De Quervain's tenosynovitis (also known as de Quervain’s tendinosis or tendinitis) is a condition characterized by inflammation and irritation of the tendons located on the thumb side of the wrist. It is one of the more common forms of tenosynovitis due to overuse. It typically affects the tendons of the abductor pollicis longus and extensor pollicis brevis muscles in the forearms. The end of a muscle becomes a tendon that attaches to bone and are very strong and flexible, similar to a rope. Squeezing a muscle applies tension on the tendon, which in turn pulls on the bone it is attached to in order to make it move. In de Quervain’s tenosynovitis, the sheath that covers the tendon, allowing a smooth movement, becomes inflamed, causing friction and pain with certain thumb and wrist motions. Pain may start in the thumb and then move to the wrist and forearm and may even be associated with a snapping or popping feeling with movement. 

How is de Quervain’s tenosynovitis diagnosed? 

Providers use the Finkelstein or Eichhoff test to check to de Quervain’s. These are physical tests that use positioning of the thumb and apply tension to elicit a pain response, which would be considered a positive result or finding of de Quervain's tenosynovitis. Plain x-rays are not useful in diagnosing this condition but magnetic resonance imaging (MRI) is, as inflamed tendons can be seen on MRI; however, usually the physical test is enough to confirm diagnosis and begin treatment. 

To report de Quervain's tenosynovitis, you will need to search the Alphabetic Index of the International Classification of Diseases, Tenth Revision, Clinical Modifications (ICD-10-CM) code set. Search under "de Quervain" or “tenosynovitis” to find the correct code, which is M65.4 Radial styloid tenosynovitis [de Quervain]. Remember, while the Alphabetic Index may show the code, never assign a code directly from the Alphabetic Index. Always confirm the code is correct by turning to it in the Tabular List, where there may be associated instructional notations or additional coding guidelines specific to the code. 

Unlike other codes for tenosynovitis in that category, M65.4 does not have additional codes for laterality. 

Common Treatments for De Quervain's Tenosynovitis

• Rest and immobilization: Resting the affected thumb and wrist and avoiding activities that aggravate the symptoms can help alleviate pain and reduce inflammation. Splinting or bracing the thumb and wrist may also be recommended.
• Medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen can help reduce pain and inflammation.
• Physical therapy: Specific exercises and stretches guided by a physical therapist can help improve thumb and wrist mobility and strengthen the muscles.
• Corticosteroid injections: In some cases, a corticosteroid injection may be administered into the tendon sheath to reduce inflammation and provide relief.
• Surgery: If conservative treatments are ineffective, surgery may be considered. The surgical procedure involves releasing the tendon sheath to provide more space for the tendons.

De Quervain's tenosynovitis is not associated with an HCC for risk adjustment purposes. Risk adjustment models are used to assess the severity of a patient's chronic conditions and adjust payment rates accordingly. However, for a localized condition like De Quervain's tenosynovitis, risk adjustment is not a factor, as it is generally treated as an acute condition rather than a chronic condition or complex illness.