A SLAP in the head

Several weeks back the robot requested a detailed look at SLAP lesions such as the one that Adam Ottavino suffered.  I'm going to attempt to give an in-depth look at the structural makeup of the shoulder: specifically the glenohumeral joint.  I say specifically the glenohumeral joint because the shoulder as we all know it is actually a combination of 3 true articulating joints- the sternoclavicular joint(S-C), the acromioclavicular joint(A-C), and the aforementioned glenohumeral joint(G-H).   Another extremely important "joint," the scapulothoracic joint, also contributes to the function of the shoulder but is not a true joint as there is no true articulations between the scapula and the thorax.  All of these joints combine to allow the shoulder complex to have a high degree of mobility.

Now to clear the joints that we aren't here to talk about:  The A-C and S-C joints function to place the scapula in the proper position for the G-H joint to allow the arm to move in space and perform functional activities like, say, throwing a baseball.  The A-C joint and S-C joint are much more stable and less likely to be injured in a baseball player, aside from Jason Motte*. 

The stability of the G-H joint has been described previously as a ball sitting on a tee.  This definition falls short however and more recent research shows it is more like a ball on a seal's nose.  The articulations at the G-H joint are the glenoid fossa and the humeral head.  The glenoid fossa is a slightly rounded surface that covers anywhere from 1/3 to 1/4 of the surface of the humeral head.  The labrum is a ring of dense fibrous cartilage that functions to make the glenoid fossa 50% deeper, as you can see in this image.  Further stability of this joint comes from the glenohumeral ligaments, the joint capsule, and the rotator cuff.

via www.eorthopod.com

Injuries to the labrum are often broken down into 2 categories: SLAP lesions and non-SLAP lesions(bankart).  SLAP stands for Superior Labrum Antreior to Posterior.  They are further broken down into either stable or unstable lesions.  Stability depends on the amount of the labrum and biceps tendon (which, as you can see from the picture, attaches into the labrum) that remains attached to the glenoid.  SLAP lesions are commonly broken down into four categories, shown here.

via www.athleticadvisor.com

In a type 1 lesion, the labrum is attached, but there is fraying and degeneration of the cartilage.  Type 2 is characterized by detachement of the superior labrum and biceps tendon.  Type 3 the superior labrum is torn away and displaced into the joint with the tendon remaining intact.  In a type 4 lesion, the tear extends into the tendon and a portion of the tendon as well as the labrum is displaced into the joint. 

The most common mechanism of injury to the superior labrum occurs from repetitive overhead throwing and excessive inferior traction.  The reasons for so many throwing injuries consists of  a combination of peel-back traction of the biceps on the labrum in the cocking phase, abnormal posterior and superior humeral head translation in cocking due to GIRD(Glenohumeral Internal Rotation Deficit), and excessive scapular protraction.  Symptoms include poorly localized pain in the shoulder that is increased by overhead and behind the back arm motions, as well as popping, catching, or grinding in the joint.  The most common cause of "dead arm" syndrome is a SLAP lesion.

There are some specific tests described for diagnosing SLAP lesions, but the most effective method of diagnosing SLAP lesions and many other intra-articular pathologies is an arthrogram. 

Treatment of SLAP lesions depends on the severity of the injury.  As with everything, some controversy exists within the research.  According to one study, arthroscopic labral debridement is not an effective long-term solution for labral pathology.  Conservative interventions should be individualized to the underlying impairments that have caused the lesion, e.g. instability, scapular dsykinesia, etc.  Surgical interventions are generally good to excellent in terms of returning patients to their prior level of activity.

As far as rehab protocols, here is a link to Dr. Brian Cole's protocol.  He is the Bulls and White Sox team physician and I recently attended a seminar in which he was one of the main speakers.  FWIW, he has been recently voted Chicago's top Doctor, among a long list of other accomplishments.  And HERE is Dr. Ben Kibler's protocol.  Dr. Kibler was the main speaker at the aforementioned seminar.  He has performed some high profile surgeries in his day, including a rotator cuff repair on no other than one of my childhood heroes, pro football hall of famer Joe Montana.  (I know that would be a HIPAA violation if I had actually been involved in the case, but I wasn't, so I can say it.)

In my opinion,  the discrepancy in the literature about when to use conservative measures in treating a SLAP lesion vs the lack of success of debridement and the success of surgical repair when necessary, along with the many different classifications of SLAP lesions (there is another researcher who expanded the classification to 7 different types) all coupled together for the differing opinions about what to do with Ottavino.  I really wanted to present a piece of literature that I stumbled across about 3 years ago on successful conservative treatment of labral tears, but I was unable to find the article.  I do recall that it required an extensive period of immobilization in an abduction sling to decrease the loading on the labrum and improve the chances for healing/scarring down of the labrum onto the glenoid.  It was a small sample size study but showed good results for return to previous level of function within 1 year.

The vast majority of the information I'm sharing with you has come from Brukner and Khan's Clinical Sports Medicine and Dutton's Orthopaedic Examination, Evaluation, and Intervention.

*I would like to know the cause of Motte's A/C sprain.  I think this is an injury people should be scratching their heads about a little more than Freese or Penny or any other recently injured Redbird.  The A/C joint doesn't just sprain on its own, it takes a hit or fall to injure those things (I'm looking at you, Sam Bradford).  So my question is, did Motte get injured horsing around somewhere, or was it on one of those crazy sliding/falling/throwing plays he's had this year? 

Please feel free to post questions on this or suggest future injury related posts you would like to see.  I'm thinking a post on Freese would be a good one, but I'd need more information about what all is actually going on in that ankle to do it justice.