Femoroacetabular hip impingement behind sports hernia
MedWire News: A large proportion of athletes with sports hernias also have femoroacetabular impingement (FAI) of the hip on the same side of the body, results of a magnetic resonance imaging (MRI) study show.
The researchers speculate that FAI may alter hip biomechanics leading to increased stresses across the lower abdominals and ultimately to a sports hernia. In addition, they suggest that underlying FAI may be a cause of continued groin pain after sports hernia repair.
"We hope that our study encourages physicians who see sports hernia and chronic groin pain in athletes to further investigate the possibility of FAI and in turn can recommend better treatment options for this puzzling condition," said lead investigator Kostas Economopoulos (University of Virginia, Charlottesville, USA), who presented the findings at the annual meeting of the American Orthopaedic Society for Sports Medicine in Baltimore, Maryland, USA.
Noting that FAI has been shown to change the mechanics of gait, the researchers hypothesized that athletes with underlying FAI may be more prone to develop a sports hernia due to these increased stresses.
They conducted a retrospective review of all 43 patients who underwent surgical treatment for 56 proven sports hernias at their institution from 1999 to 2011. MRI, computed tomography (CT) scans, or X-rays were examined for radiologic signs of FAI.
Economopoulos et al report that 37 (86%) of 43 patients displayed radiographic evidence of FAI. Of the 43 patients, 29 had isolated Cam lesions (67%), two (5%) had isolated Pincer lesions, and six (14%) had combined Cam and Pincer lesions.
Cam lesions were identified in 42 hips (75%) on the ipsilateral side of the hernia and 13 (46%) Cam lesions were found in hips without associated hernia. The average alpha angle of hips on the side of the hernia was significantly higher at 74.98° than the 60.98° of hips without an associated hernia on its side. Pincer lesions were identified in nine (16.1%) of the 56 hernias and in two (7.14%) of 28 hips without associated hernias.
The average acetabular retroversion of hips with associated hernias was significantly higher at 13.17° than the 15.59° of hips without hernias.
"Our study illustrated that those patients with FAI tend to have a change in hip biomechanics which in turn leads to increased stress across the groin. With these stresses a sports hernia (tear to the oblique abdominal muscles), is more likely to occur," said Economopoulos.
By Andrew Czyzewski