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Hand & Wrist

Kienbock's Disease: loss of blood supply to a wrist bone.

Wrist pain, stiffness, and reduced grip from loss of blood supply to the lunate, one of the small carpal bones of the wrist. Treatment is staged by imaging, with the goal of offloading the lunate and preserving a functional wrist.

Written bySteven J. Lee, MD · Double Fellowship-Trained · Hand & Sports Medicine
Last reviewed · June 2026

Kienbock's disease is avascular necrosis of the lunate, meaning the lunate, one of the small carpal bones in the center of the wrist, loses its blood supply and begins to weaken. Over time the bone can soften, fragment, and collapse, which changes the mechanics of the entire wrist.

Patients typically notice gradual wrist pain, stiffness, and a weaker grip, often without a clear injury. Because the early stages can resemble a simple wrist strain, the diagnosis is sometimes delayed. The outlook depends heavily on the stage at which it is caught, which is why imaging and staging are central to deciding on treatment.

What happens to the lunate

When the lunate loses its blood supply, the bone is no longer able to maintain and repair itself under the normal loads of the wrist. In the early stages the bone looks structurally intact but shows changes on MRI. As the disease advances, the bone can flatten, fragment, and collapse, after which the surrounding carpal bones shift and wrist arthritis can follow.

Symptoms

Common complaints include:

  • Gradual central wrist pain, often without a clear injury
  • Stiffness and reduced wrist motion
  • Decreased grip strength
  • Tenderness over the back of the wrist at the lunate

Staging and the role of imaging

Kienbock's disease is staged using imaging. X-rays may be normal very early, so an MRI is often used to detect the loss of blood supply before the bone changes shape. As the disease progresses, X-rays show flattening, fragmentation, and collapse, and CT can detail the bone. Staging matters because treatment is matched to the stage, from observation early to reconstructive or salvage procedures in advanced collapse.

Why ulnar variance matters

The relative lengths of the two forearm bones at the wrist, called ulnar variance, influence how load passes through the lunate. When the ulna sits shorter than the radius (negative ulnar variance), the lunate bears more stress, which is relevant to both the development of the disease and the choice of treatment. Procedures that level the joint aim to shift load away from the lunate.

Dr. Lee's approach

Dr. Lee's approach to Kienbock's disease is staged. The first step is accurate diagnosis and staging with X-ray and MRI, because the right treatment depends entirely on how far the disease has progressed and on the patient's ulnar variance. In the earliest stages, immobilization and careful observation may be appropriate while the situation is monitored.

When intervention is warranted, the strategy is to offload the lunate and preserve the wrist. Options range by stage and may include a joint-leveling osteotomy to redistribute load, procedures intended to restore blood supply (revascularization), and, in advanced collapse, salvage procedures such as proximal row carpectomy or a partial wrist fusion. The unifying goal across all stages is to relieve pain and protect wrist function for the long term.

Early-stage treatment

In early disease the emphasis is on protecting and offloading the lunate:

  • Immobilization and activity modification
  • Careful observation with monitoring of the stage over time
  • Joint-leveling osteotomy to shift load off the lunate in suitable cases
  • Revascularization procedures intended to restore blood supply

Advanced-stage and salvage options

When the lunate has collapsed and the wrist mechanics have changed, salvage procedures relieve pain while preserving a functional, if altered, wrist. Options include proximal row carpectomy and partial wrist fusion, chosen based on the pattern of damage and the patient's needs. The goal is durable pain relief and a useful wrist.

Recovery timeline

Recovery depends on the procedure performed:

  1. Early weeks
    Immobilization protects the wrist or the surgical reconstruction while early healing takes place.
  2. Weeks 6 to 12
    Progressive motion and strengthening under hand therapy guidance as healing allows.
  3. Beyond 12 weeks
    Continued recovery of motion and grip over the following months, with the timeline varying by the procedure performed.

What patients commonly misunderstand

A few points worth clearing up:

  • It is not a simple wrist sprain. Kienbock's disease involves loss of blood supply to a wrist bone. Persistent central wrist pain without a clear injury deserves imaging, including an MRI, rather than being dismissed as a strain.
  • The stage drives the treatment. Early disease may be managed with immobilization or joint-leveling procedures, while advanced collapse may need salvage surgery. Accurate staging is essential.
  • The goal is to preserve the wrist. Across stages, treatment aims to offload the lunate and protect wrist function, not simply to remove the bone.

This page is general educational content authored by Dr. Lee. It is not a substitute for individual medical advice. Every patient's case is different, book a consultation to discuss yours.

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Patient questions

Kienbock's disease, answered.

  • What is Kienbock's disease?

    Kienbock's disease is avascular necrosis of the lunate, meaning one of the small carpal bones in the center of the wrist loses its blood supply and begins to weaken. Over time the bone can soften, fragment, and collapse. It typically causes gradual wrist pain, stiffness, and decreased grip strength, often without a clear injury.

  • How is it diagnosed and staged?

    Diagnosis combines the clinical exam with imaging. X-rays may be normal in the earliest stages, so an MRI is often used to detect the loss of blood supply before the bone changes shape. As the disease advances, X-rays show flattening, fragmentation, and collapse. Staging is important because treatment is matched to how far the disease has progressed, and the relative length of the forearm bones (ulnar variance) is also assessed.

  • How is Kienbock's disease treated?

    Treatment is staged. In early disease, immobilization and observation may be appropriate, and joint-leveling osteotomy or revascularization procedures can offload the lunate and aim to preserve it. In advanced collapse, salvage procedures such as proximal row carpectomy or a partial wrist fusion relieve pain while preserving a functional wrist. The unifying goal is to offload the lunate and protect wrist function.

  • Why does ulnar variance matter?

    Ulnar variance is the relative length of the two forearm bones at the wrist. When the ulna sits shorter than the radius, the lunate bears more stress, which is relevant both to how the disease develops and to the choice of treatment. Joint-leveling procedures are designed to shift load away from the lunate, which is why this measurement is part of the evaluation.

Next step

Central wrist pain that will not resolve? Early staging changes the options.

Kienbock's disease is easier to manage when it is caught and staged early, before the lunate collapses. The first step is an accurate diagnosis with X-ray and MRI, so the treatment can be matched to the stage and aimed at preserving the wrist.

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