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The Ligament Injury That Gets Called a Sprain and Ends in Arthritis
A scapholunate (SL) ligament tear is a torn ligament between two small wrist bones, usually from a fall on an outstretched hand. The X-ray often looks normal, so it gets called a sprain.
The clue: pain on the back of the wrist, a click, and weakness pushing up on the hand, still there at 6 weeks. Partial tears often settle with splinting and specific strengthening over about 3 months. Complete tears do best repaired within roughly 6 weeks, with 6 to 12 months to full loading.
There’s a small ligament deep in your wrist holding two of the little carpal bones together, the scaphoid and the lunate. It’s a few millimeters across and it does an unreasonable amount of work.
Fall on an outstretched hand and it can tear.
The X-ray usually looks normal. The wrist is swollen and sore. It gets called a wrist sprain, and everybody goes home.
Left alone, this one has a known ending, and the ending is a wrist full of arthritis roughly a decade later. It’s the single most consequential thing hiding behind the word sprain.
What is a scapholunate ligament tear?
Your wrist isn’t one joint. It’s eight small bones arranged in two rows, sliding and rotating against each other in a choreography held together entirely by short, tough ligaments. (Map here: wrist anatomy, the carpal bones explained.)
The scaphoid and the lunate sit side by side in the first row, and they naturally want to rotate in opposite directions under load. The ligament between them is what stops that.
Tear it, and they start doing exactly what they always wanted to do. The scaphoid tips forward, the lunate tips back, and the neat spacing between the bones opens into a gap.
Now the load paths through the wrist are wrong. Cartilage that was designed to be loaded across a broad surface gets loaded on an edge instead, and it wears through at that edge over years.
The wear follows a predictable sequence that hand surgeons have mapped and named: SLAC wrist, scapholunate advanced collapse. It starts at one corner of the scaphoid, spreads across the wrist, and ends as advanced arthritis in a wrist that was “just sprained” in someone’s twenties.
(Predictable is the important word. This isn’t bad luck. It’s mechanics running their course.)
What does a scapholunate tear feel like?
The location is the first clue. Pain on the BACK of the wrist, in the middle-to-thumb side, just past the end of the forearm bone. Press along there and there’s a specific tender spot.
Then the behavior:
- A click or a clunk with certain movements, especially rotating the wrist side to side. (More on that in wrist clicking and popping.)
- Pain and weakness loading the wrist bent backwards: push-ups, pressing up out of a chair, a plank, leaning on a counter.
- Grip that’s noticeably weaker than the other side, and painful at the end of the squeeze.
- And the giveaway: it’s still doing all of this at six weeks, when a real sprain would be long finished.
How is a scapholunate ligament injury diagnosed?
Important thing to know about the imaging: a standard X-ray often misses this. Early on, the gap only opens when the wrist is under load, so it can look perfectly normal at rest.
- Scaphoid shift test (Watson test): the examiner presses on the scaphoid while moving your wrist side to side. A painful clunk as the bone pops back in place is the classic finding. Useful, not conclusive.
- Stress X-rays: a clenched-fist view loads the wrist and can open the gap. A gap of more than about 3 millimeters between the two bones is suspicious. Radiologists call it the Terry Thomas sign, after a gap-toothed British comedian. (Same gap, different smile.)
- MRI or MR arthrogram: shows the ligament itself. Good, but small partial tears can still hide. See your hand and wrist MRI report explained.
- Wrist arthroscopy: a camera in the joint. The most accurate way to grade the tear, and the surgeon can often treat it in the same sitting.
Which means “the X-ray was normal” does not clear this injury, in exactly the same way it doesn’t clear a scaphoid fracture. Same fall, same normal X-ray, two different things that both bite you later.
A big fall with a deformed wrist, or numbness in the thumb and index finger, is a different conversation: that can be a perilunate dislocation, and it’s an emergency.
Is it too late to fix a scapholunate tear?
This is a condition with a real window. Name it, find where you are in it, act while it’s open.
- OPEN (roughly the first 6 weeks): the torn ligament ends are still there and still healthy enough to be stitched back together. Repairing something that exists is a fundamentally easier operation with better results.
- CLOSING (months later): those ends have retracted and scarred. There is nothing left to sew. The operation becomes a reconstruction, borrowing tendon to build a substitute ligament, and reconstructions are longer, harder and less reliable than repairs.
- SHUT for the ligament (years later, arthritis arrived): the conversation stops being about the ligament at all. It becomes about salvage: fusing part of the wrist, or removing a row of bones. Those operations work, in the sense that they reduce pain. They also permanently cost you movement.
Six weeks buys a repair. Six months buys a reconstruction. Six years buys a fusion.
