The 'Sports Hernia': A Common Cause of Groin Pain
Simon Kemp, MB, BS; Mark E. Batt, MB, BChir
THE PHYSICIAN AND SPORTSMEDICINE - VOL 26 - NO. 1 - JANUARY 2021
In Brief: Athletes who participate in sports that require repetitive twisting and turning at speed, such as soccer or ice hockey, may be at risk of developing a 'sports hernia'—disruption of the inguinal canal without a clinically detectable hernia. Insidious onset of unilateral groin pain is the most common symptom. Concurrent pathologies, such as osteitis pubis and adductor tenoperiostitis, may complicate diagnosis. Plain radiographs and a bone scan can aid differential diagnosis, but herniography is not recommended. Surgery is the preferred treatment. Structured rehabilitation should enable athletes to return to sports activity 6 to 8 weeks after surgery.
Injuries to the groin may constitute 5% of all sports injuries (1) in male and female athletes and are particularly common among male and female soccer players, 28% of whom have a history of groin pain in some series (2). Particularly in male athletes, causes of groin pain without a clinically detectable hernia are increasingly ascribed to disruptions to the inguinal canal, especially in cases resistant to conservative treatment. These disruptions are often termed "sports hernia," "sportsman's hernia," or "athletic pubalgia."
Little has been published on the prevalence of this condition among athletes, but Lovell (3) found sports hernias during surgery in 50% of 186 male athletes—the study included 186 males and 3 females—who had had groin pain lasting longer than 8 weeks. The condition has occurred in athletes in a wide range of sports but appears to be particularly common in activities requiring repetitive twisting and turning movements at speed. These include soccer, ice hockey, field hockey, tennis, and Australian rules football. It has also been infrequently reported in women (4,5), who describe tenderness at the site of the superficial inguinal ring. This infrequency may be a result of either the limited female participation in the sports previously studied, such as soccer, ice hockey, and Australian rules football, or the gender differences in the anatomy of the inguinal canal. This article largely focuses on male athletes.
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.
A Spectrum of Pathology
The inguinal canal, which carries the spermatic cord in males and the round ligament in females, is a passage about 4 cm long that runs obliquely downward and medially parallel to and just above the inguinal ligament (figure 1). 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 (4) 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 (5) found a weakening of the transversalis fascia with separation from the conjoined tendon in all of his 16 cases. Simonet et al (6) found tears in the internal oblique muscles in the 10 elite ice hockey players they studied. Malycha and Lovell (7) describe an incipient direct inguinal hernia with an associated bulge in the posterior inguinal wall extending anteriorly in 80% of cases in their series of 50 athletes. Yet another pathology is proposed by Williams and Foster (8), 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.
Researchers suggest (5,6) 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.
A Complete Diagnosis
History. The predominant complaint of athletes with a sports hernia (table 1) 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 (4). Insidious onset is often described by runners (5), while sudden onset is more common in ice hockey (6) and soccer players (4). 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 adductor 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 (9). The pain increases with sudden movements, acceleration, twisting and turning, cutting, and kicking, and it may be provoked by coughing and sneezing.
Physical exam findings. 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 midinguinal 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 et al (10), in a prospective, multidisciplinary evaluation, found that 19 of 21 athletes who had pain for longer than 3 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 (3) found that 27% of his study's 189 athletes who had chronic groin pain also had multiple pathologies; in those found to have a sports hernia, 26% had a secondary diagnosis. Identifying any coexisting pathologies is important in an effective management plan.
Radiographic studies. 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 (11,12) 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 (13) 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 (14) 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.
We do not routinely use herniography in our 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.
In the future, dynamic ultrasonography may be the best noninvasive method to demonstrate posterior wall defects (15).
Differential diagnosis. 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. (For more information on differential diagnosis, see "Managing Groin Pain: Even When the Cause Is Not Obvious," November 1995, page 54.)
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.
There are a variety of surgical techniques, most of which are minor variations of standard hernia repair. Gilmore (4), however, describes a modified herniorrhaphy with plication of the transversalis fascia and emphasizes the importance of a repair of the conjoined tendon, with reattachment to the pubic tubercle and inguinal ligament. Williams and Foster (8) describe a less complex repair involving approximation of the torn edges of the external oblique aponeurosis. Treatment of this condition in women involves excision of the round ligament and closure of the inguinal canal.
Rates of surgical success, defined as a full return to preinjury activity levels, have been reported to be 63% (16), 72% (5), 80% (17), and 93% (7). However, none of these studies was a randomized, controlled trial. Eighty percent of the athletes in these series who were not cured by surgery may have had alternative or additional treatable diagnoses (18), which suggests the importance of identifying and treating overlapping diagnoses before surgery.
Specific rehabilitation that avoids sudden, sharp movements should enable athletes to return to sports participation within 6 to 8 weeks of surgery. All aspects of pelvic flexibility, strength, and stability should be addressed throughout this period. Athletes should begin isometric abdominal and adductor exercises on the first day after surgery, increasing the number of sets and repetitions during the first week and then progressing to a concentric and eccentric strengthening program. They should begin walking during the first week after surgery and progress to jogging by day 10. Straight-line sprinting is encouraged from day 21, and the subsequent introduction of sport-specific exercises should enable a full return to sport after 6 to 8 weeks of rehabilitation. Overlapping conditions should also be addressed, and coexisting osteitis pubis or adductor tendonopathy may indicate a more gradual return to athletic activity (19).
Since preventing this condition is easier than treating it, prevention should be considered for those who are at risk, especially those whose sports involve repetitive twisting and turning movements at speed. Soccer and ice hockey players are at increased risk of a number of injuries to the groin, particularly to the adductor muscles, pubic symphysis (osteitis pubis), and inguinal canal (sports hernia). Pelvic and hip inflexibility, instability, or imbalance may contribute to the development of these conditions and consequently should be the focus of screening in the preparticipation examination.
Unfortunately, strategies for prevention are currently conjectural. However, since osteitis pubis and sports hernia may have similar causes (20), exercises used for preventing osteitis pubis may also help athletes avoid a sports hernia. Such exercises should increase the flexibility and strength of muscles arising from and acting across the pubic rami and should emphasize their symmetrical conditioning. Particular attention should be paid to the strength and flexibility of the hip flexors, abductors, adductors, abdominals, and pelvic stabilizing muscles. Functional, controlled closed-chain strengthening and improvement of pelvis stability should also be emphasized.
Dr Kemp is a lecturer in sports medicine at the University of Nottingham, England, and a team physician to the English Basketball team. Dr Batt is a senior lecturer and honorary consultant in sports medicine at the University of Nottingham. Drs Kemp and Batt are members of the British Association of Sports Medicine and the American College of Sports Medicine. Dr Batt is a charter member of the American Medical Society for Sports Medicine. Address correspondence to Simon Kemp, MB, BS, Centre for Sports Medicine, Dept of Orthopaedic and Accident Surgery, Queens Medical Centre, Nottingham, NG7 2UH, United Kingdom; address e-mail correspondence to [email protected].
Copyright (C) 192021. The McGraw-Hill Companies. All Rights Reserved