Brought to you by
ECR 2015 / C-2375
Athletic pubalgia: a detailed didactic approach
This poster is published under an open license. Please read the disclaimer for further details.
Congress: ECR 2015
Poster No.: C-2375
Type: Educational Exhibit
Keywords: Athletic injuries, Education, Diagnostic procedure, Ultrasound, MR, CT, Musculoskeletal system, Musculoskeletal soft tissue, Anatomy
Authors: A. Corazza, A. Arcidiacono, S. Perugin Bernardi, R. Sartoris, D. Orlandi, E. Silvestri; Genoa/IT
DOI:10.1594/ecr2015/C-2375

Findings and procedure details

 

1. IMAGING

 

 

A combined MR-US approach allows a detailed investigation of the anterior pelvis and groin. High-resolution ultrasound is an effective technique to accurately identify tendinopathies and muscle tears; in addition, dynamic evaluation adds several important information about biomechanics of the superficial structures around the pubic symphysis and can be also very helpful to exclude the presence of a true inguinal hernia, during a valsalva manoeuvre. The only disvantage of the ultrasound examination is the inability to demonstrate inflammatory and degenerative bony processes. A high-resolution ultrasound system with high-frequency probe (7-15 MHz) was used.

 

MR is currently considered optimal for the simultaneous assessment of osseous and soft tissue structures. 1.5 Tesla MR of the anterior pelvis with surface coils were performed; T1- and T2-weighted turbo-spin-echo (TSE) sequences were obtained, oriented along the three orthogonal planes.

 

Knowledge of the basic anatomy and imaging appearance of the musculoskeletal structures around the pubis is essential for the correct assessment of their injuries in symptomatic athletes.

 

 

 

 

 

2. NORMAL ANATOMY

 

 

PUBIC SYMPHYSIS

 

The pubic symphysis is an amphiarthrosis, a joint with a limited range of motion, composed of the two pubic bones, the interposed articular disk and four ligaments ( Fig. 1 ). There is no true joint capsule.

 

The pubic bone consists of three portions:

 

  • the body articulates with the contralateral pubic bone by meaning of a quite irregular surface, covered by hyaline cartilage that is in very close contact with the fibrocartilaginous disk. It houses the pubic crest which arises from its medial upper margin and the pubic tubercle, an osseous process laterally located, on which the inguinal ligament attaches. From the pubic tubercle arises the pecten, a ridge that crosses the superior pubic ramus up to the arcuate line.
  • the superior pubic ramus contributes to the formation of the the anterosuperior portion of the acetabular fossa and the obturator foramen. The junction with the ilium is called iliopectineal eminence.
  • the inferior pubic ramus forms the anteroinferior part of the obturator foramen.

 

The articular disk and four ligaments are the most important stabilizers of the joint.

 

  • the articular disk is a fibrocartilaginous absorber interposed between the two pubic articular surfaces particularly important in dissipating axial and shear forces applied to the joint, together with the superior and inferior pubic ligaments.
  • the superior pubic ligament is a bundle of collagen fibres that runs on the superior surface of the symphysis connecting the two pubic tubercles ( Fig. 2 ).
  • the inferior pubic ligament (or arcuate ligament) is a thick fibrous band tense along the inferior margin of the joint. Some fibres blends superiorly with the articular disk and  inferiorly with the aponeuroses of the gracilis and the adductor longus muscles.
  • the anterior pubic ligament consists of a deep layer that merges with the articular disk ( Fig. 3 ) and a superficial layer that blends with the aponeurosis of the rectus abdominis and the external oblique muscles.
  • the posterior pubic ligament is a thin bundle composed of few transversely oriented fibers, located on the posterior surface of the symphysis.

 

The most important functions of the pubis symphysis in athletes are:

 

-       to stabilize the anterior pelvis (limited degree of motion);

 

-      to protect the joint from injuries during walking and running (the wide contact surface of the joint allows a good distribution of the shear forces during movements and the two pubic rami transmit compressive forces generated at the symphysis to the ilium and ischium bones).

 

 

 

 

MUSCLES

 

A number of different muscles insert on and around the pubic symphysis, sharing similar mechanisms of injury and common clinical manifestations.

 

 

 

Rectus abdominis muscle

 

Proximal Origin: V, VI, and VII costal cartilage, inferior margin of the xiphoid process, costoxiphoid ligaments.

 

Muscle belly: superficially located in the anterior abdominal wall, near the linea alba ( Fig. 4 a,b,c); it is three times wider at the proximal origin from the lower rib cage than at the attachment on the pubis (this fact may contribute to the greater frequency of rectus injuries near the pubic symphysis).

