Femoroacetabular impingement

Femoroacetabular impingement (FAI)

1. Anatomy and Pathology

The hip is a ball-and-socket joint. The socket is formed by the acetabulum,

which is part of the large pelvis bone. The ball is the femoral head, which is the

upper end of the femur (thighbone).

A slippery tissue called articular cartilage covers the surface of the ball and the

socket. It creates a smooth, low friction surface that helps the bones glide easily

across each other.

The acetabulum is ringed by strong fibrocartilage called the labrum. The labrum forms a gasket around the socket, creating a tight seal and helping to provide stability to the joint.

What is FAI.

Femoroacetabular impingement (FAI) is a condition where the bones of the hip

are abnormally shaped. Because they do not fit together perfectly, the hip bones

rub against each other and cause damage to the joint [Ganz, 2003 #196].

In FAI, bone spurs develop around the femoral head and/or along the

acetabulum. The bone overgrowth causes the hip bones to hit against each other,

rather than to move smoothly. Over time, this can result in the tearing of the

labrum and breakdown of articular cartilage (osteoarthritis).

Types of FAI

There are three types of FAI: pincer, cam, and combined impingement.

Pincer. This type of impingement occurs because extra bone extends out over

the normal rim of the acetabulum. The labrum can be crushed under the

prominent rim of the acetabulum.

Cam. In cam impingement the femoral head is not round and cannot rotate

smoothly inside the acetabulum. A bump forms on the edge of the femoral head

that grinds the cartilage inside the acetabulum.

Combined. Combined impingement just means that both the pincer and cam

types are present.

1. Normal. B. Pincer. C. Cam D. Combined

How FAI Progresses

It is not known how many people may have FAI. Some people may live long,

active lives with FAI and never have problems. When symptoms develop,

however, it usually indicates that there is damage to the cartilage or labrum and

the disease is likely to progress. Symptoms may include pain, stiffness, and

limping

Cause

FAI occurs because the hip bones do not form normally during the childhood

growing years. It is the deformity of a cam bone spur, pincer bone spur, or both,

that leads to joint damage and pain. When the hip bones are shaped abnormally,

there is little that can be done to prevent FAI.

Because athletically active people may work the hip joint more vigorously, they

may begin to experience pain earlier than those who are less active. However,

exercise does not cause FAI.

Symptoms

People with FAI usually have pain in the groin area, although the pain

sometimes may be more toward the outside of the hip. Sharp stabbing pain

may occur with turning, twisting, and squatting, but sometimes, it is just a dull

ache.

If your symptoms persist, you will need to see a doctor to determine the exact

cause of your pain and provide treatment options. The longer painful

symptoms go untreated, the more damage FAI can cause in the hip.

The role of acetabular labrum

A ring of fibrocartilage (fibrous cartilage) that runs around

the acetabulum (cup) of the hip joint and increases its depth. The head of the

femur (the bone in the thigh) fits in the acetabulum. The labrum deepens this

cavity and effectively increases the surface (and strength) of the hip joint.

Arthroscopic finding of acetabular labrum viewing from anterolateral portal.

How labral injuries occur;

The six most common causes of acetabular labrum tears are:

! trauma

! hip dysplasia (congenital abnormality)

! degeneration

! capsular laxity

! femoro-acetabular impingement.

! Psoas impingement

! Anterior Inferior Iliac Spine

Treatment:

First line treatment: is by avoiding positions of impingement such as Ballet

activity, and attempting to correct any biomechanical abnormalities with

physiotherapy. In addition, the core stability and muslce exerise surrouding

femoral head

hip joints are very important. Relieve pain with non steroid antiinflammatory

agents as well as intraarticular injection of local anesthesic agent including steroid.

Definitive treatment: is by correcting the anatomical abnormality.

Arthroscopic acetabular labral repair and cam osteochondroplasty may be performed in hospital under general anaesthetic if conservative treatment fails. The acetabular labrum reattached to the refreshed acetabular rim, rim trimming and the femoral head-neck junction is re-shaped to correct the cam impingement.

Other treatment to the acetabular cartilage may be undertaken at the same time. [Philippon, 2007 #279] [Bedi, 2008 #121] Finally, capsular closure is also essential to stabilize the joint.

In case of global severe pincer lesion, it is also necessary to perform a

acetabular osteotomy to solve the underlying problem

in addition to or instead of arthroscopy.

We also perform labral preservation including labral refixation and

reconstruction.

