Small ligament, big consequence

Monday, September 16, 2013

The mantra for a successful quarterback is pretty simple: three to five step drop, set feet, step into the throw and follow through. It is not, as Cleveland Browns’ quarterback Brandon Weeden found out, follow through into the opponent’s helmet. The accidental collision damaged Mr. Weeden’s thumb, making it difficult for him to grip the ball and his game day was over. In the quarterback’s job description, the ability to have a strong grip on the ball is a prerequisite and that ability depends upon an intact ulnar collateral ligament (UCL) of the thumb.

Some quick anatomy.  So that everybody is on the same page when discussing hand injuries, doctors use specific location descriptors. The palm side of the hand is palmar but is sometimes also referred to as volar.  The opposite of palmar is dorsal, the back of the hand. The two wrist bones, the radius and ulna are landmarks that are used as landmarks. The radius is located on the thumb side of the wrist and the ulna on the little finger side.  Each finger then has a radial side and an ulnar side.

UCL diagramassh.org

The genius of the thumb is its ability to oppose and touch all the other fingers. It allows the hand to grasp things and power is generated only if the thumb is stable. That stability is due to a small band of tissue or ligament that runs from the ulnar side of the first metacarpal to the ulnar side of the first phalanx, crossing the metacarpophalangeal joint at the base of the thumb. Tear or sprain the ulnar collateral ligament and grip strength fails because the thumb literally slides off the side of the hand.

When Mr. Weeden followed through and hit his hand on an opponent’s helmet, his thumb was likely stretched away from the hand, spraining the ligament, either stretching or tearing its fibers.  He couldn’t continue because he couldn’t grip the ball. X-rays were normal because it was not a bony injury and he now awaits an MRI to decide his fate.

Sprains are classified as grade 1, 2 or 3. Ligament fibers are stretched but not torn in a grade 1 sprain. Grade 2 sprains describe a ligament that is partially torn and in a grade 3 sprain the ligament is completely disrupted. Physical exam can attempt to decide if the ligament is intact by feeling for a “stop” when the ligament is stressed, but this is not an exact science and sometimes the hand muscles can go into spasm and give a false sense of ligament stability. Stressing the ligament isn’t done until x-rays have been completed and are normal. The mechanism of injury may cause fragments of bone to be pulled away with the damaged UCL and stressing the joint might displace the bone fragments.

Once the bones are found to be normal, an MRI will not only give the answer but direct the treatment.

Grade 1 and 2 UCL sprains can be treated with splinting to allow the ligament to heal itself and it may take 3-4 weeks to get better.

Surgery is reserved for grade 3 UCL sprains because completely ruptured tendon is associated with an unusual complication. The torn end of the ligament can finds itself tucked under the adductor pollicis muscle, making it impossible for it to become reattached. This complication is called a Stener lesion, named after Dr. Stener who first recognized and described it. Surgery is often required for sprains associated with bony fractures.

The use of eponyms or descriptive names is common in medicine and the UCL sprain has two. An acute ulnar collateral ligament sprain is also known as a skier’s thumb, describing the mechanism of falling on outstretched hand where the ski pole grip acts as a fulcrum, splaying the thumb radially away from the rest of the hand and stretching the UCL. Chronic damage to the UCL was first described in European gamekeepers who would wring the neck of game animals like chickens and the repetitive motion would stretch and weaken the UCL.

The bad news for Mr. Weeden is that there is no quick fix to make the ulnar collateral ligament heal itself and there is no mind over matter potential to overcome pain to be able to play. Until the UCL heals, by surgery or with time, the ability to grip, handoff and throw a football is lost. And that is on the top of the quarterback’s job description.

 

 

This entry was tagged , , , ,

Leave a Reply