Ligamentum Teres Tear: Causes, Symptoms, Diagnosis, and Treatment

What is a torn ligament of the head of the femur?

A torn ligament of the head of the femur, specifically referring to the ligamentum teres, is an injury to a small, yet significant, intra-articular ligament within the hip joint that provides minor mechanical stability, proprioceptive feedback, and critically, acts as a conduit for a branch of the obturator artery supplying blood to the femoral head.

Anatomy of the Femoral Head and Hip Joint

To understand a torn ligament of the head of the femur, it's essential to first grasp the basic anatomy of the hip joint. The hip is a highly stable ball-and-socket joint, formed by the spherical head of the femur (thigh bone) fitting into the cup-shaped acetabulum of the pelvis. This anatomical configuration, along with a strong joint capsule, surrounding ligaments (iliofemoral, pubofemoral, ischiofemoral), and powerful musculature, contributes to its stability and wide range of motion. The acetabulum is further deepened by a ring of fibrocartilage called the labrum, which enhances joint congruence and stability.

The Ligament of the Head of the Femur (Ligamentum Teres)

The "ligament of the head of the femur" is formally known as the ligamentum teres, or the round ligament of the femur. It's a relatively small, triangular, intra-articular (within the joint capsule) ligament that originates from the acetabular notch and inserts into a small depression on the femoral head called the fovea capitis.

While historically considered vestigial due to its minor role in gross mechanical stability, modern understanding highlights several crucial functions:

• Minor Mechanical Stabilizer: It offers some resistance to hip dislocation, particularly in flexion, adduction, and external rotation, but its primary mechanical role is limited compared to the larger extra-capsular ligaments.
• Proprioception: It contains nerve endings that contribute to the joint's sense of position and movement (proprioception), providing feedback to the brain about hip joint status.
• Vascular Conduit: Most importantly, the ligamentum teres typically carries a branch of the obturator artery (the foveal artery) to the femoral head, particularly significant for blood supply in children and adolescents, though its contribution diminishes in adulthood. A tear can compromise this blood supply, especially in younger individuals.

Causes of a Torn Ligamentum Teres

Tears of the ligamentum teres are often associated with specific mechanisms or underlying hip pathologies. Common causes include:

• Traumatic Injury:
  • Falls: Especially falls onto a flexed, adducted, and internally rotated hip.
  • Sports Injuries: High-impact sports, contact sports, or activities involving sudden twisting, pivoting, or forced movements of the hip (e.g., martial arts, gymnastics, dance, soccer).
  • Hip Dislocation or Subluxation: Even a transient subluxation can stretch or tear the ligament.
• Repetitive Microtrauma: Chronic, repetitive movements that push the hip to its end ranges of motion, leading to gradual degeneration and tearing.
• Associated Hip Pathologies: Tears are rarely isolated and often occur in conjunction with other hip conditions that alter joint mechanics or predispose the ligament to injury:
  • Femoroacetabular Impingement (FAI): Abnormal contact between the femoral head/neck and the acetabulum, particularly cam or pincer impingement, can compress and damage the ligament.
  • Hip Dysplasia: Shallow acetabulum leading to increased stress on intra-articular structures.
  • Labral Tears: Often co-exist, as both structures are subjected to similar stresses.
  • Joint Laxity: Generalized ligamentous laxity can place more stress on the ligamentum teres.
  • Osteoarthritis: Degenerative changes within the joint.

Symptoms of a Ligamentum Teres Tear

The symptoms of a torn ligamentum teres can vary but often include:

• Deep Hip Pain: Typically felt in the groin area (anterior hip), but can also be referred to the buttock, lateral hip, or thigh. The pain is often described as a dull ache, but can be sharp with certain movements.
• Mechanical Symptoms:
  • Clicking or Popping: A sensation or audible sound during hip movement.
  • Catching or Locking: A temporary inability to move the hip, often followed by a click as it releases.
  • Giving Way: A feeling of instability or the hip suddenly buckling.
• Pain with Specific Movements: Exacerbated by prolonged sitting, standing, walking, or activities involving hip flexion, adduction, and internal rotation (e.g., getting in/out of a car, putting on socks).
• Limited Range of Motion: Though less common than with other hip pathologies, pain may restrict movement.
• Instability: A subtle feeling of the hip being "loose" or not tracking correctly.

Diagnosis

Diagnosing a ligamentum teres tear can be challenging due to its small size and intra-articular location, and because its symptoms often overlap with other hip conditions.

