While the diagnosis mainly relies upon a good clinical evaluation, imaging does help play a role in the diagnosis of a sports hernia. The following studies are usually performed:
DYNAMIC ULTRASOUND: This is a very important imaging study performed during the initial clinical evaluation by the surgeon. The ultrasound probe will be placed on the inguinal crease and the floor is evaluated. The patient will then be asked to tighten their core muscles or do a small sit-up. This increases the intra-abdominal pressure and helps identify an area of weakness on the inguinal floor in real-time. No other imaging modality does this. If a bulge is seen on the inguinal floor, then a sports hernia is confirmed.
MRI PELVIS - ATHLETIC PUBALGIA PROTOCOL: This is a special protocol to look more closely at the muscle attachments at the hip and anterior pelvis. It is preferred to be performed on a 3-Tesla MRI or stronger to get the best images. While a standard pelvic MRI, or 1.5-T MRI might be adequate in some cases, if the injury is significant enough/ However, often the cross sectional angles of the images do not focus on the areas of concern and the image quality is not good enough to see the more subtle findings. Some of the more common findings on MRI that can indicate a sports hernia include:
- Osteitis pubis: The term osteitis pubis is a radiographic finding that essentially means ‘Pubic bone inflammation’. This occurs when there is a muscle imbalance of the rectus abdominis muscle, adductor longus muscle, and/or the inguinal ligament at the pubic bone. All of these structures come together and form an aponeurotic plate. The fusion of the tendon fibers and ligament attaches to the pubic bone. With an injury, the muscle may start to pull more in one direction or another, causing excess stress on the pubic bone, which in turn causes an inflammatory reaction.
- Secondary cleft sign: This sign represents a tear of the adductor longus origin and aponeurosis.
- Muscle tear: While a complete muscle tear or avulsion is possible, more often these are partial or incomplete. More importantly, they are often very minimal. But this further confirms that there is an underlying core muscle injury or sports hernia.
- Aponeurotic plate avulsion: This describes a more significant injury to the attachments of the muscles at the pubic bone. As mentioned earlier, muscles and ligament not only attach to each other from above, below, and the side, they also attach to the pubic bone posteriorly. When the aponeurotic plate is avulsed, the muscles are often at their appropriate location and length; therefore, they have not retracted as one would imagine. However, the plate has lifted slightly off of the bone.
- Inguinal hernia: The two most common inguinal hernia types are direct or indirect hernias. This means that there is actually abdominal fat or intestines in the inguinal canal. If there is a hernia noted on imaging, surgery is recommended to fix the problem.
XRAY (PELVIS OR HIP): While this is not the preferred study for a sports hernia, it is often performed initially when your treating physician is looking for an explanation for your groin pain. When the xray shows other pelvis pathology it is recommended to work those up. The xray can show hip pathology and come abdominal conditions, but overall is does not help with a sports hernia diagnosis. The only find that can point to a core muscle injury, would be osteitis pubis. This would then usually warrant a pelvic MRI study.