The bone surfaces of our skeleton interface with each other through the joints.
The joints can be of different types depending on the relative movement between the bones that compose them: in some cases they connect two or more bones with extreme mobility, such as the hip, the knee, the shoulder; in other cases they joins together bones with limited mobility, such as the bones of the spine; in other cases they join absolutely immobile bones, such as those of the skull.

The joints, especially those subject to load and more involved in the movement, can be afflicted by pathologies that can lead to the need for joint replacement surgery.

These pathologies are multiple, they can be of different nature (degenerative, traumatic, congenital) and highly disabling.


Osteoarthritis is a degenerative pathological process of the articular surfaces that involves the entire joint (bone, cartilage, joint capsule).

It is a very common condition that usually occurs between the ages of 50 and 60, but can also occur at a younger age. It is classified as “primary” osteoarthritis when the origin is not known, or as “secondary” when it arises as a result of inflammatory processes (arthritis), endocrine (diabetes or gout), congenital (dysplasia) or traumatic, which alter morphology and joint function.

The arthritic pathology manifests itself with the wear and the gradual reabsorption of the articular cartilage, thinning of the articular space, anomalous production of bone (osteophytes), deformation of the articular edges, thickening of the capsule with formation of calcifications, resulting in acute pain and severe limitation in the movement.
The diagnosis is easily recognizable based on the symptoms and a simple radiographic examination. Therapy is planned based on the stage of progress.
The most affected joints are those of the hip (coxarthrosis), of the knee (gonarthrosis) and of the shoulder (omarthrosis).
The most effective therapy for the treatment of osteoarthrosis is surgery, with the prosthetic replacement of the articular edges involved. Pharmacological therapies, physiotherapy treatments, cortisone infiltrations or anything else can temporarily relieve pain but do not constitute a definitive solution.


Rheumatoid arthritis is a chronic and progressive inflammatory polyarthritis with autoimmune pathogenesis of the synovial joints.

It differs from arthritis because it initially affects the synovial membrane and not the cartilage, it affects with less frequency and at a more youthful age compared to osteoarthritis. Women are more affected (3: 1 ratio). It affects 1-2% of the population and the number of cases increases with age, in fact 5% of women over 55 are affected. Onset is mainly observed at the end of adolescence or between the 4th and 5th decade of life; a second peak is observed between 60 and 70 years.

An early variant of RA consists of rheumatoid arthritis of childhood.


Osteoporosis is a systemic and metabolic disease of the skeletal system, which occurs in the elderly and with greater incidence in women.

The result is an increase in the fragility of bones that are more easily subject to fractures.


In a normal situation, the joints of the lower limb (hip, knee and ankle) appear to be aligned on a common axis called the mechanical axis or load axis.

This axis in the tibia corresponds to the diaphyseal axis (anatomical axis) while in the femur the anatomical axis differs from the mechanical one, forming an angle of about 6 degrees (angle of physiological valgus).

If this alignment is modified there is a pathological situation with axial deviation, with consequent alteration of the articular biomechanics which over time leads to wear of the cartilage of the areas subjected to load bearing.