Hip arthroscopy, also known as hip joint mirroring, has established itself in recent years as a minimally invasive procedure for certain hip problems. It allows for small incisions to be made to inspect the joint and simultaneously treat tissue damage. Especially in active, athletic patients or young adults suffering from hip pain, this procedure appears at first glance to be an ideal solution: less tissue trauma, shorter rehabilitation times, and the joint remains intact. However, these hopes are not always fulfilled - particularly not in cases of hip dysplasia.

Hip dysplasia is one of the most common congenital malformations of the hip joint and affects many people, often without them noticing it for years. Over time, pain, mobility problems, and even osteoarthritis can occur. Many affected individuals then look for the most gentle treatment methods possible to save their hip. Hip arthroscopy seems to be a promising option here - but in the case of hip dysplasia, reality is often sobering. This article sheds light on why this is the case and what alternatives are available.

What is hip dysplasia?

Hip dysplasia is a malformation of the hip joint in which the acetabulum does not adequately cover the femoral head. This leads to an incorrect pressure distribution in the joint, which in the long term favors cartilage damage, labral damage, and eventually osteoarthritis.

Causes and Development

Hip dysplasia is usually congenital. Common causes include genetic factors, position in the womb, and certain risk factors such as breech position at birth. If it is not detected and treated early, this can lead to persistent complaints and premature joint wear.

Symptoms

Typical symptoms are:

• Groin pain, especially during movement
• Initially hypermobility, then restrictions on mobility
• Cracking noises in the joint
• Feeling of instability

Individual risk factors for hip dysplasia

Not every hip dysplasia is the same. The degree of malformation, patient age, activity level, and existing comorbidities play a crucial role. Young, physically active patients with mild dysplasia tend to consider arthroscopy - but results are often disappointing. Precise diagnostics, including imaging and clinical examination, are essential to make the right treatment decision.

Long-term biomechanical consequences of hip dysplasia

Untreated hip dysplasia leads to excessive stress on certain joint structures in the long term. The labrum, cartilage, and bone itself are exposed to increased stress. Even if arthroscopy provides short-term relief, the underlying cause remains. The risk of early osteoarthritis and ultimately a necessary hip replacement increases. Studies show that patients with dysplasia who undergo arthroscopy require a prosthesis sooner on average than patients without dysplasia.

Conservative alternatives in the treatment of hip dysplasia

Not every patient with hip dysplasia needs immediate surgery. In early stages, targeted conservative measures can help:

• Physical therapy to strengthen stabilizing muscles
• Pain therapy for symptomatic relief
• Hip-centering exercises to improve biomechanics
• Weight reduction to reduce joint stress

However, the underlying problem remains: a malposition cannot be corrected conservatively. Therefore, these measures are more suitable for delaying surgery.

Hip arthroscopy - what is it?

Hip arthroscopy (hip joint mirroring) is a minimally invasive procedure in which a camera is inserted into the joint through small incisions. This allows the doctor to inspect the joint and simultaneously treat damage. Typical indications for hip arthroscopy include:

• Labral damage
• Cartilage defects
• Loose bodies
• Impingement (CAM or Pincer impingement)

Procedure of hip arthroscopy

The intervention is performed under general anesthesia or spinal anesthesia. The leg is slightly stretched to allow access to the hip joint. Through small incisions, the surgeon inserts a camera and special instruments. This allows him to inspect the structures in the joint and perform treatments such as cartilage smoothing, labrum refixation, or removal of bone growths.

Benefits of hip arthroscopy

• Minimal incisions: Less scarring
• Faster recovery: Less tissue damage compared to open surgery
• Targeted treatment: Direct access to joint structures

Good indications for hip arthroscopy

While hip arthroscopy is often not useful in hip dysplasia, there are numerous other indications for which it represents an effective treatment option. These include in particular:

• Femoroacetabular Impingement (FAI): In this osseous deformity, there is a pinching between the femoral head and acetabulum. Arthroscopy can remove excess bone material and improve mobility.
• Labral tears without structural dysplasia: In cases of traumatic labral tears, a repair can be performed to restore labral function.
• Cartilage damage: Isolated, non-degenerative cartilage defects can be smoothed or treated with modern cartilage therapies.
• Loose bodies: Detached cartilage or bone fragments can cause blocking pain and can be removed arthroscopically.
• Synovitis: Inflamed synovial tissue can be removed, reducing pain and inflammatory processes.

The exact indication should always be made after a thorough clinical examination and imaging by an experienced specialist.

Why hip arthroscopy is often not successful in hip dysplasia

Hip arthroscopy cannot address the actual problem of hip dysplasia - the inadequate bony coverage of the femoral head. Here are the central reasons:

1. Biomechanical problems persist

The lack of coverage leads to an increased load on the labrum and cartilage. An arthroscopy can smooth or remove damaged structures, but the actual cause of the incorrect loading remains. This often leads to the symptoms recurring after a short time.

2. Degenerative labral damage

In hip dysplasia, labral damage is usually not traumatic, but degenerative. The labrum tries to compensate for the lack of coverage, which leads to overload. Removing the labrum can further worsen stability, as the labrum plays a crucial role as a sealing ring and shock absorber in the joint.

3. Risk of further instability

A dysplasia is inherently an unstable joint. The removal of damaged tissue can exacerbate this instability, leading to more pain and faster wear and tear.

4. Insufficient long-term results

Studies show that hip arthroscopies in patients with hip dysplasia often result in poorer long-term outcomes. Pain and limited mobility often return because the underlying malalignment persists. This often leads to further surgeries.

5. Stress from repeated interventions

Many patients undergo further surgery after an unsuccessful hip arthroscopy – often a more extensive procedure, such as a periacetabular osteotomy or even a hip replacement. This not only prolongs the overall treatment duration but also increases physical and psychological stress.

When can hip arthroscopy still be useful in cases of hip dysplasia?

A hip arthroscopy can be useful in cases of hip dysplasia when there are accompanying pathologies that need to be treated independently of the dysplasia. Examples include:

• Impingement: If, in addition to dysplasia, there is a CAM or Pincer impingement, excess bone material can be removed to improve mobility and alleviate pain.
• Loose bodies
• Synovitis (synovial inflammation)

Alternative treatment options for hip dysplasia

Since hip arthroscopy cannot address the structural problems associated with dysplasia, other procedures are often more promising in the long term.

Periacetabular osteotomy (PAO)

In the early stages of dysplasia, a periacetabular osteotomy can be performed. The acetabulum is surgically reoriented to improve coverage of the femoral head, stabilizing the joint and reducing the strain on the labrum.

Short-stem prosthesis

If advanced osteoarthritis is already present, a hip replacement is often the best option. Especially in young patients, a short-stem prosthesis is a suitable choice. This preserves more bone substance than conventional prostheses and allows for easier revision later on, if needed.

Conclusion: Hip arthroscopy is often not suitable for hip dysplasia

Hip arthroscopy may be an effective solution for many hip problems - but in cases of hip dysplasia, it rarely shows lasting success. The inadequate coverage of the femoral head remains, ensuring that pain and instability persist or even worsen. While concomitant pathologies such as impingement or loose bodies can be treated arthroscopically, the actual structural problems of dysplasia can only be sustainably addressed through osteotomies such as PAO or - in cases of advanced wear - through a hip prosthesis.

Therefore, individuals suffering from hip dysplasia should seek comprehensive advice from a specialist to obtain the best possible treatment plan.