January 2, 2012

Collateral Damage

Rounding Up the Usual Suspects: Tommy John Surgery

by Corey Dawkins and Ben Lindbergh

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Tommy John surgery: three words that no player wants to hear. It doesn’t matter that technology, surgical techniques, and rehabilitation methods have significantly improved since the first surgery in 1974. All the injured player knows is that he’s going to be down for a while and that he’s not guaranteed to return to his pre-injury performance level. In 2011, several key players went down with Tommy John surgery (TJS), including Adam Wainwright, John Lackey, Daisuke Matsuzaka, Joba Chamberlain, Jorge De La Rosa, Brett Anderson, and Jenrry Mejia, and we also saw the return of Stephen Strasburg after TJS in 2010. We’ve touched on the surgical procedure before, but for our first installment of Collateral Damage in 2012, let’s review the ins and outs of Tommy John Surgery.

Anatomy
Unlike many of the other injuries we’ve discussed, the anatomy of TJS is fairly straightforward. The UCL arises off the medial epicondyle of the humerus and involves three major components. The anterior oblique bundle is a little over three-quarters of an inch in length and despite its small size is the main stabilizer between 20 and 120 degrees of flexion, making it the most stressed part during pitching. When the elbow is fully extended, the UCL, bony articulations, and other soft tissues like the capsule split the stress fairly evenly—roughly one-third for each.

When the elbow is moved into a more functional range of motion near 90 degrees, the UCL significantly increases its contribution to valgus stability to 50 percent or more. The contribution to valgus stability of the bony articulations, such as the one between the humerus and radial head on the outside aspect of the elbow and the joint capsule, drop to around 10 to 15 percent. The other components of the UCL include the posterior oblique bundle, which is a weak thickening of the joint capsule and works as a secondary stabilizer only at 30 degrees of flexion, and the transverse bundle, which has no effect on valgus stability.

Source: Drugster.info

Several muscles play a part in the UCL’s functioning and combine to form the flexor-pronator mass that we commonly hear about. The flexor carpi ulnaris (FCU) flexes the wrist toward you when you are looking at your palm and also deviates towards the little finger, giving it a vital role that we will explore later on. The flexor carpi radialis (FCR) works in conjunction with the FCU to flex the wrist; it moves the hand towards the thumb instead of the little finger.

Another important muscle is the flexor digitorum superficialis (FDS), which starts at the medial epicondyle of the humerus and the UCL itself. This muscle travels down the forearm before splitting off and attaching at the fingers. This allows the middle knuckle of each finger to flex. The palmaris longus also originates off the medial epicondyle of the humerus and is the tendon most commonly used for reconstruction of the UCL. It is absent in 25 percent of the population, and the easiest way to figure out if you have it is by mimicking the image below.

Source Umich.edu – Palmaris longus

Source:Bestpractice.bmj.com- elbow and forearm muscles

The ulnar nerve—you know, the funny bone—is also located in the medial elbow. After coming down the arm, it travels around the posterior aspect of the medial epicondyle and into the cubital tunnel, which is created as it extends from the medial epicondyle to the olecranon. Its ceiling is composed of various soft tissues, while its floor is made up of the joint capsule, the olecranon, and the UCL.

The cubital tunnel is the major restraint for the ulnar nerve as it passes through the posteromedial elbow. As the elbow flexes, the roof is at its tightest, because the two attachment points are the furthest apart. In extension, the tunnel becomes looser (as does the UCL). After passing through the cubital tunnel, the ulnar nerve travels down the forearm underneath the flexor carpi ulnaris (FCU) before heading into Guyon’s canal. Don’t worry; there won’t be a quiz, and you don’t have to remember all of that if you don’t want to. Just know that with chronic insufficiency of the UCL or severe acute injuries to the UCL, the ulnar nerve can become injured or inflamed.

Mechanism of Injury
The vast majority of injuries that result in TJS stem from a chronic, cumulative effect that chip away at the UCL’s integrity until a single episode sets it over the edge. One study involving Dr. David Altchek found that the average amount of time between the onset of elbow pain or symptoms and surgery was 24.5 months. We see it most often with pitchers, but there have been plenty of cases of position players undergoing the surgery as well. Position players are more at risk for traumatic UCL ruptures associated with fractures or dislocations.

The late cocking phase of the pitcher’s delivery creates the most significant valgus forces that the UCL, flexor carpi ulnaris (FCU), and flexor digitorum superficialis (FDS) must dissipate. In the acceleration phase, the flexor pronator muscle mass if most active, while the FCU and FDS continue to provide dynamic stabilization. The dual action of the FCU, which flexes the wrist during acceleration while still providing stability to the elbow, increases the risk of injury and, more importantly for future TJS patients, fatigue. In addition, the FCU is the only muscle that overlays the UCL at 120 degrees of flexion, so those with extreme elbow flexion angles at late cocking are prone to having more force transferred to the UCL.

The UCL isn’t finished with its work during the deceleration phase of throwing. There is little valgus force being applied to the elbow, but the anterior bundle of the UCL is crying out in pain—okay, maybe that’s a little melodramatic—as it helps to resist the distraction force being applied to the elbow.

In recent years, more attention has been devoted to the role of glenohumeral internal rotation deficit, or GIRD for short. GIRD occurs when there has been a shift in the rotational range of motion of the shoulder, specifically over 20 degrees for a proper diagnosis.

Source: Eliteathletichealth.com -GIRD

What we see in these cases is that the total rotation range of motion stays the same—180 degrees in this example—but that there is an increase in greater external rotation from the first picture to the second. As a result, the internal rotation decreases. Sometimes it’s much worse than this, but often the difference is right around 20 degrees.

