When Hand Pain Is Osteoarthritis

Aching, stiff fingers and wrists can be a sign of osteoarthritis in the hands. Large, arthritic knuckle joints can make it more difficult to get rings on and off. These changes may also cause some people to feel self-conscious about the appearance of their hands.¹Marshall M, Watt FE, Vincent TL, Dziedzic K. Hand osteoarthritis: clinical phenotypes, molecular mechanisms and disease management. Nat Rev Rheumatol. 2018;14(11):641‐656. doi:10.1038/s41584-018-0095-4

Hand osteoarthritis can affect just one joint, such as the joint at the base of the thumb, or several joints in the fingers, wrist, and thumb.

How Osteoarthritis Affects Hand Function

Pinching and gripping objects may become more difficult, making tasks such as picking up a quarter, putting toothpaste on a toothbrush, and using a mobile phone challenging.

Exactly how osteoarthritis affects hand function depends on which joints are involved²Lee HJ, Paik N-J, Lim J-Y, Kim KW, Gong HS. The Impact of Digit-related Radiographic Osteoarthritis of the Hand on Grip-strength and Upper Extremity Disability. Clinical Orthopaedics and Related Research. 2012;470(8):2202-2208. doi: 10.1007/s11999-012-2253-3:

• Arthritis in the thumb and middle, ring, and pinky fingers is associated with weaker grip strength.
• Arthritis in the thumb and index finger is associated with weaker pinch strength.
• Wrist arthritis is associated with carpal tunnel syndrome,³Shiri R. Arthritis as a risk factor for carpal tunnel syndrome: a meta-analysis. Scand J Rheumatol. 2016 Mar 29:1-8. [Epub ahead of print] PubMed PMID: 27022991. which can weaken hand grip and cause numbness and tingling, particularly in the thumb, index, and middle fingers.

Not surprisingly, people who have osteoarthritis in the thumb, index finger, and/or middle finger—the digits required for gripping and pinching objects—tend to report more problems than people who have osteoarthritis in only the ring or pinky finger.²Lee HJ, Paik N-J, Lim J-Y, Kim KW, Gong HS. The Impact of Digit-related Radiographic Osteoarthritis of the Hand on Grip-strength and Upper Extremity Disability. Clinical Orthopaedics and Related Research. 2012;470(8):2202-2208. doi: 10.1007/s11999-012-2253-3

Hand dominance and arthritis One study found 80% of hand arthritis cases involve people’s dominant hands.⁴Damman, W. et al. Do comorbidities play a role in hand osteoarthritis disease burden? Data from hand osteoarthritis secondary care cohort. J. Rheumatol. 44, 1659–1666 (2017). As cited in Marshall M, Watt FE, Vincent TL, Dziedzic K. Hand osteoarthritis: clinical phenotypes, molecular mechanisms and disease management. Nat Rev Rheumatol. 2018;14(11):641‐656. doi:10.1038/s41584-018-0095-4 A separate study found that osteoarthritis was not as strongly associated with hand dominance.⁵Lutsky K, Kim N, Medina J, Maltenfort M, Beredjiklian PK. Hand Dominance and Common Hand Conditions. Abstract Only. Orthopedics. 2016 Mar 17:1-5. doi: 10.3928/01477447-20160315-02. [Epub ahead of print] PubMed PMID: 27018604. It may be that people are more likely to seek medical care when the dominant hand is affected.

Hand Joints Are Most Affected By Osteoarthritis

The hand has 27 joints.⁶Sharp JT, Young DY, Bluhm GB, et al. How many joints in the hands and wrists should be included in a score of radiologic abnormalities used to assess rheumatoid arthritis?. Arthritis Rheum. 1985;28(12):1326‐1335. doi:10.1002/art.1780281203 Each finger has 4 joints—3 knuckles and 1 joint that connects its long bone in the hand (called a metacarpal bone) to the wrist. The thumb has 3 joints and the wrist contains 8 joints.

While any joint in the hand can develop osteoarthritis, the joints most often affected include:

• The proximal interphalangeal (PIP) joints, or middle knuckles of the fingers
• The distal interphalangeal (DIP) joints, or the end-most joint of the fingers and thumb
• The basilar joint (sometimes called the first carpometacarpal joint) at the base of the thumb
• Certain joints of the wrist that connect the wrist’s 8 carpal bones with each other and the bones of the forearm (the radius and ulna)

The metacarpophalangeal (MCP) joints, the largest knuckles of the hand, are less likely to be affected by osteoarthritis.

How Hand Osteoarthritis Develops

Where bones meet to form a joint, their surfaces are covered with smooth, slippery cartilage. This cartilage provides a cushion between the small bones of the hand, protecting them from rubbing directly against each other. When this cartilage deteriorates, it is called osteoarthritis.

Exactly what causes cartilage to deteriorate is not clear to researchers,¹Marshall M, Watt FE, Vincent TL, Dziedzic K. Hand osteoarthritis: clinical phenotypes, molecular mechanisms and disease management. Nat Rev Rheumatol. 2018;14(11):641‐656. doi:10.1038/s41584-018-0095-4 and may vary from person to person. The hands do not bear weight but its joints undergo stress on a daily basis, such as when carrying objects or gripping items. Aging and genetics also play roles.

As cartilage deteriorates, other changes in the hand also occur:

• Friction between bones can lead to the development of bone spurs (these spurs are typically what make arthritic knuckles look bigger).
• The bone underneath damaged or missing cartilage may develop cysts and areas of abnormal swelling called bone marrow lesions.
• The delicate membrane that encapsulates each small finger joint can become inflamed.
• The area where tendons insert into bone, called entheses, can also undergo inflammatory changes.

While bone spurs tend to be permanent, the other changes may get better or worse. They can lead to permanent damage or go away altogether.

Read more about Osteoarthritis Causes

How Hand Arthritis Causes Pain

Cartilage does not contain nerves, so damaged cartilage is not a source of pain. Likewise, bone spurs are normal signs of aging, and not necessarily a cause of pain. Rather, arthritic hand pain and stiffness occur when the changes described above lead to inflammation and swelling. In addition, bone cysts seem to be directly associated with osteoarthritic pain.

When Hand Arthritis Is Serious

Hand arthritis can be a serious cause for concern if it prevents a person from being able to care for themselves, particularly if they live alone. Hand arthritis can also be serious if it leads to severe carpal tunnel syndrome. Advanced carpal tunnel causes numbness and/or tingling and weakness in the thumb and associated fingers, and can result in permanent nerve damage if left untreated. In either of these cases, consultation with a medical professional is advised.

Read more: Is My Hand and Wrist Pain Caused by Carpal Tunnel Syndrome or Something Else? on Sports-health.com