Radiological investigations can help in groin pain syndrome diagnosis. Pelvic X-rays highlighting the pubic symphysis are always advisable to rule out possible bone erosion, pubic branch dissymmetry, osteoarthritis (also frequent in young subjects), hip joint pathology, and especially tumors or avulsion fractures [85–87]. It is important to emphasize how through a dynamic X-ray made in alternating monopodalic support, the so-called flamingo views (Fig. 8.1), when a vertical offset greater than 3 mm between the pubic horizontal branches is found, we can make the diagnosis of symphysis instability [44, 88, 89]. Musculoskeletal ultrasound (US) finds its indication in inguinal hernia suspicion. It can highlight edema areas, hematomas (in the case of muscle–tendon tears), myxoid degeneration areas, chondral metaplasia or metaplastic calcification, and fibrosis [30, 90] with the advantage of having the possibility of being carried out in dynamic conditions. This highlights musculofascial movements and, in particular, inguinal bulging (inguinal canal posterior wall weakness). However, US currently falls short in the identification of inflammatory and degenerative bone processes.

Nuclear bone scan is a highly sensitive but nonspecific tool. Every type of symphysis bone lesion of traumatic, tumoral, or infectious etiology would lead to an increased uptake activity at the symphysis level [30, 91, 92]. However, a previous uptake that normalizes after conservative treatment is an important factor which may play a role in making a decision for possible return to sports activity [91, 93, 94].

Magnetic resonance imaging (MRI) is considered the gold standard examination providing detailed information concerning both bone and insertion structures [8, 30, 86, 89]. An MRI groin pain-specific protocol should include sequences covering the entire bony pelvis as well as higher-resolution sequences dedicated to the pubic symphysis region. A relatively outperformed model like a 1.5 T MRI unit is an adequate instrument to generate high-quality images of the pelvis, while a 3 T scanner can offer indubitable advantages in signal and resolution but is also prone to generate more imaging artifacts [95]. Images must be acquired in standard coronal, sagittal, and axial planes; however, it is important to underline that coronal oblique imaging plane performed along the anterior margin of the iliac crest is a very important sequence for optimal assessment of the rectus abdominis/adductor longus common aponeurosis at the pubic level [96]. Some authors proposed the use of intravenous contrast, but its use generally adds little in the identification of lesions, and a non-contrast protocol at 1.5 T can be considered standard [52].

One of the most important advantages in the use of MRI for the assessment of patients affected by groin pain is its high sensitivity for a wide array of both musculoskeletal and visceral lesions that may concur to the symptomatology. In effect, it is not uncommon to discover an unsuspected lesion with pelvic MRI. For these reasons, it is important to include in MRI protocol several large field of view sequences covering the entire bony and visceral pelvis even if there is a strong suspicion for a simple pubic symphysis lesion. In fact, it is not uncommon that the groin pain is caused by bursitis, benign and malignant soft tissue tumors in various locations around the pelvis, visceral pelvis sources such endometriosis and inflammatory bowel disease, osseous injuries such stress fracture, primary osseous tumor such as osteoid osteoma, or scarring and fibrosis related to prior herniorrhaphy. With a deep MRI evaluation protocol, the majority of these lesions should be observed or at least suspected [97].

Concerning the type of exercise, the study with the strongest evidence considers strengthening exercise as the main component of the work plan [80, 98, 99]. Target muscles involved are the adductor, abductor, hip flexor, and deep and superficial abdomen muscles. The progression begins with isometric contractions and continues with concentric and eccentric exercises, reaching the functional standing position. This is to be as similar as to those required by the athlete’s specific sport activity during the last stage of the rehabilitation protocol. Isokinetic exercises should also be present throughout the protocol. Holmich et al. [80] used a predetermined graduated exercise protocol, while many researches adopt the following criteria for exercise progression:

The available evidence suggests that strengthening exercise represents an important component in an effective work plan. However, variability between the different protocols in terms of the muscle concerned does not allow for a conclusion to be reached on the specific target muscle group [80, 98, 99]. Conversely, research shows a uniformity of exercise progression from the isometric modality to be completed by sport-specific functional standing positions.

To the best of our knowledge, only one reliable study may be found in the available literature providing enough detail concerning intervention frequency and duration of exercise [80]. This study suggests a work plan of 90 min of strengthening exercises for the hip and abdominal muscles to be performed three times per week for an overall duration of 8–12 weeks. According to this research, the outcome is good, allowing the athlete to return to sport activities without groin pain.

