Hip Osteoarthritis: Causes, Symptoms, and Treatments

Osteoarthritis of the hip, also known as coxarthrosis, is a chronic inflammatory condition characterized by the wear and tear of the articular cartilage present in the hip joint. This degenerative disease can significantly impact the quality of life of affected individuals, limiting mobility and causing persistent discomfort. This article aims to provide a comprehensive understanding of hip osteoarthritis, exploring its causes, symptoms, stages, and treatment options.

A Look at the Hip Joint

The hip joint, also known as the coxofemoral joint, is a critical part of the human body that connects the lower limb to the trunk. It is the joint that links the head of the femur (thigh bone) to the acetabulum of the pelvic bone. The hip joint is essential for maintaining an upright position and facilitating the movement of the lower limbs.

The hip joint's anatomy is characterized by the perfect fit between a spherical joint surface (the head of the femur) and a concave joint surface (the acetabulum). This structure allows for high mobility. The hip joint is equipped with ligaments, a joint capsule, layers of articular cartilage on the surfaces of the acetabulum and head of the femur, synovium, and synovial bursae. Additionally, tendons and muscles surround the hip joint, contributing to its motility.

Understanding Hip Osteoarthritis

Hip osteoarthritis, or coxarthrosis, is a chronic inflammatory disease that affects the hip joint. It is characterized by the progressive wear and tear of the articular cartilage within the joint. This condition is synonymous with hip arthritis and hip osteoarthritis.

Osteoarthritis is a form of arthritis that involves the degeneration or "wear and tear" of the articular cartilage. Of the numerous forms of arthritis that exist, osteoarthritis is the most widespread, affecting millions of people worldwide.

Causes and Risk Factors

Coxarthrosis is typically the result of a degenerative process that affects the articular cartilage covering the surface of the acetabulum and head of the femur. This degeneration leads to the thinning of the cartilage, resulting in abnormal rubbing of the underlying bone portions, which subsequently become inflamed.

Several factors contribute to the development of coxarthrosis, including advanced age, hip trauma or fractures, joint or bone infections affecting the hip, and congenital hip diseases. Sometimes, coxarthrosis may occur without any identifiable cause, a condition referred to as idiopathic coxarthrosis.

While these factors can increase the risk of developing coxarthrosis, other risk factors include a sedentary lifestyle, obesity, diabetes, and the presence of other forms of arthritis. Coxarthrosis can affect one (unilateral) or both (bilateral) hip joints, depending on the conditions that trigger the degeneration of the articular cartilage.

Symptoms and Stages

Coxarthrosis is marked primarily by pain that manifests in various locations around the hip. Patients typically experience discomfort in the outer hip area, groin, buttocks, and the anterior-upper thigh. This pain not only affects mobility but also contributes to stiffness within the joint, further complicating daily activities.

The pain associated with this kind of arthritis may vary in intensity and is often exacerbated by certain positions or movements, leading to an increased difficulty in performing tasks that require bending or twisting at the hip. Over time, the affected joint may exhibit a reduced range of motion, accompanied by a grinding sensation or audible clicking sounds due to the deterioration of cartilage.

Stages

Coxarthrosis develops progressively through three main stages, each characterized by an increase in symptom severity and impact on joint function:

1. Early Stage: Pain during this stage is typically intermittent, occurring after moderate to high-intensity physical activity. It may subside with rest and is not constant. There is minimal impact on joint function, although slight stiffness may be noticed after periods of inactivity or upon waking in the morning.‍
2. Intermediate Stage: As the condition worsens, pain becomes more persistent and intense, often extending over a larger area of the hip. It may begin to occur even during periods of rest or with minimal activity. Mobility decreases noticeably, and individuals may start to experience significant difficulties with daily movements such as walking, climbing stairs, or standing for prolonged periods.‍
3. Advanced Stage: Pain is continuous and severe, occurring even without physical activity. It becomes a constant companion, significantly affecting the quality of life. There is a marked restriction in hip movement, with severe stiffness and potential deformity. At this stage, surgical interventions such as hip replacement may be considered to restore mobility and reduce pain.

Diagnosis

The diagnostic process for coxarthrosis typically begins with a physical examination and medical history. Depending on the circumstances, further diagnostic procedures may include imaging tests (such as hip X-rays, MRI, and ultrasound), blood tests, and arthroscopy for diagnostic purposes.

Treatment Options

The treatment of coxarthrosis primarily depends on the severity of the condition. In cases with mild or moderate symptoms, conservative therapy involving rest, medication, and physiotherapy may suffice. However, in severe cases, surgical intervention may be necessary.

Conservative treatments aim to alleviate symptoms but cannot reverse the damage to the articular cartilage. They may include rest from high-impact activities, medication to control pain and inflammation, and physiotherapy to improve joint mobility and flexibility.

Surgical treatments for coxarthrosis include resurfacing surgery and hip replacement surgery. Resurfacing surgery involves replacing the articular surface of the acetabulum and the head of the femur, while hip replacement surgery involves replacing the acetabulum and the head of the femur with artificial components.

An emerging treatment option is regenerative medicine, which involves intra-articular infiltration of mesenchymal stem cells (MSC) from human adipose tissue. This treatment leverages the remarkable capabilities of MSCs to differentiate into a layer of hyaline-like cartilage, partially restoring the original cartilage layer.

Prognosis and Prevention

Coxarthrosis is a chronic disease with a tendency towards continuous worsening. However, thanks to medical advancements, patients can benefit from effective treatments that can significantly improve their quality of life. While there are no definitive prevention measures for coxarthrosis, controlling body weight, engaging in regular low-impact physical activity, and preventing hip injuries can reduce the risk of developing this condition.