When diagnosing hip pain, the first thing many people think of is osteoarthritis – specifically coxarthrosis . However, osteoarthritis is often simply ruled out, leading to the conclusion that it can't be a serious hip problem. This is dangerous. There are numerous hip conditions that are congenital or develop in childhood/adolescence – and these can cause significant discomfort, even if signs of osteoarthritis are only apparent late or not at all. For younger patients, this can have fatal consequences if changes are overlooked or treated too late.

This article will tell you:

• how osteoarthrosis and coxarthrosis are defined, how they develop
• what secondary osteoarthritis is
• which hip diseases are frequently overlooked (e.g. hip dysplasia, retroverted acetabulum, Perthes disease, slipped capital femoral epiphysis, femoroacetabular impingement)
• how these diseases are recognized, diagnosed and treated – also with regard to artificial hip joints (total hip replacement)
• when surgery makes sense – and why “waiting as long as possible” isn't always the best option
• What patients should pay attention to – including advice to consult a hip specialist

Osteoarthritis, coxarthrosis and secondary osteoarthritis: terms and basics

What is osteoarthritis?

• Osteoarthritis is a joint disease characterized by degenerative wear and tear of the articular cartilage. When it affects the hip joints, it is specifically referred to as hip osteoarthritis or coxarthrosis .
• Characteristic symptoms include pain during exertion, start-up pain (e.g., after prolonged sitting), restricted movement, and possibly rubbing or grinding noises.

What is coxarthrosis?

• Coxarthrosis refers to osteoarthritis of the hip joint. In this condition, the cartilage between the femoral head and the acetabulum wears down, leading to impaired joint function.
• The causes are varied: age, overuse, misalignments, previous illnesses or injuries.

Primary vs. secondary osteoarthritis

• Primary osteoarthritis : Osteoarthritis in which no clear triggering mechanism (such as misalignment, injury, pre-existing condition, etc.) can be identified. Usually slow and age-related.
• Secondary osteoarthritis : Osteoarthritis that develops as a result of a known pre-existing condition of the hip, such as misalignment, childhood illness, trauma, overuse, etc. These forms often begin earlier and can be more severe.

Why ruling out osteoarthritis ≠ solving the problem

• Just because images (e.g., X-rays) don't clearly show osteoarthritis doesn't mean there are no hip problems. Many conditions cause pain, restricted movement, muscle problems, or mechanical conflicts that haven't yet led to visible cartilage wear or where the wear isn't presented in a typical way.
• Young adults and adolescents in particular often have anatomical misalignments that only lead to osteoarthritis later – but already cause significant discomfort.

Common hip conditions that are often overlooked – explained in detail

dysplasia
is a congenital or childhood-undiagnosed malformation of the hip joint. It results in the femoral head not being fully and securely seated in the acetabulum. Patients often experience pain in the groin or on the side of the hip, especially when walking or standing for extended periods. A slight limp or muscle tension may also occur. Diagnosis is made through clinical examinations, gait analysis, and special X-rays that measure angles such as the acetabular roof angle and the center-corner angle. An MRI is often performed additionally to visualize labral or cartilage damage. If left untreated, hip dysplasia frequently develops into secondary osteoarthritis of the hip (coxarthrosis) in young adulthood. In severe cases, a total hip replacement (THR) is therefore necessary at a young age.

Retroverted Acetabulum
: A retroverted acetabulum is a malposition of the hip socket, which is rotated too far posteriorly. This can be congenital or acquired. Affected individuals often report groin pain or discomfort when flexing and internally rotating the hip. Diagnostic procedures require specific X-rays and CT/MRI scans to determine the acetabular angle and version. If left untreated, this malposition leads to increased mechanical pressure on the articular cartilage, which can result in labral tears and premature cartilage wear. In the long term, this often leads to secondary osteoarthritis.

