Total Hip Replacement (THR)

Indications for total hip replacements

Pain is the main indication for a total hip replacement in 90% of cases. It is usually advised for hip arthritis, which is causing severe pain and lack of functionality. Arthritis of the hips is a very debilitating disease because it is a weight-bearing joint with a wide arc of range of motion. Arthritis of the hips affect walking, stair climbing, sitting and is also characterised by night pain. The only other indication is to repair functional stability in cases where the joint or surrounding bone has been destroyed due to a hip fracture or severe trauma to the hip and pelvis.

The decision to do a total hip replacement is only considered once all non-surgical options such as analgesics, anti-inflammatory medications and adjustment of activities of daily living have been tried. Only severe hip pain that affects all activities of daily living, (especially sleeping and walking) warrants a total hip replacement. You, as the patient, will be able to decide if the pain is severe enough for a total hip replacement. If you are in doubt, it may be better to take the time to think about it. Delaying the decision will not lead to complications.

The aim of a total hip replacement

Through advances in medicine and the management of chronic diseases in the 21st century, life expectancy is increasing rapidly. These days people playing sports, even competitively, at a much older age has become the norm. For this reason, Dr Morkel is aware that many of his patients expect more from their total hip replacement and have these joint replacement surgeries at a younger age.

Not only are patients expecting greater longevity from hip arthroplasty, but also demanding more stability whilst putting more strain on the prosthesis. The newer designs for hip arthroplasty have resulted in increased longevity and with less host bone resorption compared to the earlier designs. Modern day hip replacements are safe and robust prostheses that will allow younger patients more functional abilities and last longer so that the patient can carry on with their sport and hobbies at the same level.

Because the aim of a total hip replacement is that it will last more than 20 years with excellent functioning for that period, it is important that the orthopaedic surgeon prioritise the alignment and soft tissue tension

Surgical approaches for hip replacements

Total hip replacements are the oldest of joint replacement surgeries, and the results are better than with the other joints due to it being a ball and socket joint. Unlike the other joints which are limited to one approach, there are 3 major surgical approaches to the hip joint when performing total hip replacement surgery. All 3 of these surgical approaches have their pros and cons.

Posterior approach:

The posterior approach is one of the traditional surgical approaches to the hip replacement. It is done while the patient lies on his or her side. An incision is made along the outside of the hip, and the hip joint is accessed from behind the thighbone. Almost any implant can be inserted with this approach. It provides excellent exposure and allows for complex revision surgery. With posterior approach surgery, there is a higher incidence of dislocations but only when performed by inexperienced orthopaedic surgeons.

Anterior lateral approach:

With the anterior lateral approach, one of the traditional approaches, excellent exposure of the hip joint is achieved with the patient on positioned on his or her side and the incision made directly down the outside of the hip. This approach has less risk of post-op dislocations and is also an excellent approach for revision surgery due to the good exposure of the joint. The disadvantage is that a small percentage of patients can have temporary abductor muscle weakness. With modifications to the approach, this very seldom occurs.

Anterior approach:

The direct anterior approaches to hip replacement surgery were developed in France, and it is gaining popularity in the rest of the world. It is reported to allow for smaller skin incisions. Although this exposure is good in an experienced orthopaedic surgeon's hands, it doesn't provide enough exposure for revision surgery. With this approach, access to the femoral canal can be difficult

Which of the three approaches is used will depend on your specific case. Dr Morkel will be able to discuss which approach would be best and the reasoning behind his choice. It has become preferable to do total hip replacements through smaller incisions making it minimally invasive per definition. While Dr Morkel aims to perform surgery through minimally invasive techniques, the most important aspect is that he chooses the most appropriate approach for the hip arthroplasty to provide the best outcome through correct alignment and tension of the prosthesis to improve the longevity of the prosthesis.

Enhanced recovery after Hip Arthroplasty

Soft tissue healing after a total hip replacement depends on the approach used, but is Dr Morkel's aim for better healing. The approach may impact the longevity of the prosthesis, how early the patient is mobile and also plays an important role in prevention of complications. Your recovery after a hip arthroplasty will depend on the approach that was taken by your orthopaedic surgeon.

Dr Morkel will discuss rehabilitation, physical therapy, and any lifestyle changes that might be required post-surgery. The advantage of early mobilisation after arthroplasty is that it means less pain and lower risk of deep vein thrombosis. For early mobilisation that is started the same day as the operation, a multidisciplinary approach which involves the anaesthetist, physiotherapists and all the nursing staff, is needed. Lifestyle changes may have to be made after surgery as you may need to avoid high-impact sports, heavy lifting or climbing. You can expect to be back to your normal activities within 4 weeks of surgery. Full recovery may take up to a year

Complications of Hip Arthroplasty

Recurrent dislocations

The general incidence of dislocations following total hip replacements is: There seems to be a higher incidence of dislocations with hip replacements performed through the posterior approach, but experienced surgeons can achieve the same figures with all the different approaches. With Dr Morkel's attention to detail in the alignment of the prosthesis, tension of soft tissue and post-operative rehabilitation, he is able to assist in preventing hip dislocations of his patients.

Deep vein thrombosis

There is a risk for deep vein thrombosis (DVT) in primary total hip replacements and pulmonary embolism as a complication. Prevention of DVT is important and depends on good hydration, early mobilisation, foot pumps, and chemical trombo-prophylaxis (low molecular heparin, Warfarin and newer anticoagulants).

Infections

There is always a risk of infection with major surgeries, and despite advances in prevention and antibiotics, it remains a concern. Prevention is still the best way to cure. For that reason, after a total hip replacement, the patient is investigated for any possible source of infection. Intra-operatively the principles that we adhere to prevent infections is laminar flow operating theatres, prophylactic antibiotics, accurate and precise surgical techniques, prevention of haematomas (collection of blood in operating sites) and special care with barrier nursing. Superficial infections can be treated effectively with antibiotics, but deep chronic infection might need a revision of the prosthesis.

Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is a chronic pain condition most often affecting one of the limbs (arms, legs, hands, or feet), usually after an injury, trauma or trauma to that limb. CRPS is believed to be caused by malfunction of the peripheral and central nervous systems. Although rare, it can occur after hip arthroplasty. It is important that it is diagnosed early, and pain modulation treatment is started early for resolution of this potentially debilitating condition.

Heterotopic bone formation

Heterotopic bone formation in the muscle surrounding the hip can occur in 12% of hip replacements. This can lead to temporary stiffness and in severe cases require removal of the extra bone, once it has matured.