back top
Diagnosis and Treatment of Hip Disorders
Foot & Ankle Banner sidebar

Diagnosis and Treatment of Hip Disorders

Cartilage injuries of the hip typically involve damage to the acetabulum (hip socket) or the femoral head (ball) of the hip joint. However, by far the most common injuries occur on the side of the acetabulum.

Intended audience

This article is intended for anyone suffering from damage to their articular cartilage and their families who would like to find out about disorders of the hip and their treatment, as well as anyone interested in cartilage problems.

Figures

Total Hip

What cartilage disorders occur in the hip?

Of the cartilage injuries on the acetabular side, the majority are related to ‘femoroacetabular impingement’ (FAI), or what is commonly referred to as hip impingement. This occurs when there is a mismatch between the ball and socket of the hip joint. A conflict then occurs between the ball and the socket, which leads to a pinching or ‘impingement’, which ultimately damages this area of the hip.

The impingement can result in tearing of the labrum and damage to the nearby articular cartilage of the hip socket (acetabulum). This is an extremely common problem, and hip preservation specialists spend considerable amount of time treating this type of hip impingement. Consequently, such specialists are constantly searching for better ways to manage these challenging problems.

Cartilage injuries can also occur on femoral head part of the joint. Fortunately, femoral head cartilage injuries are less common, as they are generally less forgiving and harder to successfully treat than those on the acetabular side.

How do cartilage injuries of the hip develop?

Femoral head cartilage injuries tend to be more commonly associated with trauma. An example is the athlete who has sustained a partial dislocation (subluxation) of the hip. In this scenario, as the femoral head gets pushed out of the socket, a ‘divot’ can be inflicted on the surface of the femoral head cartilage, which may cause significant damage to the femoral head.

Acetabular injuries tend to develop in a more subtle fashion, and are almost always associated with hip impingement resulting from a long-standing (chronic) conflict or mismatch between the ball and socket, as described above. This mismatch only occurs when the hip is in a flexed position (when the bent knee is forced up towards the chest). Patients therefore tend to experience pain with activities that involve this motion, referred to as ‘flexion’ of the hip.

Indeed, hip flexion is used by doctors to test whether hip impingement is present. The physician will place the hip in a ‘flexed’ position by forcing the bent knee toward the chest and towards the opposite side of the body. This is called the ‘impingement test’ – if it causes pain, it is quite likely that the hip cartilage and/or labrum have been injured.

This so-called FAI, or hip impingement, is an extremely common problem. It is by far the most commonly encountered problem during hip arthroscopy.

The earlier the diagnosis is made, the higher the chance the patient can be successfully treated with hip arthroscopy. The reason for this is simple – if the problem is recognised earlier in a patient’s life, the cartilage will not have had the chance to become severely damaged. The more severe the cartilage damage, the harder it is to achieve a pain-free existence after surgery.

Which cartilage repair techniques are used in the hip?

As in cartilage injuries of the knee, patients have varying degrees of cartilage damage in their hip. In its mildest form, the front (anterior) edge of the acetabular cartilage is simply soft. This is called a grade 1 classification.

As the disease progresses, or the impingement progresses, the articular cartilage starts to ‘delaminate’ (separate), from the underlying bone in that region. This is a grade 2 or grade 3 lesion or defect. When you run a probe along the articular cartilage you see what is called a wave sign, which is an early sign of delamination (separation). If this progresses and becomes a grade 3 lesion, you can see the cartilage start to separate from the bone.

A grade 4 lesion is where there is not only delamination, but the cartilage is starting to peel away from the bone, which is similar to that seen in a severe cartilage injury of the knee.

If the articular cartilage is intact and still attached to the labrum, typically nothing further is done. The underlying impingement that is causing it is taken care of, which usually allows the stress from the cartilage to be eliminated, and these patients improve readily.

However, cartilage repair is attempted if there is a disruption of the cartilage, particularly frayed cartilage at the junction between the cartilage and the labrum, which is not uncommon. The labrum in that region will be repaired, and the continuity between the cartilage damage and the labrum restored.

In more severe cases, where there has been a delamination and exposed bone, cartilage restoration will be performed. Usually, the first line treatment is microfracture, as it would be for the knee. Several studies have looked at microfracture for acetabular cartilage defects, and generally reported good results. Success rates range from 80% to 90%, with most studies showing good or excellent results.

Non-surgical treatments should also be considered in patients who are suffering from articular cartilage-related pain, whether it is due to osteoarthritis or more specific (focal) areas of cartilage damage. Similar to treatments of the knee, various injectable solutions may prove soothing to the painful hip joint. These include viscosupplements (hyaluronic acid lubricants) and ‘orthobiologic’ products, including platelet rich plasma and mesenchymal stem cells, which are cells that are capable of becoming a variety of different cell types.

While it is too early to tell whether these types of injections can actually stimulate a healing response in the cartilage, we do know that some patients can experience relief from their hip pain for varying periods of time after these injections.

Patients should talk to their hip doctor as to which type of treatment best suits their situation.

What is the expectation for a patient in terms of their recovery?

Fortunately, patients with grade 4, or more severe, articular cartilage injuries of the acetabulum have better outcomes than the typical patient with a grade 4 lesion in the weight-bearing surface of the knee.

Similar to an osteotomy in the knee, an osteoplasty of the hip takes the weight off the cartilage defect. Osteoplasty involves removal of the ‘impinging bone’, and so the stress that created the articular cartilage defect is eliminated. The subsequent microfracture procedure is therefore less exposed to stress and heals more readily.

Patients undergoing these procedures typically need crutches for 4–6 weeks, depending on the individual surgeon’s preference over weight bearing and the individual rehabilitation programme. Patients are allowed to perform a limited range of motion during that period and some simple exercises.

After 4–6 weeks, the patient is allowed to progress to weight bearing, as tolerated, and then to more aggressive strengthening exercises. An athlete who has undergone a microfracture procedure can return to their sport as soon as 4–6 months.

Frequently asked questions

The most common question that patients ask is:

  • What happens if the microfracture does not work?
  • What are the options for treating this area if I continue to have pain?

That leads to a discussion about second-line treatments, which is currently an area of controversy, as well as intense research, just as it is in the knee.

Many case reports and case studies have been published on treatments for articular cartilage lesions of the acetabulum and the femoral head, ranging from autologous chondrocyte implantation (ACI) of the femoral head to OATS (osteoarticular transfer system), as well as osteochondral allograft. Fibrin glue, along with other types ofbioscaffolds and allogenic cartilage grafts, has also been used in the area.

Thank You for Your vote

How useful did you find the information on this page?

Rating

5 (1 vote)