By D. Gordon Allan, MD, FRCS(C)
Over the past several years, there have been many changes to techniques used for hip and knee replacement surgeries. Some changes have presented challenges, but many of the changes have reduced the length of hospital stay, postoperative pain and total recovery time. In this article I will outline some of these important changes and discuss how they impact patients.
Minimally Invasive Surgery
Several years ago, the term “minimally invasive surgery” was applied to joint replacement. I believe it was mostly a marketing tool to boost a surgeon’s case volume and complete in aggressive markets. There is hardly anything minimally invasive about a surgery that can produce life altering complications. The term “minimally invasive” was coined to reflect the use of a dramatically shorter incision during surgery, yet patients experienced new challenges do to the change in technique. Initially, negative outcomes included significantly longer surgeries and more complications (fractures, component malpositioning, poor fixation, etc.) that resulted in early failure and reoperation. We no longer measure success by striving to make very small incisions. However, length of incisions has decreased over time and there are many more important variables that hasten recovery and reduce discomfort.
Reduction of Inflammation
Both before and in the days after surgery, anti-inflammatory medicines are utilized. The use of Celebrex and Decadron (a steroid) help tremendously with postoperative pain. A recent study demonstrated that the use of Decadron before and the day after surgery decreased pain, narcotic use, nausea and length of hospital stay. Decadron is a cost-effective and well-known medicine.
It has been known for years that the avoidance of intravenous narcotics speeds recovery, reduces nausea and improves attendance at therapy sessions, hence promoting an earlier discharge. Despite this, many surgeons continue to use a PCA pump (patient controlled analgesia) in the mistaken belief that it is somehow beneficial to the patient.
Spinal anesthesia is preferred over a general anesthetic as there is much less nausea and confusion, plus there is no “hangover” feeling. Patients are more alert and ready to participate in therapy. Most times, particularly for knee surgery, a nerve block is done to provide hours of pain relief without the need for narcotics.
I use multimodality pain management that includes Celebrex, Decadron, intravenous acetaminophen (Tylenol), Tramadol (a synthetic opioid pain medicine), oxycontin (a long acting oral narcotic), Norco (a short acting oral narcotic) and a muscle relaxant. Intravenous morphine is reserved for intense, immobilizing pain. Combined with a nerve block, these patients are not over sedated. The different modalities are used synergistically to reduce pain while avoiding the sedative effects of high-dose intravenous narcotics.
This approach has greatly reduced my patient’s length of stay and most healthy individuals, with good help at home, can be discharged the day after joint replacement. In contrast to years ago, patients would routinely spend three nights in the hospital and many older patients would be discharged to a nursing home.
Blood Loss Reduction
Several years ago, patients would either predonate their own blood or have family members donate for them. This practice is not any safer than using banked blood and actually is more costly. Most of this blood was wasted, and this practice is no longer utilized.
Currently we use a medicine called tranexemic acid given intravenously during surgery. This drug reduces the body’s natural tendency to break down clotted blood and thereby reduces surgical and post operative blood loss. As a result, only a very small minority of total joint patients requires a blood transfusion.
Top: Total Knee Replacement
Bottom: Partial knee replacement
Partial Knee Replacement
Patients with osteoarthritis localized to one part of their knee may be candidates for partial knee replacement. The advantage of partial versus total replacement is that the recovery period is faster and the knee feels more normal. The cruciate ligaments are retained so motion, stability and nerve feedback is maintained. Patients with severe deformity or inflammatory arthritis (i.e. Rheumatoid arthritis) are not candidates. Alignment of partial knee replacement is crucial to their longevity. One way proper alignment can be achieved is with robotic assisted surgery.
Computer Navigated/Robotic Assisted Surgery
Computer navigated surgery has been around for years but has failed to demonstrate clear advantages in routine cases over traditional bone preparation for hip and knee replacement. This technique adds considerably to the operative time and expense. Occasionally, when there is significant bone deformity, surgical navigation can be a great assistance.
Recently, computer navigation has been merged with robotic assisted surgery. This technique known commercially as MAKOplasty® has been very effective in preparing the bone and assuring optimal alignment of partial knee replacement and cup placement in total hip replacement. I have been using this technique since 2012 and have been very pleased with the results.