Femoroacetabular impingement (FAI)
is caused by a malformation of the femoral neck (CAM type) or an overhanging acetabulum (pincer type). During movement, a mechanical conflict arises between the acetabulum and the femur. Typical symptoms include groin pain, which occurs with deep flexion or rotational movements, but also at night or after prolonged sitting. Often, mobility is significantly restricted. Diagnosis includes clinical impingement tests, special X-rays, and an MRI, often with contrast to visualize labral tears. If the impingement is left untreated, cartilage and labral damage can develop, leading to secondary osteoarthritis of the hip and necessitating total hip replacement.

Perthes disease
is a circulatory disorder of the femoral head in childhood, usually occurring between the ages of 4 and 11, and more frequently in boys. Symptoms include limping, pain in the hip or knee, and restricted movement. Over time, permanent deformity of the femoral head can develop. The diagnosis is made using X-rays, often supplemented by MRI to assess the extent of the circulatory disturbance. Without timely treatment, the deformities can lead to uneven stress on the joint, which in the long term causes secondary osteoarthritis of the hip. Many affected individuals therefore require a total hip replacement (THR) by middle adulthood.

Slipped capital femoral epiphysis (SCFE)
is a condition that typically occurs during the growth spurt of puberty, often affecting overweight adolescents. In SCFE, the femoral head slips out of place on the growth plate. Symptoms include gradual pain in the hip or knee, a significant limitation of internal rotation, and sometimes sudden, acute pain in cases of complete slippage. Affected individuals develop external rotation of the leg. Special X-ray views, such as the Lauenstein projection, are used for diagnosis. An acute slippage requires immediate surgical stabilization to prevent permanent damage. If the condition is not diagnosed in time, it can lead to permanent deformity of the femoral head, which in turn can cause labral and cartilage damage and potentially result in secondary osteoarthritis or coxarthrosis in young adulthood.

Other Causes of Hip Pain
Besides these typical conditions, there are other, less common causes. These include avascular necrosis of the femoral head outside of childhood, inflammatory joint diseases such as rheumatoid arthritis, infections, or the consequences of injuries. Misalignment of the hip joint or muscular imbalances can also lead to chronic hip pain. All of these conditions, if left untreated, can eventually lead to secondary osteoarthritis and thus to a significant loss of hip joint function.

Late consequences: Secondary osteoarthritis & coxarthrosis

• As mentioned above, secondary osteoarthritis from pre-existing damage: misalignments, childhood illnesses, slippage, overloading, etc.
• Studies show that, for example, hip dysplasia is a significant risk factor for early hip osteoarthritis – many patients with dysplasia need an artificial hip joint between the ages of 25 and 50.
• Following Perthes disease, many affected individuals develop a deformity of the femoral head in adulthood, which can disrupt joint congruity and thus lead to premature coxarthrosis.
• In cases of slipped capital femoral epiphysiology (SCFE), the risk of developing osteoarthritis later in life is high – depending on the severity and treatment: studies indicate a risk of between approximately 15% and 70% if the slippage is pronounced.

Diagnostics: How can hip diseases be detected early?

To avoid misdiagnosis or underdiagnosis, the following steps are crucial:

1. Medical history

• Onset of symptoms: sudden or gradual, since when, course
• Type of pain: exertion, rest, night, sitting, walking, sports
• Radiation: groin, thigh, knee
• Previous hip conditions or childhood illnesses, surgeries, malpositions
• Growth age, weight, lifestyle (sports, stress)

1. Clinical examination

• Check hip movement: flexion, extension, internal/external rotation, abduction
• Specific tests for impingement (e.g., flexion + internal rotation)
• Gait pattern, leg length, external rotation, limping
• Muscle status, stability

1. Imaging

• X-ray images : pelvic overview, special projections (Lauenstein, Dunn, etc.)
• View of tile roof angles, tile roofing, tile version (retro version), shape of the femoral neck (CAM/Pincer)
• MRI: Cartilage, labrum, early signs of deformities or cartilage damage
• If necessary, CT scans for precise 3D assessment of misalignments

1. Further diagnostic testing if needed

• Laboratory tests if inflammatory causes are suspected
• Gait analysis
• If necessary, consult a pediatric orthopedist if pre-existing childhood conditions are suspected

Treatment options

Depending on the illness, age, extent and symptoms, there are various treatment approaches.

