On July 14th, 2018, the Cincinnati Reds’ outfielder Scott Schebler was injured when he collided with the wall to make a catch against the Cardinals. Schebler hit the wall hard with the main impact on his right shoulder. He immediately exited the game.

Initial X-rays were normal. Additional X-rays were sought on Wednesday July 18th and showed a sprained acromioclavicular (AC) joint in his right shoulder.

The acromioclavicular joint is where the collarbone (clavicle) meets the shoulder blade (scapula) at the top outer edge of the shoulder. There is no motion in this joint. When sprained, it can hurt with overhead and across body movements. A forceful impact, usually during a direct collision with a solid object or surface, can cause the ligaments supporting this joint to stretch. Some of the fibers are torn. This is referred to as a sprain. If some of the ligaments are completely torn, the AC joint may dislocate.

AC sprains and even most dislocations are allowed to heal naturally. There is no need for protection and hockey players and American football players often return to play immediately. It may be weeks before the shoulder is comfortable enough to play baseball effectively. It is not known how long Schebler is to be out.

This blog was written by Katharine Clement and David Ring.

On June 13th, 2018, the Los Angeles Angels’ third baseman Zack Cozart had a sore shoulder after he dove for a ground ball. The team doctors said it was a left shoulder subluxation. Subluxation means that the joint came slightly out of joint, partially tearing some ligaments, but did not result in dislocation.

He sought an independent opinion from Dr. Neal ElAttrache, head team physician for the Los Angeles Dodgers and Los Angeles Rams as well as orthopedic consultant to the Los Angeles Angels of Anaheim, Los Angeles Clippers, Los Angeles Kings, Anaheim Ducks and the PGA Tour. An MRI was obtained showing a tear of the labrum in his left shoulder. The working diagnosis is a torn labrum.

The socket of the shoulder joint is called the glenoid. The glenoid is quite flat. The glenoid labrum is a circular rim of flexible cartilage that deepens and helps stabilize the shoulder joint. This is called the glenoid labrum.

Surgery was recommended to repair Cozart’s torn labrum and he will be out for the remainder of the season.

This blog was written by Katharine Clement and David Ring.

Tommy Kahnle—one of the New York Yankees’ most reliable relief pitchers last year—is going on the disabled list. His performance was poor early in the season, which he ascribed to lost velocity in his fastball. While shoulder pain was never mentioned, a recent news report describes MRI findings of “biceps and shoulder tendinitis”.

The biceps anchors in two places in the shoulder. One of the anchor tendons passes right through the joint. Changes in this part of the biceps tendon are expected with age. They accompany the expected age-related changes in the small muscles that rotate the shoulder. The tendons (parts that the muscles use to move the bones) of those small muscles are flat and thin and cover (or cuff) the head (the ball) of the shoulder joint. After age 40, we all develop rotator cuff tendinopathy. There is thinning of the tendons and defects may develop. Genetic factors likely affect how quickly this advances.

Throwing athletes get tendinopathy at a younger age and in a slightly different form. Studies of professional baseball pitchers with no symptoms often find MRI changes in the biceps and rotator cuff tendons (https://www.ncbi.nlm.nih.gov/pubmed/12975193). That makes it difficult to be sure when an MRI finding is causing symptoms and when it is just an incidental finding.

It’s not clear if the doctors treating Tommy found something more than the typical changes on MRI. And it’s not clear how they have decided that Tommy’s symptoms are likely related to the findings. Periods of rest and a routine of shoulder strengthening exercises are often tried to calm the symptoms and increase throwing effectiveness.

This article was made by Paul Bonilla and David Ring