Musculoskeletal Ultrasound for Accurate Diagnosis and Optimal Rehab

If you or a loved one has ever had a traumatic injury or stumped your doctor with regional pain from an unknown source, you have probably had an Xray or MRI. Those imaging methods are the most common types of diagnostic imaging for musculoskeletal pain, used to give your doctor a glimpse of what’s going on “under the hood.”

The problem with traditional imaging tools is that they give you still images, usually taken by a technician. Your doctor does not see the results until after they are processed, which can be within an hour or two for Xray, or within several days for MRI. In addition, both methods have inherent safety issues that make them inappropriate for some patients.

With still images, it is easy to overlook important clues about the source of pain, or miss hidden damage to bones, nerves and soft tissues that were not captured by the camera. Musculoskeletal diagnostic ultrasonography provides a safe, inexpensive and accurate alternative for detecting damage to the body’s structures and monitoring the healing process. Ultrasound technology is also showing promise as a tool for biomechanical analysis, helping athletes perform better with less risk of injury.

Ultrasound works by transmitting millions of high-frequency sound waves per second into the patient’s body, using a probe that can be moved and repositioned along the surface of the skin to gain a variety of views. When the sound waves hit a barrier, like an organ, bone, muscle, nerve or connective tissue, they echo back to the probe and are relayed to the ultrasound device. The reflected waves are calculated in terms of distance from the probe to the barrier, using the speed of sound and the time of each echo’s return. That information is then displayed as a two-dimensional image on the ultrasound screen, giving us a view of the body’s structures.

Accurate diagnosis immediately after an injury is key to getting the rehab ball rolling. If you are an athlete, early diagnosis means faster return to sport. Musculoskeletal diagnostic ultrasonography is fast, accurate and portable. An athletic injury can be examined right on the playing field, reducing the athlete’s risk of further injury and giving coaches a heads up if the athlete needs to be taken out of the game.

Instantaneous diagnosis in the rehab clinic means no delay in treatment. The patient can often be evaluated and treatment begun in the same session. During the diagnostic exam, the patient becomes an active participant in their own diagnosis, giving feedback and working with the clinician to reposition joints and limbs, so no damage goes undetected.

Your joints and muscles work interdependently to produce movement. Joint kinematics studies the position, angle, velocity, and acceleration of body segments in relation to one another. Joint kinematics is used during gait analysis to identify deficient motor patterns that may lead to injury and reduce performance. There are many tools for measuring joint kinematics, but they are often uncomfortable for the patient, which can detract from natural movement patterns.

A promising recent development is the use of a wireless sensor system using ultrasound technology. Only one wearable ultrasonic sensor is required, minimizing discomfort for the patient. The system measures joint angles, velocity and acceleration in terms of the speed of sound. The technology is inexpensive, accurate and less complex than other systems for measuring joint kinematics.

As your body heals, ultrasonography helps us accurately assess your rate and degree of recovery. Premature return to sport is one of the biggest causes of re-injury. MSUS imaging allows the athlete, coach and doctor to view damaged tissues in real time, with the athlete in motion.

Peak muscle torque is one marker for recovery that tells how much force a muscle or muscle group can produce. For example, measurements of knee extensor torque in the quadriceps may be used to evaluate ACL rehabilitation. Traditionally, isokinetic dynamometry has been the tool of choice for evaluating peak muscle torque, but it is unable to isolate the individual muscles of the quadriceps group.

Real-time ultrasound imaging enables us to view and measure the strength and function of each muscle with the knee in multiple positions, something that is not possible with isokinetic testing. We can use ultrasound to evaluate the muscle thickness of the individual muscles, to see which are healing, and which are underperforming. We can also compare muscle thickness of the injured and uninjured sides of he body, to get a baseline for recovery.