The Wilson Test is a knee orthopaedic test commonly associated with osteochondritis dissecans of the medial femoral condyle. A positive result may involve familiar knee pain during extension with tibial internal rotation that reduces when the tibia is externally rotated. The test may support assessment reasoning, but it does not confirm osteochondritis dissecans on its own.
Osteochondritis dissecans, often shortened to OCD, is an osteochondral condition involving subchondral bone and the overlying articular cartilage. It most commonly affects the knee, particularly in adolescents and young active people, and may present with vague activity-related pain, swelling, stiffness, catching or locking.
The Wilson Test is a provocative knee test traditionally associated with OCD lesions of the medial femoral condyle.
It is commonly used alongside:
knee history and symptom behaviour
observation for swelling
Sweep Test or patellar tap
knee range of motion
joint-line palpation
meniscal testing
functional squat or step-down assessment
imaging where clinically appropriate
Current clinical resources emphasise that OCD diagnosis and lesion stability are usually assessed using radiographs and MRI rather than a physical test alone.
Test name: Wilson Test
Also known as: Wilson’s Test, Wilson Sign
Body region: Knee
Purpose: Assess pain response associated with possible osteochondritis dissecans of the knee
Commonly associated presentation: Osteochondritis dissecans of the medial femoral condyle
Positive finding: Familiar pain during knee extension with tibial internal rotation that reduces when the tibia is externally rotated
Negative finding: No familiar pain, locking or symptom change during the test movement
Best used with: History, swelling assessment, knee ROM, functional testing and imaging where appropriate
Key limitation: Diagnostic accuracy values for the Wilson Test are not well established, and imaging is usually needed to assess OCD lesions
The Wilson Test is a knee special test used to assess symptom response during knee extension with tibial rotation.
The traditional rationale is that internal tibial rotation during knee extension may bring the tibial spine into contact with a classic OCD lesion location on the lateral aspect of the medial femoral condyle. External tibial rotation may reduce this impingement and reduce symptoms.
The test may assess:
pain during knee extension
pain change with tibial rotation
possible mechanical irritation
symptom reproduction near terminal extension
side-to-side symptom difference
catching or locking response
The Wilson Test should not be used as a stand-alone diagnostic test.
The Wilson Test may help support assessment reasoning when OCD of the knee is suspected.
It may help professionals:
assess familiar knee pain during extension
identify whether tibial rotation changes symptoms
compare the symptomatic and non-symptomatic knee
document pain, catching or locking
guide further assessment selection
support referral or imaging discussion where appropriate
monitor symptom irritability over time
The test is most useful when it reproduces the client’s familiar symptoms and when the history is consistent with OCD.
The Wilson Test assesses symptom response during a specific knee movement pattern.
It may provide information about:
pain during knee extension
symptom change with tibial internal rotation
symptom relief with tibial external rotation
possible mechanical irritation around the medial femoral condyle
catching or locking response
side-to-side difference
It does not directly identify:
osteochondral lesion size
lesion stability
cartilage integrity
loose body presence
meniscal injury
ligament injury
exact cause of pain
readiness to return to sport
This test may be useful for:
exercise professionals
rehabilitation practitioners
strength and conditioning coaches working with allied health teams
performance coaches
movement assessment professionals
students learning knee assessment
professionals using Measurz or MAT for structured assessment recording
It may be relevant for clients who report:
activity-related knee pain
vague deep knee pain
recurrent knee swelling
stiffness after activity
catching or locking
pain during knee extension
reduced confidence with running, jumping or sport
adolescent or young athlete knee symptoms
OCD is often discussed in adolescent or young adult athletic populations, but symptoms and assessment findings should still be interpreted with caution and referred appropriately when suspected.
Use the Wilson Test when the history suggests possible osteochondral involvement and controlled knee movement testing is appropriate.
