Wrist Orthopaedic Test: Scapholunate Ligament

The scapholunate ligament is a key wrist stabiliser between the scaphoid and lunate. Injury can contribute to radial wrist pain, clicking, grip weakness and dynamic instability, especially after a fall or loaded wrist extension injury. Recent research highlights that scapholunate ligament lesion diagnosis is not standardised and that clinical and radiological methods vary in reliability, so assessment should combine history, physical examination and imaging/referral when needed.  

Introduction

A client reports radial wrist pain after falling onto an outstretched hand, catching a weight, landing in a push-up position or loading the wrist in extension. They may describe clicking, clunking, weakness, reduced grip confidence or pain with weight-bearing.

Scapholunate ligament assessment should not rely on one test. It should combine trauma history, symptom location, palpation, wrist ROM, grip strength, Scaphoid Shift Test findings, functional loading tolerance and referral or imaging decisions.

Quick Summary

Topic: Scapholunate Ligament Assessment
Body region: Radial wrist, scaphoid, lunate, scapholunate interval
Purpose: Assess suspected scapholunate ligament injury or instability
Key findings: Radial wrist pain, tenderness over the scapholunate interval, painful clunk, instability sensation, grip weakness or pain with loaded extension
Best used with: Scaphoid Shift Test, wrist ROM, grip strength, trauma history, imaging/referral and comparison side
Key limitation: Physical examination alone does not confirm scapholunate ligament injury

What Is the Scapholunate Ligament?

The scapholunate ligament connects the scaphoid and lunate and helps coordinate carpal motion. Injury may disrupt normal wrist mechanics and contribute to instability or degenerative change if significant and untreated.

Scapholunate injury is commonly considered after a fall onto an outstretched hand or sudden loaded wrist extension.

Why It Is Assessed

It is assessed when a client presents with radial wrist pain, clicking, clunking, grip weakness, pain with weight-bearing or wrist instability symptoms after trauma or repetitive loading.

Assessment helps decide whether the client may need modified loading, further testing, imaging or referral.

What It Assesses

Scapholunate ligament assessment looks for patterns suggesting ligament injury or instability. It does not directly visualise the ligament unless imaging or arthroscopy is used.

Clinical findings may include tenderness, painful clunking, altered movement, apprehension, grip weakness and symptoms with wrist loading.

Who It Is Useful For

This assessment may be useful for gymnasts, weightlifters, manual workers, racquet sport athletes, contact sport athletes and clients with post-trauma radial wrist symptoms or pain during loaded wrist extension.

When to Use This Assessment

Use when radial wrist pain, clicking, clunking or instability symptoms raise suspicion of scapholunate involvement.

When Not to Use or When to Be Cautious

Use caution with acute trauma, suspected scaphoid fracture, severe swelling, major pain, deformity, neurological symptoms or recent surgery. Refer when fracture or significant ligament injury is suspected.

Equipment Required

Pain and symptom scale
Grip dynamometer if available
Measurz recording workflow
Optional goniometer
Optional referral/imaging notes

How to Apply This in Practice

History

Record mechanism of injury, onset, swelling, clicking, clunking, instability, weight-bearing symptoms and previous wrist trauma.

Observation

Check swelling, hand use, guarding and comparison with the other side.

Palpation

Assess tenderness over the scapholunate interval and surrounding radial wrist structures.

Movement

Record wrist flexion, extension, radial deviation, ulnar deviation and pain location.

Functional loading

Assess pain with gripping, pushing, weight-bearing or sport-specific loading where safe.

Special testing

Use Scaphoid Shift Test/Watson Test when appropriate, and document pain, clunk, apprehension and comparison side.

Referral reasoning

Refer or recommend medical assessment when trauma history, swelling, persistent pain, instability or fracture suspicion is present.

Positive and Negative Test Interpretation

Findings may support scapholunate involvement when radial wrist pain, scapholunate interval tenderness, painful clunking, grip weakness and trauma history align. These findings do not confirm ligament injury on their own.

A lack of findings reduces suspicion but does not exclude subtle or dynamic instability. Symptoms may only appear under load, fatigue or sport-specific positions.

Sensitivity, Specificity and Diagnostic Accuracy

Diagnostic accuracy for scapholunate ligament assessment depends on the specific test and reference standard used. Current evidence indicates that diagnosis is not standardised and that clinical and radiological methods vary in reliability.  

Condition or presentation: suspected scapholunate ligament injury or instability
Population: clients with radial wrist pain or suspected ligament injury
Test variation: palpation, Scaphoid Shift Test, functional loading and imaging-supported assessment
Reference standard: varies; MRI, dynamic imaging, intraoperative findings or arthroscopy
Sensitivity: not applicable to the assessment cluster as a whole
Specificity: not applicable to the assessment cluster as a whole
Positive likelihood ratio: not available for the whole assessment cluster
Negative likelihood ratio: not available for the whole assessment cluster
Key limitations: variable clinical tests, dynamic instability, normal laxity, imaging limitations and inconsistent reference standards

A 2024 study assessed sonography during Watson testing in people with scapholunate ligament lesions confirmed by MRI and intraoperative findings, suggesting that dynamic imaging may improve objectivity during clinical testing.  

Reliability and Validity

Reliability depends on the specific assessment component, examiner skill, pain criteria, side-to-side comparison and whether findings are recorded precisely.

Validity is strongest when history, symptoms, manual findings, function and imaging/referral decisions are considered together.

Common Errors and Limitations

Common errors include relying only on the Scaphoid Shift Test, ignoring scaphoid fracture risk, treating painless clicking as pathology, not comparing sides and failing to record trauma mechanism.

Limitations include intermittent instability, normal laxity, pain guarding, imaging variability and lack of one definitive clinical test.

Practical Applications

Use scapholunate ligament assessment to identify clients who need modified wrist loading, progress monitoring, imaging discussion or referral.

How to Record This in Measurz

Record test/topic name, side tested, trauma mechanism, pain score, symptom location, swelling, tenderness, wrist ROM, grip strength, clicking/clunking, instability sensation, Scaphoid Shift Test result, functional loading response, comparison side, confidence in result and referral recommendation.

Related Tests / Internal Links

Scaphoid Shift Test
Wrist Extension Test
Wrist Radial Deviation Test
Wrist Ulnar Deviation Test
Grip Strength Test
Finkelstein Test
Supination Lift Test
Allen Test

FAQs

What does the scapholunate ligament do?

It helps stabilise and coordinate movement between the scaphoid and lunate bones.

What symptoms may suggest scapholunate injury?

Radial wrist pain, clicking, clunking, grip weakness and pain with loaded wrist extension may raise suspicion.

Can clinical testing confirm a scapholunate ligament tear?

No. Clinical testing may support suspicion, but imaging or specialist assessment may be needed.

Is painless clicking always abnormal?

No. Painless clicking should be recorded but interpreted cautiously.

What should be recorded in Measurz?

Record trauma history, pain, tenderness, wrist ROM, grip strength, clunking, instability and referral reasoning.

Key Takeaways

Scapholunate ligament assessment should combine history, palpation, testing and function.
Physical examination alone does not confirm a ligament tear.
Painful clunking after trauma is more meaningful than painless clicking.
Dynamic imaging may help in selected cases.
Measurz should capture trauma, symptoms, movement, grip and referral notes.

References

Mares, O., et al. (2024). Catch the shift: Ultrasound diagnosis of scapholunate lesion during Watson test. JSES Reviews, Reports, and Techniques.

British Journal of Surgery Abstract. (2024). Ultrasound-based measurement of dorsal scaphoid displacement during Watson test for diagnosis of scapholunate ligament injury.