 

Distal insertion: consists of a medial tendon, that inserts on the anterior pubic body (it merges with the anterior pubic ligament), and a lateral tendon, that attaches on the pubic crest and tubercle; the two components form a continuous fibrous band and they are not clearly observable ( Fig. 5 ). The distal attachment of the rectus abdominis muscle blends together with the proximal tendon of the adductor longus muscle to form a common fibrous aponeurosis that broadly attaches to the periosteum of the anterior aspect of the pubic body and that likely merges with the anterior pubic ligament and the interpubic disk ( Fig. 6 ). This common aponeurosis is located in close relationship with the superficial inguinal ring.

 

Function: the most important for maintaining the stability of the anterior pelvis (together with the adductor longus muscle); it provides muscle tone to the ventral abdominal wall, especially during straining; flexion of the trunk; antagonist to the diaphragm during respiration.

 

Innervation: lower costal and subcostal nerves (from the caudal six or seven thoracic nerve roots).

 

Vascularization: inferior epigastric arteries, subcostal artery, posterior lumbar arteries and deep circumflex iliac artery.

 

 

 

External oblique abdominis muscle

 

Proximal Origin: external surfaces and inferior borders of the V to XII ribs.

 

Muscle belly: the largest and the most superficial of the flat muscles of the lateral and anterior abdominal wall ( Fig. 7 ). It continues in a broad aponeurosis that occupies the anterior wall of the abdomen and takes part to the formation of the inguinal canal inferiorly ( Fig. 8 ).

 

Distal insertion: iliac crest, pubic tubercle, linea alba.

 

Function:  rotation of the trunk; pull the chest downwards and compression of the abdominal cavity (valsalva maneuvre); limited actions in both flexion and rotation of the vertebral column.

 

Innervation: ventral branches of the lower six intercostal nerves and subcostal nerve on each side.

 

Vascularization: lower intercostal arteries (cranial portion), deep circumflex iliac artery and iliolumbar artery (caudal portion).

 

 

 

Internal oblique abdominis muscle

 

Proximal Origin: dorsolumbar fascia of the lower back, anterior 2/3 of the iliac crest, lateral half of the inguinal ligament.

 

Muscle belly: the muscle belly is located deep to the external oblique and just superficial to de transverse oblique muscles. The muscle fibres are perpendicular oriented to that of the external oblique muscle.

                                                                                                             

Distal insertion: pecten pubis (via a conjoint tendon with the transversus abdominis muscle), inferior borders of the X through XII ribs, linea alba.

 

Function: antagonist to the diaphragm during respiration, same side rotation of the trunk (it acts with the external oblique muscle of the opposite side to achieve this torsional movement).

 

Innervation: lower intercostal nerves (VI-XI), subcostal nerve (XII) iliohypogastric nerve and ilioinguinal nerve.

 

Vascularization: subcostal arteries.

 

 

 

Transversus abdominis muscle

 

Proximal Origin: Iliac crest, inguinal ligament, thoracolumbar fascia, costal cartilages VII-XII.

 

Muscle belly: it is so called for the direction of its fibers, the deepest of the flat muscles of the abdomen, located immediately beneath the internal oblique muscle.

                                                                                                               Distal insertion: xiphoid process, linea alba, pubic crest and pecten pubis (via conjoint tendon with the internal oblique muscle).

 

Function: compression of the abdominal content providing thoracic and pelvic stability

 

Innervation: lower intercostal nerves (VI-XI), subcostal nerve (XII) iliohypogastric nerve and ilioinguinal nerve.

 

Vascularization: subcostal arteries.

 

 

 

Adductor longus muscle

 

Proximal Origin: anterior margin of the pubic body, below the pubic crest (common aponeurosis with the rectus abdominis muscle) ( Fig. 9 ). The proximal tendon lies in close proximity to that of the gracilis muscle (Fig. 10).

 

Muscle belly: the most superficial of the three adductor muscles ( Fig. 11 ), it lies lateral to the gracilis muscle, posterior and medial to the pectineus muscle (at the proximal third of the thigh) and deep to the sartorius, vastus medialis, vastus intermedius muscles (at the reminder two distal thirds).

 

Distal insertion: middle third of the femoral linea aspera.

 

Function: adduction of the thigh and also hip flexion and internal rotation.

 

Innervation: anterior branch of the obturator nerve (from the L2, L3, and L4 nerve roots).

 

Vascularization: adductors artery (from the deep femoral artery), femoral artery, medial femoral circumflex artery and descending genicular artery.

 

 

The adductor longus muscle is most often injuried at its proximal myotendinous junction; being the  blood supply relatively poor, at this level the tendon is less able to resist strain and repair itself. In particular, tears initially involve the anterior fibres, better developed than the posterior ones (more directly attached to the bone).

 

 

 

Adductor brevis muscle

 

Proximal Origin: anterior pubic body, inferior pubic ramus.

 

Muscle belly: it is located just below the external obturator muscle, posterior to the pectineus and adductor longus and anterior to the adductor magnus muscles ( Fig. 12 ).

