1. Tallness can increase the stress on joints. By simple mechanics, tall people place increased stress on their joints. “It’s easier to use a wrench with a long handle because you have a mechanical advantage,” says Dr. Schmalzried. “When people are tall, the forces can be quite high because there is a larger distance between the chest and knee. If the weight of the torso is high, because there is a bigger lever arm, there are higher stresses around the knees than for someone who is shorter.”
When people are tall and not overweight, the forces applied to their joints are still high but proportionate, because the surface area of their joints is proportionately larger and the load is evenly distributed. When tall patients lose weight, the loss really reduces the stresses on their joints.
2. Plan appropriately for implant size. When surgery is necessary for tall patients, surgeons must make sure they have implants that will fit the patient’s larger bone structure. “You want to be able to get their bone size correctly measured so the prosthesis you have will fit them,” says Dr. Schmalzried. “Most of the time, it’s taken for granted that one of the general implant options will fit your patient because most patients fall within the average, bell-shaped curve – but there are exceptions!”
The same is true for smaller patients, he says. If the implant is too big or too small, it could cause complications, and additional surgeries may be necessary.
3. Height doesn’t factor into arthritis development. Tall patients may think that they are at an increased risk of developing arthritis later in life, but there aren’t any studies that currently support the correlation. However, there are studies that show a correlation between sustaining sports-related injuries or being overweight and developing joint arthritis. “If you’re tall and overweight, it’s more likely that the overweight part caused the additional wear on the joints,” says Dr. Schmalzried.
Many competitive athletes are on the taller end of the spectrum, and athletes are known to develop arthritis in their joints, but this condition isn’t necessarily due to their height or participation in sports. It’s more likely that a specific trauma to the joint, such as an ACL tear, caused early onset arthritis. “Simply having been a football player doesn’t put you at increased risk for arthritis,” he says. “But when you look at very big people who might have been athletes, the likelihood that they’ve had ad significant trauma to a knee or hip is pretty high.”
4. Genetic predisposition for disorders may not relate to height. There are several genetic reasons why a patient might be predisposed to an orthopedic condition, but height isn’t one of them. A tall person, such as a former professional basketball player that Dr. Schmalzried has worked with, might also have a condition that advances osteoarthritis, such as hip dysplasia. “Hip dysplasia is more common among small women than men, but people like this tall male basketball player can also have it,” he says. “In hip dysplasia, the socket is a little too small for their femoral head, and the joint wears out prematurely.”
However, playing competitive sports could enhance this condition and speed up its effects. Competitive athletes are constantly putting a great amount of stress on their joints, and if they are predisposed for osteoarthritis it could occur at a younger age for them. “As an analogy, tires are supposed to go so many miles, but if the left front tire is out of alignment, the mechanical environment isn’t going to work and that tire will wear out prematurely,” he says. “In a similar way, arthritis usually occurs because the mechanical environment of the hip or knee isn’t quite right and that’s why the joint wears out prematurely. If you are a competitive athlete, you have a greater total mileage on your joints than average people.”
Learn more about Dr. Thomas Schmalzried.
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