Arthritis
Arthritis is the degeneration or wearing out of a joint. This process usually takes many years to occur, but trauma can significantly speed this process. The arthritis and joint degeneration will start years to decades before the first symptoms start. The pain often starts after a small injury and thus commonly people feel it was this that caused the problem, which is partially true. The injury can often be the last straw to an otherwise degenerating joint.
The natural history of arthritis is for an exacerbation followed by partial resolution leaving some residual pain. Exacerbations will slowly become more frequent and last longer, with the residual pain becoming greater each time, until it is painful and restricting all the time. In the early stages symptoms can be helped with anti-inflammatories and tramadol, also glucosamine and chondroitin, physiotherapy, acupuncture and chiropractics in selected people. Unfortunately none of these treatments have been shown to reliably alter or slow the natural course of the disease. The only cure is to replace the joint. This is very large surgery and all appropriate non-operative alternatives need to have been entertained and / or failed before consideration is given to this.
Arthroplasty
Arthroplasty is the replacement of joint surfaces. The hip and the knee are very common areas of arthritis. With the ageing population there has been and will be a further, steady increase in the amount of joint replacements required.
Hip Arthritis
Hip arthritis presents as pain in the buttock, groin, thigh and can travel down to the knee. The range of motion decreases and often flexion of the hip and internal rotation reciprocates the pain. X-rays are commonly characteristic, showing narrowing of the joint and extra bone formation. Occasionally the diagnosis is not completely clear as back pathology can mimic hip pathology. Here a steroid injection in the hip can help differentiate between the two.
Hip Osteoarthritis: http://orthoinfo.aaos.org/topic.cfm?topic=A00213
Hip replacement surgery is arguably one of the greatest advancements in medicine in the 20th century, rating up there with the discovery of antibiotics. Hip replacement is an extremely reliable procedure that has the ability to turn a person crippled with pain, back into an active member of society and in some situations back to sports.
A total hip is performed by cutting the top of the femur off and replacing it with a metal stem and a ball of variable size depending on the patients anatomy. The acetabulum or hip socket is reamed out and a new cup is placed in with a polyethylene (plastic) liner. We as orthopaedic surgeons have been trying to perfect hip replacements ever since it was first popularized by John Charnley in the 1960’s. We go through phases of making great leaps forward, punctuated by steps backwards. New technology is commonly introduced, however since a good hip replacement will last 15 or so years, it is not until new technology has been shown to reliably last longer than this that it can be considered superior. Many new advances which seemed very promising in laboratory or early studies, have been found to fail comprehensively when placed into people (ASR hip, modular necks). For this reason I only perform replacements that have components that have a track record proven in the New Zealand, Australian, Swedish and other International Joint registries. I also use components that are tailored to the individual, so I use both cemented and uncemented components. I use the cemented Exeter V40 femoral stem with the trident cup or the uncemented Corail stem with a pinnacle cup. I use these as they are the two most common stems and the two most common combinations in New Zealand as reported by the New Zealand Joint Registry in 2012 as can be found in the link below. The reason they are the most commonly used is because they are arguably the best components available today.
http://www.nzoa.org.nz/system/files/NJR%2014%20Year%20Report.pdf