MRI case–control studies
| Study | Cunningham et al(2007) | Robinson et al(2004) | Zoga et al(2008) | Brennan et al(2005) | Verrall et al(2001) | Paajanen et al(2008) |
|---|---|---|---|---|---|---|
| Case-study group participants (incl. sports type, gender, age) | 100 athletes (soccer) 95 Male, 5 Female. Age: 17–38 | 52 athletes (35 soccer, 13 rugby, 4 athletics), of whom 27 previous surgery 51 Male, 1 Female. Age 17–36 | 141 patients (127 athletes: 41 American football, 23 soccer, 15 running, 14 hockey, 34 others) 134 Male, 7 Female. Age 17–71 | 18 athletes (15 soccer, 3 rugby) Male. Age 19–32 | 89 athletes (Australian football) Male. Age 17–33 | 16 athletes (13 soccer, 1 cross-country skier, 1 runner, 1 ice-hockey) 14 Male, 2 Female. Age 22–38 |
| Controls | 100 athletes (50 rowers, 50 soccer) Sex unknown. Age :18–28 | 6 athletes (5 soccer, 1 rugby) Male. Age 17–37 | 25 (physical activity unknown) Male. Age 18–39 | 70 athletes (rowers) Male, Age 17–34 | Group 1: 17 distance runners Group 2: 10 sedentary men | 20 athletes (10 soccer, 10 ice-hockey)Male. Age 19–27 |
| Inclusion criteria | Cases: Debilitating groin pain and symptoms and signs at pubic symphysis Controls: Asymptomatic, hip pain and pain from sacroiliac joints | Cases: Groin pain>3 months Controls: no groin symptoms or injury, no groin surgery | Cases: Patients referred with diagnoses ‘athletic pubalgia” and ‘sports hernia” Controls: Asymptomatic | Cases: Patients referred with suspicion of groin injury Controls: Asymptomatic | Cases: recruited at end of pre-season after 6 weeks intensive training Control 1: age-matched, min. 6 weeks intensive training Control 2: no prior history of groin pain, no physical exercise within 6 weeks, age-matched | Cases: Osteitis pubis (established by exclusion of other groin disorders, typical clinical history and signs, pelvic radiographs isotope bone scan and MRI) Controls: Asymptomatic |
| Exclusion criteria | Cases: Sports hernia at clinical examination before referral Controls: groin pain | Cases: Acute groin injury, insufficient clinical and surgical details available | Cases: Inadequate MRI of pubic region. Images older than 120 days from time of physical examination | Not described | Not described | Cases: Inguinal hernias, iliopsoas and abdominal muscle-related pain. chronic prostatitis.tendinitis of the groin, bursitis or hip disorders |
| Clinical findings (1) type of examination (2) findings | (1) Not described (2) Groin pain for average of 3 months | (1 and 2) Not described | (1) Not reproducible but details given (2) 93 positive for rectus abdominis tendon lesion, 15 for adductor compartment lesion,71 for both, 16 for osteitis pubis (not defined) | None | (1) Not reproducible but details given (2) 52 athletes positive for current groin symptoms and signs (tenderness on palpation of symphysis and superior pubic rami) | (1) Not described (2) All cases have tenderness of pubic symphysis >3 months. 3 cases with adductor-type pain on palpation |
| Diagnostic entity used by authors | Osteitis pubis | Adductor dysfunction | Athletic pubalgia | Osteitis pubis | Osteitis pubis | Osteitis pubis |
| Radiology protocol (1) Field strength (2) Sequences | (1) 1.5T (2 )Coronal T1& STIR, axial T2 | (1) 1.5T (2) Coronal: T1& STIR, axial T2. Oblique axial: T1, T2 FatSat, T1Fatsat postgadolinium | (1) Cases: various (117 at 1.5T, 2 at 3.0T, 16 at 0.2–0.3T, 6 at 0.6–0.7T) Controls: 1.5T (2)Protocols not defined | (1) 1.5T (2) Cases: coronal T1 and STIR, axial T2 Controls: coronal STIR only | (1) 1.5 and 1.0 T (2) Coronal and axial:T1 and T2 FatSat | (1) 1,0 T (2) Coronal and axial: T1 and STIR |
| Additional radiologic examinations | None | None | None | Pelvic radiographs Fluoroscopy-guided injection of contrast in symphyseal joint | None | Pelvic radiographs and isotope bone scan |
| Evaluation of MRI scan | 2 Radiologists blinded to side of symptoms. Diagnosis by consensus. Presence of secondary cleft sign Degenerative changes at symphyseal joint | 2 Radiologists blinded to clinical details. Diagnosis by consensus BMO (graded 0–2) Degenerative changes at symphyseal joint Musculotendinous structures of the groin & abdominal wall Graded at 1 and 2 reading (0–2) | 3 Radiologists blinded to clinical details. Diagnosis by consensus BMO (not graded) Osteitis pubis (BMO with degenerative changes at symphyseal joint) Abnormal rectus abdominis and adductor tendons Presence of secondary cleft sign | 2 Radiologist: 1 blinded and 1performing fluoroscopy-guided injections.Diagnosis by consensus Presence of secondary cleft sign BMO (not graded) Degenerative changes at symphyseal joint | 2 Radiologists blinded to clinical details. Diagnosis by consensus BMO (graded 0–3 and extent>2 cm) Degenerative changes at symphyseal joint Abnormal conjoint tendon Inguinal hernia | 2 Radiologists blinded to clinical details. Diagnosis by consensus BMO (graded 0–3) Degenerative changes at symphyseal joint Abnormal conjoint tendon Abnormal adductor enthesis |
| Reproducibility of radiology | None | Interobserver agreement | None | Interobserver agreement | None | None |
| ‘Gold standard’ used | Injection of contrast in pubic symphyseal cleft to demonstrate secondary cleft sign (CSG only) | None | Physical examination in 141 cases Surgery in 102 cases | Fluoroscopy-guided injection of contrast in symphyseal joint | None | Surgery in 8 patients not responding to conservative treatment of groin pain |
| Conclusions/results | Secondary cleft sign in 48.8%, osteitis pubis in 9% of cases. Both in 43%. Secondary cleft sign and BMO only present in cases but not controls. | Abnormal anterior pubis and enthesis enhancement correlates significantly with clinical side of symptoms All other abnormal imaging findings show no correlation with clinical side of symptoms | Positive MRI findings in 138 cases: Secondary cleft sign in 66 cases, BMO in 63 cases. MRI sensitivity 68% and specificity 100% for rect. abdom., 86% and 89% for adductor lesions compared to surgery | Secondary cleft sign identified with 100% sensitivity and specificity on MRI and fluoroscopy. Present in 12 cases. Secondary cleft sign corresponds to side of symptoms | 72% of athletes (62 cases and 8 runners) have pubic BMO. 62% of those (47 cases and 5 runners) have current groin pain and symptoms at clinical exam | The difference in BMO in the 3 groups (surgical, conservative and control) is not statistically significant, although grade 3 oedema is not found in asymptomatic controls |
BMO, bone marrow oedema.