Despite its complexity, hip replacement surgery is a procedure with a high success rate. Although any surgical procedure carries the risk of complications, they are quite rare. It is important for patients to understand these risks prior to consenting to surgery. You should discuss the possible complications with your surgeon and learn about ways to lessen your risks.
Squeaky Hip or Noisy Hip
Noise related to total hip replacement is a questions asked frequently enough by post operative patients that we have dedicated a section in our patient forum to the topic. Our panel of experts address concerns about noise associated with some types of hip implants, including metal-on-metal and ceramic-on-ceramic.
Blood clots in the leg veins are one common risk of hip replacement surgery. Occasionally they dislodge and travel through the heart to the lungs (pulmonary embolism). A pulmonary embolism is potentially very serious but not overly common. Blood thinners, compressive calf cuffs and exercise are all prescribed to help avoid clotting.
Misalignment of implants
Another of the more common problems with hip replacement surgeries result from misalignment of the implants, specifically the angle of the cup. Misalignment can lead to loosening, undue wear, pain and post-op hip dislocation.
Practice makes perfect and the more such replacements a surgeon does, the lower his error rate should be. Therefore, patients can minimize this risk by making sure the surgeon they choose has some considerable experience in hip replacements.
There is some evidence that the risk of dislocation is lower in anterior approaches in hip replacement surgery and/or by using an implant with a large femoral head. Dislocations mostly occur in people who have weak muscle tone around the hip joint or tend to take risks with position early after surgery. But the most common reason is misalignment of the implants.
In the first six weeks after the surgery, the ball is only held in the socket by muscle tension. During this time, before scar tissue forms around the ball, and before muscle strength returns, the hip is more likely to dislocate. A physical therapist can help teach appropriate movements and exercises for the post-op recovery period.
If a patient has repeated dislocations, a brace may need to be worn for several months to prevent further dislocation until the hip regains tone but ultimately, corrective surgery may be needed to resolve the problem.
Again, practice makes perfect. The more replacements a surgeon does, the lower his error rate should be. Choosing a surgeon with considerable experience in hip replacements will minimize the risk of dislocation.
Leg length differential (LLD)
On occasion, there is a discrepancy between the length of one leg compared to the other. In some cases, surgeons will note post-op patients experiencing actual leg differential or apparent leg differential.
Actual is when the measurement from one bony point to another shows a discrepancy.Where there is an actual bony discrepancy before surgery, some leg length difference may be unavoidable though surgeons make very effort to achieve accurate leg length by measuring during surgery and adjusting cuts in the bone.
Apparent is when the measurement between the bony points are the same but the patient still feels a discrepancy because the pelvis is tilted. This is because the patient has been accommodating body balance to cope with the pain. Apparent leg length discrepancy can be resolved with careful therapy and exercises.
Some patients complain in the first few weeks following surgery that their leg feels too long. This is very normal until the body has adjusted from the pre-operative adaptation to the arthritic joint.
Infections are rare with joint replacement surgery but can involve primary infection, late onset infection or even a superficial infection.
Hip replacement surgery is conducted in a filtered operating room with sterile instruments. Antibiotics are given to the patient before, during and after the operation to lower the risk for infection.
Even with these precautions, infections can still occur. The risk for infection is increased in patients with rheumatoid arthritis or diabetes, patients who have been taking cortisone for prolonged periods, patients whose joint previously was infected and patients who had infection in another part of their body during surgery.
Implant loosening from the bone is the most concerning potential problem in the long-term. Loosening can be the result of infection but usually it is or the result of faulty techniques during surgery, poor bones, damaged and softened by osteoporosis or rheumatoid arthritis, obesity or unnecessary force as in accidents but the most common reason is that the implant just works loose from the bone.
The more experienced the surgeon, the lower his or her error rate should be. Be sure to find a surgeon with considerable experience in hip replacements to lower the risk of post-op implant loosening.
Fractures can occur around or at the end of the prosthetic stem, generally due to inaccurate positioning of the implant Occasionally the prosthesis stem itself can break, usually the result of extreme trauma or (in very rare cases) product failure.
The femur (thighbone) can be split or cracked during hip replacement surgery due to poor use of instruments during bone preparation or unexpectedly soft bone. There are a variety of straps and wires that can be used to fix such fractures and often the recovery is not overly complicated unless the fracture is severe when a period of non-weight bearing may be required.
Allergic or other reactions
Debris from implants can cause tissue reactions and are usually produced due to improperly positioned cups which abrade the head or from an inherent allergy in the patient such as a nickel allergy. However, reports of proven allergies to metal implants are relatively rare. Allergy to plastic implant components has never been reported.
Although these are the most common complications of hip replacement surgery, they do not happen often. 98% of all hip replacements occur without any significant problems. There are several other risks involved with hip replacement surgery and you should be sure to discuss all of them with your surgeon before consenting to surgery.
image credit: Matt Kowal’s