• Clinical History and Physical Examination: A detailed history of injury mechanism and symptom onset. Physical examination involves specific provocative tests (e.g., FADIR test – Flexion, Adduction, Internal Rotation; FABER test – Flexion, Abduction, External Rotation; hip scour test) that may reproduce pain or mechanical symptoms.
• Imaging Studies:
  • X-rays: Primarily used to rule out bony abnormalities like fractures, signs of FAI, or osteoarthritis.
  • Magnetic Resonance Imaging (MRI): Can sometimes visualize tears, but its sensitivity for ligamentum teres tears is limited due to the ligament's small size and complex orientation.
  • MR Arthrography (MRA): Involves injecting contrast dye into the hip joint before an MRI. This technique enhances visualization of intra-articular structures and is more sensitive for detecting ligamentum teres and labral tears.
  • Diagnostic Injection: An anesthetic injection into the hip joint can help confirm if the hip is the source of the pain. If pain is significantly reduced after the injection, it points to an intra-articular problem.
• Hip Arthroscopy: Considered the gold standard for definitive diagnosis and often simultaneous treatment. A minimally invasive surgical procedure where a small camera is inserted into the joint, allowing direct visualization of the ligamentum teres and other intra-articular structures.

Treatment Options

Treatment for a torn ligamentum teres depends on the severity of the tear, the patient's symptoms, activity level, and the presence of any associated hip pathologies.

Conservative Management

Initial treatment often focuses on non-surgical approaches:

• Rest and Activity Modification: Avoiding activities that exacerbate pain.
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): To manage pain and inflammation.
• Physical Therapy: A structured program to:
  • Improve hip and core strength (especially glutes, hip rotators, and abdominal muscles).
  • Enhance joint stability and proprioception.
  • Correct movement patterns and biomechanical imbalances.
  • Restore pain-free range of motion.
• Corticosteroid Injections: May provide temporary pain relief, but do not address the underlying tear.

Surgical Intervention

If conservative measures fail or if symptoms are severe and debilitating, surgical intervention via hip arthroscopy may be recommended. Surgical options include:

• Debridement: Removing the torn or frayed portions of the ligament. This is the most common approach.
• Repair or Reconstruction: In some cases, particularly in younger patients or when the tear is amenable, the ligament may be repaired or reconstructed using grafts. This is less common due to the ligament's complex anatomy and vascular supply.
• Addressing Concomitant Pathologies: During arthroscopy, the surgeon will also address any associated conditions such as labral tears, FAI (e.g., osteoplasty to reshape bone), or cartilage damage, as these often contribute to the symptoms and can impact long-term outcomes.

Recovery and Rehabilitation

Recovery after a ligamentum teres tear, whether managed conservatively or surgically, involves a structured rehabilitation program.

• Post-Surgical Phase: Typically involves a period of protected weight-bearing (crutches) and restricted range of motion to allow initial healing.
• Physical Therapy Progression:
  • Phase 1 (Early): Focus on pain and swelling control, gentle range of motion exercises, and muscle activation (e.g., isometric exercises).
  • Phase 2 (Intermediate): Gradually increasing strength, flexibility, and proprioceptive exercises.
  • Phase 3 (Advanced): Progressing to functional movements, balance training, and sport-specific drills, gradually returning to pre-injury activity levels.
• Adherence: Consistent adherence to the physical therapy program is crucial for optimal recovery and preventing re-injury. Full recovery can take several months.

Prevention

While not all tears are preventable, certain strategies can reduce the risk of ligamentum teres injury:

• Proper Warm-up and Cool-down: Prepare muscles and joints for activity and aid recovery.
• Gradual Progression: Avoid sudden increases in training intensity, volume, or complexity, allowing the body to adapt.
• Strengthening Hip and Core Musculature: Develop strong glutes, hip rotators, and core muscles to provide dynamic stability to the hip joint.
• Maintain Hip Mobility: Ensure adequate, but not excessive, hip flexibility. Avoid consistently pushing the hip to extreme end-ranges of motion, especially under load.
• Biomechanics and Technique: Focus on proper movement patterns and technique in sports and daily activities to minimize undue stress on the hip joint.
• Address Underlying Issues: If you have known FAI, hip dysplasia, or other biomechanical issues, work with a healthcare professional to manage them proactively.

When to Seek Medical Attention

If you experience persistent hip pain, especially if it's accompanied by mechanical symptoms like clicking, catching, or a feeling of instability, it's important to consult a healthcare professional. Seek immediate medical attention if you experience:

• Sudden, severe hip pain after a traumatic event.
• Inability to bear weight on the affected leg.
• Deformity around the hip joint.

An early and accurate diagnosis is key to effective management and preventing potential long-term complications or further joint damage.