It may be useful when the client reports:
vague activity-related knee pain
deep knee pain
recurrent effusion
stiffness
catching
locking
pain near terminal knee extension
symptoms during running, jumping or stairs
symptoms that are not clearly explained by simple soft tissue irritation
The test is more meaningful when symptoms are familiar and change with tibial rotation.
Use caution with:
acute traumatic knee injury
large swelling or suspected haemarthrosis
suspected fracture
locked knee
severe pain
high irritability
suspected unstable osteochondral fragment
recent knee surgery
inability to safely flex or extend the knee
marked guarding
Stop testing if:
sharp pain occurs
the knee catches or locks
symptoms escalate quickly
the client feels unsafe
guarding prevents controlled movement
the client asks to stop
If the client has a locked knee, sudden swelling, significant trauma, severe night pain, fever, redness, unexplained systemic symptoms or major loss of function, the finding should be escalated for appropriate medical review.
Treatment table or chair
Pain scale
Symptom location notes
Measurz recording workflow
Optional comparison-side notes
Optional referral or imaging notes where appropriate
Position the client sitting with the lower legs hanging over the edge of a table, or lying supine if that version is preferred.
The seated version is commonly described in clinical teaching resources.
Explain the test before starting.
The client should understand that the test involves controlled knee movement with lower-leg rotation and that it will stop if symptoms become uncomfortable or unsafe.
Client sits on the edge of a table
Hip is flexed
Knee begins flexed to approximately 90 degrees
Lower leg hangs freely
Thigh remains supported
Client stays relaxed
Stand or sit beside the tested knee
Support the lower leg
Control tibial rotation
Observe pain response, guarding, catching or locking
Common hand placement includes:
one hand stabilising or supporting the knee or distal thigh
one hand controlling the lower leg, ankle or foot
optional palpation around the medial femoral condyle or joint region if appropriate
Avoid forceful pressure over painful tissue.
Monitor for:
hip rotation
thigh movement
quadriceps guarding
hamstring guarding
ankle substitution
facial expression
withdrawal response
The movement should be controlled and symptom-limited.
A commonly described Wilson Test sequence is:
Flex the knee to approximately 90 degrees.
Internally rotate the tibia.
Slowly extend the knee.
Observe whether pain occurs, especially around 30 degrees from full extension.
If pain occurs, externally rotate the tibia.
Continue or repeat extension and observe whether symptoms reduce.
A positive response is classically described as pain during extension with tibial internal rotation that is relieved by tibial external rotation.
Ask the client to:
keep the leg relaxed
report pain, catching or locking
identify the exact symptom location
say whether the symptom is familiar
rate pain from 0–10
tell you immediately if they want the test stopped
Example instruction:
“I’m going to gently rotate your lower leg and straighten your knee. Tell me if this reproduces your familiar knee pain, catching or locking, and whether the feeling changes when I rotate your leg the other way.”
A positive Wilson Test may include:
familiar knee pain during extension with tibial internal rotation
pain around the medial femoral condyle region
pain near the final part of knee extension
catching or locking during the movement
symptom reduction when the tibia is externally rotated
clear side-to-side difference
The most meaningful finding is familiar pain that changes with tibial rotation.
A negative finding involves:
no familiar pain during the movement
no catching
no locking
no meaningful symptom change with tibial rotation
no clear side-to-side difference
Stop if:
sharp pain occurs
the knee catches or locks
symptoms escalate quickly
guarding prevents safe movement
the client feels unsafe
the client asks to stop
Use slow and controlled movement
Do not force knee extension
Do not force tibial rotation
Avoid repeated provocation in irritable knees
Record whether external rotation relieved symptoms
Consider referral or further assessment if OCD is suspected
A positive Wilson Test may increase suspicion of osteochondral involvement, particularly OCD of the medial femoral condyle, when it reproduces familiar pain during extension with tibial internal rotation and symptoms reduce with tibial external rotation.
