Here’s the setting. Masters competition, clean and jerk with a  toe to bar ladder (sound familiar), 50 year old male lifts a barbell for a clean and jerk and feels a searing rip in his arm and has to drop the bar. He cannot lift his arm away from his side and is in agony, maybe had a little “bursitis in past” but nothing bad enough to stop him. Second scenario is 40ish year old 930 class filled with bunch of overachievers and one of them keeps getting some pain in the side of her arm halfway down the arm everytime she reaches in front or to the side trying to lift kettlebells. She has been waking up at night with some pain and has noticed that her numbers have been dropping as she tries to protect her arm and shoulder pain from getting worse. Both people may have rotator cuff tears. Both people may have torn one of his rotator cuff muscles. Rotator Cuff tears are probably on of the the most mispronounced things that we deal with in Orthopedic Surgery. Not Rotor Cuff, Not Rotor Cup, but rotator cuff. We call it a cuff because it forms a cuff of tissue that surrounds the humerus and lifts or rotates the shoulder joint. Made up of 4 separate muscles , the cuff is responsible for most activities of daily living with regards to shoulder function. Some things that you cannot do with a decent sized tear of the rotator cuff….brush teeth, reach into a cabinet, lift a gallon of water, reach behind back, throw a ball, carry a heavy object in front of you or to the side, sleep well.
Now there are differing severities of tears and different sizes. A lot of people can live with small tears of their cuff and may not exhibit any weakness or may not have any pain. The most common muscle that is injured is called the supraspinatus which lifts your arm off to the side and helps lift it overhead. If the tear becomes big it can then tear into the next muscle or the infraspinatus tendon. The infraspinatus helps to externally rotate your arm, that is to rotate your hand away from your body vs. towards your abdomen. Here is a side view of a tear of the supraspinatus the biceps tendon is seen towards the front of the shoulder.
This is a real life picture of a full thickness rotator cuff tear. Small tear.
Here is a bigger full thickness tear. Note how retracted the tendon can get which can make it difficult to stretch the tissue back to where it belongs.
If the tendons have been torn for a long time like over 1 year, they pull away from the bone, becoming atrophied and scarred. The tissue also can lose its strretchiness (real medical word) and make it impossible to reattach if it is an chronic tear that happened in the past. This is what a repair looks like for a medium sized tear. Note the sutures passing through the tendon and then being tied down the to bone like a boat at a pier.
This is what it looks like before the tear is tied down. Anchors go into the bone and then the sutures are passed through the tendon.
There are different sizes of the tear. The inital tearing can be what is called a partial tear where the attachment site of the tendon to the bone is partially disrupted. Decision for treatment is made based on how symptomatic the patient is and how big the partial tear is. We call the attachment site the footprint of the rotator cuff. If I know the footprint is typically 16mm of tendon attached to bone and at the time of surgery I see 8 mm of bone exposed then I know it is a 50% tear of the tissue as seen here.
If something is torn greater than 50% we usually repair it. If it less than that we can shave it or smooth it edges.  An MRI is good at saying full thickness tear or not, but it is not great at showing how big a partial tear is sometimes and so it can take looking inside the shoulder and measuring the tear making an intraoperative decision whether to repair it or trim it.
Full thickness tear MRI
Partial thickness tear MRI
The rehab from the repair can be substantial. You can check it out at  6 weeks of intermittent sling use, no reaching or lifting or actively elevating arm. PT will start passive range of motion of stretching your arm without actively moving it. Typing and writing are OK. After 6 weeks you can move actively your arm by yourself. Strengthening begins and getting moderate strength by 4 months  followed by another 3 -4 months to get stronger. For heavy duty lifting, people will say 9 months to 1 year to get back full strength. I would put Crossfitting at high levels in the last category. For cross fitters I can make up modified workouts for people at different stages of their rehab.
The cuff is extremely important for shoulder function. It allows full pain free range of motion when it is working, when it is not people don’t realize how important it is in life. Prevention means taking it easy when lifting at a level that you are comfortable with. If starting CrossFit, it means not loading up the barbell like a roll of lifesavers and seeing how many different colors you can put in there. It means you have to gradually build up your weights to a level that you are comfortable with and then proceed from there. Once again, being over 40 means that you have to be smarter than your youthful counterparts. When snatching and jerking, your strongest body part has to be your head, not your shoulders.