Any time an incision is made and the inside of the body exposed, an infection can occur. You will receive antibiotics on the day of surgery to prevent a surgical wound infection from developing. If you have a body mass index (BMI) over 40, your risk of infection is significantly increased and weight loss is recommended before proceeding with hip or knee replacement surgery. If an infection develops around an artificial hip or knee, you will require another surgery to wash out the wound and exchange some of the components. You will be on IV antibiotics for 6 weeks after that surgery and followed by infectious disease physicians. If the infection is not cured, the implants may need to be removed for a period of 8-10 weeks with another course of IV antibiotics. Re-implantation occurs after this period, but recovery is delayed significantly.
Most patients undergoing hip and knee replacement will not lose enough blood to require blood transfusion. If you develop a large collection of blood under the skin (hematoma), you may have to return to the operating room to have it evacuated (removed).
It is extremely rare to have a motor nerve injury during anterior approach hip replacement. The main nerve at risk is the lateral femoral cutaneous nerve, which gives you sensation on top of the thigh. This nerve only provides sensation and does not control muscle function. This nerve is rarely permanently injured. Some patients will have numbness on top of the thigh after surgery. This area is usually small and will continue to decrease in size over 2-3 months. After knee replacement surgery, you will have a small numb area to the outside portion of the knee. The genicular nerve passes under the patella (knee cap) and is unavoidable during any incision in the front of the knee. This area will decrease in size over time.
Leg Length Inequality
This is one of the most common patient complaints following traditional hip replacement surgery. The anterior approach, which is utilized by our surgeons, addresses this issue by using fluoroscopic x-rays in the operating room to ensure equal leg length while adjustments can still be made. Even with x-ray assistance, small leg length differences can occur but are rare.
Dislocation can occur with extremes of movement, especially during the first 2-3 months after surgery. The risk of dislocation is significantly reduced using the anterior approach to the point that no dislocation precautions are used after surgery. If a dislocation occurs, you will have to return to the hospital to have your hip put back in place.
Fracture During Surgery
It is possible to fracture the femur bone while implanting the femoral stem of the artificial hip. The component is wedged tightly into the canal of the femur taking care not to use too much force, but on occasion, a crack in the bone will occur. If this does occur, we can expect the bone to heal without problem. If this happens, restrictions may be placed on weight bearing after surgery. Fractures can also occur during knee replacement surgeries but these are extremely rare.
A blood clot, or deep vein thrombosis (DVT), is a known postoperative complication of joint replacement. If a DVT develops, it can travel to the lungs causing a pulmonary embolus (PE) which is life threatening. All patients after hip replacement are placed on blood thinners for this reason. You will have compression stockings and leg compression boots in the hospital to increase circulation. Symptoms of DVT/PE include new or unusual leg or calf pain, chest pain and shortness of breath. If you experience any of these symptoms at home, please consult with a medical doctor.
Increased Risk for Smokers
Smoking greatly increases your chances of infection, wound complications, and deep vein thrombosis. Smokers also are at increased risk for pulmonary complications in the hospital. If you smoke, it is in your best interest to stop before considering surgery.
Increased Risk for Obese
If your BMI is over 35, your risks of surgery are increased. Patients with BMI over 40 have extreme obesity and are at very high risk. Complications that are seen in obese patients at increased rates are wound dehiscence (pulling apart), infection, blots clots (DVT), dislocation, fractures, implant loosening, prolonged hospital stay and poorer overall satisfaction rates. Your wound may be closed with non-absorbable suture due to high dehiscence rates and a special vacuum dressing may be applied which stays on for 2 weeks after surgery. If your BMI is above 45, you will not likely be a candidate for surgery.