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11 Articles in Volume 10, Issue #6
Assessing Pain of the Pediatric Patient in the Emergency Setting
Testosterone Replacement in Chronic Pain Patients
Why Some Patients Require High Dose Opioid Therapy
Raising Pain Tolerance Using Guided Imagery
Long-Standing Groin Pain in a Male Athlete
FDA’s Proposed Risk Evaluation and Mitigation Strategy (REMS) for Opioids
Platelet Rich Plasma Prolotherapy as First-line Treatment for Meniscal Pathology
Cluster Headache
Effectiveness of Laser and Non-Coherent Light Therapies
Opinion on Preliminary Guidelines for the Clinical Diagnostic Criteria for Fibromyalgia
Doctors May Now Electronically Prescribe Schedule II Drugs

Long-Standing Groin Pain in a Male Athlete

Case report of chronic unilateral pain from a sports-related groin injury is discussed along with proposed pathophysiology, diagnosis, and treatment.

The groin is defined as the area delineated by the anterior super-ior iliac spine, the pubis and the inguinal ligament, as well as all containing structures. Groin pain seen in athletes has been categorized using many different terms—sports hernia, athletic pubalgia, and hockey groin. First described by Gilmore in 1980 as a dilation of the superficial inguinal ring, current research speculates that the etiology is multifactorial. Now a common diagnosis in high- intensity athletes involved in sports requiring rapid changes of direction while running, a sports hernia is any condition causing unilateral pain in the groin region without a demonstrable hernia. This pain may arise from muscles, tendons, bones, bursa, fascia, nerves and joints.1 In this paper, a clinical case will be presented followed by a discussion of sports hernias including the proposed pathophysiology, diagnosis, and treatment, as well as a case-specific discussion of the topic.

Case Report

BH is a 21-year-old male who presented for an acupuncture evaluation after complaining of groin pain since age 16. He was an avid lacrosse player in high school and had to stop playing due to the severity of the pain. On a scale of one to ten, BH stated the pain was a ten at its worst. He described the pain as stabbing and pulling in nature with an insidious onset. It was exacerbated by heavy activity and alleviated by sitting still. The pain started in the right lower quadrant of the abdomen and radiated to the right testicle.

BH sought medical care at the age of sixteen. He had an extensive workup by an urologist and all tests were negative; sexually transmitted diseases, testicular torsion and epididymitis, among other conditions, were ruled out. Feeling relieved that the pain was not caused by a “serious” condition but frustrated at not having an explanation, BH then saw an orthopedic surgeon. The patient underwent another expensive workup and was incidentally found to have a central broad-based disc herniation at L4-5. He left this second doctor and another costly workup feeling frustrated and without an explanation for his groin pain. Finally, after several years of dealing with the pain on a daily basis, he sought acupuncture as a last resort.

Presentation

On physical exam, BH was a healthy-appearing, muscular man in no apparent distress. The groin pain described in the patient’s history was reproduced with flexion of hip and knee to 90 degrees on the right; in other words, BH had a positive ‘step sign’ (see Figure 1). However, when the hip was flexed and the knee extended, the pain was not reproduced (see Figure 2).

Figure 1. The ‘step sign’: with the hip and knee flexed to 90 degrees, the rectus femoris muscle is isolated. The test is positive when pain is reproduced. Figure 2. Hip flexion test: with the hip flexed to 90 degrees and the knee extended, the iliopsoas muscle group is isolated.

The patient had full (five out of five) muscle strength in all muscle groups in the lower extremity bilaterally. The patient was neurovascularly intact and had normal reflexes with a +2 patellar and Achilles reflex and down-going Babinskis bilaterally. Range of motion was tested and was with in normal limits with the exception of a decrease in anteversion (hip internal rotation). Many special tests were performed as presented in Table 1. All tests were negative except for a decrease in sensation over the L4 dermatome as expected from the MRI results.

