Research Review By Dr. Shawn Thistle©

Date Posted:

Jan. 2009

Study Title:

Sports hernia: A systematic literature review

Authors:

Caudill P, Nyland J, Smith C, Yerasimides J, Lach J

Author's Affiliations:

Division of Sports Medicine, Department of Orthopedic Surgery, University of Louisville, Kentucky, USA.

Publication Information:

British Journal of Sports Medicine 2008; 42: 954-964.

Background Information:

The incidence of groin pain among professional athletes overall is estimated to be 0.5-6.2%. Due to the nature of their sports, soccer and hockey players injure this area at a higher rate. To illustrate, injury data from the National Hockey League indicates that 13-20 groin injuries occur each year per 100 players(1) – this represents a significant problem. At any given time, most NHL fans could name 2-3 top players that are out of action because of a “groin injury”.

Injuries to this area can be anatomically complex, and difficult to diagnose and treat. They can also be chronically disabling for the athlete, and pose a significant threat to lucrative sporting careers.

The term “sports hernia” has recently been popularized in the media, despite the poorly defined nature of this injury. The anatomical culprits and general terminology used to define this injury varies widely. Some experts believe this is the most common cause of groin pain in athletes, while others consider it very rare.

This review paper attempted to clarify this oft-confusing injury by summarizing the existing literature on the pathogenesis, differential diagnosis, conservative treatment, and post-surgical rehabilitation of sports hernias.

Pertinent Clinical Details:

The actual definition of a sports hernia remains controversial. Many sources define it as a bulge or incipient posterior inguinal wall hernia that leads to lower abdominal or groin pain and loss of inguinal canal integrity, without the presence of a true hernia. Additional descriptions have included abnormalities of the rectus abdominus (RA), partial avulsion of the internal oblique (IO) muscle from the pubic tubercle, tearing within the IO itself, and abnormality of the external oblique (EO) muscle and aponeurosis.

All of these problems could weaken the inguinal wall or ring. The authors of this review suggest that the most succinct definition may be: “…the phenomena of chronic activity-related groin pain that is unresponsive to conservative therapy and significantly improves after surgical repair.” [pg. 954]

In general, the etiology of chronic groin pain normally falls into one of 4 categories:
  1. adductor longus dysfunction
  2. osteitis pubis
  3. sports hernia
  4. hip pathology (femoroacetabular impingement, capsule or labral injuries, chondral defects)
Characteristics of Sports Hernia
  • in general, this injury occurs more frequently in men (most commonly in their 20s), but it can and does occur in women
  • patients are normally involved in sports requiring cutting, pivoting, kicking, and sharp turns
  • normally the pain is insidious, gradually worsening, diffuse, unilateral, located in the groin, and may radiate to the medial upper thigh or perineum
  • pain with athletic activity or sport-specific movements is considered necessary for this diagnosis
  • pain radiates across the midline into the scrotum and testicles in approximately 30% of cases
  • pain is aggravated by sudden movements, Valsalva/sneezing/coughing, resisted sit-up/trunk flexion or hip adduction
  • many patients will present with multiple pathologies (see differential diagnosis section below)
Pathogenesis of Sports Hernia
  • chronic groin injury car arise from repetitive strain/overuse, increased shear forces across the hemipelvis, loss of dynamic stability of the abdominal wall and spinal stabilizing musculature, and deficiencies in hip/leg muscle strength, coordination, and functional balance
  • excessive shear forces can occur when the adductor muscles contract to stabilize a planted leg – this can weaken or disrupt the IO or transversalis fascia attachments to the inguinal ligament
  • reduced hip internal/external rotation ROM has been associated with chronic groin injury and also with transversalis fascia and conjoined tendon attenuation – it is theorized that the pubic symphysis has to accomplish more rotational/torsional movement when hip motion is deficient, which may initiate a sports hernia
  • strength imbalances are thought to contribute to the development of sports hernias – particularly overdeveloped/strong adductors in conjunction with weak lower abdominal musculature
  • due to the proximity of numerous anatomical structures, it is likely that sports hernias often coexist with other injuries
Differential Diagnosis