Direct Anterior Approach for Total Hip Replacement
This approach is unique in that no muscles or tendons are cut and the posterior hip capsule is untouched. As a result, patients recover very rapidly, their hips are stable and they do not have to follow the usual posterior hip precautions. A special operative bed that helps with gaining access to the hip facilitates this surgery. Both Springfield hospitals have two of these beds. I have been doing this approach since 2008 and have done more than 600 cases in this fashion. Most patients leave the hospital the following day and are often free of walking aids within days. The direct anterior approach has radically changed my hip practice.
New Thoughts on Anticoagulation
For years, total joint patients were vigorously anticoagulated with blood thinners after surgery as surgeons feared blood clots could be fatal if they traveled to the lungs. We used such drugs as Coumadin or Heparin. Recently it has been found that we are actually causing more complications and expense with this approach. I now assess the individual risk of each patient for the development of clots and treat most patients less aggressively than in the past. As a result, they are experiencing less surgical bleeding and fewer infections.
Importance of High Surgical Volume
Many studies have demonstrated that surgeon and hospital volume play a very large roll in the complication rate of joint replacement surgery. The high volume creates very good data for objective outcomes. Each year, I complete more than 500 primary and revision joint surgeries, and both Springfield hospitals are high volume joint centers.
Metal on Metal Bearings
Some early failures of metal on metal total hip prostheses have been in the news over the past few years. The ASR cup by Depuy is the most well known of these implants. Not all metal on metal bearings will fail, but it is very important for these patients to have very close follow-up to detect bone and soft tissue damage before it becomes irreparable. These implants can fail from poor wear at the bearing surfaces, loosening of the cup and through corrosion at the junction of the metal ball and stem. Yearly exams along with X-rays are essential. If problems are suspected, a blood test to determine the level of Cobalt and Chromium can be done, and a specialized MRI can look for tissue destruction and fluid collection. If problems are encountered, a change of the bearings is required.
Life-Long Follow Up of Prosthetic Joints
All joint replacements need to be followed with periodic X-rays throughout the patient’s life. Bearings will wear very slowly over time and this can produce a reaction by the body against the foreign particles created by this wear. In turn, this can lead to destruction of the bone around the implants which, if allowed to go on unchecked, can result in the loosening of the implants or even fracturing of the bone. This could be a catastrophic event that may be very difficult to repair. Therefore, X-ray assessment is essential every few years. Often, the bearings can be changed out in a relatively minor surgery if wear is detected.
Antibiotics Prior to Dental Procedures
Dental procedures or other interventions can allow bacteria into the bloodstream; therefore, joint replacement patients are prescribed antibiotics prior to these procedures. While there is no clear consensus, most physicians would agree that patients should take antibiotics for two years following a joint replacement. I currently ask my patients to use antibiotics whenever they see the dentist, indefinitely.
We are now very focused on ensuring that our patients’ health is optimal prior to embarking on elective joint replacement. We ask that our diabetic patients have excellent control of their sugars, and we decline surgery until their hemoglobin A1C is less than 7. We ask smokers to quit several weeks prior to surgery. We test everyone for Methicillin Resistant Staphylococcus Aureus (MRSA), and those who test positive receive treatment before surgery and a different antibiotic during surgery. We also test for malnutrition (protein level in blood) and vitamin D deficiency, which are corrected prior to surgery. Very obese patients are at risk for many complications, foremost of which are infection and implant malpositioning. We typically ask that patients reduce their body mass index (BMI) to less than 40 prior to surgery.
Although joint replacement surgery is largely a very successful and life-changing surgery, it should not be entered into without ensuring that the patients’ medical status is optimized and that a high volume, experienced surgeon and facility are selected. In doing so, the outcome should be maximized and the risk of complications minimized.
For more information about the services discussed in this article, or to schedule an appointment, call (217) 547-9100.
This article was published in the April-June 2014 edition of ”FYI from OCI”, a quarterly publication created by the Orthopedic Center of Illinois. To see the full publication, click HERE.