A positive result is more meaningful when it matches:
adolescent or young active client history
activity-related knee pain
recurrent effusion
stiffness
catching or locking
pain near terminal knee extension
reduced sport tolerance
imaging findings where available
A positive result does not confirm OCD on its own.
Other factors may contribute to symptoms during the test, including:
meniscal irritation
patellofemoral pain
synovitis
cartilage irritation
ligament-related pain
bone bruising
capsular sensitivity
general knee irritability
poor relaxation during testing
A negative test may suggest this specific rotational extension movement does not reproduce symptoms.
However, a negative Wilson Test does not exclude OCD or other osteochondral pathology.
Some clients may only report symptoms during:
running
jumping
stairs
deep squatting
sport-specific loading
fatigue
repeated activity
mechanical catching episodes
Interpretation is stronger when combined with history, swelling assessment, range of motion, functional testing and imaging where clinically appropriate.
High-quality diagnostic accuracy values for the Wilson Test as a stand-alone test appear limited.
At the time of writing:
Sensitivity: no high-quality published value found for this exact test and population
Specificity: no high-quality published value found for this exact test and population
Positive likelihood ratio: not well established
Negative likelihood ratio: not well established
Reference standard: not consistently established for the clinical test
Current OCD guidance places more emphasis on imaging than on any single physical test. Orthobullets summarises that diagnosis may be made radiographically, while MRI is usually required to determine lesion size, stability and cartilage injury.
A 2022 update on knee OCD similarly states that MRI is indicated in young active people with knee pain and/or effusion to support early diagnosis and treatment planning, particularly by assessing lesion stability.
Practical interpretation:
A positive Wilson Test may increase suspicion when it reproduces familiar symptoms.
A negative Wilson Test does not exclude OCD.
The test should not be used to determine lesion stability.
Imaging is usually needed when OCD is suspected.
The result should be interpreted with history, swelling, mechanical symptoms, age, activity profile and other assessment findings.
Specific reliability values for the Wilson Test appear limited.
Reliability may be influenced by:
client position
knee flexion angle
tibial rotation amount
movement speed
symptom irritability
examiner hand placement
whether familiar pain is required
whether symptom relief with external rotation is tested
client guarding
comparison-side testing
Validity is stronger when:
symptoms are familiar
pain occurs during extension with tibial internal rotation
symptoms reduce with tibial external rotation
the client has activity-related knee pain
swelling or mechanical symptoms are present
imaging findings support OCD where available
Validity is weaker when:
pain is vague or unfamiliar
pain location is unclear
symptoms do not change with tibial rotation
the knee is highly irritable
symptoms are better explained by meniscal, patellofemoral, ligament or inflammatory factors
Because OCD lesion diagnosis and stability assessment rely heavily on imaging, the Wilson Test should be viewed as an assessment reasoning tool rather than a definitive clinical test.
Common errors include:
forcing knee extension
forcing tibial rotation
moving too quickly
not asking whether pain is familiar
not checking whether external rotation relieves symptoms
interpreting any knee pain as positive
failing to record the angle where pain occurs
not documenting catching or locking
not considering meniscal or patellofemoral sources
using the test as a stand-alone diagnosis
Limitations include:
limited diagnostic accuracy evidence
limited published reliability data
symptom overlap with other knee conditions
does not identify lesion size or stability
does not replace radiographs or MRI
may be negative despite OCD
may be positive due to other knee pathology
less useful in very painful, swollen or locked knees
The Wilson Test may help professionals:
assess symptom response during knee extension with tibial rotation
document whether symptoms change with rotation
compare symptomatic and non-symptomatic knees
identify whether further osteochondral assessment may be needed
support referral or imaging discussion where appropriate
monitor symptom irritability over time
For athletes, it may be used alongside:
training load review
jumping and landing history
running symptom history
knee swelling assessment
range of motion testing
squat or step-down assessment
return-to-sport confidence measures
For younger clients, recurrent swelling, activity-related pain, catching or locking should be taken seriously and escalated when appropriate.
