Shoulder Inflammation

With the baseball season coming upon the homestretch, the push for the playoffs is really starting to heat up. It has been quite some time since our local Seattle Mariners have been in serious contention. The Detroit Tigers are currently neck and neck with the Mariners fighting for the second American League Wild Card spot. The Tigers were dealt a pretty significant blow on August 12th when one of their starting pitchers, Justin Verlander, a recent league MVP and Cy Young Award winner, was told that he would have to sit out some games due to shoulder inflammation.

Joint inflammation may stem from inflammation of bursa(e), fluid filled sacs that provide cushion between bones, tendons, and/or muscles around a joint. They reduce friction and allow for free movement of surfaces moving in different directions. When inflamed, a normally slippery bursa becomes thickened and swollen, causing it to lose its ability to glide, which can become more irritated with movement. If you follow the Mariners, you may recall that this is a similar issue that afflicted top pitching prospect Taijuan Walker early on in spring training this year, preventing him from being able to compete for a spot in the starting rotation. While inflammation can be caused by an acute trauma such as a contusion, it is typically the result of a repetitive overuse injury caused by prolonged and excessive pressure. With a professional baseball pitcher, you can see how this could become an issue as their job description requires them to repetitively use their shoulder for prolonged periods of time. However, this is a very common injury that brings patients into our office all the time and can affect people of all ages and skill levels.

The general treatment plan for shoulder inflammation calls for ice and rest. While this can reliably help reduce the inflammation and thus pain level and discomfort, it doesn't change the underlying cause of the injury. Poor biomechanics often contribute. During Taijuan Walker's rehab, he worked on the mechanics of his pitch delivery. The can be deduced that the Mariners coaching staff and sports medicine team believed that there was a part of his delivery that was placing undue pressure on his shoulder which caused this inflammation in the first place. In fact it had been reported that he was complaining of shoulder soreness even before spring training started. But since finally coming back, armed with a refined delivery, he hasn't had any issues with his shoulder, recently striking out 13 batters in a start for AAA Tacoma.

The situation with Justin Verlander is slightly different. While the injuries are similar, from reports that I have seen the inflammation in Taijuan Walker's shoulder appears to be isolated to one particular area whereas the source of inflammation in Justin Verlander's shoulder was more complex. In addition, Taijuan Walker just recently turned 22, while Justin Verlander is 31 and pitching in his 10th major league season. Until this most recent incident, he hadn't missed a single game due to injury in his entire career. It would seem that if there were a biomechanical issue involving his delivery, this problem would have surfaced at some point in the past 10 years. A topic that will be covered in another blog post but that is relevant to this situation is injury recovery as we age. Being a pitcher in professional baseball takes an enormous physical toll; being asked to step on the mound every 5 days and torque various joints and limbs repeatedly (~100 times) in order to hurl a baseball at extreme velocities is no small task. Of all the pitchers in baseball, Justin Verlander has had one of the largest workloads, pitching over 200 innings in each of the past 7 years. As Justin Verlander ages, as with the recreational athlete, he is not going to be able to recover as quickly or efficiently as he once could. This case of shoulder inflammation could just be a case of father time finally catching up to him.

While Taijuan Walker seemed so have recovered fine, and Justin Verlander's recovery going well enough that he is tentatively scheduled to return to action this weekend, there are still instances where despite sufficient rest and biomechanical changes, the inflammation doesn't completely resolve and residual pain and discomfort remain. This is where a target intervention such as a corticosteroid injection can come into play and be quite helpful. It is widely believed that cortisone works in large part by  by reducing inflammation. Injecting cortisone into the inflamed area, reduces inflammation and pain. One of the potential downsides is that corticosteroids, if accidentally injected into the body of a tendon can weaken that tendon, increasing the likelihood of rupture or tearing. Most of this risk is associated with the most common way of doing these injections, using palpation or landmark guidance. As discuss in our previous post on musculoskeletal ultrasound, when doing a landmark based injection, there is no way to know for sure where the medication actually ended up. As you can see in the picture below taken from that blog post, the size of the bursa (indicated by the black arrow) is tiny, especially compared to the needle being used to inject the medication. As you can imagine, the chances of being able to get the medication into that small space based on palpation alone is quite slim. Thus the risk of weakening the tendon by exposing them to corticosteroids is likely the result of missing the bursa and injecting the medication directly into the tendon. When patients come into our office we can visualize the inflamed bursa and get feedback from the patient about where their symptoms are coming from in real time. Then if the doctor determines that the patient would be a good candidate for an injection, the needle can be directed towards the target with certainty, and the medication can be seen while administered in real time.