Table 1. Special Tests Performed in Physical Examination of Patient BH
Test Name What it tests Result
Heel walking Tibialis Anterior L4, L5, S1 Negative bilaterally
Toe Walking Gastrocnemius S1 Negative bilaterally
Seated straight leg raise Disk herniation Negative bilaterally
Lasegue (straight leg test) Disk herniation Negative bilaterally, pain at 80
Bragger’s (straight leg test with dorsiflexion) Sciatica or nerve root irritation Negative bilaterally
Flip Sign Radicular pain Negative bilaterally
Slump Radicular pain Negative bilaterally
Faber’s Sacroilitis WFL left, right decrease anteversion
Thomas Iliopsoas contracture Negative bilaterally
Thompson test Achilles tendon rupture Negative bilaterally

Discussion of Sports Hernias

Representing 5-7% of all injuries, sports hernias are common among athletes involved in sports that require cutting, pivoting, kicking and sharp turns such as soccer, football and lacrosse.2 In recent years, more attention has been paid to sports hernias with well-known and successful athletes, such as Donovan McNabb, succumbing to their affliction. In 2005, McNabb underwent season-ending surgery after a hard tackle exacerbated his sports hernia. Despite the media hype, the etiology, onset, and even terminology vary widely in the literature.1 Generally thought to be the result of repetitive microtrauma, sports hernias typically develop in an insidious fashion with symptoms arising from lower abdominal musculature and muscles of the upper thigh. The term ‘sports hernia’ is misleading since there is no demonstrable hernia. They are more commonly seen in males, with the pain being described as unilateral and diffuse with possible radiation to the medial thigh, perineum and testicles (see Table 2). The pain is aggravated by heavy activity, laughing and valsalva maneuvers.3

Table 2. Commons Symptoms of Sports Hernias
  • Unilateral groin pain
  • No palpable hernia
  • Insidious onset
  • Pain-free at rest
  • Not relieved by conservative measures
  • Possible radiation to medial thigh

While the symptoms are not disputed, various pathophysiologies have been described in the literature. Some define sports hernias as a bulge or defect in the posterior inguinal wall resulting in a loss of integrity of the inguinal canal without the presence of an obvious hernia4; while others attribute the condition to a muscular defect or avulsion of the muscles of the pubic tubercle that leads to weakness of the inguinal wall or ring.5 Other studies have shown the pain to be due to an actual nerve entrapment causing referred groin pain. The rectus abdominus, in combination with adductor pathology, have been cited as the most common soft tissue defects together with iliopsoas, rectus femoris and sartorius involvement as the most frequently affected non-adductor groups.6

The groin region is complex and contains a number of muscles, nerves, tendons and organs. Thus, the differential of groin pain in an athlete is vast, including:

  • intra-abdominal pathology such as appendicitis or irritable bowel syndrome,
  • genitourinary abnormalities such as sexually transmitted diseases,
  • testicular torsion,
  • nephrolithiasis,
  • referred pain from the thoraco-lumbar spine,
  • nerve entrapment,
  • muscle strain, and
  • hip pathology.

Once life-threatening conditions are ruled out, the diagnosis is made primarily by the history and physical exam. The classic symptoms described must be present for six to eight weeks and the patient must fail conservative treatment to be diagnosed with a sports hernia. Patients must also be pain-free at rest with pain returning upon resumption of activity.1,4

When such pain persists, a range of imaging studies may be performed to confirm that there is not another cause of the pain. It is important to note that these studies may not confirm the diagnosis of a sports hernia, but they do provide valuable information in defining other potential pathologies. The literature states that Magnetic Resonance Imaging (MRI) may be useful in demonstrating muscular abnormalities and edema as well as other pathologies such as true hernias.7 Other studies suggest that ultrasonography may be useful since it is non-invasive and less expensive than MRI. It can provide valuable information about the location and extent of tendinous injuries by highlighting hypoechoic areas representing partial tendon tears.8 How-ever, like ultrasonography in all medical fields, it is operator-dependent and has variable reproducibility.