The duration of conservative treatment is between a minimum of 2–3 weeks [14] and a maximum of 6 months generally [100]. The majority of authors agree on a duration of around 6 months [23, 92, 94, 101–104]. In summary, it is clear that the variation in duration of rehabilitation work plans used reflects the variation in the severity and multifactorial characteristics of groin pain.

In essence, the majority of studies report the use of one or more co-interventions, from manipulation techniques and massages [92, 102–104] to anti-inflammatory [18, 98, 100, 101, 105] and corticosteroid medication [58, 106, 107]. Some studies included jogging, running, and cycling as co-interventions [56, 98, 99, 104]. Furthermore, some studies underline the importance of physiotherapist-supervised exercise programs [56, 99, 102].

As previously discussed, groin pain syndrome may be caused by several pathologies responding to conservative therapy. However, if conservative therapy fails, then a surgical option must be considered. In this final section, we will briefly describe the most common diseases requiring such treatment.

Athletes are susceptible to inguinal (direct and indirect) hernias like the general population and sometimes even more, especially in sports like weightlifting. However, in athletes, direct hernias are more frequent [108]. Real-time dynamic US during a provocative maneuver, such as Valsalva, may help visualize a subtle hernia possibly causing symptoms only during sport activity and otherwise difficult to detect. The risk of complications such as bowel incarceration and strangulation is not an issue in this case; it is impossible to participate in sports due to pain. This is why in most cases posterior wall weakness of the inguinal canal are surgically repaired [109].

Even though surgical treatment is successful in the large majority of cases, one should bear in mind the possibility of surgical complications and, in some cases, the inability to achieve prior levels of athletic performance [52]. It has been proposed that this variability in surgical repair outcome is occasionally due to the increasing stabilization of the pubic region because of progressive fibrosis [52]. However, patients with inguinal hernia have little chance of success with conservative treatment [52, 110]. After herniorrhaphy, an average of 87 % of the athletes have a positive outcome and are able to return to full and unrestricted athletic activity in 4 weeks or less [29, 110, 111].

Sports hernia, also known as sportsman’s hernia, athletic hernia, and incipient hernia, represents a difficult clinical problem [112].

The diagnosis of sports hernia is formulated when no inguinal hernia is found but there is persistent inguinal pain during sports activity. The symptoms resemble an hernia and are present only during sport. We must also point out that some authors underline that sports hernia is often associated with femoroacetabular dysplasia and/or femoroacetabular impingement [113].

There also is no hernia present on physical examination and ultrasound, hence the term sports hernia (Fig. 8.2). Sports hernias rarely improve without surgery [11, 114–118], and surgical repair should be considered when conservative treatment over a period of 6–8 weeks has failed. Careful examination has to additionally exclude other potential pain sources [112, 119].

Some authors propose laparoscopic repair with prosthetic mesh [120, 121]. This “tension-free” technique involves placing prosthetic material suitably shaped, non-absorbable, and biocompatible. This acts as mechanical reinforcement of the abdominal wall [120, 121]. However, the mesh has no elasticity and creates more scar tissue, and mesh-related complications can occur years after surgery. Another laparoscopic method used for the treatment of sport hernias is inguinal release procedure [122]. After laparoscopic repair, the recovery before full return to competition is generally between 2 and 8 weeks [110, 115, 119, 123–128].

Some authors prefer open surgical inguinal repair: Shouldice repair, Maloney darn, or Bassini with or without adductor longus tenotomy or only the “minimal repair” of the weak area of transversalis fascia [14, 129, 130]. In a meta-analysis study [119], the authors found that the period of time to return to sport is on average 17.7 weeks for patients who underwent open approaches and 6.1 weeks for laparoscopic repairs. Several authors underline mesh-related complications such as infections with chronic groin infection and fistula formation. These complications sometimes require mesh removal [131] or cause mesh migration and penetration into the bladder or bowel [132, 133]. In addition, a foreign body reaction with decrease of arterial perfusion and testicular temperature [134] accompanied by secondary azoospermia may occur [134, 135].

