Labral Tears & FAI

The information on this page should not replace necessary medical consultations with a qualified health professional. I am not a doctor, I am a patient who has done a lot of research on this injury and am just trying to help others out there who may be searching for a reason for their hip pain. If you think this is an injury you may have, please see your medical doctor.

Acetabular Labral Tear

labral tear 2006

My (tiny) Labral Tear ~ MRI arthrogram 20 Dec 2006

labral tear

My Labral Tear (now more prominent)~ MRI arthrogram 22 Aug 2008

An acetabular labral tear is a tear in the fibro-cartilage that lines the rim of the hip socket. It is an injury that is often misdiagnosed and overlooked by doctors meaning that sufferers can go for years without appropriate treatment. Left untreated, this can result in increasing pain and joint degeneration such as arthritis.
Labral tears are often associated with acute twisting and load-bearing injuries and bony abnormalities such as dysplasia and impingement.

Symptoms:
Symptoms of an Acetabular labral tear can be, but are not limited to locking, popping and catching of the joint, lower back pain, buttock pain and pain when sitting, bending and twisting.

Diagnostic Testing:
Initial tests may include plain radiographs (x-rays) to rule out bony abnormalities such as stress fracture or dysplasia. Labral tears however do NOT show up on an x-ray. If a labral tear is suspected, the key diagnostic test is an MRI-Arthrogram. This is where you have a contrast dye injected into your hip about 10 minutes before you go in for the MRI. The dye makes it easier to see what is going on in the hip and shows up the tears better than conventional MRI. To help diagnose the hip pain, a long lasting local anaesthetic is often injected with the dye. If you have pain relief after the injection (can last up to 5 hours) it means that the pain is definitely coming from within the joint and not the surrounding soft tissue. After the anaesthetic wears off, you may feel stiff and quite sore for the next day or two. Some surgeons like to inject a steroid into the joint as well, with the hope of getting long term pain relief. Some people get permanent relief and others may only get temporary or no relief at all.

Treatment:
Due to there being a poor blood supply to the labrum, acetabular labral tears do not heal by themselves and the treatment of choice is usually minimally invasive hip arthroscopy.
Hip arthroscopy is still a fairly new surgery, only really being used in the last 10-20 years. Being such a deep joint, the hip is a very difficult joint to get access to, with the operated leg needing to be distracted (foot placed in traction and pressure applied to pull the joint apart) to allow the camera and surgical tools to enter the joint space. Hip arthroscopy is now at the level that knee arthroscopies were at roughly 10 years ago, so surgeons are still learning better techniques.
Tears can be debrided (removed) if too degenerate, or repaired with sutures and/or anchors if large enough.

Femoro-acetabular Impingement (FAI)

FAI is a condition where the bones that form the hip joint (acetabulum=socket & femur=leg bone) do not fit together nicely, causing friction within the joint.

There are three types of FAI:-

1) Pincer Impingement – excess bone on the Acetabulum creates an abnormally deep socket which restricts movement of the femur and causes pinching of the labrum.

Pincer Impingement
Image from http://www.kingorthopedics.com

2) Cam Impingement – excess bone on the head/neck junction of the femur, restricting flexion.

Picture from http://www.kingorthopedics.com
Image from http://www.kingorthopedics.com

3)  Mixed Impingement – a mixture of both Cam and Pincer Impingements

Image from http://www.kingorthopedics.com

Image from http://www.kingorthopedics.com

Symptoms:
FAI symptoms can include groin ache, buttock and lower back pain, knee pain, reduced hip range of motion, popping, clicking, snapping and catching. It can also cause other problems such as trochanteric bursitis, ITB syndrome and sciatica.

Diagnostics:
The first test is the clinical exam. Your range of motion will be assessed and certain physical tests such as the ‘impingement test (flexion at 90deg with internal rotation and adduction)’ will be performed that may suggest impingement.
Plain x-rays may or may not show FAI or the true extent of it as the angle of the x-rays is very important. Additional specific views such as ‘cross-table lateral’ or ‘false profile’ may be obtained to give the best view of the femoral neck.
FAI will show on MRI and a lot of surgeons are now obtaining CT scans with 3D reconstruction to get a better view of exactly where the impingement is. CT scans however are not always required for a diagnosis of FAI and expose you to a lot of radiation so are best to avoid if possible.

Treatment:
Traditional treatment for FAI is a trochanteric flip osteotomy. In this invasive technique a large incisision is made down the lateral thigh. The surgeon cuts off the outer-most section of the greater trochanter to protect blood supply and muscle attachments and flips it out of the way before dislocating the hip anteriorly. This allows the surgeon full access and an unobstructed view of the joint. Both cam and pincer impingements as well as labral tears can be remedied this way.
Cam impingement is usually reduced with a high speed burr and sufficient offset will be tested for intraoperatively. It is important that the surgeon does not remove too much bone as this can result in a weak bone susceptible to fracture and it is also important that the surgeon removes enough bone so as not to leave remaining impingement.
Pincer impingement is treated by removing the labrum over the area with bony overgrowth, shaving back the bone and reattaching the labrum with sutures and anchors.
When the surgery is finished, the joint will be relocated and assessed for ROM. The greater trochanter will be screwed back together and the wound sutured or stapled closed.
Retroverted acetabulums may require a much more severe surgery such as Periacetabular Osteotomy (PAO) where several cuts are made in bones of the pelvis and the whole pelvis is realigned.

Thankfully now, a lot of surgeons are performing less invasive FAI surgeries via an arthroscopic technique. Not all FAI patients can be treated this way, but a lot can be and it will depend on your anatomy and technical skill of your surgeon.
Arthroscopy negates the need for dislocating the hip, however it may reduce the amount of access the surgeon has to the joint.

Being such a specialized surgery with few orthopaedic surgeons in NZ and around the world (although there are more and more every year) who are familiar with and skilled at treating labral tears and FAI I would recommend that anyone who is going down the path of diagnosis and treatment seeks out a surgeon who is well experienced with these particular problems.