Why this book was written

After many years of working intensely with trochlear dysplasia, and reviewing a large number of scientific and historical papers, it became clear that the knowledge was scattered. There was a need to collect all essential information in one place — for surgeons, physiotherapists and clinicians who want to understand this condition properly.

The book also highlights the important contributions of Prof. Dr. Roland Biedert, whose work has significantly shaped modern understanding of trochlear dysplasia.

What the book covers

• The book includes:
• anatomy and biomechanics of the trochlea
• how trochlear dysplasia develops
• imaging techniques (X‑ray, MRI, CT, ultrasound)
• how to interpret trochlear morphology
• modern measurement methods (LTI, sulcus angle, depth)
• classification systems
• surgical principles
• overview of all trochleoplasty techniques
• practical tips for clinical evaluation
• how AI may assist in future assessment
• It is a science‑based review built on a large number of peer‑reviewed articles.

Who should read it

• The book is particularly relevant for:
• orthopaedic surgeons
• sports medicine physicians
• physiotherapists
• radiologists
• researchers
• medical students
• patients who want to understand their condition
• Understanding trochlear dysplasia is essential for providing correct treatment — especially for patellar instability.

Key scientific insights

Readers highlight several important concepts:

Trochlear dysplasia is a proximal problem

The dysplasia is most pronounced where the patella enters the trochlea. Skyline X‑rays taken in too much flexion may appear normal even in dysplastic trochleae.

MRI provides unique information

MRI shows cartilage morphology, which often differs from bony anatomy seen on X‑ray or CT.

Measurements vary by level

Sulcus angle, LTI and depth change significantly depending on where they are measured. The first axial slice showing both facets is the most clinically relevant.

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Readers comments

Jeff Morton, Advanced Physiotherapy Practitioner

Here are 3 takeaways on trochlea dysplasia that have influenced my practice, from this great book by Lars Blønd (there are plenty more but too many for a social media post)

1. Trochlea dysplasia is a proximal problem. It’s most pronounced where the patella enters the trochlea and gradually gets deeper the more distal into the trochlea.
This means that if you see decent trochlear depth on a skyline X-ray taken in too much flexion, that’s expected, even in a dysplastic trochlea.
And on the images that can capture other signs (a true lateral); crossing and double contour signs are only readable when the posterior femoral condyles are perfectly aligned.

2. MRI holds significant value as it can demonstrate the cartilage, which will often deliver different angles and measurements to the bony anatomy provided by XR and CT. I think of this like the snow cap on top of a mountain.

3. Trochlea measures (sulcus angle, LTI e.t.c) will significantly vary by where they are measured in the trochlea. A lot of research to date doesn’t comment on this and it might be worth clarifying if it’s not clear and clinically valuable on reports. Measuring on the first axial slice where both medial and lateral facet cartilage is visible is for the best as it’s the most proximal readable level, so it captures the zone where dysplasia is most prominent.

Plenty to think about as a physiotherapist in orthopaedic and rehab settings

Christoph Schaeffeler, MD

Highly recommend this book for everyone who has a deeper interest in PFJ instability.

Josip Vlaic, MD

Excellent book for all knee lovers

Why patients should understand trochlear dysplasia

Trochlear dysplasia was poorly understood just 10 years ago. Many clinicians are still not fully updated. Patients who understand their condition can better ensure they receive correct treatment.

Where to buy the book

You can find the book through the publisher’s website. The full table of contents is available on Google Scholar.

About the author

Lars Blønd MD Orthopaedic surgeon specializing in patellofemoral disorders, trochlear dysplasia and trochleoplasty. Author of multiple scientific publications and international instructor in patellofemoral surgery.

FAQ

What is trochlear dysplasia?

A condition where the trochlear groove is too shallow or flat, increasing the risk of patellar instability.

Why is this book important?

It gathers decades of scientific knowledge and clinical experience into one comprehensive resource.

Who should read it?

Surgeons, physiotherapists, radiologists, researchers and patients with patellar instability.

Does MRI show trochlear dysplasia better than X‑ray?

MRI shows cartilage morphology and often provides more clinically relevant measurements.

Is trochlear dysplasia hereditary?

There may be genetic factors, but research is ongoing.

Does trochlear dysplasia always require surgery?

No. Treatment depends on severity, symptoms and associated anatomical factors.