Posterior wall of the inguinal canal and ilioinguinal nerve entrapped
Another anatomic structure responsible for pain is the genital branch of the genitofemoral nerve which can be compressed by bulging of the posterior wall of a weak or incompetent inguinal canal, including laceration of the transverse fascia with protrusion of the preperitoneal fat. This condition may be associated with increased size of the angle of convergence between the insertion of the rectus muscle along with the conjoint tendon and the inguinal ligament resulting in an enlarged external inguinal ring. In addition, an alteration of the confluence between this tendon and the adductor muscle may be present, observing a fibrosis of these structures in chronic forms above the pubic crest.
In current reports [10–12], there is a discussion about the biomechanical alterations determined from “femoroacetabular impingement (FAI)”, in particular cam type, and development of sports hernia.
The frequent association of these diseases should make us reflect on which disease starts first; in any event, there is an agreement on the treatment of both after a multidisciplinary evaluation.
12.2 Symptomatology and Physical Findings
Pain develops during or at the end of exercise or the day after the game. It is usually unilateral but occasionally bilateral and is located above the projection of the inguinal ligament to the lower lateral edge of the rectus abdominis muscle and often radiating to the scrotum (30%) and the proximal region of the thigh that is along the path of the adductor longus. Pain persists after a game and is accompanied by a difficulty in getting out of bed during the next 2 days.
The onset is insidious; it subsides with rest and reappears with sports activity return. The player is not able to kick with a combined movement of hip extra rotation. Pain is exacerbated by movement that involves sudden twisting and acceleration of the torso, by sneezing and coughing .
Clinical examination starts with the patient standing upright; occasionally, a slight bulge in the groin is observed. The simple palpation of the inguinal area above the pubic insertions of conjoint rectal muscle generally doesn’t elicit pain.
The exploration through the scrotum (Fig. 12.2) reveals a dilated superficial inguinal ring due to the external oblique aponeurosis and/or conjoint tendon tear.
Exploration through the scrotum with enlarged external inguinal ring
The thrust of the explorer finger will cause a deep and sharp pain enhanced by a crunch movement. If the patient coughs during this manoeuvre, you can feel a weak impulse of the posterior wall of the inguinal canal, and when a dislocated or entrapped nerve is found, the pain may continue even after the exploration (Fig. 12.1). This is a specific hallmark. To confirm the origin of pain, it is possible to make a lido test with the injection of local anaesthetic medially to the superior anterior iliac spine . The immediate but temporary resolution of pain can help in differential diagnosis.
In order to exclude other associated diseases, you must carry out some semiological manoeuvres. The frequent association with cam FAI may be hypothesized with positive impingement test.
The pressure exerted on the pubic symphysis should suggest an osteitis. A positive squeeze test can highlight insertional lesions of the adductor muscles .
12.3 Instrumental Diagnosis
Dynamic ultrasound examination is certainly the most accessible but highly operator-dependent procedure . An excellent knowledge of normal and pathologic groin anatomy is required. The examination may show macroscopic injuries of the conjoint tendon and of the aponeurosis of oblique external muscle. The lesions of the posterior wall of the inguinal canal are distinguished by a moderate and convex bulging associated with tear of the transversalis fascia and very small protrusions of peritoneal fat (Fig. 12.3). The picture is of an incipient direct inguinal hernia. The image capture is performed starting from the baseline condition, during a sit-up or when asked to contract the abdominal muscles (Valsalva). The local innervation and its course cannot be shown by ultrasound, but this is the area where we find entrapment or compression of the ilioinguinal nerve during open surgery. MRI is an examination of high diagnostic accuracy for muscle and tendon injuries; it allows us to define many associated diseases. It is required in second line to define more complex situations such as hip pathologies and pubis osteitis. The test is also made in basal condition and during Valsalva [17–19].
Tears of the transversalis fascia and protrusion of peritoneal fat and nerve compression
The athlete’s history helps us to decide between a conservative and surgical treatment. The acute onset of symptoms suggests a conservative approach with anti-inflammatory therapy and rest. The specific physiotherapy required to redress the balance between the abdominal muscles, rectum and external oblique, internal and transverse and the most powerful adductor muscles will have to continue for a period of 8–12 weeks, depending on the severity of injury. The difference in the competitive level will have to be considered in choosing treatment. After 12 weeks, if there are still conditions for not playing a match, surgical treatment is called for. Although symptoms mainly refer to one side, it is preferable to operate on both sides in order to restore fair distribution of lines of force.
Surgical techniques proposed in the treatment derive from those used in traditional surgery for hernias [20, 21]. The open techniques with or without the mesh implant (Figs. 12.4 and 12.5) are designed to reconstruct the transversalis fascia, to reduce the angle between conjoint tendon and inguinal ligament and in strengthening the internal inguinal ring (Fig. 12.6). The association of a decompression or neurolysis of ilioinguinal and genitofemoral nerves and more rarely of iliohypogastric nerve depends on their anatomical position in the context of the injury observed. The observation is possible only with open repair techniques.