Caution note for adolescent patients

Dr Marc J Philippon reported that female patients had worse clinical

outcomes than male patients (mHHS of 89 v 99, P <.002), and only female

patients underwent secondlook surgeries. This higher incidence of

capsulolabral adhesions in the female population is not fully understood;

however, it may be associated with the underlying bony pathology,

hormones, or postoperative compliance with therapy. [Philippon, 2012 #602]

In patients who had open growth plates and in whom the cam lesion did not

communicate with the physis, a focal osteoplasty was performed on the femoral

head-neck junction. If a significant cam lesion was identified with

communication with the physis, then a staged procedure was recommended,

addressing the cam lesion after closure of the physis. [Philippon, 2012 #602]

Caution note for elder patients,

If labrum is severe degeneration or disruption, hip arthroscopic labral could be

beneficial treatment for those patients.

We usually harvest iliotibial band from ipsilateral side, tubulization is

performed to make appropiriate graft material. We perform arthroscopic labral

reconstruction if needed in case of labral severe degeneration or disruption.

2009 Am J Sports Philippon et al

In patients aged 50 years or older with 2 mm of joint space or less and low

preoperative modified Harris Hip Score, worsen clinical outcome and early

conversion to THR was seen [Philippon, 2012 #606].

If severe chondral damage ( > grade 3) are seen arthroscopically, worsen clinical

outcome and lower survivorship (converted to THA) [McCarthy, 2011 #243].

If labral injuries are associated with paralabral cysts, cyst should be removed as

much as possible.

Microfracture (Bone Marrow Stimulation) technique for Cartilage damage

If patients have localized chondral damage, we can perform microfracture

technique to repair cartilage damage.

Microfracture technique has been developed to treat chondral damage. It is

most common procedure used to treat. The procedure involves making

multiple perforations into the subchondral bone in the areas where cartilage is

deficient, which allow stem cells to fill the void out of the cartilage defect.

Duration of hospitalization;

Two days to one week.

Wear Brace for one to three weeks depending on patient‘s stability.

Please avoid walking for more than 2 hours and sitting on japanese toilet for at

least two months.

Postoperative rehabilitation protocol

Each of patients underwent post-operative rehabilitation protocol consist of

four phase.

During phase I, reducing inflammation and protecting the repaired

tissue is the cornerstone of the initial rehabilitation process following surgery

(day 1 to 4 weeks). We place patients in a brace for 2 to 3 weeks to protect the

hip and limit abduction and rotation. Gentle passive range of motion (ROM)

exercise is initiated during the first week, under supervision of a

physiotherapist. Then, continuous passive motion (CPM) is used to avoid

adhesive capsulitis by applying 0 to 90 degrees of hip flexion for up 4 hours a

day, for 2 weeks. Weight bearing is restricted to 20 pounds of flat-foot weight

bearing, for the first three weeks. If microfracture was performed, weightbearing

limitations are extended to 6 weeks. Active hip flexion is limited

during phase I (the first 4 weeks), to minimize the risk of hip flexor

inflammation.

During phase II (weeks 4 to 8), the patients improve their mobility,

stability and proprioception activity. Endurance strengthening is commenced

only after range of motion is maximized, and, after a good stability in gait and

Bledsoe Philippon Post-Arthroscopy Hip Brace

Application Instructions CP020204 Rev B 08/07

NEW LIGHT WEIGHT AND EASY TO USE POST-ARTHROSCOPY HIP BRACE

Council Directive 93/42/EEC

of 14 June 1993 concerning

Medical devices

This device is offered for sale by or on the order of a physician or other qualified medical professional. This device is not intended for reuse on a second patient or for extended use beyond 180 days. This device is not intended to prevent injuries or reduce or eliminate the risk of reinjury.

Indications: This device is indicated to help provide limited motion control of hip flexion when needed following hip arthroscopy.

Contraindications: Contraindicated for controlling fractures of the femur or pelvis.

WARNING: Do not leave this device in the trunk of a car on a hot day or in any other place where the temperature may exceed 150˚ F (65˚ C) for any extended period of time. If any additional pain or symptoms

occur while using this device, seek medical attention.

Warranty: This device is warranted to be free from defects in material and workmanship for a period of 90 days. This warranty is applied to devices that have not been modified or subjected to misuse, abuse or neglect.

For product information or questions pertaining to sales or service, please

contact your area sales representative or Bledsoe Brace Systems directly.

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movement is demonstrated. Throughout this phase, there is no low impact

aerobic conditioning.

Patients are allowed to progress to phase III (weeks 9 to 11) only if

passive ROM is symmetric, pain free, with a normal gait pattern. During this

phase, aerobic conditioning is advanced, using weight bearing activities, with a

goal of 30 min of continuous exercise at a low to moderate intensity.

