Iliopsoas Tendinopathy

Original Editor - Shejza Mino

Top Contributors - Shejza Mino, Lucinda hampton, Kim Jackson, Wendy Snyders, Leana Louw and Rishika Babburu  

Introduction

In general, the iliopsoas muscle contributes to a variety of lumbopelvis problems, and the iliopsoas tendon is a common cause of hip pain and dysfunction, ranging from asymptomatic snapping hip syndrome to symptomatic irritation of the tendon and related bursa.

Excessive tightness of the iliopsoas muscle may cause increased friction, or result in an audible snap, when the tendon travels over the underlying bony landmarks. These landmarks include the anterior inferior iliac spine, iliopectineal eminence, bony ridge of the lesser trochanter or the anterior capsule of the femoral head, This condition is known as "asymptomatic internal snapping hip syndrome" when painless. However, when pain/dysfunction is experienced with the audible snap, there are various terms used to describe the condition including "painful internal snapping hip, internal coxa saltans, iliopsoas tendinitis, iliopsoas tendinosis, iliopsoas tendinopathy, iliopsoas bursitis, or iliopsoas syndrome". Due to the close proximity of the Iliopsoas tendon and the related bursa, inflammation of one of these structures inevitably causes inflammation of the other. Therefore, the literature reports that a diagnoses of iliopsoas tendinitis and iliopsoas bursitis are synonymous, as the clinical presentation, evaluation, and management are nearly identical.

The term Iliopsoas tendonitis is often used and implies inflammation of the tendon or area surrounding the tendon. Studies have revealed the presence of inflammation in the acute phase however, chronic tendon pathologies lack an inflammatory process and are instead characterized by a failed healing response and tendon degeneration. For this reason, it is arguably more accurate to classify this condition as a tendinopathy when referring to it generally.

Clinically Relevant Anatomy

The iliopsoas refers to the combined iliacus and psoas muscles. The two muscles are commonly separate entities in the abdomen and merge together in the thigh.

The origin of the deep fibers of the psoas major is at the transverse process of the T12 to L5 vertebrae. The superficial fibers originate from the outer surfaces of lumbar vertebra and adjacent intervertebral discs. The origin of the iliacus muscle is in the iliac fossa of the pelvis.

The psoas major and illiacus muscles merge between L5-S2. The iliopsoas runs from the pelvis to the thigh under the inguinal ligament and the tendon travels anteriorly across the acetabulum between the anterior inferior iliac spine (laterally) and the iliopectineal eminenence (medially) to eventually attach onto the lesser trochanter of the femur. The iliopsoas bursa is located between the iliopsoas musculotendionous junction and the underlying bony pelvis. The bursa has been reported to communicate with the hip joint in ~15% of the adult population.

Nerve supply:

• The iliacus component of the iliopsoas muscle is innervated by the femoral nerve (composed of anterior rami of L2-L4)
• The psoas component of the iliopsoas muscle is innervated by direct branches of the lumbar plexus (anterior rami of L1-L3)

Vascular supply:

• Iliolumbar artery & medial femoral circumflex artery.

Function:

• Flexion & external rotation of the hip

Epidemiology

In general, iliopsoas pathologic conditions (including tendinitis, bursitis, snapping and impingement) have been deemed to be the main cause of chronic groin pain in roughly 12-36% of athletes and in 25-30% of athletes with acute injury to the groin region

Data on the prevalence of iliopsoas tendonitis remains unknown however, it more commonly affects young adults and is mildly more prevalent in females

Etiology

The two most common causes of irritation to the iliopsoas tendon is acute injury and overuse injury from repetitive microtrauma:

• Acute injuries typically result from either eccentric contraction of the muscle or brisk flexion against an extension force that surpasses the capacity of the tendon. Less commonly, acute musculotendinous  injuries to the iliopsoas is caused by traumatic event.
• Overuse injuries may result from any activity requiring repetitive hip flexion or repetitive external rotation of the hip. Chronic injuries in any tendinopathy occur when the body's ability to repair itself is exceeded by repetitive micro trauma.

Other reported causes:

• Commonly, psoas tendinopathy occur secondary to repetitive flexion of a hip that is in external rotation. The condition is commony referred to as "dancer's hip" or jumper's hip", as associated movements are a predisposing factor to injury.
  • More than 90% of ballet dancers reporting an audible click, pop or snap in the hip.
• Individuals who participate in rowing, track and field, uphill running, soccer, gymnastics, hurdling and resistance training may be at increased risk of a psoas tendionpathy injury.
• Adolescents during growth spurts have relatively decreased flexibility of the hip flexors, potentially putting them at greater risk.
• Rheumatoid arthritis has been reported as a cause of Iliopsoas bursitis (closely associated to iliopsoas tendinitis).

