Imaging of groin pain in athletes: patterns of injury at MRI and gender differences therein

Abstract

Aim: The purpose of our study was to review a large cohort of athletes of all levels presenting with groin pain who underwent investigation with MRI and to determine what the commonest patterns of injury were. We aimed to explore whether particular findings were commonly found in association and whether measurable gender differences exist in the incidence of specific injuries.

Materials and methods: Imaging records were reviewed to identify MRI studies of the pelvis performed for the investigation of groin pain in patients who were active in sports/athletic pursuits. Findings were classified and recorded as follows: injury to the common rectus abdominis/adductor longus origin, injury to the short adductor muscles, pubic bone oedema, pubic symphysis degenerative changes, hip joint injury and 'other'. The prevalence of specific injuries in female athletes compared to males was analysed using relative risk ratios.

Results: A total of 470 athletes underwent MRI for the investigation of groin pain during the study period. Forty-six were female, and 424 were male. Female athletes were significantly less likely to have rectus abdominis-adductor longus (RR = 0.31, p = .017), short adductor (RR = 0.14, p = .005) or hip (RR = 0.41, p = .003) injuries. Pubic bone degenerative changes were much more common in female athletes (RR = 7.37, p = .002).

Conclusion: Significant gender differences exist in the frequency with which specific injuries are observed. Female athletes are also significantly underrepresented; this is likely a multifactorial phenomenon; however, the possibility of unconscious referrer bias must be considered.

Keywords: Athletic groin pain; Athletic imaging; Femoroacetabular impingement; Groin pain imaging; Sports imaging; Sports medicine.

Fig. 1

Sagittal STIR image of the pelvis in a 32-year-old male athlete demonstrating a tear at the rectus abdominis/adductor longus insertion (white arrow)

Fig. 2

Coronal STIR image of the pelvis in a 26-year-old male athlete demonstrating linear signal intensity along the inferior margin of the superior pubic ramus (white arrow)—this is the superior cleft sign

Fig. 3

Coronal STIR image of the pelvis in a 29-year-old male athlete demonstrating linear signal intensity along the inferior margin of the inferior pubic ramus (white arrow)—this is the secondary cleft sign

Fig. 4

Coronal STIR image of the pelvis in a 21-year-old male athlete demonstrating bone marrow oedema in the pubic bones bilaterally (arrows) spanning the pubic symphysis

Fig. 5

A Coronal T1-weighted image of the pelvis in a 34-year-old male athlete demonstrating subtle protuberance at the femoral head-neck junction (arrow) in keeping with Cam-type impingement morphology. There is associated early degenerative partial-thickness chondrosis at the hip joints. B Axial T2-weighted image in the same patient demonstrating a small left paralabral cyst (arrow) consistent with an underlying labral tear

Fig. 6

A and B Axial STIR images of the pelvis in a 28-year-old female athlete with right groin pain demonstrating oedema along the anterior margins of the right sacroiliac joint (arrows) in keeping with sacroiliitis

Fig. 7

A (coronal STIR) and B (axial STIR) images in a 22-year-old male athlete with right groin pain demonstrate a tear of the right rectus femoris muscle

Fig. 8

Combinations of injuries