Can a scapholunate tear heal without surgery?
Partial tears where the bones haven’t shifted often can be managed without surgery: a period of splinting, then a specific strengthening program aimed at the muscles that help hold the scaphoid in position. Done properly this is genuinely effective, and it’s skilled work rather than generic wrist exercises.
- Splint: a wrist splint holding the wrist near neutral, usually full time for about 4 to 6 weeks, off only for skin care and the exercises your therapist allows.
- Then rehab: roughly 6 to 12 weeks of graded control and strengthening work.
- What a complete tear won’t do: heal back together on its own. A splint can calm it down. It can’t close a gap that’s already opened.
Complete tears with the bones already separating are surgical, and the sooner the better for the reasons above.
What exercises help a scapholunate injury?
The aim is control, not just strength. Some muscles help hold the scaphoid in place; others pull the gap wider. Your therapist chooses which, and when. In my experience a typical program starts something like this:
- Dart-thrower’s motion: move the wrist from back-and-thumb-side down to palm-and-little-finger-side, like throwing a dart. This plane puts little strain on the SL ligament. 10 slow reps, 3 times a day.
- Isometric holds: push the hand gently against your other hand without the wrist moving, in the directions your therapist picks. Hold 5 to 10 seconds, 10 reps, 2 to 3 times a day, pain staying low.
- Position sense drills: with eyes closed, move the wrist to a set angle and check how close you got. Retrains the joint’s own sensors, which a torn ligament also damages.
- Loading, later: weight-bearing on the hand (push-up position, plank) is introduced last, usually from around 3 months, and progressed slowly.
Hard, heavy fist-clenching early on is the one to avoid unless you’re told otherwise. A tight fist drives the bones apart.
How long is recovery after scapholunate surgery?
Recovery is long either way. Your surgeon’s protocol comes first. A typical repair or reconstruction runs roughly like this:
- Weeks 0 to 8 to 10: cast or splint, often with pins holding the bones while the ligament heals. Fingers, elbow and shoulder kept moving. Hand up for swelling.
- Weeks 8 to 12: pins out, splint weaned, gentle active wrist movement starts. Stiffness is normal here.
- Months 3 to 6: control and strengthening progress. Light loading starts.
- Months 6 to 12: return to full loading, heavy work and impact sport. Some permanent loss of the extremes of wrist movement is common…the trade for a stable wrist.
When can I work, drive and go back to the gym?
- Desk work: often 1 to 2 weeks after surgery, one-handed and in the splint. Sooner with non-surgical treatment.
- Manual work: light duties around 3 months. Heavy lifting, tools and vibration usually 6 months or more after surgery.
- Driving: usually not in a forearm cast. Once it’s off, the test is whether you can control the wheel in an emergency. See driving after a hand injury.
- Gym, yoga, push-ups, gymnastics: anything that loads the wrist bent back is last to return, often 6 to 12 months after surgery. Start on fists or handles, not flat palms.
What a hand therapist does differently
- Asks “how did you fall?” and presses on the exact spot on the back of the wrist, instead of stopping at “the X-ray was fine”.
- Picks which muscles to load. Generic wrist curls can work against an unstable SL joint.
- Tracks grip strength in kilograms against the other hand, so progress is measured, not guessed.
- Flags the wrist that isn’t settling back to the surgeon while the repair window is still open.
The short version
A fall, pain on the back of the wrist, a click, weakness pressing up on it, and still going at six weeks: that is not a sprain, and a normal X-ray does not settle it.
Ask for proper imaging while the ligament is still repairable. This is one of the few injuries on this site where the difference between six weeks and six months is the difference between a stitch and a fusion.
Get it checked today if
- The wrist looks deformed or out of shape after the fall.
- Numbness or tingling in the thumb, index and middle fingers that started with the injury.
- Severe pain that isn’t easing with rest, ice and elevation, or fingers you can’t move.
- Tenderness in the hollow at the base of the thumb. That’s a scaphoid fracture until proven otherwise.
Get it checked if
- Back-of-wrist pain after a fall is no better at 2 weeks.
- A new click or clunk in the wrist since the injury.
- Pushing up from a chair or holding a plank hurts and feels weak.
- You were told “sprain, normal X-ray” and it’s still sore at 6 weeks.
A sprain gets better on its own. This one gets worse on a schedule.
Written by Nigel Chua, hand occupational therapist in practice since 2005. Thousands of hands, wrists and elbows assessed and treated. My credentials are here. This article explains; it doesn’t examine. A wrist still painful and clicking at six weeks after a fall needs imaging, not more patience.
Every article on this site is written using the Closing Window Method: name the window your condition runs on, find where you are in it, and act while it’s still open.