Within the last three years, increased attention has been played to the role of GIRD in various injuries, including those involving the UCL. In fact, in 2009, this study found a strong suggestion of a connection between GIRD and UCL insufficiency.

Diagnosis
A careful history and physical examination is key to properly assessing mild injuries and cases of chronic laxity. With minor injuries, there is no significant amount of laxity that would be a dead giveaway for a UCL injury. Players will often complain of medial or posterior elbow pain that is worst when throwing, especially during the late cocking and acceleration phases. A slow, gradual decrease in throwing velocity over a span of years often accompanies UCL degradation.

The athlete will often be tender in this area, and in acute cases, a loss of motion can occur. There can be pain with resisted wrist flexion, and a pitcher can also complain of numbness or tingling going down the inside of his arm to his little finger, which again occurs more often in acute ruptures.

There are two main tests to evaluate the UCL performed during the physical examination. A valgus force is applied to the elbow in full extension and also at about 30 degrees of flexion. The clinician feels for any laxity or reproduction of the patient’s symptoms. The other test is called the “milking maneuver” and is much more specific to the UCL because of its dynamic aspect.

Plain x-rays are not very useful except in the case of acute injuries where there is concern for fractures. MRIs can be useful in the acute setting if there is active swelling or inflammation. MRI arthrograms are an improvement and can help see undersurface tears that are common in chronic cases. One of the best methods for evaluating the UCL through diagnostic imaging is using an ultrasound. This enables the practitioner to see how much looseness there is during dynamic motion and is therefore much more likely to reproduce the symptoms.

Treatment
Conservative treatment involves rest for several weeks to months while following the therapy guidelines. Focused strengthening of the FCU and FDS are aimed at supporting the UCL directly, while other exercises are performed to ensure proper throwing mechanics and limit GIRD. Throwing is introduced around the three-month mark, after which a graduated return to throwing is completed.

But what about the procedure itself? Early on, the muscles were completely detached, and the ulnar nerve was moved in order to provide the best access to the ligament and the joint. Things have changed.

Before surgery, the surgeon will check to see if the player has the palmaris longus muscle via the method described above. If the palmaris tendon is not present, the surgeon can use a tendon from the hamstring, knee, or foot, or a cadaver graft. Cadaver grafts have a higher rate of failure as the player tries to return to the field. If the palmaris longus is present, which is in the case in 75 percent of the patients, the surgeon will harvest that tendon during surgery. In addition to being under general anesthesia, the patient is usually given a nerve block during the surgery to help with the pain.

The palmaris longus harvesting is performed by making a transverse incision across the wrist and identifying the tendon. A second incision is made about eight cm above the first incision, and the tendon is once again identified. In a step that some find disturbing, the surgeon then pulls on the tendon from both incisions to make sure the same tendon has been isolated. Most often a tendon stripper is used, with only one incision being made.

A diagnostic arthroscopy is performed to look for any loose bodies or other pathologies. A direct arthroscopic stress test can also be performed at this time. Normal elbows have about one to two millimeters of opening, but UCL-incompetent elbows have a three millimeter or greater opening between the coronoid and medial humerus.

An approximate four-inch-long incision is then made on the inside aspect of the elbow. The surgeon takes care to avoid the ulnar nerve and branches of the median nerve as they split the flexor-pronator muscle mass lengthwise. This is a change from earlier incarnations, when surgeons used to detach the muscle from the bone completely, and is generally less painful following surgery. There are some cases in which the detachment is necessary, but it does not affect the long-term results.

Once the level of the UCL has been reached, tunnels are drilled through the humerus and ulna, where the anterior bundle of the UCL starts and finishes. The docking technique that many hear about involves three holes in the humerus and two in the ulna. Instead of weaving the graft through the tunnels and suturing the graft to itself, the sutures are now tied together at the back edge of the humerus.

Source CPRTherapy.org

An alternative to the docking technique is the figure-of-eight technique. This involves two holes on both the humerus and the ulna.

Source CPRTherapy.org

The ulnar nerve can also be moved to a new permanent position at this time, although that is not done routinely as it was in the past. This is known as the ulnar nerve transposition and is performed most often in the presence of pre-surgical neurological symptoms.

The end result after all is said, done, and stitched up looks like this:

Source The Slanch Report – Post Tommy John Elbow

Rehabilitation
Rehabilitation principals and techniques have also improved over the years. As usual, each surgeon has his or her own protocol based on the specific technique performed. Immobilization is fairly short compared to other surgeries and is usually discontinued after about 10 days. That’s not to say the players can go flapping their arms about at that time. Range of motion is restricted for the first several weeks in order for everything to heal.

Most players start formal physical therapy around the end of the first month, have their full motion back by eight weeks, and can begin bench-pressing after around three months. A throwing program starts around the fourth month, but pitching has to wait until the sixth month from flat ground and about four to six weeks longer from the mound. Pitchers can expect to start pitching in competitive situations anywhere from nine to twelve months after surgery, although gradual improvement can be expected for up to two years after surgery.

Summary
And there we have it: ulnar collateral ligament injuries explained. While it would be great if we could completely eliminate UCL injuries and resulting TJS, that’s probably never going to happen. UCL injuries will always be around, though hopefully less frequently as medicine continues to advance. However, over 100 major leaguers who have undergone TJS have returned to an elite level of play, which shows why this injury that was once a career-ender is no longer regarded with quite the same level of dread.

Corey Dawkins is an author of Baseball Prospectus. Follow @CoreyDawkinsBP
Click here to see Corey's other articles. You can contact Corey by clicking here
Ben Lindbergh is an author of Baseball Prospectus. Follow @benlindbergh
Click here to see Ben's other articles. You can contact Ben by clicking here