Generally, conservative measures such as rest, restricted activity and use of non-steroidals are tried first, followed by physical therapy aimed at stabilizing and strengthening the pelvis and hip.3 If a patient fails conservative therapy and continues to have pain after six to eight weeks, surgical exploration is indicated.3 Some surgeons focus on the external elements of the inguinal canal and repair the external oblique fascia or enforce the groin with the rectus abdominus, while others support the use of mesh placement similar to an inguinal surgery repair.9 There is no consensus to support any particular procedure—both laproscopic and anterior approaches have been used and have about a 90% success rate. Most patients return to full activity within two to six weeks of laproscopic repair and one to six months of open repair.10 Others who believe the problem lies in the lower abdominal muscles or nerve entrapment treat it accordingly.11

Anatomy Revisited

The majority of all groin injuries can be attributed to muscle strains, most notably found in the adductor and hip flexor groups. The anatomy of the groin involves a confluence of structures that can be highly variable. As described above, the literature cites muscle involvement as a possible etiology of sports hernias. The patient, BH, described groin pain that radiated to the testicular region and inner thigh, which is innervated by the twelfth thoracic nerve and the first lumbar nerve. When examining the lumbar plexus, it is evident that the three major nerves which supply sensation to the groin —the iliohypogastric, the ilioinguinal and the genitofemoral nerves—all share common nerve roots: lumbar nerves one and two (see Figure 3). The anatomy of these nerves varies immensely from person to person12 thus the etiology may differ in each individual. A general idea of the course of the nerves along with keeping an open mind in regards to the anatomical variations is crucial.

Figure 3. The lumbar plexus: comprised of nerve roots L1-4, the lumbar plexus provides sensation and motor function to the lower extremity. Gray’s Anatomy. 15th Edition, Gramercy, 1988.

The first lumbar nerve branches to form the ilioinguinal nerve and the iliohypogastric nerve. They both traverse the psoas major and the transversus abdominus. The ilioinguinal nerve generally passes medially across the quadratus lumborum and iliacus before traveling through the superficial inguinal ring to give sensation to the inner groin and medial thigh, whereas the iliohypogastric nerve travels posteriorly to the kidneys and divides into a lateral and anterior branch at the iliac crest.

The first and second lumbar nerves combine to form the genitofemoral nerve, which is responsible for both the efferent and afferent limbs of the cremasteric reflex. It again emerges on the anterior surface of the psoas major and divides into two branches: a femoral branch which supplies skin anterior to the upper part of the femoral triangle and the genital branch which, in males, travels through the superficial inguinal ring and supplies the cremaster muscle and scrotal skin.

An irritation in any of these nerves could be responsible for the referred pain in the groin seen in patient BH. The fact that the pain was reproduced when the rectus femoris was isolated during the ‘step sign’ test suggests that there is a muscular component to the pain. Hip pathology has been cited as a cause of groin pain and it is important to understand the anatomy of the two major hip flexors: the iliopsoas and rectus femoris muscles.

The term, iliopsoas, is used to refer to a group of three muscles—the psoas major, psoas minor and iliacus (see Figure 4). These muscles are distinct in the retroperitoneal abdomen and usually indistinguishable in the thigh. The psoas major originates along the lateral surfaces of vertebral bodies T12-L4. The psoas minor originates along the transverse processes of L1-5, and the iliacus originates in the iliac fossa of the pelvis. The psoas major unites with the iliacus at the level of the conjoint tendon and crosses the hip joint to insert on the lesser trochanter. The psoas minor inserts at the iliopectineal arch. To isolate the iliopsoas muscle, the patient lays prone and the hip is flexed to 90 degrees with an extended knee, approximating origin and insertion, as shown in Figure 2. Innervated by lumbar nerve roots two, three and four, the iliopsoas is the strongest hip flexor and is important for standing, walking and running.

