Island residents and visitors have been warned about the high prevalence of tick-borne diseases and skin cancer on the Vineyard. But meanwhile, another medical malady has been quietly eating away at the health of the Island population.

For reasons that still remain unclear, people on Martha's Vineyard suffer from fractures of the fifth metatarsal - the small bone that runs along the outer edge of the foot - in unprecedented numbers.

"We have the world's largest collection of these fractures, by an extraordinary amount," said Island orthopedic surgeon Dr. Raymond (Rocco) Monto, who treats an average of two or three new breaks each week. "No one's ever seen it in the numbers that we do."

Having documented the treatment of more than six hundred of the fifth metatarsal fractures since he began tracking them six years ago, Dr. Monto has formally presented his findings at the American Orthopaedic Foot and Ankle Society and is soon to be published in the Journal of Foot and Ankle Surgery. He said that, based on his reports, some doctors in the orthopedic field are now calling it the Vineyard fracture.

"We are the largest ever published - by many, many hundreds," Dr. Monto said. "And because we've seen so many of them, we've really become the focus of this - which is weird," he continued.

"When I presented my findings at some of these big meetings, they thought that I was making it up because the numbers were so high," Dr. Monto said. "They figured it was either that, or else people out here were just clumsy."

Metatarsals are the five long bones that run lengthwise in the middle of the foot. The fifth metatarsal is the outermost bone, which can be quite prone to injury.

The common break - formally known as an avulsion fracture - occurs when the ankle is severely turned and the connecting tendon rips off a tiny fragment of the soft end of the bone.

"It's like the pull start on a lawn mower," Dr. Monto said. "As the ankle turns over, the tendon yanks on the bone."

The causes of breaks on the Vineyard do not fall under any one particular reason - people twist their ankles going up or down stairs, hiking on Island trails, playing basketball or working in the construction trades. One patient broke his fifth metatarsal while stepping off the ferry.

Dr. Monto speculates that the high rates result from the mix of an active population, combined with irregular terrain and a widespread use of casual, loose-fitting footwear such as clogs and sandals.

"It's just the nature of the Vineyard," Dr. Monto said. "It's the kinds of activities you see here, along with all the stone walkways and Island topography. I think that's really what drives it."

The demographics from his findings span all ages - Dr. Monto has treated fifth metatarsal fractures on patients as young as five and old as 95, with an average age of 44. He has seen the breaks in about twice as many women as men - a bias that he believes may reflect risks due to osteoporosis.

Dr. Monto also found that the fractures do not discriminate between year-round and seasonal residents, nor among short-term Island visitors.

"It doesn't seem to break down seasonally," he said. "It's a year-round problem for us here."

A popular orthopedic surgeon with a national reputation in sports medicine, Dr. Monto has worked extensively with U.S. national soccer teams. His interest in the fifth metatarsal started during his work with soccer players, but did not pick up until after he came to the Vineyard from Philadelphia ten years ago. He also opened a satellite clinic on Nantucket in 1999, which accounts for about 25 per cent of his fifth metatarsal patients.

"It was a novelty to me until I moved my practice to the Vineyard and discovered that I was essentially in the middle of an epidemic of metatarsal fractures," Dr. Monto said.

"At first I thought it was an interesting finding, and sort of an oddity when I came here. But then I kept seeing more and more of them," he added. "And it seems to be continuing at the same pace we've seen. The numbers continue to accumulate."

Dr. Monto noted that he treated three new metatarsal fractures the other week, and that rarely a day goes by where he does not see a new break or meet with a healing metatarsal patient. He said he believes strongly in preventative care, but that‚ when it comes to the fifth metatarsal fractures, there is not much he can do.

"This is not something we could stop from happening, because it's really become such an ingrained thing," he said. "But our treatment is relatively benign and predictable. And luckily it works for most people."

While the current standard of care for fifth metatarsal fractures is a short-leg cast that prohibits patients from putting weight on the foot, Dr. Monto has treated the injury with a modern walking boot that allows patients to walk while immobilizing the foot and protecting the fracture site. The small bone then usually heals itself.

Dr. Monto claims that his treatment is more simple and cost-effective than the industry norm. With the walking boot, most patients are able to ditch their crutches within a week and return to a normal range of activity within a month.

Because his practice is on an Island, Dr. Monto has also been able to follow the recovery of patients over time. And after a two-year follow-up with more than 500 patients, he found them all to be symptom-free with no complications or required physical therapy.

"I have never got an overwhelming response from this, because the treatment is so relatively simple. It's not what I consider sexy orthopedics," Dr. Monto said. "But we have found that, using a modern functional brace, the fracture heals very fast. Very, very rarely do we have to do any surgery."

He said he has also used innovative treatments - such as ultrasound bone stimulation - to speed the healing of some fractures that are more sluggish, and that his office has had a lot of success in getting even the most stubborn bones to heal.

Dr. Monto noted that his wife, Jennifer, suffered a fifth metatarsal break while pregnant with their daughter Siena a few years ago. But he himself has never had the fracture.

"Not me," he said. "I'm lucky."