Groin pain is a common symptom that occurs in both physically active people and the general population. The causes can be diverse and range from muscular problems to nerve irritation to serious hip joint diseases. Often, the hip is overlooked as the origin of the complaints, although hip pathologies are frequently responsible for groin pain. In this comprehensive blog post, we will explain the anatomical structure of the hip joint in detail, highlight the connections between hip pathologies and groin pain, discuss possible differential diagnoses, and examine common misdiagnoses.

Anatomy of the hip joint

The hip joint (Articulatio coxae) is a central joint of the human musculoskeletal system and connects the femur to the pelvis. It is a ball-and-socket joint that allows for high mobility in multiple directions and simultaneously bears the body weight.

Bony structures

The main bony structures of the hip joint are:

• Femoral head: The spherical upper part of the femur that fits into the hip socket.
• Acetabulum: The hip socket of the pelvis that receives the femoral head.

These bony structures together form the hip joint and enable movements such as flexion, extension, abduction, adduction, and internal and external rotation.

Cartilage and labrum

The articular surfaces of the femoral head and acetabulum are covered with hyaline cartilage, which acts as a shock absorber and enables low-friction movements. Additionally, the acetabulum is surrounded by a fibrocartilaginous structure, the labrum acetabulare, which deepens the joint socket and contributes to the stability of the joint.

Ligaments and capsule

The hip joint is surrounded by a strong joint capsule, which is reinforced by several ligaments:

• Iliofemoral ligament: Runs from the iliac spine to the femur and prevents excessive extension of the hip joint.
• Pubofemoral ligament: Connects the pubic bone to the femur and limits excessive abduction.
• Ischiofemoral ligament: Extends from the ischium to the femur and inhibits internal rotation.

These ligaments provide stability to the hip joint and limit extreme movements.

Musculature

The movements of the hip joint are made possible by a variety of muscles:

• Flexors: Muscles like the iliopsoas muscle flex the hip joint.
• Extensors: The gluteus maximus muscle extends the hip joint.
• Abductors: Muscles like the gluteus medius lift the leg laterally.
• Adductors: Muscles like the M. adductor longus bring the leg towards the midline of the body.
• Rotators

A harmonious interaction of these muscles is essential for the functionality and stability of the hip joint.

Relationship between hip pathologies and groin pain

Groin pain can often be attributed to diseases or injuries of the hip joint. This is due to the close anatomical and functional connection between the hip and groin. The following are some common hip pathologies that can cause groin pain.

Coxarthrosis (hip osteoarthritis)

Coxarthrosis refers to the degenerative wear of the hip joint, in which the articular cartilage is increasingly broken down. This leads to pain, which is often localized in the groin and can radiate into the thigh or knee. Typical symptoms include start-up pain after periods of rest, load-related pain, and limited mobility of the hip joint. In advanced stages, pain at rest can also occur.

Hip dysplasia

Hip dysplasia is a congenital or acquired malformation of the hip joint in which the acetabulum does not adequately cover the femoral head. This leads to instability of the joint and can cause pain and premature osteoarthritis in young adulthood. Groin pain is a common symptom, often accompanied by a feeling of instability or a "snapping" in the joint.

Femoroacetabular impingement (FAI)

Femoroacetabular impingement describes an impingement syndrome in the hip joint caused by structural changes in the femoral head or acetabulum. Two main forms are distinguished:

• Cam impingement: A deformity of the femoral head leads to a suboptimal fit in the acetabulum, resulting in a mechanical conflict between femur and acetabulum, particularly during flexion and rotational movements.
• Pincer impingement: An excessively pronounced acetabulum leads to the entrapment of the labrum acetabulare and the adjacent joint structures.

Both forms of FAI can cause groin pain, which typically occurs during sports activities and intensifies with prolonged sitting or strenuous exercise. If left untreated, impingement can lead to long-term cartilage damage and osteoarthritis.

Labral lesions

The labrum acetabulare is a cartilaginous structure that surrounds the acetabulum and increases the stability of the hip joint. Damage or a tear of the labrum can cause groin pain, which is often described as deep-seated. Typical symptoms include a 'clicking' or 'snapping' in the joint as well as movement restrictions.

Labral lesions can occur due to trauma, degenerative changes, or as a result of FAI. Diagnosis is usually made by magnetic resonance imaging (MRI) with contrast agent.

Trochanteric bursitis

Inflammation of the bursae in the hip region, particularly the trochanteric bursa, can cause pain in the lateral hip area, which can radiate to the groin. Typically, the pain is exacerbated by pressure on the greater trochanter.

Differential diagnoses of groin pain

In addition to hip-related causes, there are numerous other conditions that can cause groin pain. These include:

• Inguinal hernia: A protrusion of abdominal organs through a weak spot in the abdominal wall can lead to stabbing groin pain, especially under stress.
• Adductor problems: Muscle injuries or tendon irritations of the adductor musculature are particularly common in athletes and can be accompanied by groin pain.
• Nerve compressions: Irritation of the femoral nerve or obturator nerve can cause neuropathic groin pain.
• Gastrointestinal causes: Diseases of the intestine, such as diverticulitis or appendicitis, can also mimic groin pain.

Common misdiagnoses for groin pain

Groin pain is often misdiagnosed, as symptoms of various conditions overlap. The following incorrect diagnoses are particularly common:

• Misinterpretation of hip pathology as inguinal hernia: Early signs of coxarthrosis or FAI are often misinterpreted as inguinal hernia.
• Confusion with muscular problems: Adductor problems are often diagnosed, although a structural hip disease is present.
• Back problems as a cause



Conclusion: Groin pain often originates in the hip joint!

Groin pain is a complex symptom with diverse causes. It is particularly important not to overlook the hip as a possible origin of the complaints. A thorough diagnosis with clinical examination, imaging, and, if necessary, interventional tests is essential to make the correct diagnosis and initiate effective therapy. Especially in cases of persistent or unclear groin pain, hip-related causes should always be considered.

Therefore, it is advisable to consult a hip specialist early on to rule out serious conditions and initiate targeted treatment. An early diagnosis can significantly improve the prognosis and prevent long-term limitations.