Patellofemoral Literature

For Medical Students

What the Question Was

The question was why the front of the knee hurts and why the patella leaves its groove, and the first answers were about alignment. 4.15.1 covers patellar tracking.

The alignment answer produced the measurements and the tests that are still taught, including the quadriceps angle and the apprehension test. 4.15.3 covers the apprehension test.

The question shifted once imaging showed the trochlear shape, because shape explained more of the instability than alignment did. 4.15.8 covers trochlear dysplasia.

What It Showed

The work established that patellar instability is mostly explained by structural features rather than by soft tissue laxity alone.

It established that the provocation tests are useful for instability and weak for pain, which are two different problems at the same site. 4.15.9 covers patellofemoral pain.

It did not produce a reliable clinical examination for the structural features themselves, which is why imaging carries them. 4.1.6 covers that relationship.

MRCS Level

What Was Done

Insall and colleagues worked on alignment and on the quadriceps angle, which produced the measurement and the realignment reasoning that followed from it. 3.12.6 covers the Q angle.

Dejour and colleagues described the trochlear and patellar features associated with instability from imaging, which moved the explanation from alignment to shape. 4.15.8 covers trochlear dysplasia.

Fulkerson worked on anterior knee pain and on the distinction between pain and instability, which separated two populations that had been treated as one. 4.15.9 covers patellofemoral pain.

Comparative work on the clinical tests, including the apprehension test, the glide, the tilt and the compression tests, set them against imaging and against operative findings. 4.15.4 covers patellar glide.

The medial restraint was characterised anatomically and biomechanically, which gave the apprehension test a mechanism. 3.12.5 covers the medial restraint's function.

What It Showed

The comparative work established that the apprehension test is the most useful clinical test for instability, because it adds the symptom to the finding. 4.15.3 covers the apprehension test.

It established that patellar translation alone is unreliable, since physiological laxity is wide and bilateral. 4.23.3 covers the hypermobile patient.

It established that the compression and grind tests are uncomfortable in normal knees, which limits their use for pain. 4.6.5 covers patellar tenderness.

It established that the structural features associated with instability are radiographic rather than clinical, which fixed imaging's role. 4.1.6 covers that relationship.

No sensitivity, specificity or likelihood ratio appears on this page, under decision 023 and decision 022 together. The ranking is what is recalled reliably; a specific percentage written from memory would look exactly like a correct one.

FRCS Level

What It Showed

At decision level the literature separated the instability pathway, which has structural answers, from the pain pathway, which largely does not.

Instability with structural features is a surgical conversation, and the examination's job is confirming the instability. 4.19.4 covers the paediatric instability assessment.

Instability with generalised laxity and no structural feature is a different conversation, and the examination is what distinguishes it. 4.23.3 covers the hypermobile patient.

Anterior pain without instability has no reliable structural correlate, which is why its literature is less satisfying and its treatment largely non operative. 4.15.9 covers patellofemoral pain.

The medial restraint's characterisation made a specific reconstruction possible, which is the clearest line from this literature to an operation. 4.20.6 covers that assessment.

What It Changed

It moved the explanation of instability from alignment to shape, which changed the imaging and the operations. 4.15.8 covers trochlear dysplasia.

It made the apprehension test the key clinical test, and demoted translation measured alone. 4.15.3 covers the apprehension test.

It separated anterior pain from instability as populations, which changed what each is offered. 4.15.9 covers patellofemoral pain.

It left anterior pain without a clinical test that performs well, which is the unfinished part. 4.6.5 covers patellar tenderness.

Fellowship Level

What It Changed

At fellowship level this literature produced the section's clearest example of imaging displacing an examination, and the consequences follow from that.

The features that decide the operation are measured on images, so the examination's role narrowed to establishing that the instability is real and symptomatic. 4.15.3 covers the apprehension test.

The clinical inference of trochlear shape is unreliable, so a clinician who infers it is working outside what the literature supports. 4.15.8 covers trochlear dysplasia.

Rotational and torsional contributions were characterised later and are still less often assessed than the coronal ones, which is a gap in practice rather than in the literature. 4.19.7 covers torsional assessment.

Anterior pain remains a diagnosis of exclusion with a weak examination and no structural target, and the honest position is that this literature did not solve it. 4.15.9 covers patellofemoral pain.

What to Read Now

Chapter 3.17 carries the patellofemoral biomechanics literature, which explains why shape matters more than alignment.

The dysplasia classification literature is the reading for the structural question, and it is imaging rather than examination work. 4.15.8 covers trochlear dysplasia.

The anterior knee pain literature is the reading for the unsolved half, and it is where the absence of a structural target is discussed. 4.15.9 covers patellofemoral pain.

The medial restraint literature is the reading behind the reconstruction. 4.20.6 covers that assessment.

No reference list appears on this page. No source was retrieved, and under decision 022 a named author with a described finding is the most this process can honestly supply, with no year, journal or citation attached.