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Femoroacetabular impingement


  1. Your pathology 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 [1].



2.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.

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.

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.

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


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. 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.


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.


First line treatment: is by avoiding_cc781905-5cde-3194-bb3b- 136bad5cf58d_positions of impingement such as Ballet activity,_cc781905-5cde-3194-bb3b -136bad5cf58d_and attempting to correct any biomechanical abnormalities_cc781905 R elieve pain with non steroid anti-inflammatory_cc781905-5cde-3194-bb3b- 136bad5cf58d_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_cc781905- 5cde-3194-bb3b-136bad5cf58d_may be performed in hospital under general_cc781905-5cde -3194-bb3b-136bad5cf58d_anaesthetic if conservative treatment fails.  The acetabular labrum reattached_cc781905-5cde-3194- bb3b-136bad5cf58d_to the refreshed acetabular_cc78 -5cde-3194-bb3b-136bad5cf58d_rim, rim trimming and the femoral head-neck junction is_cc781905-5cde- 3194-bb3b-136bad5cf58d_re-shaped to correct the cam impingement. Other_cc781905 -5cde-3194-bb3b-136bad5cf58d_treatment to the acetabular cartilage may_cc781905-5cde -3194-bb3b-136bad5cf58d_be undertaken at the same time. [2] [3] Finally,  capsular plication is also essential if applicable .

In case of global severe pincer lesion,  it is also necessary to_cc781905- 5cde-3194-bb3b-136bad5cf58d_perform a acetabular osteotomy to solve the underlying problem in addition to_cc781905-5cde-3194 -bb3b-136bad5cf58d_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.[4]


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 [5] was recommended, addressing the cam lesion after closure of the physis.

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 appropriate graft material. We perform arthroscopic labral reconstruction if needed in case of labral severe degeneration or disruption.

In patients aged 50 years or older with 2 mm of joint space or less and low preoperative modified Harris Hip Score, worse clinical outcome and  early conversion to THR was seen[Five].


If severe chondral damage ( > grade 3) are seen arthroscopically, worsen clinical outcome and lower survivorship (converted to THA).



If labral injuries are associated with paralabral cysts, cysts should be removed as much as possible.

But, our resent study demonstrated that Arthroscopic FAI correction and labral preservation surgery provide favorable clinical outcomes for patients over 70 years old in the absence of significant osteoarthritis and severe acetabular chondral damage. Patients in their 50s and 60s have a higher risk of both THA conversion and progressive osteoarthritis, while patients aged over 70 years show no evidence of progressive osteoarthritis. Chronologic age in isolation is not an absolute contra-indication to hip arthroscopy. (Honda and Uchida et al KSSTA)

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.

Postoperative rehabilitation protocol


Each of the patients underwent post-operative rehabilitation protocol consisted of four phases.

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, weight -bearing 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._cc781905-5cde-3194-bb3b- 136bad5cf58d_

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 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.

Intra and Postoperative 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 veins,[a] predominantly in the legs.swelling, redness, warmth, and engaged superficial veinsPulmonary embolism, a potentially life-threatening 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.

    1. Recommendations Early post-operative mobilization (ideally on the day of surgery). Use of below-knee elastic antithrombotic stockings on the contralateral extremity intra-operatively.



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

In 218 hip arthroscopies performed in children and adolescents, Nwachukwu et al.50r 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_cc781905-5cde-3194-bb3b- 136bad5cf58d_

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


  1. Recommendation early 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. , 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.


5. Insufficient wound healing



6. Traction-related injuries

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.

  1. 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.

  2. Soft tissues injury may be affected, including the scrotum and the labia majora, with injury ranging from oedema\  or haematoma formation7 to pressure necrosis

  3. 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).

  1. Instrument Breakage

The thick soft-tissue envelope around the hip makes manipulation of the arthroscope and instruments difficult, even in the presence of distraction.FiveThe 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.Laboral re-tear

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


10.  Intra-thracic and intra-bdominal extravasation

  We have never experienced those types of complications.



Complication associated with your present illness

If you have pynorrhea or cavity of your teeth, bacteria could spread surgical site infection.  Other medical issues could cause postoperative risk.

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