Conjoint Tendon

Formerly referred to as the inguinal aponeurotic falx, the conjoint tendon is a structure located at the bottom section of the internal abdominal oblique’s common aponeurosis and the Transversus Abdominis, when it enters into the crest of the pectineal line and the pubis, just behind the shallow inguinal ring. It is normally conjoint with the internal oblique abdominal muscle tendon, but it is also possible for them to be detached. The conjoint tendon forms the medial section of the inguinal canal’s posterior wall.

The conjoint tendon acts as a protective layer to that section of the abdominal wall which is usually weak. Weakening or defects of the conjoint tendon can trigger or aggravate a direct inguinal hernia.

Direct inguinal hernia tends to project out from the Hesselbach’s triangle, bordered within the inferior epigastric vein and artery, the rectus abdominus, and the inguinal ligament, superolaterally, medially, and inferiorly respectively. This is different from an indirect inguinal hernia which laterally projects out from the inferior epigastric artery and typically occurs due to problems in closing of the deep inguinal ring during the embryonic stage.

Conjoint tendon: Structure and Functions

The conjoint tendon can be describe as a layer of connective tissue which connects the pelvis to the transversus abdominis, the deepest of the 4 muscles of the abdomen. The name gets its origin from its structure which is often conjoined or continuous with eth internal oblique tendon, another important muscle in the abdomen. The muscles of the abdomen tend to end just above the pelvis’ pubic crest. The conjoint tendon in association with the tendons of the external oblique muscles and the rectus abdominus form a continued part of the fibrous tissue that connects the pelvis to the abdominal wall and thus protects the internal organs. It also forms a part of the inguinal canal’s upper border.

The conjoint tendon is a paired bodily structure which begins on both sides of the lower abdomen at the lower section of the transversus abdominus muscle. It occurs slightly inside and runs almost parallel to the inguinal ligament, a strap of connective tissue which stretches diagonally from the iliac crest present on the upper part of each hip bone towards the middle of the pubic bone. The conjoint tendon was previously considered as aponeurotic due to the presence of all of transversus abdominis muscle fibers that finish as a band of connective tissue referred to as an aponeurosis. This aponeurosis runs down the midline of the muscled abdomen and forms the inside or medial border of the muscle and tapers near the end point of the muscle at the pelvis, eventually inserting into the tendon.

Due to the curved shape of the tendon, the conjoint tendon was also previously considered as ‘falx,’ a Latin word which means sickle. The tendon combines with fibers from the lower part of the internal oblique muscle and as it descends it bends inwards, obliquely crossing toward the pubic bone. It inserts next to the crest of the pubis, the onward-extending curve occurring on both pubic bones where they connect ion the center to form a joint called the pubic symphysis. The conjoint tendon also connects to the pectineal line which is a ridge present along the public bone’s upper border.

The conjoint tendon is one of the many fibrous tissues that fill up the space present in the pelvis’ anterior wall and its main function it to protect the soft tissue and organs occurring inside the area. However, the tendon also features a weak spot on the abdominal wall called Hesselbech’s triangle, thereby increasing the risk to the development of a direct inguinal hernia.

Symptoms of direct inguinal hernia

Some of the signs and symptoms of direct inguinal hernia associated with the conjoint tendon are as follows:

• Pain in the abdomen flanks/sides
• Pain in lower abdomen
• Pain in groin.
• Inflammation of muscles and joints of the upper thighs and lower abdomen.
• Testicle pain in affected men
• Severe and prolonged pain when sneezing, coughing, or engaging in physical strenuous activities and sports.

Treatment of direct inguinal hernia

Treatment of direct inguinal hernia associated with conjoint tendon is dependent on the severity of the condition.

• Pain killers and other medications may be given for pain alleviation.
• Patient will be advised bed rest for about 4 weeks without any strenuous physical activity. It is followed by physical therapy which involves stretching of the lower extremity and lower abdominal muscles, strengthening of the main core muscles, and increasing flexibility of the tendons. Physical therapy is mainly aimed at correcting the imbalance between the muscles that drive into the pubic bone.
• In severe cases, surgery may be required. Surgery is followed by an extensive rehabilitation process. Recovery is dependent on the severity of the condition and the patient’s response to the surgery and ensuing physical therapy.