Sportsmans Groin: The Inguinal Ligament and the Lloyd Technique

Groin pain is a catch all phrase used to define a common set of symptoms that affect many individuals. It is a common condition affecting sportsmen and women (1, 2) and is often referred to as the sportsman groin (SG). Multiple surgical operations have been developed to treat these symptoms yet no definitive imaging modalities exist to diagnose or predict prognosis. This article aims to discuss the anatomy of the groin, suggest a biomechanical pathophysiology and outline a logical surgical solution to treat the underlying pathology. A systematic clinical and imaging approach with inguinal ligament and pubic specific MRI assessment, can result in accurate selection for intervention. Close correlation with clinical examination and imaging in series is recommended to avoid misinterpretation of chronic changes in athletes.


Imaging Diagnosis
Specific magnetic resonance imaging (MRI) protocols have been reported as useful in the diagnosis of groin related pathology in athletes [14]. Recently, the use of MRI in the diagnosis of groin pain and adductor related pathology has been challenged [15,16], possibly due to the risk of misinterpretation of chronic imaging changes in asymptomatic athletes. These studies include changes in various anatomical structures and assess a multitude of MRI findings in the various groin anatomical structures. Inclusion of the hip and femoro-acetabular impingement is a major confounding factor in the diagnostic predictive value of MRI, sometimes leading to early and often unnecessary surgical intervention [18].
Very few studies have focused on the pubis and its attached structures, assessing the utility of clinical and MRI findings. A recent large prospective cohort study of athletes, using both specific clinical and MRI protocols and patient reported outcome measures, found the posttest odds ratio of clinical examination with MRI, conducted in series, increased as much as 6-fold [17]. Falvey, et al. termed this attachment the pubic aponeurosis (PA), which was described as a common confluence of the rectus abdominus and the adductor origin, without mention of the inguinal ligament. Using this definition, the presence of pubic bone marrow oedema was strongly related to the site of pain in their large cohort (p < 0.001).
No study so far focused specifically on the inguinal ligament and its relationship to site-specific bone marrow oedema. The imaging characteristics of the medial portion of the inguinal ligament and its pubic enthesal attachment were not specifically assessed.
Specific findings with inguinal ligament pathology are the morphology of the medial entheses of the inguinal ligament and site-specific bone marrow oedema of the pubis A band or cord like inguinal ligament maybe seen at surgery or on MRI imaging (Figure 3a, b, c).

Biomechanics and Surgical techniques
In sports with lower limb centric rotational movements, specifically football with repeated pivoting forces with the lower limb in external rotation and extension, the vectors on the pubis may be out of balance. In this position, the inguinal ligament along with the pubic synchondrosis, provides a stabilising force, when significant pulls by the adductor and secondarily the rectus abdominus occur, when kicking the ball. Adductor tendinopathy is a commonly recognised injury as a part of the sportsman groin. Gilmore, initially popularised the concept of pain in this region as the Gilmore's groin. Whereas, his repair focused mainly on a torn external oblique, conjoined tendon, as many as 40% of sportsmen may have an adductor or rectus tear [6]. Procedures that repair the attachments in this region with reattachment of the adductor tendon attachment, have been proposed by Meyer, et al. after diagnosis using a combination of clinical and MRI findings [7].
The inguinal ligament release technique described by Lloyd, et al. in 2008, was developed to specifically treat athletes with tenderness on the pubic tubercle at the attachment of the inguinal ligament. The procedure is performed laparoscopically whereby the inguinal ligament is divided and released from the pubic bone and the groin reinforced with a mesh. The operation is similar to a standard laparoscopic inguinal  hernia repair. In addition, any scar tissue or sutures from previous surgery are removed, any thickening of the pectineus fascia is released and if thickened, the lateral few millimetres of the rectus sheath insertion, divided [9]. Studies have reported more than 90% of athletes return to full fitness levels, at a four-week follow up following the procedure [10].

Differential Diagnosis
MRI is useful in the assessment of structures that produce groin related symptoms. In the hip, psoas bursitis and tendinopathy can present with groin related symptoms. MRI can demonstrate hyperintense T2 signal within the tendon at its insertion, mucoid changes in the bursa or feud within the bursa. Trochanteric bursitis can be differentiated with Ultrasound and MRI as a cause of symptoms which can sometimes be more central in location. Athletes involved in throwing sport can also present with central midline pain at the pubis related to strain of the rectus abdominus or related to strains of the oblique muscles of the abdomen-a side strain injury. This can be assessed on high resolution MRI imaging and graded accordingly.
It is important to distinguish hip articular and bone related pathology such as stress fractures and femeroacetabular impingement. These can be assessed using a combination of radiographs and MRI. Postoperatively, neuromas of the ilioinguinal and genitofemoral nerves, seromas and mesh related pathology can be assessed using ultrasound. The post-operative integrity of the mesh can be dynamically assessed using ultrasound (US). Infection though rare primarily, as a cause of groin symptoms, can occur after interventions such as injections or postoperatively and imaging with MRI and US are helpful in its detection.

Conclusion
SG Pain is a common condition affecting more than 5% of athletes involved in kicking or twisting sports. The abdominal core muscles play a pivotal role in the cause of SG as their forces are transmitted through the inguinal ligament onto the pubic tubercle. The inguinal ligament release technique with additional mesh repair is a procedure specifically developed to treat the target lesion and allow early return to sport. A systematic clinical and imaging approach with inguinal ligament and pubic specific MRI assessment, can result in accurate selection for intervention. Close correlation with clinical examination and imaging in series is recommended to avoid misinterpretation of chronic changes in athletes.