Emmanuel P. Estrella, MD, MSc
Research Associate Professor
Institute of Clinical Epidemiology - National Institutes of Health
Clinical Associate Professor
Department of Orthopedics
University of the Philippines - Manila College of Medicine
Module Objectives
At the end of this module, the reader should be able to:
1. Know the epidemiology of hand osteoarthritis
2. Diagnose hand osteoarthritis
3. Enumerate the treatment for hand osteoarthritis
Overview
One of the most frequently involved regions in osteoarthritis is the hand. Hand osteoarthritis (HOA) can be defined in many ways. They can be defined radiographically and clinically. Radiographic osteoarthritis is characterized by radiographic signs of joint space narrowing, osteophyte formation, subchondral sclerosis and subchondral cysts formation (FIGURE 1).
Figure 1. Joint narrowing in Hand osteoarthritis
The clinical criteria by the ACR include: hand pain, aching or stiffness and three of the following four criteria:
• Hand tissue enlargement of two or more of ten selected joints,
• hard tissue enlargement of two or more distal interphalangeal joints
(DIPJs),
• fewer than tree swollen metacarpal joints (MCPJs) and
• deformity of at least one of ten selected joints (FIGURE 2).
Figure 2. Joints involvement in hand osteoarthritis
Epidemiology
The estimates of prevalence of hand OA may vary depending on age, sex and geographic area of the population. Radiographic osteoarthritis ranges from 21% in the US population to 92% in a Japanese population. Prevalence estimates for HOA is generally higher than those reported for hip and knee OA. It is well recognized that the condition has a female preponderance and is increasing with age (FIGURE 3).
Figure 3. Graph showing the incidence of hand osteoarthritis between men and women across age groups
It was estimated that at least one hand will develop a lifetime risk of symptomatic HOA by 85 years old would be 40%, with 47% of women and 25% of men developing the disease.
Genetic Risk Factors
Several studies have shown that genetic factors play an important role in HOA, especially in the nodal subset. One study showed found Heberden’s and Bouchard’s nodules in relatives of 36% and 495 of women with HOA, as compared to 17% and 26% respectively, in the general population. Other epidemiologic evidence supporting genetic component in HOA include the greater concordance I monozygotic twins than in dizygotic twins, and the increased risk of HOA in the first degree relatives with HOA.
Environmental Risk Factors
Some correlation was reported between body weight and the occurrence of HOA, however, no definite relationship was shown between the effect of heavy manual work on HOA. Although HOA mostly occurs in women at the time of menopause, the relationship with the sexual hormones is still controversial. The existence of clear risk factors for HOA is still not fully established, especially in DIPJ localization. In case of the PIPJ and thumb base joint, there is a possible relationship with manual activity, hypermobility and OA.
Burden of Disease
Symptomatic HOA was associated with poor self-reported general health. A number of studies have shown that the presence of HOA has been associated with atherosclerosis and cardiovascular disease. The association was analogous to increased cardiovascular mortality in patients with painful OA of the large joints compared to the general population. Patients with HOA are frequently dissatisfied with the appearance, especially with Bouchard’s and Heberden’s node deformity.
Pathology of Hand Osteoarthritis
Subset of Hand OA
Nodal OA, Generalized OA and Thumb base joint OA
There are three major determinants of the pattern of polyarticular involvement: symmetry, clustering by row, and clustering by ray (in descending order). One study found an association between hand and knee OA, especially between PIPJ and knee OA (Baltimore study). In case of the basal thumb arthritis, a causal relationship was found with articular hypermobility (FIGURE 4).
Figure 4. Basal thumb arthritis
Polyarticular involvement is common but may include other types of OA (FIGURE 5).
Figure 5. Joint involvement in the different types of arthritis of the hand
Erosive OA
Erosive OA is associated with more severe hand disease, with its acute inflammatory onset and high degree of clinical impairment. According to some studies, (Belhorn), erosive OA is more common in postmenopausal women, the DIPJ is most commonly involved, followed by the PIPJ.
This type is characterized by central erosions and “gull-wing” deformity (FIGURE 6).
Figure 6. Characteristic central joint erosion and gull-wing appearance in erosive hand
osteoarthritis
Treatment
Symptomatic treatment is the mainstay in the management of HOA. Pharmacologic management include the use of NSAIDs. Non-pharmacologic approach include appropriate exercises, and orthotics. Surgical options exists especially for basal thumb arthritis, which include arthrodesis, excision of the trapezium or arthroplasty.