Pelvis, Hip and Groin 235 Pelvis, Hip and Groin 15 Wayne Gibbon and Ernest Schilders CONTENTS Box 15.2. Conventional radiography ● 15.1 Introduction 236 The value of conventional radiographs resides is their ability to rapidly, simply and inexpen- 15.2 Anatomical Considerations 237 sively demonstrate acute bony injury, late stress 15.3 Osteitis Pubis 242 injury to bone, arthropathy and coincidental 15.3.1 Symphyseal Stress Injury 242 osseous condition e.g. primary and secondary 15.3.2 “True” Osteitis Pubis 246 bone tumours and skeletal infection 15.4 Pubic Osteomyelitis 248 ● Stress radiographs are of limited value for 15.5 Stress Fractures 249 assessing pelvic instability 15.6 Hip Joint Dysfunction 251 15.7 Sacroiliac Joint Dysfunction 252 15.8 Entheseal Injury 252 Box 15.3. Computed tomography 15.9 “Sportsman’s Hernia” 256 ● 15.10 Parasymphyseal Muscle Tears 256 The indications for CT in athletes with pelvic, hip and groin pain are limited but include bony 15.11 Iliopsoas Tendinopathy 258 abnormalities at complex anatomical sites such 15.12 Nerve Entrapment 259 as the sacroiliac joints, diagnostic confi rmation 15.13 A Unifying Concept for of specifi c local conditions e.g., myositis ossifi - Groin Pain in Athletes 260 cans circumscripta and causes of referred pain 15.14 Conclusion 261 to region e.g., lumbar spondylolysis Things to Remember 261 References 262 Box 15.4. Ultrasound ● Sonography is able to demonstrate acute and Box 15.1. Magnetic resonance imaging chronic tendon injury, defi ne the extent of muscle tears and correlate imaging abnormali- ● This is probably the fi rst line investigation for ties with site of anatomical tenderness most causes of pelvic, hip and groin pain in ● athletes due to its high anatomical detail and Ultrasound is also useful in studies requiring a ability to demonstrate a wide range of osseous dynamic component e.g., Valsalva Manoeuvre and soft-tissue pathologies for functionally assessing hernias, conditions where Colour or Power Doppler imaging may ● Conventional MR imaging acts as a “water map” be helpful e.g., hip synovitis and for guiding a for demonstrating bone marrow and soft-tissue range of percutaneous diagnostic and thera- edema whereas fat-suppressed contrast enhanced peutic procedures studies demonstrate hyperaemia and therefore acts as a surrogate market for infl ammation ● Intra-articular contrast may be helpful in dem- W. Gibbon, MD, PhD, Professor onstrating conditions such as hip labral tears E. Schilders, MD 18th Seventh Ave, St. Lucia, Brisbane Q 4067, Australia 236 W. Gibbon and E. Schilders Table 15.1. The differential diagnosis of groin pain 15.1 1. Muscle tear Introduction a) Adductor group – adductor longus – adductor brevis – gracilis Chronic hip, groin and pelvic pain are major causes b) Rectus femoris of morbidity in professional and elite athletes and c) Rectus abdominis these problems are often inter-related. Groin injuries d) Oblique/tranversalis (inferior portions) are the commonest cause of chronic injury in a wide d) Hamstring group range of sports, especially football. Depending on e) Sartorius f) Ilio-psoas which published data is chosen they constitute up to 2. Tendinitis or tear 27% of injuries in soccer (Ekstrand and Gillquist a) Adductor origin – adductor longus 1983), 12% in American Football (Moretz et al. 1978), – adductor brevis 11.3% in rugby (Hornof and Napravnik 1969) and – gracilis 6.6% in Australian-rules football (Seward et al. 1993). b) Rectus femoris c) Ilio-psoas In soccer players, groin injuries tend to be associated 3. Bone or apophysis avulsion with a prolonged recovery and 50% of players with a) Adductor origin groin pain will have symptoms that persist for more b) Anterior inferior iliac spine/apophysis than 20 weeks after initial injury (Nielsen and Yde c) Ischial apophysis d) Anterior superior iliac spine/apophysis 1989). Therefore, as they constitute 55% of overuse e) Lesser trochanter/apophysis injuries, the impact on a team’s performance is great 4. Bursitis (Fifa 1992). a) Ilio-pectineal Great diagnostic diffi culties exist refl ecting the fact b) Ilio-psoas that the causes of groin pain are protean (Table 15.1) 5. Pubic symphysitis/osteitis pubis 6. Pubic osteomyelitis and also possibly refl ecting clinical prejudice. In one 7. Stress fracture study reviewing the case-notes of 189 athletes with a) Inferior pubic ramus chronic groin pain, 27% were found to have multiple b) Parasymphyseal pathologies (Lovell 1995). One possible explana- c) Femoral neck tion for the diagnostic confusion could be that there 8. Entrapment neuropathy a) Ilio-inguinal nerve neuralgia may indeed be more than one diagnosis in many b) Obturator neuralgia athletes. However, this confusion could also be due c) Genito-femoral causalgia to the fact that many of the diagnoses are anatomi- 9. Hip pathology cally and/or biomechanically linked. Consequently, a) Osteoarthrosis adequate treatment requires the addressing of more b) Slipped capital femoral epiphysis Holmich 10. Inguinal lymphadenitis than one of these clinical