Hip arthroscopy involves placing a telescope into the joint via a small keyhole incision. The telescope is attached to a video monitor allowing excellent visualisation of the joint, which has not previously been possible.
Through one or two other keyhole incisions, instruments can be placed in the joint to allow surgery to be performed. Hip arthroscopy is a much more challenging operation than a knee arthroscopy. The hip joint is much deeper than the knee joint, the surrounding muscles with their corresponding nerves and blood vessels, makes approaching the joint more difficult and manoeuvring the telescope and instruments more of a challenge.
The hip joint is quite constrained as a ball and socket joint and considerable traction on the leg and countertraction on the groin is necessary to force the joint apart to allow passage of the arthroscope and instruments into the joint. This needs to be performed on a special operating table, as well as using x-ray guidance for placement of the arthroscope and instruments. Hip arthroscopy is a new and evolving technique and as time passes its role in the treatment of certain hip problems will become clearer. Hip arthroscopy is very useful in treating the patient who has loose bodies and localised areas of inflammation within the hip. It can aid in the diagnosis of hip pain for which the reason may not be obvious.
It is most commonly used for the treatment of labral tears. The labrum is the stiff cartilage ring around the socket of the hip joint, which connects the bony socket in the pelvis to the more supple soft tissue joint capsule. Its role is to form a tight seal for the hip joint to allow the hip to stay lubricated and function normally. The labrum, like the meniscus in the knee , can tear due to a traumatic event or due to degenerative/wear and tear changes. In the younger patient, often the sports person, who has had a traumatic event resulting in a torn labrum and a painful click is felt in the groin with certain movements. Treating this tear with an arthroscopy is often very successful in relieving the painful click.
Traditionally it was felt that the labrum doesn’t heal and hence repairing it is unsuccessful and so trimming the labral tear is often recommended. Recent evidence has shown that some labral tears can heal and so recently much effort has been put into repairing the labrum in certain situations. Recently there has been much research into the causes of labral tears and early hip arthritis. It appears it is very common for internal impingement of the hip to be the primary cause.
Often a bony lump arises on the front of the femoral head and neck and or the front of the bony acetabulum/socket arises and this can squeeze, nip and tear the intervening labrum in positions of hip flexion and rotation. Removing the bony lumps/impinging lesions appears to be a very useful procedure to reduce the pain and disability of impingement which may protect the hip in future from further degeneration. Typically this procedure involves arthroscopically evaluation the hip, repairing or trimming the labrum depending on its appearance, treating any damage to the joint surface and using a mechanical shaver to smooth of the bony lump usually on the femoral neck that has formed. This is a very difficult procedure takes considerable time and needs very specialised equipment to achieve the desired result.
Often a number of investigations such as x-ray, MRI and CT scans will need to be performed beforehand. When the tear is in an older patient is due to a degenerative process, and there is significant arthritic change in the hip then hip arthroscopy is unlikely to be successful. It can still be useful, but the patient should realise that hip arthroscopy is only 70% reliable for relieving pain and clicking. Once significant arthritis is occurring then a hip arthroscopy is probably of no benefit and occasionally the patient’s symptoms may be worse following their surgery. In these cases it is probably better to wait until hip replacement surgery is necessary. Good results are being obtained with treating hip impingement arthroscopically.
Pain and function typically show significant improvement. In the long term it is hoped that this treatment will slow down the progression of arthritic change in the hip but this will not be known for some time. It is not uncommon for patient to need repeated surgery over time. This may indicate the complexity of this type of surgery. Hip arthroscopy is definitely an emerging field and more and more is being learnt and being able to be performed as time goes.
Complications
Although hip arthroscopy is a challenging and difficult operation, the incidence of complications is quite low; at around 2-5% and almost all resolve with time. Most complications are secondary to the need for significant traction to perform the procedure as well as injury to superficial nerves from placements of the arthroscopic incisions.
Bruising and numbness about the groin and genitals can occur due to the traction set up. Great care is taken to avoid damage as much as possible. Numbness over the front or sides of the thigh is possible due to injury to nerves from the instruments. Infection, deep venous thrombosis (DVT) or injuries to the sciatic nerve or other deep structures are very uncommon.
The more complex the surgery the higher the risk of complications. When using implantable devices for labral repair for instance there is the chance of damage to the joint or breakage of instrumentation that may be difficult to retrieve. When removing impingement type lesions there is risk of damaging healthy joint surface inadvertently, there is a very low risk of causing a fracture to the head or neck of the femur or producing instability of the hip if too much tissue is removed.
Recovery
Hip arthroscopy may be performed as a day surgery case or it may require an overnight stay. Recovery depends on the pathology being treated. Younger patients with labral tears or loose bodies may have almost immediate recovery. Whereas a patient who has a degenerative labral tear may take several weeks to recover, while others with significant arthritic damage may not have much improvement at all.
Do I Need a Hip Arthroscopy
Not all patients with impingement type hip pain need an arthroscopy. It is difficult complex surgery so it is important that one’s symptoms and signs and significant enough to go through surgery. Many patients pain and disability can settle with simple activity modification. Often specialised physiotherapy can go along way to settling and controlling one’s symptoms.
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