Musculoskeletal Ultrasound

One of the underrated tools that Drs. Chimes and Hyman have at their disposal when diagnosing and treating patients is the use of musculoskeletal ultrasound.

Most people are probably familiar with ultrasound to some extent, physical therapists will often apply therapeutic ultrasound to injured tissues and ultrasound is typically used to visualize unborn babies. Musculoskeletal ultrasound  is closer to the ultrasound utilized during pregnancy, the idea being that the probe emits super high frequency ultrasonic waves which go through a gel medium before being transmitted through the skin and different body tissues (such as muscles and tendons) before bouncing back and being received by the probe.

The frequency of these ultrasonic waves produces an image that is incredibly high resolution (3 times higher than MRI). The ability to view these images in real time is unique compared to other imaging modalities, allowing the doctors to observe the dynamic movement of body structures. An additional benefit of this is the ability for the patient to give feedback in real time, this is important because it is clinically significant whether or not the patient is experiencing any pain at the location of the probe where inconsistencies are observed. This can help the doctors discern whether the irregularities are concordant with their symptoms or simply incidental.

Patients will often come into our office and state that they have had a previous cortisone injection performed by another physician. While they probably did have a corticosteroid injected, that isn't really the relevant detail. More important is where the medication was placed, and how it got there. Historically, and the way that most physicians today do these injections is on a landmark basis. What that means is the doctor will insert the needle and once a landmark is reached (often when the needle hits a bone), then the placement of the needle will be adjusted relative to that landmark before the medication is injected. While injections done with this method can give patients relief, this technique doesn't completely take into account the variety in each person's anatomy or allow for the precision required to reliably hit the intended target. Even if the target is missed, it is likely that the medication was somewhat absorbed by being injected in the general area, giving the patient variable levels of relief.

Having the ability to use musculoskeletal ultrasound to guide these injections has been shown to dramatically increase the efficacy of these injections (check out these two articles). The ultrasound machine allows the target structure and the needle to be visualized in real time, which has multiple benefits. First, by seeing the needle in real time, landmarks do not need to be used, making the procedure more comfortable for the patient by allowing the physician to avoid having the needle touch down on bone, which can often be quite painful. Another advantage of using ultrasound is that the needle can be more precisely directed towards the target, allowing the doctor to know exactly where the medication is being injected. This can be helpful in a situation where the injection doesn't offer the patient any relief, allowing the doctor to definitively rule out that particular structure as the pain generator.

Let's use shoulder pain as a common example.  The supraspinatus is a structure that can contribute to shoulder pain in many patients. One example of an injection where the benefit of ultrasound is obvious is a subacromial bursa injection where medication is injected into the subacromial bursa directly above the supraspinatus, bathing the tendon in medication. The placement of the medication is especially important because if the medication were to be injected directly into the tendon and there was even a small tear present, it could lead to even further degradation. The subacromial bursa itself is maybe a millimeter or two thick, smaller than the width of the average needle used to inject it, as you can see in the images below. You can see how even the best sports medicine physicians in the world would have trouble reliably hitting this target when using a landmark based technique.

This is an width of the average needle used to inject medication. You can see how small it is.

As you can see in this ultrasound image, the bursa (indicated by the arrow) is a very thin fluid filled sac smaller than the tip of the needle