Figure 4. Hip flexors of ventral thigh. psoas major and minor, iliacus and rectus femoris muscle. Adapted from Gray’s Anatomy.

Commonly thought of as a knee extensor, the rectus femoris muscle flexes the hip and is innervated by the same three lumbar nerves that innervate the iliopsoas group, namely lumbar nerves two, three and four. Located in the middle of the anterior thigh, the rectus femoris originates by two tendons, anteriorly in the anterior superior iliac spine and posteriorly from a groove above the acetabular brim. It inserts into the patella along with the three other quadriceps muscles: the vastus medialis, vastus intermedius and vastus lateralis. Since the rectus femoris originates in the pelvis and crosses the hip joint, it can act as a lever to flex the leg at the hip. It is a weaker hip flexor when the knee is extended because it is already shortened and suffers from active insufficiency (the inability of a muscle that spans two joints to reach a full contraction force due to the limit in the muscle length). In essence, raising a straightened leg will recruit the iliopsoas muscle group more. To isolate the rectus femoris, the patient lays supine, and the hip and knee are flexed to 90 degrees to approximate origin and insertion, as seen in the ‘step sign” special test (see Figure 1).

Discussion

Since a sports hernia is not visible, cannot be palpated and often cannot be confirmed with imagining studies, a thorough physical exam is crucial not only to obtain the diagnosis but also to control the cost of the workup. When thinking about the etiology of groin pain, it is important to determine the intensity and location of the patient’s symptoms. In the case of BH, a thorough musculoskeletal exam was performed encompassing all muscle groups, leading to the diagnosis of referred groin pain secondary to nerve irritation caused by the rectus femoris muscle. It is important to think of all muscle groups. Had each hip flexor group not been isolated, the diagnosis may not have been made.

Often, it is thought that the muscle pathology is due to the muscles attaching to the pelvis since the pelvis acts as a central point for the body and takes so much force with high impact athletics. However, any muscle damage or hypertrophy affecting a nerve could cause this radiating pain. One can imagine a man with hypertrophied or enlarged biceps. When this man puts on a shirt, one can clearly see the hypertrophy as stretched, tight-fitting sleeves. This is similar to what happens internally with muscle hypertrophy—as the muscle grows within the fascia, excess pressure is placed on surrounding structures. With the variable anatomy of the groin region, it is important to isolate each muscle group in the physical exam. As seen in patient BH, the groin pain in the ilioinguinal, genito-femoral and iliohypogastric region was reproduced when the rectus femoris muscle group was isolated during the ‘step sign’ test. Perhaps, as an athlete, the constant motion and activity causes muscle hypertrophy, which results in actual nerve entrapment, strain on fascial structures or compression of the conjoint tendon leading to irritation of the nerves that traverse it.

In patients with nerve injuries, it would be interesting to investigate the role that acupuncture can play in aiding the diagnosis as well as treatment. For instance, in the liver meridian13 there is a point named Yin Lian, which is located on the proximal end of the thigh below the pubic tubercle and on the lateral border of the long abductor muscle of the thigh. When isolated, this point directly targets the genitofemoral nerve. Perhaps, acupuncture points like this one would be able to reproduce symptoms and aid in diagnosis.

Conclusion

Apart from the physical exam, it would be invaluable to have a more effective screening tool for this condition. Since athletes are in constant motion, testing for muscle injury is limited in this population due to the likelihood of elevated creatinine kinase at baseline. Thus, a heavy emphasis is placed on special tests and imaging. With recent advances in imaging, some studies are focusing on the use of MRI in distinguishing soft tissue injury. While this is a promising tool, the importance of a solid musculoskeletal physical exam cannot be overstated. As seen with BH, a physical exam and thorough knowledge of anatomy not only leads to the diagnosis but decreases the health care cost by eliminating unnecessary tests, as well as giving the patient peace of mind with an accurate diagnosis and appropriate treatment.

Last updated on: December 17, 2012
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