Before arriving at a diagnosis of sports hernia, the prudent clinician must investigate thoroughly for the following conditions:
  • referred pain from hip pathologies such as synovitis, bursitis, snapping hip syndrome, femoral head avascular necrosis or slipped epiphysis, femoral neck stress fracture, OA/rheumatoid arthritis
  • lumbosacral strain
  • iliolumbar ligament injury
  • sacroiliac joint pathology
  • entrapment of the ilioinguinal, obturator, genitofemoral, or lateral femoral cutaneous nerves
  • pubic bone stress reactions, osteitis pubis
  • ”true” hernias
  • prostate, gynecological, urinary tract problems, etc.
Clinical Examination

The following elements are reported to be consistently found in patients with “sports hernias”:
  • inguinal canal tenderness
  • dilated superficial inguinal ring
  • pubic tubercle tenderness
  • hip adductor origin tenderness
The following pain provocation tests are recommended when investigating for this condition:
  1. have the patient squeeze their knees together while supine with knees bent 90° and hips flexed 45°
  2. have patient squeeze their feet together while supine with 30° of hip flexion and slight adduction and internal rotation of the hips
  3. FABER or quadrant tests
It is important to note that sufficient clinical efficacy data for these tests (sensitivity/specificity and predictive values) does not yet exist. These recommendations are based primarily on expert opinion and case series analysis.

Diagnostic Imaging
  • imaging is generally used to rule out other conditions, rather than to identify a sports hernia
  • standard radiographs may reveal pubic symphysis widening or erosion and other skeletal pathologies
  • bone scan and/or CT may effectively rule out stress fractures
  • MRI may effectively identify soft tissue injury, and provides the best detail for imaging this area
  • MR arthrography could be considered in patients with numerous positive clinical tests
  • diagnostic ultrasound may represent the best choice as it permits dynamic assessment of the area

Clinical Treatment & Rehabilitation:

Although the success rate of conservative treatment for sports hernias is considered to be low, manual therapists in all disciplines can play an important role in the identification, treatment, rehabilitation, and prevention of this injury. Specific methods of treating this injury using manual methods have not been sufficiently studied to make concrete recommendations. There are however, some practical principles that can be applied to this patient population:
  • conservative treatment generally begins with 6-8 weeks of rest
  • this is followed by a progressive program consisting of resistance exercise for hip adductors in combination with flexibility and core stability training; this progresses to sport-specific movement patterns and gradual return to play – this process can take 10-12 weeks depending on the severity of the initial injury
  • treatment and early rehabilitation is often accompanied by a course of NSAID medication
  • electro-therapeutic modalities have not been sufficiently studied for this condition
Post-Surgical Rehabilitation
  • early, sharp sudden motions must be avoided
  • Week 1: isometric abdominal and hip exercises, walking increased by 5min/day and stair climbing
  • Week 2: active hip exercises, stationary cycling and basic TrA core stability
  • Week 3: flexibility work, resistance band/tubing hip exercises, active core work, jogging and swimming
  • Week 4: forward running, progressive resistance core work, light upper body exercise
  • Week 5: sprinting, multi-directional running, ball skills, kicking, continue core progression, gradual return to sport
  • Week 6: unrestricted exercise and return to sport
Off-Season Training Implications
  • it has been suggested that poorly designed off-season strength and conditioning programs may facilitate groin damage and sports hernias by overdeveloping leg strength while neglecting integrated core and lower abdominal stability – adductor strains occur 20x more frequently in the preseason in NHL players, supporting this theory
  • programs should focus on progressive core stabilization and pelvic ring stability in conjunction with resolution of hip muscle strength and extensibility imbalances
  • there is some evidence that hockey players with groin injuries have weaker hip adductors than those without: strengthening of this group can be achieved with exercises such as sumo squats, side lunges, sliding board movements (skating simulator), ball squeezes, “on ice” kneeling “pull togethers”, slide skating, combined angle lunges with overhead unilateral arm motions

Study Methods:

A comprehensive Medline literature search was conducted to identify relevant studies. Review articles and case series were included in this review, as they form the bulk of the literature on this topic. 104 papers were retrieved and included in this review.

Additional References:

  1. Emery CA, Meeuwisse WH, Powell JW. Groin and abdominal strain injuries in the National hockey League. Clinical Journal of Sports Medicine 1999; 9: 151-156.