Kienböck’s disease is a condition where the blood supply to the lunate, a small bone in the center of your wrist, gets cut off. Without steady blood flow, the bone gradually dies, weakens, and eventually collapses. This process, called avascular necrosis, leads to increasing wrist pain, stiffness, and loss of grip strength over time. It most commonly affects adults between their 20s and 40s, and it almost always involves just one wrist.
Why the Lunate Loses Its Blood Supply
The lunate sits right in the middle of the wrist’s eight small carpal bones, acting as a keystone that transfers force between your hand and forearm. Most people have two arteries feeding blood into the lunate, but some people are born with only one. That anatomical variation leaves less margin for error: if that single vessel is damaged or compressed, the bone has no backup supply.
The exact trigger isn’t always clear. Repeated stress or trauma to the wrist, differences in the relative length of the two forearm bones (the radius and ulna), and that reduced blood vessel anatomy all appear to play a role. When the ulna is naturally shorter than the radius, a condition called negative ulnar variance, extra mechanical load gets placed on the lunate with every grip or push. Over time, that added pressure may damage the already vulnerable blood supply. In many cases, though, no single cause can be identified.
How Symptoms Develop
Kienböck’s disease tends to progress through four recognized stages, and how it feels depends on how far along it is.
In the earliest stage, the lunate looks completely normal on standard X-rays. You might notice a vague ache in the center of your wrist, some mild swelling, or discomfort when gripping objects. Because the X-ray appears fine, this stage is often mistaken for a sprain or dismissed entirely. As the disease advances into stage two, the bone begins to harden and show changes on imaging, but it hasn’t yet changed shape. Pain becomes more consistent, and you may notice your wrist doesn’t bend as far as it used to.
Stage three is where the lunate starts to fracture and collapse under load. At this point, wrist motion becomes noticeably limited, grip strength drops, and pain with everyday tasks like turning a doorknob or lifting a bag becomes hard to ignore. In the most advanced stage, the collapsed lunate disrupts the alignment of the surrounding wrist bones, and arthritis develops across the joint. Pain and stiffness can become constant.
Getting an Accurate Diagnosis
Standard X-rays can detect Kienböck’s disease once the bone has started to change shape or density, typically from stage two onward. But in the earliest stage, when the bone still looks normal on X-ray, MRI is essential. MRI can reveal the loss of blood flow inside the lunate before any structural damage is visible, picking up changes in the bone’s signal that reflect dying tissue. It’s also the most accurate tool for determining which stage you’re in, which directly shapes treatment decisions.
One limitation: MRI sometimes has difficulty distinguishing stage one from stage two when certain signal patterns overlap. In those cases, a CT scan or repeat X-rays can help clarify the picture. Your doctor will also examine your wrist for tenderness directly over the lunate (the center of the back of your wrist) and test your range of motion and grip strength to gauge functional impact.
Nonsurgical Treatment for Early Disease
When Kienböck’s disease is caught early, before the lunate has collapsed, the initial approach is usually conservative. The goal is to reduce pressure on the bone and give it a chance to recover some blood flow. That typically means immobilizing the wrist in a splint or cast for several weeks to months, combined with anti-inflammatory medication to manage pain and swelling.
Activity modification matters, too. If your work or hobbies involve heavy gripping, pushing, or vibration exposure, reducing those forces on the wrist helps limit further damage. Physical therapy can maintain finger mobility and forearm strength while the wrist is protected. The reality, though, is that conservative treatment works best as a holding strategy in early disease. It can relieve symptoms and slow progression, but it doesn’t restore blood flow to the bone. Many people eventually need surgical intervention as the condition advances.
Surgical Options by Disease Stage
Leveling Procedures
For people with negative ulnar variance (a shorter ulna) and stage two or early stage three disease, one of the most studied operations is radial shortening osteotomy. The surgeon removes a small slice of the radius bone in the forearm, shortening it so that the mechanical load across the wrist is distributed more evenly. This takes pressure off the lunate and can halt the collapse process.
Long-term data on this procedure is encouraging. A study following patients for a minimum of 20 years after radial shortening found that pain remained reduced in all patients at the two-decade mark, and X-rays showed no further collapse of the lunate in any case. The good clinical results seen at 10 years held steady through 20 years, making it one of the most durable options for the right candidate.
Revascularization
Another approach aims to restore blood flow directly. A surgeon transplants a small piece of bone along with its attached blood vessel, usually taken from a nearby bone in the forearm or wrist, and grafts it into the lunate. This is most often considered for younger patients with earlier-stage disease where the bone hasn’t fully collapsed. Recovery requires a period of immobilization while the graft heals and new blood supply establishes itself.
Salvage Procedures for Advanced Disease
When the lunate has already collapsed or arthritis has spread to surrounding bones, the options shift toward salvage surgeries. One common approach is proximal row carpectomy, where the surgeon removes the entire row of wrist bones closest to the forearm (including the collapsed lunate) and allows the remaining bones to articulate directly with the radius.
This sounds dramatic, but functional outcomes are surprisingly good for stage three disease. In a study following 18 patients for an average of 10 years after the procedure, wrist motion averaged 78% of the opposite, healthy wrist, and grip strength averaged 87% of the other side. Functional limitation scores were minimal, meaning most patients returned to near-normal daily use. The procedure is less reliable for stage four disease, however, where early joint degeneration between the remaining bones is more likely to cause persistent pain.
For the most advanced cases with widespread arthritis, partial or total wrist fusion may be the final option. Fusion eliminates pain by locking the affected bones together, but it permanently limits wrist motion. It’s generally reserved for people who have exhausted other options.
What Recovery Looks Like
Recovery timelines vary significantly depending on the procedure. After a radial shortening osteotomy, the forearm bone needs to heal at the surgical site, which typically means a cast or splint for several weeks followed by gradual rehabilitation. Most people return to full activity within three to six months. After a proximal row carpectomy, rehabilitation focuses on regaining wrist motion and rebuilding grip strength over a similar timeframe, though maximum improvement can continue for up to a year.
Regardless of the procedure, hand therapy plays a central role. A therapist will guide you through exercises to restore range of motion, manage swelling, and progressively strengthen the wrist. The goal isn’t necessarily to get back to 100% of your previous function, but to reach a level where pain is controlled and you can use your hand comfortably for work and daily life. For most people who are treated before end-stage disease, that goal is realistic.