conditions ( et 11. Hernia al. 1999) and, therefore, medical imaging has a most a) Direct inguinal important role in patient management, i.e. in defi n- b) Indirect inguinal ing as precisely as possible the underlying injury and c) Femoral disease processes. d) Obturator e) Spigelian The problem of groin pain in athletes is not a 12. Genito-urinary new one. Pierson (1929) was probably the fi rst to a) Orchitis describe chronic stress injury to the symphysis pubis b) Prostititis or “osteitis pubis” in 1929. He termed the condition c) Scrotal trauma/haematocele osteochondritis of the symphysis pubis which indeed d) Low renal calculus 13. Haematoma better refl ects the articular nature of the injury. Spi- a) Direct blow nelli described osteitis pubis in athletes as early as b) Tear of inferior epigastric artery (Rectus sheath) 1932 (Spinelli 1932). This condition has also been 14. Referred pain termed dynamic osteopathy (Losada and Saldias a) Spine – spondylolysis 1968) and tenosteochondrosis of the pubis, refl ecting – Scheuermann’s disease – high lumbar disc prolapse the dynamic nature of the condition and the inter- b) Sacro-iliac joint – instability relationship of bone, joint and tendon aetiological – sacro-iliitis components (Rosenklint and Anderson 1969). – osteoarthrosis Subchondral trabecular fracture as a cause for groin 15. Acute abdominal/pelvic viscus infl ammation 16. Idiopathic pain in athletes was reported by Williams in 1978. Pelvis, Hip and Groin 237 Pubic symphyseal osteomyelitis was fi rst described in noses made by 5 specialists (general surgeon, ortho- an athlete in Adams and Chandler (1953) and the paedic surgeon, urologist, nuclear medicine physi- differentiation between infl ammatory osteitis pubis cian and radiologist), in 21 athletes complaining of and low grade pubic osteomyelitis has remained a unexplained chronic groin pain. These investigators diagnostic problem in athletes ever since. found that in 90% of cases more than one diagnosis Probably the fi rst description of adductor muscle was made and in 14% of cases the specialists made injuries in athletes was in ten-pin bowlers in Hoon four or more different diagnoses for each patient. (1959). Wiley was the fi rst investigator in the English The authors concluded that “the fi nal diagnosis (and literature to associate traumatic osteitis pubis with treatment) often refl ects the specialty of the doctor abnormalities of the gracilis tendon origin in 1983. and as a result alternative causes of groin pain are This single case report described the signifi cant histo- overlooked”. Further clinical investigation in ath- pathological fi ndings seen in the excised tissue at the letes, who are not cured by hernia repair, will pro- gracilis enthesis. These included a mixture of viable duce an alternative treatable diagnosis in more than and non-viable bone fragments, extensive fi brosis and 80% of cases, most of which are subsequently cured an absence of infection, suggesting a chronic traction by addressing the more latterly diagnosed condition. phenomenon at the osseotendinous junction inferior Conversely, adductor origin symptoms often subside margin of the symphysis pubis. Although this was the following hernia repair. Therefore, the mechanism for fi rst record of the condition in the English literature, adductor origin injury appears to be linked in some it had been described 20 years earlier in the German way to that of the “pre-hernia complex”. It could be literature (Schneider 1963). Wiley in his report also implied from these results that the actual diagnosis commented on the fact that avulsion of the gracilis made in athletes with groin pain refl ects clinical prej- tendon origin is associated with concurrent avulsion udice (Fredberg and Kissmeyer-Nielsen 1996) of the ligamentous support of the inferior region of and that greater recognition of the interlinked nature the symphysis and avulsion of bony fragments at the of the different conditions is required. edge of the pubis (Wiley 1983). This infers a rela- tionship between the stability of the symphysis and tendinous avulsion. Pelvic adductor syndrome as a cause of groin pain in footballers was fi rst postulated in Reideberger et al. (1967), rectus abdominis ten- 15.2 dinopathy in Martens et al. (1987) and adductor Anatomical Considerations longus tendinopathy in Akermark and Johansson (1992). There are a signifi cant number of errors is the clas- Carnevale (1954) described a condition, he sical description of the soft tissue attachments to termed inguinocrural pain in footballers, which was the pubic bodies (Fig. 15.1). In only 3% of groins probably an early description of the “sportsman’s does a conjoint tendon representing the fused infero- hernia”, i.e. an imminent, but non-palpable, direct medial aponeuroses of internal oblique and transver- inguinal hernia. This has subsequently been thought sus abdominis actually insert into the pubic tubercle to be a common cause of unexplained chronic groin and adjacent pubic crest as is classically described.