yogabook / pathologie / hip-impingement FAI

hip-impingement (femoro-acetabular impingement FAI)

Definition of

It was not until 2003 that hip impingement was identified as one of the most important causes of secondary coxarthrosis and arthroscopic treatment was established as a causal treatment. Many people would be prone to this if they used their range of motion, but due to their lifestyle and exercise habits, they may remain pain-free into old age.

Distinguish between the two frequently mixed forms:

1. Cam or camshaft impingement, more common in young people who have a thickening of the femur: this bony protrusion of the femur causes it to strike the edge of the acetabulum or the cartilage lip there, which damages it (shearing off to the point of coarthrosis). Sports such as gymnastics, ice hockey or soccer then tend to tear off the cartilage due to movement radii that trigger impingement. Progression often faster than with pincer impingement.
2. Pincer impingement: an oversized cartilaginous covering of the acetabulum leads to impingement of the femur and its (protective, osteophytic) thickening, which worsens the situation and symptoms. At the same time, the cartilage shrinks to zero, so that bone meets bone, which represents advanced osteoarthritis. Wide flexion is particularly problematic for pincer impingement.

There are also impingements with extra-articular causes:

1. Psoas impingement: an irritation of the tendon of the psoas major
2. subspinal impingement: painful contact of the femoral neck with the SIAI
3. Foveal impingement: changes in the lig. capitis femoris (acetabular ligament) such as tears and deformations lead to impingement

Primary causes of changes in the hip joint that can lead to impingement are: Perthes‘ disease, epiphyseal separation(separation of the growth plate of the femoral neck from the head, especially in boys before puberty) and coxa vara (growth disorder with a flattened CCD angle).

Cause

1. (see definition)

Predisposing

1. Sport that strains the hip joints
2. Women between 30 and 40 years of age often have a too deep socket with a correct head or the acetabulum points too far dorsally

Diagnosis

1. X-ray (under load for evidence of osteoarthritis), CT, MRI
2. Tests and signs: McCarthy test, Drehmann sign, FADDIR test

Symptoms

1. often asymptomatic in the early phase, possibly for life (see above)
2. Reproducible, movement-dependent, stabbing hip/groin pain, often initially only felt in terminal movements, often also in the ventral/lateral thigh, especially during and after physical exertion and sport, possibly also after prolonged sitting, e.g. when driving. In contrast to muscle stretching pain, impingement pain is not finely graded but almost binary.
3. With psoas impingement: audible and palpable snapping in the groin
4. Pain is mainly triggered by abduction and flexion (especially with endorotation).
5. Maximum minor restriction of flexibility
6. Rare: Limping as an avoidance/sparing reaction
7. at an advanced stage, even the smallest movements hurt

Complications

1. Cox osteoarthritis

Therapy

1. in mild cases: Avoidance of the pain-causing impingement to limit progression. Drug therapy: NSAIDs for inflammation; PT; PT can also have a negative effect in the case of cam impingement.
2. In case of failure of conservative therapy or pronounced changes: Surgery, e.g. for cam impingement recontouring using a burr, now often arthroscopic. If necessary: repositioning osteotomy