Patients are allowed to progress to phase IV (weeks 12 to 16) when hip

muscle testing with a hand-held dynamometer reaches 90% of the uninvolved

hip. The goal of phase IV is to allow safe and gentle sport-specific drills, to

prepare the patient to return to pre-injury sport or work activities. Gentle sportspecific

or work agility exercises are initiated.

4. Complication (risk and probability)

General anesthesia

・

1. Deep vein thrombosis, or deep venous thrombosis, (DVT) is the

formation of a blood clot (thrombus) in a deep vein,[a] predominantly in the

legs. Non-specific signs may include pain, swelling, redness, warmness,

and engorged superficial veins. Pulmonary embolism, a potentially lifethreatening

complication, is caused by the detachment (embolization) of a

clot that travels to the lungs. Together, DVT and pulmonary embolism

constitute a single disease process known as venous thromboembolism.

a Recommendations Early post-operative mobilisation (ideally on the day

of surgery). Use of below-knee elastic antithrombotic stockings on the

contralateral extremity intra-operatively.

2. Septic arthritis（1/218, 0/534 in our hospital）

In 218 hip arthroscopies performed in children and adolescents,

Nwachukwu et a reported one case of suture abscess in a proximal portal

of a patient undergoing arthroscopy for Perthes’ disease.

3. Adhesive arthritis

After hip arthroscopy, adhesions tend to develop between the capsular side of

the labrum and the capsule , although they have also been described in the

peripheral compartment between the femoral neck and the capsule after open

femoral osteochondroplasty. Adhesions are thought to cause symptoms by

impairing the sealing function of the labrum or impinging against it. Patients

complain of groin pain and demonstrate restricted flexion and rotation, with a

positive impingement sign. MR arthrography is the benchmark diagnostic

procedure

Small percentage (6%) of our patients required subsequent arthroscopic

surgery.

a Reccommendationearly post-operative movement is considered the best

prevention.

4. Complex regional pain syndrome（less than １％）

Complex regional pain syndrome is an uncommon form of chronic pain that

usually affects an arm or leg. Complex regional pain syndrome typically

develops after an injury, surgery, stroke or heart attack, but the pain is out

of proportion to the severity of the initial injury, if any. The cause of

complex regional pain syndrome isn't clearly understood. Treatment for

complex regional pain syndrome is most effective when started early. In

such cases, improvement and even remission are possible

・

5. Insufficient Wound healing

6. Traction related injury

Nerve injury

Nerve injury is uncommon, but can be a significant problem. The most

commonly affected nerves include the sciatic nerve, the lateral femoral

cutaneous nerve (sensation to the thigh), and the pudendal nerve. Injury to any

of the nerves can cause pain and other problems. Usually, most cases improve.

a They are localized in the area of the groin where the pudendal nerve is

primarily at risk, although one case of pudendal nerve palsy has also been

reported.

b Soft tissues injury may be affected, including the scrotum and the labia

majora, with injury ranging from oedema¥ or haematoma formation7 to

pressure necrosis

c Reversible erectile dysfunction

Recommendation; Continuous traction should not exceed two hours, with

intermittent traction used in prolonged procedures. The force should be limited

in most cases to < 22.7 kg (50 lbs).

7. Instrument Breakage

The thick soft-tissue envelope around the hip makes manipulation of the

arthroscope and instruments difficult, even in the presence of

distraction.5The curvature of the articular surfaces poses further problems

and also predisposes to instrument bending or breakage,

8. Vascular injuries

Minor bleeding is common during hip arthroscopy, but is easily controlled

either with a transient increase in fluid-pump pressure or with coagulation at

the source using the radiofrequency (RF) ablation probe.

We have experienced one case who had small artery injury that cause

hematoma surrounding soft tissue. He needed embolization at two days after

surgery.

9. Labral re-tear

Even though satisfactory labral preservation surgery, repaired labrum could not sometimes heal well depends on patients healing potential. Rarely, we need revision arthroscopy

10. Intra-thracic and intra-bdominal extravasation

We have never experienced those types of complications. But some reports

proposed the failure of maintaining irrigation pression cause extravasation.

Complication associated with your present illness

If you have pynorrhea or cavity of your teeth, bacteria could spread surgical

site infection. Other medical issue could cause postoperative risk.

Second Opinion

Patients can always be offered the opportunity to seek a second opinion

concerning the proposed treatment or procedures. This may be obtained if

desired.

Wakamatsu Hospital for the University of Occupational and

Environmental Health