Femoral Impact Syndrome

What is defined as femoral impact syndrome?

Femoroacetabular impingement syndrome (FAI) is an anatomical abnormality of the hip joint, in which the femoral head and acetabular have structural incompatibility that disrupts the normal mechanics of the hip.

This pathological contact of the bone surfaces during hip flexion and/or rotation leads to abnormal friction and gradual wear of the labial cartilage and articular cartilage. If not diagnosed and treated early, it can lead to chronic pain, with limited range of motion and early hip osteoarthritis.

Types of femorocoilar impingement syndrome

Femoral impact syndrome is classified into three main morphological types. The classification is carried out according to the location and type of bone deformity. In particular, the three types are the Cam type, the Pincer type and the combined type.

In the Cam type, there is an abnormality in the shape of the femoral head and/or neck, which loses its normal sphericality, presenting a projection-“bulge”. During the flexion and rotation of the hip, this projection hits the rim of the acetabulum, causing damage to the labial cartilage and consequently, over time, to the articular cartilage. This form occurs more often in young men with intense athletic activity .

The Pincer type is characterized by the overlapping of the femoral head by the acetabulum. This overlap is caused by bony projection on the anterior and/or outer lip of the acetabulum. Prolonged contact of surfaces leads to degeneration of the labial cartilage, usually in middle-aged women.

Finally, the combined type combines characteristics of both forms, being the most common variant of the syndrome. The clinical picture depends on the morphology and degree of deformity and the level of activity of the patient.

What are the causes of the syndrome and risk factors?

The causes of femoral impact syndrome are mainly related to anatomical abnormalities of the hip joint . These anatomical abnormalities can be created during childhood and development. However, there are also secondary factors that burden the anatomy or function of the joint, increasing the chances of its occurrence.

More specifically:

Genetic and hereditary factors that affect bone growth.
Developmental disorders of the hip (e.g. hip dysplasia, etc.).
Childhood diseases (e.g. Legg-Calve-Perthes disease).
History of trauma or hip fracture with healing in a defective position.
Intense and repetitive loading or overuse of the hip joint during childhood and adolescence, especially in athletes.

Femoral Acetabular Impingement Syndrome & Clinical Picture

Patients with femoral impact syndrome usually experience pain located in the anterior hip area or groin. This pain is often described as deep pain that gets worse during activities that require bending, inward or outward rotation, or hip adduction. The pain can radiate to the anterior surface of the thigh or even to the gluteal area, making diagnosis difficult initially.

In addition, several patients report feelings of entanglement, such as entanglement (“locking”) or squeaking (“squeaking”) of the joint, which indicate possible damage or rupture of the labial cartilage.

In advanced stages, pain can occur even in simple daily movements, while it is accompanied by limitation of the range of motion and stiffness of the joint.

How is the diagnosis made?

The diagnosis of femoral impact syndrome is based on the combination of clinical examination and the evaluation of imaging tests. The aim is to identify morphological changes and differentiate them from other hip diseases.

First, a detailed history is taken that includes the level of physical activity and the presence of any musculoskeletal disorders.

During the clinical examination, the range of motion and muscle strength of the hip are assessed. Special impact tests are also applied, which reproduce the characteristic pain through flexion, adduction and internal rotation of the thigh.

Imaging examinations play a decisive role.

In particular:

A simple X-ray allows bone abnormalities or protrusions to be detected.
Magnetic resonance imaging (MRI) offers detailed visualization of the joint’s soft tissues, primarily the labia and articular cartilage.
The MRI arthrogram of the hip, which is the most specific examination, and is practically an MRI with intra-articular injection of contrast. The contrast fills the joint and thus all deficits and breakdowns are erased.
CT scan, which better records the bony parts of the joint and anatomical variations.

What is the appropriate treatment to treat the syndrome?

The treatment of femoral impact syndrome is determined by:

the severity of the symptoms.
the morphological type of damage.
the degree of joint degeneration.

The conservative therapeutic approach is applied as an initial stage in patients with mild or moderate symptoms.

More specifically, it includes:

Modification of activities that cause mechanical strain on the hip joint.
Medication with non-steroidal anti-inflammatory drugs (NSAIDs) to relieve pain and inflammation.
Targeted physiotherapy to improve muscle balance and joint stability.

Physiotherapy intervention is very important for treatment.

In particular, it aims to:

improve hip stability.
strengthening the muscles of the buttocks.
restoring the normal movement of the joint.

When conservative treatment does not bear fruit or serious anatomical deformities coexist, then surgical treatment is indicated.

Arthroscopic hip reconstruction is the treatment of choice. In particular, hip arthroscopy is a minimally invasive technique that allows:

the removal of excess bone.
suturing or repairing the labial cartilage
the investigation and treatment of other coexisting faults

The aim of the operation is to relieve pain and prevent further degenerative lesions. In cases of advanced wear, where extensive osteoarthritis has already developed, total hip arthroplasty may be necessary to fully restore the patient’s mobility and quality of life.

If you experience hip discomfort, trust a physician with years of experience and leadership in the field of reconstructive surgery. Orthopaedic Surgeon Anastasios Lilikakis is the Director of the Third Orthopaedic Clinic of the Athens Euroclinic and the President of the Department of Hip & Knee Reconstructive Surgery of EEHOT. Contact us and book your appointment to receive personalized treatment.