Total Hip Replacement (THR) is a surgical procedure that replaces the damaged or diseased hip joint. There are many hip replacement designs that are available to the surgeon. Choice of type of prosthesis, fixation technique and bearing surface is based on many factors including age of patient, activity level, bone quality and bone shape. 

STANDARD HIP REPLACEMENT

• Stem (attached to ball)
  cement or uncemented fixation
  different stem design options 
• Acetabular shell (socket)
  mostly uncemented (with or without screws)
  cemented shells much less common now

Bearing Surfaces 
Different combinations: Metal, polyethylene, ceramic. The most common bearing combination is metal (ball) on polyethylene (liner), but other combinations are becoming more widely used. This transition is based on trying to improve durability of a hip replacement. Among other factors such as technique and qualify of fixation, durability of a hip replacement is influenced by materials used, age and activity level of patient. Surgeons choice of bearing materials take many factors into account. 

SURFACE REPLACEMENT

This procedure involves preserving the femoral head and neck rather than removing it completely as is done with standard hip replacements. Therefore, less bone is sacrificed, which is especially appealing to the younger patient who may need a second replacement procedure when the first "wears out." This concept of surface replacement is not a new one but has had renewed interest based on better materials (metal on metal designs) and higher demand. This type of replacement may also result in allowing higher levels of activity, which results in higher satisfaction among younger patients.

REVISION HIP REPLACEMENT

Despite the success of hip replacement surgery, there are circumstances where revision is necessary. Hip replacements can fail by different mechanisms including injury/fracture, infection and loosening. Revision surgery tends to be more difficult for patient and surgeon. Recovery and rehabilitation can be extended. This is likely related to the challenges that the surgeon encounters in surgery. The quality of the bone after removal of the hip replacement is decisions for the type of prostheses that are used, fixation of the new components and rehabilitation plan following surgery.   

Risks/Benefits/Expectations

There are risks involved with hip replacement surgery. Some complications are directly related to the surgical procedure include dislocation of the hip, leg length discrepancy, loosening of the prosthesis, nerve injury, fracture and heterotopic bone formation (excess bone growth in reaction to the surgical trauma). Other associated risks include anesthesia complications, blood clot and infection. Patients are placed on blood thinners following surgery for a period of time to minimize the risk of blood clot (deep venous thrombosis). Infection risk is minimized as much as possible with IV antibiotics before and after surgery. This in addition to special techniques in the operating room help to minimize this risk. Patients underlying medical condition has an important effect on infection risk. Patients with certain conditions can have higher risk of this complication. The need for transfusion can also be a source of complication, including transfusion reaction or disease transmission. There is a concerted effort to prevent complications and minimize risks by the team composed of the physicians, physician assistants, nurses, and physical and occupational therapists.