Joint replacements, like all other mechanical devices, wear out with time. Factors that influence the longevity of the prosthesis include activity level, weight, type of bearing surface and position of the implants. Typically the prosthesis will wear out gradually over time and changes occur on the x-rays before patients experience symptoms. The most common problem is linear wear of the plastic linear. If this is significant enough, it will require replacement. If caught early, the original cup and stem can be left in position and changing the plastic liner solves the problem. Loosening of the stem or cup of the replacement is more problematic and requires removal of the loose implant and re-implantation with a revision prosthesis.
These surgical procedures are typically fairly involved requiring considerable surgical times and roughly 5 days in the hospital. Most patients will need to have a transfusion after surgery. Most patients will receive low-molecular weight heparin for 3 weeks after surgery to reduce the risks of blood clots. Depending on the extent of the revision, weight bearing may be limited initially to allow for bony ingrowth. Total recovery often takes 3-6 months depending on the type of revision surgery. Risks after surgery are similar to primary total hip arthroplasty. However, the risk of dislocation is significantly higher than that of primary total hip replacement because revision surgeries require larger soft tissue dissection.