Friday, July 25, 2008

Soccer Players and the Plantar Plate

"I spent all my money on booze, girls and fast cars. The rest I just squandered."—George Best, English soccer star

A talented winger, George Best was renown for his extravagant lifestyle and soccer majesty. Here is a video of one of his goals, demonstrating his sheer athletic brilliance:

Football players, whether they are soccer or American football players, are prone to injuries of the foot and ankle. The hallux (great toe) can be a source of great pain, with injuries of the first metatarsophalangeal joint particularly common.

The term "turf toe" is used to describe various injuries of the 1st MTP joint, but classically refers to a hyperdorsiflexion injury of this joint. Other mechanisms of turf toe injury include valgus and varus injuries, as well as hyperflexion-related damage (Ohlson, B; emedicine). Structures that can be injured include the plantar plate, joint capsule, sesamoids, and adductor hallucis tendon.

Professional soccer player, who felt a "pop" and subsequent pain in the first MTP joint:

There is a tear of the plantar plate (red arrow), with fluid at the expected location of the plantar plate.

For comparison, here is an image from a normal patient, showing an intact plantar plate (green arrow). Also note the normal dorsal capsular recess (yellow arrow):

The plantar plate of the hallux arises primarily from the sesamoids and inserts on the plantar aspect of the base of the proximal phalanx.

The plantar plate supports the undersurface of the metatarsal head and resists hyperextension of the MTP joint. Injuries of the plantar plate can be extremely painful and debilitating, but these injuries usually respond to conservative treatment. When conservative management fails, surgery can be performed, and the avulsed plantar place can be reattached.
High-resolution MRI scans of the metatarsophalangeal joint can yield valuable information about the joint and surrounding soft tissue structures, particularly in high-performance athletes.

Vic David MD

Friday, July 18, 2008

Thigh Swelling and Veils

Radiologists have an unparalleled ability to look inside the human body, using our myriad machines. Starting with X-rays in the early part of the 20th century, radiologists eventually integrated ultrasound, CT, and MRI into their imaging armamentarium. These technologies, and others, give physicians the ability to noninvasively display the inner topography of our bodies.

In many cases, however, pictures alone do not give the answer. There is a veil over our understanding, and we cannot always make the correct diagnosis. The phrase "lifting the veil" seems to fit here; once the veil is lifted, the answer is often apparent. The phrase has been associated with wedding rituals from the dawn of civilization. In ancient Judaism, the veil was lifted prior to the consummation of the marriage. Modern brides often still wear a veil:

Photo by junebugweddings
What, then, lifts the veil for the radiologist? Often, it is the clinical history that delivers the correct diagnosis. We live in the dark ages of medical informatics— in fifty years we will look back and marvel at all the errors that are made in medicine today simply due to a lack of accurate clinical history about the patient.

Radiologists usually read their examinations in an informational vacuum. I am fortunate enough to work with great MRI technologists, who ask the patient the right questions, and usually obtain the information I need to interpret the examination properly. If the pictures do not "fit" the clinical history, then it is time for me to call the patient and/or the physician, to get the information I need to lift the veil.

Forty-five year-old woman with thigh pain and swelling:

Coronal STIR image (above) reveals a fluid collection (red arrow) in the mid right thigh, with extensive soft tissue edema.

(A) Axial T1 and (B) Axial T2 fatsat images show that the fluid collection is associated with the vastus intermedius muscle, and confirm the extensive surrounding soft tissue edema.

The patient was given intravenous gadolinium, and additional imaging was performed:

Axial postcontrast T1 fatsat image depicts rim enhancement of the fluid collection, with some associated enhancement of the adjacent muscle.

The images are there, but the veil is in place— the prescription states "MRI thigh, pain and swelling".
Why would a 45 year old woman develop an angry-looking fluid collection in her thigh? The additional clinical history obtained by the technologist tells us that there is no history of blunt trauma or athletic injury, and that the symptoms have come on over the last two weeks. The mystery remains.

So.... it's time to get more information. I call the patient, and after a few questions, the mists part. She suffers from multiple sclerosis, and injects herself in the thigh with the immunomodulator Avonex. This additional information tells us that this is a case of pyomyositits. The fluid collection is an abscess within the vastus intermedius muscle, and it will have to be drained, and the patient put on antibiotics.

This is not a difficult case, but it illustrates what Professor William Osler taught us over 100 years ago— the importance of accurate information about the patient. Fundamental truths rarely change.

Vic David MD

Friday, July 11, 2008

Buttock pain and the Tour de France

The Tour de France is a monument to human endurance. Cyclists cover over 2000 miles in just over 20 days, with some prodigious climbing through the Pyrenees mountains. Participants can consume 8000-9000 calories a day, with metabolic rates rising to 4-5 times normal. Cyclists are some tough hombres.

Endorphin highs are intoxicating, and even nonprofessional cyclists are willing to undergo a great deal of pain to keep doing their favorite activity. Many cyclists are addicted to their sport, and are out riding several days a week. Perched on top of a gangly two-wheeled contraption, unusual forces can be exerted on the human body.

Forty-five year-old avid biker with six weeks of bilateral buttock pain, left greater than right:

Coronal STIR and T1 images demonstrate subcutaneous edema and soft tissue thickening in the area (red arrows) where the biker sits on his bicyle seat.

Six weeks ago, he had adjusted the stem of his seat, and also changed his handlebar position. Riding position is a balance between comfort and power. This patient was getting older, and wanted a less aggressive riding position. He made the changes, and quickly experienced buttock pain. Interestingly, the skin overlying this area was completely normal, with no evidence of saddle sores. This edema is the result of abnormal, unrelenting pressure on the subcutaneous tissues of the buttocks. The cyclist will have to forego his endorphin high for a few weeks (as mentally painful as that might be), and alter his riding position.

One can speculate that similar changes could be seen in any riding sport. I have occasionally ridden horses, and can state unequivocally that this can be remarkably unpleasant. I did not realize just how much pain ischial tuberosities can cause until I rode a horse for a full day in Colorado, on a dude ranch last summer. I was hobbling around and sitting gingerly for a few days following that experience. I did not need an MRI to tell me that I was not cut out to be a cowboy....

Vic David MD