Kienbock’s disease: Beware of Avascular Necrosis of the Lunate

Kienbock’s disease is a rare but serious condition affecting the wrist, characterised by bone death (avascular necrosis) of the lunate bone. The lunate is a crucial carpal bone that plays a key role in wrist stability. When the blood supply to the lunate is disrupted, the bone begins to deteriorate, resulting in pain, stiffness, and loss of function. What is Kienbock’s disease, and how is it diagnosed and managed?   

What is Kienbock’s disease?

Kienbock’s disease occurs when the blood supply to the lunate is compromised, leading to bone death. 

This condition primarily affects young adults, including athletes in high-impact sports or those engaging in repetitive wrist-loading activities such as gymnastics, weightlifting, rock climbing, and racquet sports. If left untreated, Kienbock’s disease can lead to wrist arthritis and permanent loss of motion, significantly affecting an athlete’s ability to perform.

Causes and Risk Factors 

The exact cause of Kienbock’s disease is not always clear, but it is believed to result from a cut in the blood supply to the lunate. Several factors may contribute to the development of this condition:

• Repetitive Trauma and Overuse: Athletes who engage in repetitive wrist movements that stress the lunate are at a higher risk. 

• Blood Supply Anatomy Variations: Some individuals have an anatomical variation in the arteries supplying the lunate, making them more susceptible to avascular necrosis of the lunate.

• Ulnar Variance: If the ulna is shorter than the radius (negative ulnar variance), the lunate bears too much load. 

• Previous Wrist Injuries: A history of wrist fractures, ligament injuries, or chronic sprains can reduce blood supply to the lunate. 

• Systemic Conditions: Certain medical conditions, such as autoimmune disorders, may contribute to reduced blood supply to the wrist. 

Clinical Assessment of Keinbock’s Disease

The early symptoms can be vague and may resemble those of other wrist injuries, leading to a delayed diagnosis. 

Athletes with Kienböck’s disease commonly present with impact-related wrist pain that worsens over time. The pain is usually on the top side of the wrist. Other symptoms, such as stiffness, weakness, and swelling, are often present. 

Your doctor will find tenderness over the lunate. Pain typically limits the wrist’s range of motion, particularly extension. Special tests, such as the Lichtman Test (pain provoked by wrist extension and axial loading), may aid in clinical assessment.

A combination of imaging is necessary to confirm the diagnosis and determine the stage of the disease.

• X-rays are the first-line imaging. In the early stage, they may show the lunate becoming whiter (sclerosis). As the disease progresses, X-rays may reveal lunate breakdown and collapse. 

• MRI is the gold standard for early diagnosis, as it can detect bone marrow oedema and reduced vascular supply before structural damage becomes evident.

• CT scans can provide detailed information about lunate collapse, particularly in advanced stages. 

Differential Diagnoses of Avascular Necrosis of Lunate 

Several wrist conditions can present similarly, making it essential to rule out alternative diagnoses:

• Wrist Sprain or Ligament Injury: Chronic scapholunate ligament tears can mimic wrist pain and instability.

• Scaphoid Avascular Necrosis (Preiser’s Disease): This condition involves avascular necrosis of the scaphoid, another carpal bone, and can be mistaken for Kienböck’s disease.

• Distal Radius or Lunate Stress Fracture: Athletes involved in weight-bearing sports may develop wrist stress fractures, which can lead to wrist pain.

• Tendonitis (Extensor or Flexor Tendinopathy): Overuse injuries affecting the wrist tendons can cause pain similar to Kienbock’s disease.

Treatment Options for Kienbock’s Disease

The treatment of Kienbock’s disease depends on the stage of the disease. Early-stage disease is managed conservatively, and advanced cases require surgery. 

Conservative management may help slow progression and relieve symptoms in the early stages.

• Immobilisation: Wearing a wrist brace or splint can reduce stress on the lunate and allow for potential revascularisation.

• Activity Modification: Athletes should avoid high-impact or repetitive wrist-loading activities and transition to low-impact exercises.

• Physiotherapy: Strengthening exercises that focus on forearm muscles and improve wrist mobility can help maintain function and reduce pain.

• LIPUS therapy: Some studies suggest low-pulsed ultrasound may improve bone healing in avascular necrosis.

If symptoms are well controlled, athletes who receive early intervention and appropriate rest may return to sports within 3-6 months.

Surgery  

If the disease progresses to lunate collapse or if conservative treatment fails, surgery may be necessary. Several surgical options exist, depending on the severity of the condition. In the early stages, options include bone grafting and radial shortening. For advanced cases, lunate excision and partial wrist fusion are available.

Returning to full activity may take 6-12 months for those requiring surgery, with ongoing rehabilitation needed to restore strength and mobility.

Other Frequently Asked Questions about Kienbock’s Disease. 

Is Kienbock’s disease a disability? 

Not necessarily, as it depends on how early the disease is detected. The earlier the diagnosis, the better the outcome. However, if the lunate dies and collapses, osteoarthritis is inevitable and will lead to pain and disability. 

Final Word from Sportdoctorlondon about Kienbock’s Disease

Kienbock’s disease is a rare but serious condition that can significantly impact wrist function, particularly in high-impact athletes. Early recognition is key, as treatment options are more effective when initiated before the lunate collapses. Doctors should consider this diagnosis in young athletes with persistent wrist pain and stiffness.