Jumper's Knee

For Medical Students

What It Tests

Jumper's knee is tendinopathy of the patellar tendon at its origin on the lower pole of the patella, in a patient whose sport involves repeated jumping or deceleration.

Examining for it means localising tenderness precisely to the lower pole and reproducing the pain with a loaded task, which is how the diagnosis is made. 4.16.2 covers the tendon.

It matters because it presents as anterior knee pain in an athlete and is frequently investigated as something intra-articular. 4.15.9 covers the alternative.

How It Is Performed

Take the history: pain at the front of the knee that comes on with jumping or landing, worse at the start of activity, and worse after rather than during in the early stages. 4.2.11 covers aggravating factors.

Palpate the lower pole of the patella with the knee extended and relaxed, where the tenderness is focal and reproducible. 4.6.6 covers tendon tenderness.

Repeat with the knee flexed and the tendon tensioned, where the tenderness typically reduces.

Ask the patient to perform a single leg decline squat or a single leg squat, and note whether it reproduces the pain. 4.4.9 covers single leg landing.

Test resisted extension and note whether that reproduces it too.

Assess the quadriceps and the proximal control, since both contribute to the load the tendon carries. 4.4.10 covers functional screening.

What a Positive Means

Focal tenderness at the lower pole, reduced when the tendon is tensioned, with pain reproduced by a loaded single leg task, is the characteristic pattern.

Pain that is worse at the start of activity and eases as it continues, in the early stages, is a tendinopathy pattern rather than a joint one. 4.2.11 covers it.

Diffuse tenderness along the whole tendon raises a different problem, and a partial tear or an enthesopathy are both possibilities. 4.16.2 covers the tendon.

Tenderness at the tubercle rather than the lower pole is an insertional problem, and in an adolescent an apophysitis. 4.16.4 covers it.

A normal examination in an athlete with the characteristic history still supports the diagnosis, because the finding depends on the stage. 4.2.9 covers onset.

MRCS Level

How It Is Performed

In a viva this is the answer when asked about anterior knee pain in a jumping athlete, and the precise localisation is what separates it from a guess.

The expected points are the history pattern, the focal tenderness at the lower pole, the two tendon positions, the loaded single leg task, and the proximal assessment.

Say that the diagnosis is clinical and that imaging stages it rather than makes it, which is unusual in this section. 4.1.6 covers that relationship.

Say that the treatment is load management and that surgery is a late and uncommon option, which is the clinically important consequence.

Say that you would assess the proximal control and the ankle, since both change the load the tendon takes in landing. 4.4.5 covers the proximal pattern.

What a Positive Means

The reasoning expected is that the enthesis carries the highest stress in the tendon during eccentric loading, which is why the pathology sits at the origin and why jumping sports produce it. 2.4.3 covers patellar biomechanics.

Deceleration and landing load the tendon eccentrically, which is a higher load than concentric extension, and that is why the single leg decline squat reproduces the pain so reliably. 3.14.8 covers landing.

The pathology is degenerative rather than inflammatory in the established stages, which is the basis for load based treatment rather than anti-inflammatory treatment.

Proximal weakness increases the load transmitted through the knee in landing, which is why hip and trunk control are part of the assessment and the treatment. 3.12.7 covers dynamic valgus.

How Good It Is

The clinical diagnosis is reliable when the tenderness is focal and a loaded task reproduces the pain, which makes the examination the reference standard here.

It is less reliable early, when the tenderness can be subtle and the pain only appears after activity.

Imaging stages the tendon and does not change the early management, which is why the examination leads. 4.1.6 covers that relationship.

It cannot distinguish tendinopathy from a partial tear, and in a tendon that has failed to respond that distinction becomes relevant. 4.16.2 covers it.

No figures appear for any accuracy comparison on this page, under decision 023, and the comparison is the claim being made.

FRCS Level

How Good It Is

At decision level this diagnosis is one where the examination's main job is to prevent an operation on the joint.

An athlete with focal lower pole tenderness and a reproducible loaded pain needs load management and a programme, and an arthroscopy for it achieves nothing. 4.15.9 covers the parallel.

A tendon that has failed a properly delivered programme over months is the group in which surgery is discussed, and the imaging and the duration carry that decision rather than the examination.

A patient whose symptoms are bilateral and insertional raises an enthesopathy, which moves the specialty rather than the operation. 4.2.14 covers inflammatory pain.

In a patient being considered for a bone patellar tendon bone graft, a tendinopathic tendon is an argument for a different graft. 4.20.1 covers that assessment.

Where It Misleads

The commonest error is investigating the joint rather than palpating the tendon.

The second is recording anterior knee tenderness rather than the exact position.

The third is treating it as an inflammatory problem in its established stages.

The fourth is omitting the proximal assessment, which is where the modifiable contributor usually is. 4.4.10 covers screening.

The fifth is offering surgery before a programme has actually been delivered, as opposed to recommended. 4.2.34 covers previous rehabilitation.

Fellowship Level

Where It Misleads

In referred practice this diagnosis arrives either late or wrongly attached, and the examination sorts both.

An athlete with a normal arthroscopy and persisting anterior pain, tender at the lower pole, had the diagnosis available at the first consultation. 4.16.2 covers the palpation.

An athlete whose programme has failed may not have had a programme: establishing what was actually done, at what load and for how long, is the first step rather than imaging. 4.2.34 covers previous rehabilitation.

A patient with a previous graft harvest and lower pole pain has donor site pain, which is a different problem with a different prognosis. 4.20.1 covers that assessment.

An elite athlete's management belongs with their own staff, and the surgeon's role is the decision about surgery rather than the load programme. 4.23.2 covers those patients.

In medicolegal work this diagnosis is difficult to attribute to a single event, because it is an overload condition, and saying so plainly is the honest position. 4.23.7 covers that setting.