Patient's Overview
Keyhole ('arthroscopic') surgery is not new. The knee, ankle, shoulder, wrist, and other joints are all frequently arthroscoped. Yet for some reason the hip has long been regarded as difficult to arthroscope. In 1931, a researcher called Burman even said, "It is manifestly impossible to insert a needle between the head of the femur (ball of hip joint) and the acetabulum (hip socket)." Now, as we approach the millennium, keyhole hip surgery is here to stay, with many of the technical problems involved with inserting an arthroscope into a tight joint overcome. In the days before the operation was possible only open hip surgery was available, involving a large incision, a hospital stay of 7 days or longer, and the risk of exposing the joint to the ravages of arthritis in later years. To open a hip without the arthroscope requires it to be dislocated. In the process of doing so it is possible to damage vital blood vessels that supply the ball. This damage can in turn lead to arthritis.
Hip arthroscopy is usually a daycase operation and normally requires a general anaesthetic. It takes approximately 45 minutes to perform. Pressure is applied to the foot in order to distract the hip so that sufficient space can be made for the arthroscope. Fluid is passed through the hip joint under high pressure to clear any debris. Operating instruments can also be passed into the joint so that surgical procedures can be undertaken. Hip arthroscopy is not all about diagnosis. It is possible for quite complex operations to be undertaken as well. Some examples of why hip arthroscopy might be used are as follows:
Unknown hip pain
It is not possible to say a hip is normal without looking inside the joint. On one occasion over 150 loose fragments were removed from a hip joint when all preoperative scans and X-rays were reported as normal.
Hip arthroscopy in action. Distending and distracting
the hip joint to make space for arthroscope insertion.
Arthritis
(osteo- and rheumatoid) An arthritic joint can be cleaned using the arthroscope. It does not always relieve pain, but is much less invasive than a major joint replacement.
Loose bodies
Loose bodies are small fragments of bone that come adrift inside the joint, sometimes causing painful spasms and locking of hip movement. They can often be removed via the arthroscope.
Ligament and cartilage (labrum) tears
The hip contains a large ligament that can easily be torn and a structure called the 'labrum'. Though in the hip, a labrum looks like a knee cartilage and can be damaged during sport, or as a result of arthritis.
Torn acetabular labrum. This was removed
arthroscopically as a daycase operation.
Synovitis
The lining membrane of the hip joint ('synovium') can become inflamed and may occasionally need to be removed. This is easily performed arthroscopically.
Infection
The hip can become infected, just like many other parts of the body. Causes might include Staphylococcus aureus, tuberculosis, and other organisms. Hip arthroscopy is an excellent way of establishing the true nature of the infecting organism so that appropriate antibiotic treatment can be commenced, as well as cleaning out the infection itself.
Fractures
Major injuries can sometimes cause the pelvis to fracture. This can result in small bone particles breaking loose within the hip joint. These are best retrieved, hip arthroscopy being an excellent method of doing so.
Tumours
Very rarely it is possible for tumours to grow inside a hip. They can be identified and often removed using the arthroscope.
Lipoma of the hip joint. A benign, rare condition that is amenable to arthroscopic removal. All of this patient's preoperative investigations (XRay, MRI, CT, isotope scan) were normal, until hip arthroscopy revealed the true diagnosis.
Hip arthroscopy is not widely available as it requires much specialist equipment and takes a long time to learn. Complications are few, occurring in less than 2% of patients, though it should be remembered that up to 5% of people feel worse rather than better after the operation. It can also take three months to fully settle, much physiotherapy being required during this time.
Case history
Cheryl is a 45 year-old waitress. Five years ago she fell while shopping in a local supermarket, wrenching her hip as a result. She complained to her doctor who organised an X-ray. This was reported as normal so physiotherapy was arranged. This improved matters to a limited extent. Cheryl managed to carry on working part-time during this period, though had to give up her favourite sport of badminton. She was eventually referred to an orthopaedic surgeon who organised several more detailed tests, including an MRI (magnetic resonance imaging) scan. These tests were also normal. The orthopaedic surgeon was also unable to establish a diagnosis and so referred Cheryl to a specialist in hip arthroscopy. This was undertaken as a daycase operation, a torn ligament being found. The torn area was removed through the arthroscope, surgery being followed by copious physiotherapy. Within four weeks Cheryl had fully recovered and has now returned to full-time work, and badminton. She is even thinking of entering the next London Marathon!