Friday, April 25, 2008

Moises Alou's Problem Rooted in Pain

Outfielder Moises Alou is about to make his return to the Mets. He is recovering from surgical repair of a sports hernia. A what? A sports hernia occurs when there is a weakening of the muscles or tendons of the lower abdominal wall. This part of the abdomen is the same region where an inguinal hernia occurs, the inguinal canal. When an inguinal hernia occurs there is sufficient weakening of the abdominal wall to allow a pouch, the hernia, to be felt. In the case of a sports hernia, the problem is due to a weakening in the same abdominal wall muscles, but there is no palpable hernia.

The predominant complaint of athletes with a sports hernia is unilateral groin pain, though bilateral pain may also occur. The pain is usually noted during exercise, but if the patient continues to exercise with pain, it may occur during other activities. The onset is typically insidious, but in a third of cases the athlete may describe a sudden tearing sensation.

Insidious onset is often described by runners, while sudden onset is more common in ice hockey and soccer players. Athletes who present with an insidious onset often say their pain occurs at lower thresholds of activity as they continue to train or compete. The pain is most typically well localized to the conjoined tendon but may involve the inguinal canal laterally. A significant number of athletes describe pain in the abductor region and occasionally in the perineum or testicles.

The pain is most often unilateral but may be felt bilaterally. It is common for athletes to describe symptoms, unresponsive to conservative treatment, that have been present for a number of months. The pain increases with sudden movements, acceleration, twisting and turning, cutting, and kicking, and it may be provoked by coughing and sneezing.

By definition, a clinically detectable hernia is not present, so the physical findings of a sports hernia are often subtle. In an athlete who has stopped training or competing, the only physical sign might be a tender, dilated superficial inguinal ring on the affected side. Examination for this entity in males is done by inverting the scrotum with the little finger. Local tenderness over the conjoined tendon, pubic tubercle, and mid inguinal region is common and may be exacerbated by resisted sit-ups. A small cough impulse may be detected by an experienced physician but is not diagnostic. Physical exam results are often complicated by multiple pathologies, particularly adductor tendonopathy.

Ekberg, in a prospective, multidisciplinary evaluation, found that 19 of 21 athletes who had pain for longer than three months had two or more separate pathologies. The authors suggested that an adequate explanation of an athlete's symptoms might require several diagnoses. In addition, Lovell found that 27 percent of his study's 189 athletes who had chronic groin pain also had multiple pathologies; in those found to have a sports hernia, 26 percent had a secondary diagnosis. Identifying any coexisting pathologies is important in an effective management plan.

The inguinal canal, which carries the spermatic cord in males and the round ligament in females, is a passage about four centimeters long that runs obliquely downward and medially parallel to and just above the inguinal ligament. The anterior wall of the canal consists of the external oblique aponeurosis and the internal oblique muscle. The posterior wall is formed by the fascia transversalis, which is reinforced in its medial third by the conjoined tendon, the common tendon of insertion of the internal oblique and transversus, which attaches to the pubic crest and pectineal line. The superficial inguinal ring lies anterior to the strong conjoined tendon.

Disruption to the conjoined tendon is a feature of the operative findings presented by the majority of authors. Gilmore describes a disruption to the groin characterized by three surgical findings: 1) a torn external oblique aponeurosis causing dilatation of the superficial inguinal ring; 2) a torn conjoined tendon; and 3) a dehiscence between the torn conjoined tendon and the inguinal ligament, constituting the major injury.

Hackney found a weakening of the transversalis fascia with separation from the conjoined tendon in all of his 16 cases. Simonet, et al, found tears in the internal oblique muscles in the 10 elite ice hockey players studied. Malycha and Lovell describe an incipient direct inguinal hernia with an associated bulge in the posterior inguinal wall extending anteriorly in 80 percent of cases in their series of 50 athletes.

Yet another pathology is proposed by Williams and Foster, who present a less complex disruption involving a small tear in the external oblique aponeurosis at the site of emergence of the terminal branches of the anterior primary rami of the iliohypogastric nerve. These findings reflect a spectrum of injury to the inguinal canal in athletes who have persistent groin pain.

