In orthopedics and musculoskeletal medicine, a patient’s most frequent symptom is pain. Building a diagnosis from this symptom poses certain problems: first, pain is not the best indicator of serious injury. Injuries that initially are extremely painful may feel fine a few days later, while other injuries that cause little initial pain can become more unstable over time, eventually requiring more invasive (e.g. surgical) management. Second, in part due to the realities of our anatomy (including peripheral pain generators), patients are not always able to describe where the pain is coming from. These difficulties with diagnosing an orthopedic injury based on pain have led to unsuccessful treatment regimens, patient frustration, and avoidable follow-up visits. Integration of point-of-care ultrasound technology has changed the paradigm for orthopedic diagnosis, however.
Ultrasound systems optimized for use at the point-of-care have evolved since their earliest clinical applications. The technology on the market today has the focus, resolution, and “trueness” of image (vs. artificial smoothing) to help physicians overcome the difficulties of diagnosis based on pain. Orthopedic and musculoskeletal medicine physicians can use ultrasound to better pinpoint pain generators, accurately classify the severity of a patient’s injuries, and get patients on the most effective path for recovery.
Here are 5 frequent applications of point-of-care ultrasound for orthopedics diagnosis:
1. Shoulder
The shoulder is one of the best examples of a joint where patients have difficulty identifying the source of their pain. Point-of-care ultrasound has vastly abbreviated what can be a long diagnostic process, trimming the time to identifying the relevant pain generator to something like fifteen minutes.
Prior to our current point-of-care ultrasound capabilities, for instance, diagnoses might be as generic as “mechanical shoulder pain.” Even when they were more precise—something like subacromial impingement—there was still no simple way of measuring the actual subacromial space.
Consider this specific scenario: a patient presents with acute shoulder pain, and they are having trouble abducting their arm past 90°. Historically, it was difficult to tell whether that lack of movement meant acute bursitis or a complete rotator cuff tear; deciding between a pain limitation or a complete tear was largely a judgment call on the part of the physician. With ultrasound; however, the physician can simply look at the supraspinatus tendon to determine the cause of the functional limitation.
2. “Tennis leg”
One common injury called “tennis leg” occurs typically at the myotendinous junction of the medial head of the gastrocnemius, or the mid-portion of the calf muscle interior. Usually, the patient is playing a sport like tennis, where there’s a rapid contraction of the calf muscle, and they feel a “pop” and then experience intense calf pain.
Ultrasound can mean the difference between weeks of healing versus months of healing, namely by revealing whether or not there is blood pooling in the area. If there is blood pooling there, draining it can help make the patient’s recovery quite fast; if it is left there to coagulate; however, it will eventually become scar tissue, which can dramatically prolong the recovery period.
Thus, whenever patients have an immediate calf strain, use of ultrasound to diagnosis the condition means the physician can learn whether there is blood pooling (i.e. hematoma formation) in the area, and, if it has not yet coagulated, can drain the blood to improve patient comfort and speed recovery.
3. Knee
The knee’s complexity requires a high quality ultrasound device for the diagnosing physician to differentiate between injuries that might cause functional limitations. For instance, the knee demands focus at both the superficial and the deep views in order to make an accurate diagnosis; it also demands a sharp enough image to differentiate the different tissues in the region. This is achievable with our X-Porte system. When a patient comes in with a skiing injury, reporting an awkward fall after which their knee felt unstable, the ultrasound devices designed for use at the point of care can be used to evaluate in real-time the medial collateral ligament much more effectively and efficiently than if the patient were sent to get an MRI. Ultrasound also enables dynamic valgus testing. The instability is sometimes due to a grade one femoral-sided deep-band MCL tear—a painful injury, but one that tends to get better fairly quickly. Identifying this tear on the first visit allows the physician to deliver the right diagnosis, of course, but it also gives the patient immediate prognostic information about what the next steps will be.
4. Sciatica vs. hamstring tear
One of the most common injuries for soccer players is a hamstring strain. With a high hamstring injury, people have pain in the lower buttock and upper thigh—a pain distribution that is also very common if a nerve is pinched in the back (i.e, sciatica). Point-of-care ultrasound allows physicians to make the right diagnosis in cases with this pain profile, revealing problems at the hamstring tendon or even muscle/tendon tear.
Ultrasound also allows the physician to communicate better with the patient’s entire care team: zeroing in on the cause of the pain enables effective conservative management, including physical therapy and physical therapy exercises. Alternatively, it can show when the tear is bad enough to require rest, an injection to help stimulate healing, or even surgery.
A missed diagnosis, especially between sciatica and a torn tendon, is not a trivial thing. If a patient goes through months and months of treatment assuming they have a back problem that caused their buttocks and thigh pain, they will likely make very little progress. That’s frustrating for anybody, and in the case of sports medicine it also means a longer delay until the athlete can return to the field.
5. Proof of concept injections
This last ultrasound application in orthopedics is an acknowledgement that it is not just patients who can find it difficult to localize their pain—even with the most advanced technology, there are some structures that still defy immediate diagnosis.
The knee is a good example here. On just one side of the knee there may be three or four structures in close proximity to each other that might be the source of the patient’s problem. Those structures can be tested using live dynamic ultrasound maneuvers, with the pushing on a spot that might be symptomatic to learn more. And here is where the use of ultrasound is again clinically appropriate: as an important confirmation (or disconfirmation) on the initial diagnosis.
A “proof of concept injection” means injecting a needle at the diagnosed source of pain in order to deliver a small amount of anesthetic. If the anesthetic solves the problem, that diagnosis can be trusted, and a targeted therapeutic intervention can be administered.
Avoiding oversimplification
In the above applications, it may sound like ultrasound is used primarily to decide between two alternative diagnoses, body part by body part. But in physical rehabilitation and sports medicine, diagnoses must acknowledge the intimate interrelatedness of different physical structures. Ultrasound reinforces that interrelatedness, helping to tease out sports medicine diagnoses from around the neck/shoulder all the way to the foot—and to show the mechanisms by which a patient’s pain might be related.