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.
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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Toll Free Tel.1.888.BLEDSOE (253.3763)
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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