It is interesting to note that Muschaweck et al. [112, 130] after previously utilizing the Shouldice repair under local anesthesia for years, in 2000 developed a new surgical technique called the “minimal repair technique.” The aim of this surgical intervention was to stabilize the posterior wall by a tension-free suture without the use of a prosthetic mesh and by repairing only the weak spot of the transversalis fascia. The authors chose to avoid the use of a prosthetic mesh to allow the athlete’s full elasticity and muscle sliding between the abdominal muscles after surgery [112]. According to some authors, opinions regarding this technique apart from avoiding prosthetic mesh insertion have several advantages. These include not requiring general anesthesia, less traumatization, and a lower risk of severe complications. The authors underline a quicker resumption of sports activity following this surgical technique compared to the laparoscopic or open surgery with mesh insertion. They report that on average their patients resumed moderate training after 7 days and felt complete relief of pain after 14 days. Return to full activity was achieved after 18.5 days [112].

With the increase of knowledge of the pubic symphysis’ complex anatomy, the incidence of isolated adductor tension lesion has seemingly decreased [96]. In any case, adductor tendinopathy is one of the most common causes of groin pain syndrome in athletes in athletes and is most often associated with either rectus abdominis/adductor longus aponeurosis lesions or midline pubic plate lesions (i.e., lesions originate at the midline of the pubis and propagate either unilaterally or bilaterally, also called “midline core muscle injuries”). One of the main causes of groin pain syndrome is the imbalance between the abdominal and hip adductor muscles, with the abdominals too weak or the adductors too strong [5]. Adductor tendinopathy is frequently related to an adductor longus overuse or to its aponeurotic injury [136]. A vast majority of patients respond positively to conservative treatment, both in the case of overuse tendinopathy or in muscle–tendon injury. There are not many scientific papers on failed conservative treatment on chronic adductor-related groin pain [137]. Adductor tenotomy is proposed for cases nonresponsive to conservative treatment [5, 136–139]. The criteria for surgery is a history of long-standing (ranging from 3 to 48 months according to various authors) and of distinct pain at the origin of the adductor longus muscle, refractory to conservative treatment. The operation is performed by releasing the anterior ligamentous fibers of the adductor longus while keeping the fleshy part of the muscle intact on the deep aspect, thus minimizing the loss of adductor strength after surgery and constituting a template for future regrowth of the tendon. In the patients undergoing tenotomy, there is an average of 10 % postoperative strength reduction which does not result in any obvious functional or speed limitation because other muscles in the adductor group, namely, adductor brevis, adductor magnus, and pectineus, take over adductor longus function [140]. In the reported studies [129, 136, 137], the subjects returned to competitive sport after 19.8 weeks (range 27–14 weeks). The cited studies report that following surgery, 70.6 % of the subjects (range 90–62 %) performed sport activities at the same level, 24 % (range 32–9 %) performed sports activities at a reduced level, and 5 % had to stop sport activities altogether. It is interesting to note that some authors associate the adductor tendon release to a pelvic floor repair [45, 141].

Surgically treated adductor acute tears are rarely described in scientific literature. We could find only one study [138] reporting three cases of acute proximal adductor longus insertional tear repaired with anchor sutures and followed by postoperative rehabilitation. The patients followed in this study resumed their full sport ability after 5, 6, and 7 months, respectively.

Osteitis pubis is a common medical problem in soccer players, long-distance runners, and hockey players. In terms of etiology, the main risk factor is believed to be pubic symphysis instability [52]. This causes a chronic, repetitive shear and an imbalanced tensile stress of the muscles inserted on the pubic symphysis. This biomechanical alteration can cause an inflammatory response with osteitis and periostitis.

Normally, from a radiological point of view, into the MRI pubic symphysis evaluation, any subchondral bone marrow edema, bony sclerosis, or cystic or osteophytic formation is termed osteitis pubis. This type of assessment is not entirely correct. In effect, a true active osteitis pubis should include at least an element of subchondral bone marrow edema (often asymmetric) spanning the pubis joint anterior to posterior on axial fat-suppressed sequence (Fig. 8.3). This bone marrow edema extending into the anteroposterior totality of pubic rami should be distinguished from sub-entheseal marrow edema at pubic tubercle level sometimes present in a rectus abdominis and/or adductor longus tendinopathy without osteitis pubis at the symphysis [96, 142]. It is in any case important to note that osteitis pubis is strongly associated with rectus abdominis and/or adductor longus tendinopathy [96]. Osteitis pubis is normally a “self-limiting” disease and requires a lengthy treatment of 12-month duration on average [105]. The management is initially conservative with physical rehabilitation, NSAID, and/or steroid injections. The historical surgical treatment options were symphysis curettage and arthrodesis and are now abandoned by the majority of surgeons. This is due to the lack of results and frequent side effects. In most cases, adductor tenotomy/surgical abdominal strengthening is reserved for the subjects with symptoms nonresponsive to conservative treatment [52, 107].