Groin and thigh pain are often the main symptoms of hip joint pathology. Movement restriction and pain in the hip joint due to coxarthritis often lead the patient to visit the doctor.
Osteoarthritis of the hip is one of the main causes of morbidity and disability in the elderly, and it is becoming more common with the current ageing of the population in western societies. Osteoarthritis is a slowly evolving, degenerative disease that causes loss of articular cartilage as well as destruction and proliferation of periarticular bone. Stiffness and altered joint biomechanics contribute to the loss of joint function and disability.
This joint degeneration process is usually accompanied by inflammatory signs, especially synovitis, and leads in many cases to joint pain that pushes the patient to seek medical attention.
Though conventional therapies to treat hip pain, such as analgesics and physiotherapy, may be effective, there is a group of patients with symptoms that do not respond to these therapies. Arthroplasty (hip prosthesis) has become readily available to patients with coxarthritis, but there is still a small group of patients, refractory to conventional therapies, in whom surgery is inadvisable and so for whom this procedure is not an option. A common reason why surgery would be inadvisable is that the caring orthopaedic surgeon feels that it is too soon in the evolution of the disease to carry out such a radical procedure, so considers it better to delay the arthroplasty for some time. Other times, the general condition of the patient, or an excessive overweight, forces the anaesthesiologist to refuse to carry out such a risky surgical procedure.
The sensory supply of the hip joint is provided by articular branches coming from several nerves (obturator, femoral and sciatic) and by the lumbar sympathetic plexus. The most important nervous suppliers are the articular branches of the obturator nerve and of the nerve to the quadratus femoris. The most bothersome pain is the pain involved in hip flexion (which prevents climbing of stairs, walking and putting trousers on) and hip external rotation (makes difficult genital area hygiene and sexual intercourse). This pain is mostly transmitted through the obturator nerve.
Open surgical section of the obturator nerve to treat hip osteoarthritis pain has been performed in the past, but the unsatisfactory results and residual symptoms attributable to nerve section led to a gradual decline in the popularity of the procedure, and it was eventually dropped. To eliminate these problems a percutaneous RF denervation was devised. This procedure has been perfected over the years to the present day and can be applied to the elderly as well as to people with poor general condition or significant obesity. It is carried out on an outpatient basis, so no admission to a hospital is required, and percutaneously, so it is performed using needles and does not, therefore, involve cuts in the skin.
Percutaneous RF hip denervation sketch
Intra-operative picture of percutaneous RF hip denervation
The results of this surgical procedure vary according to the degree of progression of the hip osteoarthritis, but the most important thing is that, if the pain is not controlled, a hip prosthesis is always available. It is not infrequent for the initial result to be satisfactory and then the pain to come back over time, in which case the procedure will have to be repeated.