Other researchers suggest that these injuries occur because adductor action during sporting activity creates shearing forces across the pubic symphysis that can stress the posterior inguinal wall. Consequent repetitive stretching of, or a more intense sudden force to, the transversalis fascia and the internal oblique can lead to their separation from the inguinal ligament. This mechanism may also account for the common finding of coexisting osteitis pubis and adductor tenoperiostitis in these patients.

There are no diagnostic tests that can be used to detect a sports hernia. The diagnosis is made by the patient's history and physical examination. Radiographic investigations are important in diagnosing the sports hernia, principally to exclude coexisting pathologies with overlapping symptoms. Plain radiographs may demonstrate osteitis pubis, adductor tenoperiosteal lesions, symphyseal instability (demonstrated by flamingo views), hip osteoarthritis, and bone tumors.

A bone scan can be helpful in making a diagnosis of active osteitis pubis, tenoperiosteal lesions, and stress fractures. Two studies have suggested the usefulness of herniography in diagnosing a hernia in athletes with unexplained groin pain. Intraperitoneal injection of radio-opaque contrast followed by filling of the peritoneal sacs enables an assessment of the integrity of the posterior inguinal wall and inguinal canal.

Smedberg et al, described the sensitivity of herniography in detecting true direct and indirect herniation; however, hernia or weakness of the posterior inguinal wall was also found in half of the asymptomatic groin sides.

Fricker suggests that in these cases, given the natural history of the condition, bilateral repair may be appropriate. Such a view is controversial and needs further evaluation. Many authorities do not routinely use herniography in clinical practice because its effectiveness in detecting sports hernias has not been clearly demonstrated. In addition, clinicians generally do not favor its use because of its low specificity and potential morbidity. Finally, a negative herniographic result in the face of strong clinical suspicion should not be a contraindication to surgical exploration. Dynamic ultrasonography may be the best noninvasive method to demonstrate posterior wall defects.

But could the symptoms be due to something else? As has already been suggested, a range of musculoskeletal conditions may mimic the sports hernia, including osteitis pubis, adductor tendonopathy, stress fracture of the pubic rami, and ilioinguinal or obturator neuropathies. Osteitis pubis is characterized by local tenderness of the symphysis, and a bone scan typically shows increased uptake on the delayed views of either or both margins of the symphysis. Bone scanning will also confirm most diagnoses of pelvic or hip stress fracture. The pain seen with adductor pathology is usually localized to the area of injury and provoked by resisted adduction.

There are no treatments that have been shown to be effective for sports hernia other than surgery. That said, the initial treatment of a sports hernia is always conservative in hopes that the symptoms will resolve. Resting from activity, anti-inflammatory medications, ice treatments, and physical therapy can all be tried in an effort to alleviate the patient's symptoms.

If these measures do not relieve the symptoms of a sports hernia, surgery may be recommended to repair the weakened area of the abdominal wall. Because of the lack of objective findings on physical examination and the absence of a definitive diagnostic test for sports hernia, surgery is often considered only after a trial of nonoperative treatment. However, conservative treatment is rarely effective, while surgery appears to be beneficial.

In patients strongly suspected of having coexisting pathologies that contribute to functional disability or whose coexisting pathologies are not clearly diagnosed, a trial of conservative treatment is appropriate. In patients whose symptoms strongly suggest a sports hernia as the sole pathology, particularly in the professional athlete, surgery should be considered at an early stage.

In number of studies have shown between 65 percent and 90 percent of athletes are able to return to their activity after surgery for a sports hernia. Rehabilitation from surgery for a sports hernia usually takes about eight weeks. While the diagnosis and surgical repair of clinically detectable direct and indirect inguinal and femoral canal hernias are well described, the disruption seen in the sports hernia is less well understood. Familiarity with inguinal canal anatomy may clarify some of the pathophysiologic causes of the sports hernia. Awareness of typical patient history and physical examination findings and appropriate radiographic studies can help physicians select patients for surgery.

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