.ac.uk/FRAX

Teaching

  • Paul Gerdhem is involved in the supervision of undergraduate students at
    medical school and PhD-students. He was Director/Co-director of PhD-studies
    at CLINTEC 2008-2017.

Articles

All other publications

Grants

Employments

  • Affiliated to Research, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, 2025-2026

Degrees and Education

  • Docent, Karolinska Institutet, 2012
  • University Medical Degree, Karolinska Institutet, 1993

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