Conservative (non-operative)

• Physiotherapy: Building and maintaining the muscles around the hip joint, stretching exercises, mobilization
• Load adjustment: Choose sports that are easy on the joint (cycling, swimming vs. jumping, abrupt twisting movements)
• Weight reduction in cases of obesity to reduce mechanical stress
• Pain management as needed: e.g., NSAIDs
• Regular monitoring: if necessary, follow-up examinations using imaging techniques (X-ray, MRI)

Conservative treatment can be very effective, especially if started early. However, many of the aforementioned hip diseases, in cases of pronounced malformation or after growth-related changes, will sooner or later lead to a situation where conservative treatment alone is no longer sufficient.

Surgical therapy

• Osteotomy : Repositioning of the acetabulum (e.g., periacetabular osteotomy according to Ganz, etc.), femoral osteotomies, triple osteotomy, etc. Goal: Correcting malposition, bringing the acetabulum and femoral head into optimal alignment. For example, in cases of hip dysplasia or retroversion.
• Corrections in adolescence or childhood : Perthes disease: Operations to improve containment in order to reduce deformities.
• Slipped capital femoral epiphysis (SCFE) : Immediate surgery in case of acute slippage; in case of chronic course, also surgery to stabilize and prevent trajectory degeneration.
• Procedures for impingement : Arthroscopic or open surgery to remove bone protrusions and repair labral damage.
• Artificial joint (hip replacement) : This procedure is indicated when the joint is already severely damaged, pain persists despite conservative and joint-preserving measures, or malalignment and wear have progressed to the point of significantly impairing quality of life. Young patients can also be affected, particularly if pre-existing conditions such as dysplasia are present.

When is a total hip replacement necessary, even in young patients?

• If there is already severe pain, pain at rest, or restricted movement that cannot be adequately relieved by conservative and joint-preserving surgical procedures.
• When misalignments are so pronounced that they can no longer be corrected or their correction carries a high risk.
• If the articular cartilage, labrum and bone are already so badly damaged that continuing without an artificial joint would lead to permanent functional impairments, compensatory postures or osteoarthritis symptoms.
• Modern hip replacement surgery has improved significantly – materials, surgical techniques, minimally invasive approaches mean better durability, faster rehabilitation and often very good functional results.

“Waiting as long as possible” for a hip replacement – ​​a curse or a blessing?

• It is often advised to postpone surgery for as long as possible so that a hip replacement can be performed later, if necessary. This may be sensible in certain cases, but not generally.
• If malalignment is present, especially in childhood/adolescence, delayed intervention often leads to irreversible damage (deformed femoral head, cartilage tears, labral tears). Even if osteoarthritis is not yet visible, function may already be severely impaired.
• In young people with hip dysplasia or impingement, for example, it is worthwhile to perform joint-preserving surgeries early enough to delay or prevent the development of coxarthrosis or secondary arthrosis.
• Even if a total hip replacement becomes necessary sooner, many patients benefit from modern hip prostheses in the form of freedom from pain, freedom of movement, and a high quality of life. The durability of modern prostheses is significantly better than in the past; many studies show that after 10 years, over 90% of prostheses are still intact; after 20 years, usually over 80-90% are still functioning, depending on age, stress, material, etc.

