How Does APS Affect Bones and Joints? What Can I Do to Help Protect Them?

APS Program Community Q&A Series

Yu (Ray) Zuo, MD, MSCS
Yu (Ray) Zuo, MD, MSCS

Antiphospholipid syndrome (APS) affects people in different ways. Some people with APS can have problems with their joints or bones. Sometimes APS causes these problems, and sometimes they result from other causes such as age-related joint changes, low calcium or vitamin D levels, or habits such as smoking and heavy alcohol use. In this edition of the APS Program Community Q&A Series, Dr. Yu (Ray) Zuo discusses how APS can affect bones and joints and what you can do to help protect them.

Arthritis

APS can cause inflammation in the joints, which doctors call “inflammatory arthritis”. It can make your joints stiff, tender, warm, and swollen. APS arthritis most often affects small joints like your fingers, wrists, ankles, and toes.

One recent study of 1,000 APS patients from Europe reported that arthritis occurred in 39% of people with APS (1). APS patients with lupus are more likely to develop arthritis than patients with APS alone (2). APS arthritis is unlikely to cause permanent joint damage or deformity, as can be seen among patients with rheumatoid arthritis.

Osteoporosis

A systemic autoimmune disease such as APS increases your risk for osteoporosis which is a bone disease that makes bones weak and more likely to break. Notably, one study suggests that patients receiving long-term warfarin have an increased risk of osteoporosis (3). This could be one of the risk factors for osteoporosis among long-standing anticoagulated APS patients.

Other things that contribute to osteoporosis risk include taking steroids, being less physically active, having low levels of calcium or vitamin D, and being older. Osteoporosis has no symptoms (such as pain), so the only way to know if you have it is to get a bone density test. This test is a specialized X-ray scan to measure how strong your bones are.

Avascular Necrosis

This is a condition that causes bone tissue to essentially die. It usually occurs when there is not enough blood flow which weakens your bone. Over time, the bone can collapse.

While the risk of avascular necrosis is increased in patients with APS as compared with the general population, it still remains relatively uncommon. A study of 538 APS patients found that 1% had an episode of avascular necrosis (2). Prior history of fracture, heavy alcohol use, history of sickle cell anemia, and long-term high-dose steroid use are other factors that increase the risk of avascular necrosis.

In addition to working with your doctor, here are some relatively simple strategies that help protect your joints and bones:

  • Give up bad habits: Quit smoking and drink only in moderation. These changes will lower your risk of osteoporosis and avascular necrosis.
  • Maintain good nutrition: Get enough calcium and vitamin D. Eat foods that are good for bone health, such as milk or soy milk, salmon, tuna, collard greens, broccoli, kale, and cereals fortified with vitamin D.
  • Stay active: Exercise regularly. When you are less active, your muscles and joints get weaker.
  • Get screened: Get your vitamin D level checked to see if you may benefit from supplements. For patients with other risk factors for osteoporosis, ask your doctor whether you need a bone density test. 

In summary, APS can have a wide range of manifestations, and the involvement of joints and bones is not uncommon. If you are experiencing any of those problems, talk to your doctor to find a treatment plan that works for you. While many APS-related joint and bone problems need medical treatment, lifestyle changes may prevent them. 

References:

  1. Cervera R, Piette JC, Font J, Khamashta MA, Shoenfeld Y, Camps MT, et al. Antiphospholipid syndrome: clinical and immunologic manifestations and patterns of disease expression in a cohort of 1,000 patients. Arthritis Rheum. 2002;46(4):1019-27.
  2. Noureldine MH, Khamashta MA, Merashli M, Sabbouh T, Hughes GR, Uthman I. Musculoskeletal manifestations of the antiphospholipid syndrome. Lupus. 2016;25(5):451-62.
  3. Gage BF, Birman-Deych E, Radford MJ, Nilasena DS, Binder EF. Risk of osteoporotic fracture in elderly patients taking warfarin: results from the National Registry of Atrial Fibrillation 2. Arch Intern Med. 2006;166(2):241-6.

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