Clinical Presentation

The clinical presentation of symptomatic iliopsoas tendionopathy often encompasses a palpable and audible snap that results from flexion and extension of the hip. Persistent irritation of the tendon may result in inflammation to either the tendon, underlying bursa or both. Chronic irritation will not be associated with inflammation but will instead demonstrate painful degeneration and fibrosis of the tendon,

History

A history of insidious deep groin or anterior hip pain is common. Initially, pain is provoked with onset of aggravating activity, decreasing shortly after. Symptoms may progress to constant pain during activity that diminishes only with rest and lastly, to the presence of pain with both activity and rest. The diagnosis is usually delayed, with the average time between initial symptoms and diagnosis is estimated to be between 32-41 months.

• Patients may report pain with activities such as running or kicking. Additionally, tying shoe laces, rising from a seated position after prolonged sitting and inclined walking are some other examples activities of daily living that may provoke symptoms.
• Radicular symptoms along the anterior thigh down towards the knee may be reported.
• Commonly, an audible click or snap coming from the groin or hip area is reported. This is associated with internal snapping hip syndrome, a condition where the tendon of the iliopsoas muscle glides over the head of the femur, or over the iliopsoas bursa causing an audible snap that can usually be palpated.
• A tight iliopsoas muscle may cause symptoms over the anterior knee that resembles patellofemoral dysfunction.
• Dysfunction of the psoas muscle is commonly associated with various complaints to the lumbosacral region, which may include low back pain, discomfort into the gluteal or thigh region and the inability to stand fully erect,

Physical Examination

Observation:

• Signs of psoas hypertonicity such as holding the affected hip in a mildly flexed and externally rotated position, as well as anterior pelvic tilt.
• Gait: A shortened stride length may be obvious on the affected side. Additionally, increased knee flexion may be observed during heel strike and midstance phases.

Palpation:

• Increased tenderness with deep palpation of the iliopsoas muscultendionous junction within the femoral triangle. Palpation of the inguinal lymph nodes in this region should be unremarkable.
• With the patient in a prone position, the insertion of the iliopsoas tendon onto the lesser trochanter can be palpated under the gluteal fold, which may reveal pain.

Range of Motion:

• Passive hip extension (normal ~15 degrees) may be limited and/or elicit pain.
• Active or resisted hip flexion may reproduce pain.

Functional/Orthopedic testing:

• Thomas test or Modified Thomas test - can help identify excessive hypertonicity in the hip flexors
• "Iliopsoas test": Resisted hip flexion, with the hip in external rotation (performed with patient in a supine position). Any weakness and/or pain symptoms is a positive test.
• Ludloff's sign (Isolated strength muscle assessment of the iliopsoas): In a seated position with the knees extended, the patient is asked to lift the heel of the affected side off the table. Considered positive if pain is produced or weakness revealed.
• Stinchfield test: Patient performs an active straight leg raise (SLR) to 45 degrees. Then, ask patient to resist as downwards force is applied to anterior thigh. Pain and/or weakness suggests involvement of the psoas muscle or intraarticular pathology.
• Snapping hip maneuver: To begin, the affected hip is positioned in a flexed, abducted and external rotated position. The hip is passively moved into extension and internal rotation. Positive test is a palpable or audible snapping located in the inguinal regiokn. Pain provoked with this maneuver suggests iliopsoas tendinitis or bursitis.

Psoas hypertonicity may result in reciprocal inhibition of antagonist muscles and dysfunctions along the kinetic chain. Additionally screening should include signs of hip abductor weakness, spinal instability, lower cross syndrome, increased foot pronation as well as dysfunctional breathing.

Differential Diagnoses

• Tendon avulsion
• Muscle Contusion
• Femoral Acetabular Impingement (FAI)
• Avascular necrosis of the femoral head
• Stress fracture of the femoral neck
• Groin injury
• Femoral tendinitis and bursitis
• Hip osteoarthritis
• Labral tear
• Hip fracture
• Legg-Calve Perthes Disease
• Lumbosacral Disc Injuries
• Lumbosacral Radiculopathy
• Osteitis Pubis
• Slipped Capital Femoral Epiphysis (SCFE)
• Snapping Hip Syndrome
  • "Internal" snapping hip, like previously mentioned, is related to the iliopsoas tendon.
  • "External" snapping hip is related to either the iliotibial band or gluteus maximus tendon traveling over the greater trochanter
  • "Intraarticular" snapping hip can be due to loose bodies, labral tears or recurrent dislocation.

Workup

Laboratory Analysis

• Laboratory studies are only indicated if the diagnosis is unclear and may include a CBC count, erythrocyte sedimentation rate or C-reactive protein, rheumatoid factor, anticyclic citrullinated peptide antibody, antinuclear antibody, and urinalysis. These tests are useful when considering pathology to the abdomen and pelvis that may present as groin pain such as colon cancer, diverticulitis, prostatitis, salpingitis, renal calculi, appendicitis and psoas abscess,

Medical Imaging

• Radiography
• Ultrasonography
• Magnetic Resonance Imaging (MRI)

Management

Physical Therapy

• Acute Phase
• Recovery Phase
• Maintenance Phase
• Return to Play

Resources

• Psoas major
• Snapping Hip Syndrome
• Iliopsoas Bursitis