Diagnostic and therapeutic: What patients should pay attention to

If you have hip pain, here are some tips to make sure nothing is overlooked:

1. Go to a hip specialist – not just a general orthopedist. A specialist in hip and joint surgery, ideally with experience in hip replacement and joint-preserving procedures.
2. Insist on a comprehensive diagnosis – even if osteoarthritis has been ruled out. Specifically ask about misalignments, childhood illnesses (Perthes disease, SCFE), and impingement.
3. Request special images – special X-rays, MRI, etc. – to assess the version of the acetabulum, the shape of the femoral neck, any deformity, and the labrum.
4. Early therapy – physiotherapy, load modification, weight management; if indicated, joint-preserving surgery.
5. Learn about modern hip replacements – especially important if your symptoms are severe and your quality of life is suffering.
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Summary

• Not all hip problems are osteoarthritis, and just because osteoarthritis is not visible does not mean that there is no serious hip condition.
• There are many causes of hip disorders – congenital or occurring in childhood/adolescence – which can cause discomfort earlier and lead secondary osteoarthritis/coxarthrosis
• Diagnosis and treatment must be individualized; conservative methods can be helpful, but in cases of pronounced malpositions or damage, surgical interventions or hip replacement are necessary, even in young people.

Hip disorders in focus: examples and special cases

To make the above principles more tangible, here are some case studies or typical courses of events as observed in specialized clinics:

Case study A: Hip dysplasia, undetected until young adulthood

• The patient, in her early 30s, has had occasional groin pain since childhood, which was attributed to muscle tension. She is able to participate in sports, but experiences groin tension during prolonged exertion. X-rays show acetabular roof underfilling, minimal coverage of the femoral head, but no significant arthritic changes.
• Treatment measures include targeted physiotherapy, reduced stress on the joint, and, if necessary, corrective osteotomy of the acetabulum to correct misalignment. Early intervention can significantly alleviate pain, considerably improve quality of life, and delay the onset of osteoarthritis of the hip.

Case study B: SCFE (Epiphysiolysis capitis femoris), late diagnosis

• Adolescent, overweight, pain initially in the knee, later also in the hip. Diagnosis: SCFE (spondylodesis of femoral head injury) in the intermediate stage; significant slippage angle. Without treatment, there is a risk of the femoral head remaining deformed, cartilage damage, and later, osteoarthritis of the hip.
• Measures: depending on the stage, immediate surgical fixation, possibly corrective osteotomy later, monitoring, possibly early hip replacement if function is severely restricted.

Case Study C: Femoroacetabular Impingement

• Young, active patient, plays sports. Recurring discomfort when squatting deeply or sitting for extended periods, groin pain. No visible signs of osteoarthritis. Examinations reveal a CAM (camber-on-the-mouth) shape and a labral tear.
• Treatment: arthroscopic correction (removal of bone spurs, labrum repair), exercise therapy, possibly modification of sports activities. Goal: prevention of premature secondary osteoarthritis or coxarthrosis.

Why ENDOPROTHETICUM Rhein-Main & Prof. Kutzner

If you find yourself in this situation, it is particularly helpful to consult a hip specialist. The ENDOPROTHETICUM Rhein-Main, under the direction of Prof. Dr. med. Kutzner, offers:

• Extensive experience with all hip diseases – dysplasia, impingement, SCFE, Perthes disease and modern hip arthroplasty
• Expertise in joint-preserving surgeries as well as hip replacements in young patients
• modern diagnostic procedures and imaging
• Individualized therapy planning that doesn't prematurely put you off

Conclusion & Recommendations

• Hip disorders extend far beyond osteoarthritis. When experiencing hip pain, it's worthwhile to take the differential diagnoses seriously.
• Secondary osteoarthritis often arises from neglected or late-treated malpositions or childhood illnesses.
• Especially for young patients, the earlier diagnosis and intervention, the better the function and quality of life – and the later or less frequently an artificial joint will be needed.

Call to action

If you are suffering from hip pain and have only been told that "osteoarthritis has been ruled out," don't simply accept this. There could be another hip condition that requires treatment. Schedule an appointment with Prof. Kutzner at the ENDOPROTHETICUM Rhein-Main ( www.endoprotheticum.de ) . Here you will find a hip specialist with extensive experience and state-of-the-art hip replacement surgery. Together, you can conduct a precise diagnosis and receive a treatment plan tailored to your individual needs.