 

Distal insertion: inferior 2/3 of the pectineal line, superior medial ½ of the femoral linea aspera cranial to the adductor magnus muscle.

 

Function: adduction of the thigh and also hip flexion and internal rotation.

 

Innervation: obturator nerve (from the L2 and L3 nerve roots).

 

Vascularization: adductors artery (from the deep femoral artery, medial femoral circumflex artery and obturator arteries.

 

 

 

Adductor magnus muscle

 

The large triangular belly of the adductor magnus muscle, deep located in the medial thigh ( Fig. 13 ), is composed of two components with different origins and functions.

 

 

 

Adductor portion

 

Proximal Origin: lower margin of the inferior pubic ramus (ischiopubic ramus).

 

Muscle belly:  this fibres are more anterior and more horizontally oriented.

 

Distal insertion: gluteal tuberosity (medial to the insertion of the gluteus maximus muscle), medial femoral linea aspera, medial supracondylar line.

 

Function: adduction of the thigh and also hip flexion and internal rotation.

 

Innervation: obturator nerve (from the L2, L3, and L4 nerve roots).

 

Vascularization: deep femoral artery, medial femoral circumflex artery and popliteal vessels (posterior blood supply).

 

 

 

Ischiocondylar (or hamstring) portion

 

Proximal Origin: ischial tuberosity.

 

Muscle belly: this fibres are vertically oriented.

 

Distal insertion: adductor tubercle of the medial femoral condyle.

 

Function: adduction of the thigh and also hip extension.

 

Innervation: tibial division of the sciatic nerve.

 

Vascularization: deep femoral artery, medial femoral circumflex artery and popliteal vessels (posterior blood supply).

 

 

 

Gracilis muscle

 

Proximal Origin: symphysis pubis (anterior aspect), inferior pubic ramus.

 

Muscle belly: the most medial muscle, it lies medial to the adductor longus and brevis and anterior to the adductor magnus muscles ( Fig. 14 ).

 

Distal insertion: proximal anteromedial tibia (pes anserinus).

 

Function: adduction of the thigh, minor role in hip flexion and internal rotation, and also knee flexion.

 

Innervation: obturator nerve (from the L2 and L3 nerve roots).

 

Vascularization: adductors artery (from the deep femoral artery).

 

 

 

 

Pectineus muscle

 

Proximal Origin: pubic tubercle, superior pubic ramus (pecten pubis), portion of the iliopectineal eminence.

 

Muscle belly:  the rectangular belly overlies the adductor longus and brevis muscles ( Fig. 15 ).

 

Distal insertion: femoral pectineal line (between the lesser trochanter and linea aspera).

 

Function: adduction of the thigh and also knee flexion.

 

Innervation: femoral nerve (ventral portion), accessory obturator nerve (dorsal portion).

 

Vascularization: medial femoral circumflex artery and lesser contributions from obturator and femoral arteries.

 

 

 

 

 

3. BIOMECHANICS AND MECHANISM OF INJURIES

 

 

The complex anatomy of the pubic symphysis, with its interrelated muscle attachments located in close proximity to one another, reflect the complex biomechanics of this region. The intimate relationship of this tendons produces complex interactions between the forces exerted through the muscles across the pubic symphysis.

 

During rotation and extension from the waist, the rectus abdominis muscle and the adductor longus muscle act as antagonists of one another. In physiological conditions, contraction of the rectus abdominis muscle produces posterior-superior traction of the pubic region with consequent elevation of the pubis ( Fig. 16 ). In contrast, the adductor longus muscle pulls down the pubis, applying an anterior-inferior force. The balance of this tangential opposed forces applied to the common aponeurosis is crucial for anterior pelvis stability.

 

An injury to one of the two tendons predisposes the opposing one to degeneration and tearing by both altering the biomechanics (repetitive unbalanced contractions) and interrupting the anatomic contiguity of the tendon insertions. The resulting instability of the pubic symphysis may produce not only lesions in other tendons around the pubis but also an inflammatory response, with osteitis and periostitis.

 

In many athletes tendon injuries are unilateral and sometimes can cause frank disruption of the rectus abdominis–adductor longus aponeurosis from its pubic attachment. Moreover, the lesion may extend into the pectineus and adductor brevis proximal insertion, or may propagate across the midline to involve the contralateral common aponeurosis.

 

Unbalanced stress on the abdominal wall muscles can produce a weakness of the posterior wall of the inguinal canal but the detection of a true palpable hernia is rare.  Hernia-like symptoms may be related to the proximity of the injury site to the medial margin of the superficial ring of the inguinal canal or to lesion extension through the superficial inguinal ring.

 

 

POSTER ACTIONS Add bookmark Contact presenter Send to a friend Download pdf
SHARE THIS POSTER
2 clicks for more privacy: On the first click the button will be activated and you can then share the poster with a second click.

This website uses cookies. Learn more