Guide: What’s New in Hip and Knee Replacement?

Written by Dr. Richard Forster, MD

Many patients are surprised to learn that the average length of stay in hospital following knee and hip replacements for my patients is now only 2 days, with some patients opting to go home on the first post op day. In this article we will examine the major advances that have made this possible.

In addition, patients are increasingly being subjected to advertising concerning surgical techniques and implants. I’ll give you my current practice preference and the reasons behind my choices.

Shorter Hospital Stay

Patients should only be discharged from hospital when all therapy goals have been met and the patient is medically stable. This time will vary from patient to patient, however most patients are spending less time in hospital and recovering faster. Let’s look at some of the reasons this has been possible.

Preoperative Drug Cocktails are given to patients prior to surgery to help lessen post op pain and nausea. The idea is to anticipate problems before they develop.

Tranexamic acid is a drug shown to decrease post op bleeding. Not only has this decreased the need for blood transfusions, but less bleeding means decreased swelling and therefore less pain.

Local Anesthetics are now routinely used in hip and knee replacement surgery. Since patients are more comfortable, less narcotic medication is used. Narcotics have undesirable side effects such as causing drowsiness, confusion, nausea, and constipation. While sometimes necessary, lessening their use promotes earlier mobilization and recovery.

Early mobilization is now standard. The goal is to have a patient up on the afternoon of their surgery. All patients are now seen by therapists who mobilize patients ‘as tolerated’. While some patients may be too drowsy from the surgery to do this, the majority of patients can. It is my impression that patients are extremely happy to be out of bed on the day of surgery.

Recovery Once Discharged from Hospital

Over 80 percent of our patients are discharged home. Patients who live alone, have significant medical problems, or physical impairments prior to surgery may benefit from a stay in a rehab facility.

Driving is possible at 2-3 weeks after surgery as long as the patient is off all narcotic medication and can safely control their vehicle. This will of course vary from patient to patient, and can be longer if the surgery was on the right side.

Walking Aids are usually only necessary for 2-3 weeks post op, again depending on the patient.

Showers can now be taken at any time post op. I use a waterproof dressing which protects the wound and has been shown to decrease the risk of infection. It is removed one week after the surgery and then no further dressing is required. A patient can then continue to shower, but baths are deferred until 6 weeks post op.

What’s new in Knee Replacements

Implants are constantly evaluated and improved if possible. Many patients want to know ‘which knee implant will be used’. It is important to note that if any one knee implant system could demonstrate a better result, then surgeons would all use that device. Patients should beware of advertising from companies that claim an advantage with their particular product and should consult their physician. I use the ‘Zimmer Persona Total Knee’. Zimmer is a leading orthopedic company, 1 in 4 knee replacements worldwide is a Zimmer knee.

Patient Specific Instrumentation refers to instruments and/or components manufactured referenced to a patient’s MRI. While promising, a recent study has shown no significant difference in outcomes and a higher percentage of inaccurate positioning using customized cutting blocks.

Computer Navigation has been shown to improve positioning of knee components, but the difference did not reach statistical significance. In 2014, the Australian Joint Registry did report a small advantage of this method in younger patients.

What’s New in Hip Replacements?

Implants are constantly evaluated and improved if possible. One has to be careful with new technology, as evidenced by recent concerns about ‘metal on metal’ hip replacements. I’m happy to report to my patients that I have never used a ‘metal on metal’ hip replacement. Sometimes, it is wise not to be the first to embrace new technologies.

The ‘anterior approach’ is currently a ‘hot topic’ in hip replacements and is extensively marketed. I use a posterior approach because it works, it is safe, I’m comfortable with it, it is proven to have excellent long term results, and I think that many other factors are much more important than the surgical approach for the short term outcome of a hip replacement.

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