The Role of Hip Surgeons in Restoring Lost Mobility
Few of us are inclined to give a great deal of thought to the incredible role played by the 230 or so moveable joints in the human body. They range from those in the fingers that have enabled musicians to play piano concertos and authors to pen best-sellers, to those of the legs and feet that enable the ballet dancer and sprinter to excel at their arts. Of them all, it is the articulation between the pelvic girdle and the leg that is the largest and which has become an increasingly frequent concern for hip surgeons in most of the developed countries.
It is one of a group of six types of joints known collectively as synovial. In this case, it is an example of the ball and socket type and, as such, it is designed to permit the exceptionally wide range of movement associated with many human activities. When fully functional, it allows the leg to move backwards and forwards and from side to side, while also permitting a degree of rotation. However, it must be essentially frictionless. If it isn’t, hip surgeons will, almost certainly, be called on to repair the resulting damage at some future date.
There are a number of conditions that could give rise to increased friction between the articulating surfaces of the joint, and it is important to treat them in order to ease any pain and swelling. In more severe cases, treatment may be necessary to restore the patient’s mobility. Palliative measures, such as prescription painkillers and steroids can often provide relief for several years, but only a hip surgeon may be able to offer the patient a long-term solution once his or her medication starts to become less effective. This, of course, will depend on the nature of the problem
Traumatic injuries to this joint are a fairly common occurrence, particularly among elderly subjects who may be unsteady on their feet and more prone to falls. In such cases, the solution may be either pinning or fixation, and this should be conducted by specialised hip surgeons. During a pinning procedure, screws are surgically inserted into the head of the femur and then used to attach a plate, which is secured to the femora shaft by means of smaller screws. This serves to lock the two parts of the fractured bone together, immobilising them to assist healing and the restoration of structural integrity.
The second procedure, known as open reduction and internal fixation (ORIF), is generally reserved for treating more serious fractures and is often used by hip surgeons as an alternative to arthroplasty. An incision is made to reduce the fracture internally, after which a variety of metal fixtures are used in order to immobilise it. This is an option that tends to be reserved for younger subjects with good healing powers, so as to avoid the use of a prosthesis that might need to be replaced at a later stage. With elderly subjects, however, modern prostheses are now so robust that their lifespan tends to exceed that of their owners.
Recently, hip surgeons are performing a partial or total replacement of this joint far more frequently than was the case a decade or so earlier. The phenomenon appears to stem from the increased incidence of osteoarthritis. The condition causes erosion of the smooth layer of cartilage that normally covers the articulating surfaces of the acetabulum and femoral head and which, in combination with viscous synovial fluid that acts rather like lubricating oil, enables friction-free movement between the two.
The damage results in pain, swelling, and reduced mobility, and hip surgeons address these problems by surgically removing the damaged portions of the bone or bones involved and replacing them with artificial structures fashioned from tough materials. These include metals such as stainless steel, titanium, and an alloy of cobalt and chrome. Also used are the plastic known as polyethylene and, most recently, a variety of ceramics.
It is common practice to employ these materials in one of four basic combinations when assembling prosthetic joints. These are metal on plastic, metal on metal, ceramic on plastic, and ceramic on ceramic. In practice, there is no definitive evidence to suggest that any one of these four combinations may be better than any other. However, individual hip surgeons tend to have their own particular preferences. These will generally be based upon their personal experience, as well as their preferred technique of implantation.