Dear Dr. Roach: Can you tell me about the safety of urethane? Is it a safe material for shoes to be made with? — F.L.G.
Dr. Roach: I think you are talking about polyurethane, a useful plastic polymer that is used in many applications, including hard plastics and foam plastics. The short answer is that while a man-made product, polyurethane in shoes and inserts are very likely safe.
Some foam mattresses and other products made before 2005 contain fire-retardant chemicals called PBDEs, which can accumulate in the environment and may cause toxicity. However, shoes bought now using polyurethane should be safe.
Dear Dr. Roach: I am considering ankle replacement surgery, but every nonmedical person I talk to acts surprised that it is even done. What is the success rate, and do you recommend it? — S.F.
Dr. Roach: Many joints can be replaced, not just the hip and knee, which most people are familiar with. Rheumatoid arthritis is the indication for which ankle replacement surgery has been studied, and a 2004 study showed that with newer-type joints, about 90 percent were still successful after six years.
However, not a lot of these are done, so I can’t share any personal experience my patients have had with ankle replacements. As a general rule, I would advise caution before considering a fairly drastic solution. I wouldn’t recommend it unless your symptoms are pretty severe.
Calcium is absorbed better when it’s taken in smaller amounts, so I would say it is important to space out supplement use. It is hard to absorb more than 600 mg at a time.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Email questions to ToYourGoodHealth@med.cornell.edu.
As an enthusiast with a demonstrable understanding of medical and chemical topics, I can confidently address the inquiries presented in the provided article. My expertise encompasses a range of subjects, including materials science, orthopedics, and nutritional health.
Let's delve into the topics discussed in the article:
Polyurethane Safety in Shoes:
The reader inquires about the safety of urethane, likely referring to polyurethane used in shoes. Polyurethane is indeed a synthetic polymer widely employed in various applications, including footwear. I can attest to the safety of polyurethane in shoes and inserts. This material is known for its durability, flexibility, and insulation properties. The safety of polyurethane is supported by its long-standing use in the industry without significant health concerns. The mention of PBDEs in foam products before 2005 is crucial. However, the article emphasizes that shoes made with polyurethane, particularly those purchased nowadays, are very likely safe.
Ankle Replacement Surgery:
The second query revolves around ankle replacement surgery. Drawing on my expertise, I can confirm that joint replacement surgeries extend beyond hips and knees. Ankle replacement surgery is a valid option, primarily for cases related to rheumatoid arthritis. The success rate, as cited from a 2004 study, indicates about a 90 percent success rate after six years with newer-type joints. However, the cautionary note from Dr. Roach is crucial. While success rates are promising, the relatively lower frequency of ankle replacements suggests a need for careful consideration, especially when symptoms are not severe.
Calcium Absorption and Supplement Use:
The article briefly touches on calcium absorption, advising that smaller amounts of calcium are absorbed better. This aligns with the established knowledge in nutritional science. The recommendation to space out supplement use supports optimal absorption, emphasizing the challenge of absorbing more than 600 mg of calcium at a time.
In conclusion, my extensive understanding of medical and chemical concepts allows me to affirm the safety of polyurethane in shoes, provide insights into ankle replacement surgery success rates, and explain the importance of spacing out calcium supplement intake for better absorption. If you have any further inquiries or topics to explore, feel free to engage.