For Measurz users, the main value is structured recording of symptom reproduction, tibial rotation response, pain angle, mechanical symptoms and related findings.
Record:
test name: Wilson Test
side tested: left, right or both
result: positive, negative, unclear or unable to test
client position: seated or supine
starting knee angle
tibial rotation used: internal then external
angle or range where pain occurred
whether external rotation reduced symptoms
pain score from 0–10
symptom location
symptom quality
whether symptoms were familiar
catching, locking or clicking if present
guarding or apprehension
comparison side
irritability level
reason for stopping if stopped early
related findings, such as swelling, ROM, meniscal tests, patellofemoral tests or functional tests
referral or imaging notes if appropriate
interpretation notes
planned retest date if monitoring change
Record whether the main response was:
familiar pain with internal rotation
symptom relief with external rotation
catching
locking
pain in another location
no symptoms
unclear response
unable to test safely
This improves:
repeatability
communication
client education
assessment reasoning
team consistency
progress monitoring
referral communication
reporting quality
Sweep Test
Knee Range of Motion Tests
Thessaly Test
McMurray Test
Steinmann Test
Patellar Grind Test
Single-Leg Squat Test
Step-Down Test
It assesses whether knee extension with tibial internal rotation reproduces familiar pain that may be associated with osteochondritis dissecans of the medial femoral condyle.
A positive result may include familiar pain during knee extension with tibial internal rotation that reduces when the tibia is externally rotated.
No. A positive result may increase suspicion, but OCD is usually assessed using history, examination and imaging. The test does not confirm OCD on its own.
No. A negative test does not exclude OCD or other osteochondral pathology.
The traditional explanation is that internal tibial rotation may increase contact between the tibial spine and a classic OCD lesion location, while external rotation may reduce this contact.
High-quality published sensitivity, specificity and likelihood ratio values for the exact Wilson Test appear limited. Imaging is usually needed when OCD is suspected.
It is best used with history, swelling assessment, range of motion, mechanical symptom review, functional testing and imaging where clinically appropriate.
The Wilson Test is commonly associated with OCD assessment of the knee.
A positive finding may involve familiar pain during extension with tibial internal rotation.
Symptom relief with tibial external rotation strengthens the clinical relevance of the finding.
The test does not confirm OCD on its own.
Diagnostic accuracy values for the exact test appear limited.
Imaging is usually needed to assess OCD lesion size and stability.
Measurz should record side, position, tibial rotation, pain angle, symptom relief, pain score, mechanical symptoms and related findings.
American Academy of Orthopaedic Surgeons. (2022). Osteochondritis dissecans clinical practice guideline. https://www.aaos.org/quality/quality-programs/osteochondritis-dissecans/
Accadbled, F., Vial, J., & Sales de Gauzy, J. (2018). Osteochondritis dissecans of the knee. Orthopaedics & Traumatology: Surgery & Research, 104(1S), S97–S105. https://doi.org/10.1016/j.otsr.2017.02.016
BMJ Best Practice. (2026). Osteochondritis dissecans: Symptoms, diagnosis and treatment. https://bestpractice.bmj.com/topics/en-gb/591
Bruns, J., Werner, M., & Habermann, C. (2018). Osteochondritis dissecans: Etiology, pathology, and imaging with a special focus on the knee joint. Cartilage, 9(4), 346–362. https://doi.org/10.1177/1947603517715736
Masquijo, J., & Kothari, A. (2019). Juvenile osteochondritis dissecans of the knee joint: Current concepts review. EFORT Open Reviews, 4(5), 201–212. https://doi.org/10.1302/2058-5241.4.180079
Mestriner, A. B., Ackermann, J., & Gomoll, A. H. (2022). An update on osteochondritis dissecans of the knee. Orthopedic Reviews, 14(5). https://doi.org/10.52965/001c.38829
StatPearls. (2024). Osteochondritis dissecans of the knee. NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK538194/
