Contact Us  |  Locations

Shahin S. Rad, M.D.
Fellowship Trained in Hip, Knee & Shoulder Replacement

16311 Ventura Boulevard, Suite 1150,
Encino, CA 91436
Phone: 818-477-0787

Culver City
3831 Hughes Ave, Suite 105
Culver City, CA 90232
Phone: 424-603-6984

Is a robot going to do your next joint replacement?

Is a robot going to do your next joint replacement?

Robotic surgery does not eliminate the need for human surgeons, but some feel that it does make the humans better surgeons. The robot can help to eliminate human errors in surgery, making delicate procedures more precise.

There is great debate about how much robotic surgery helps when compared to traditional surgery, but there is no questions that many doctors and patients want this technology available.

Robots Used in Orthopedics

Robots can perform, or help perform, a variety of tasks during surgery. In orthopedics, most robotic applications have focused on joint replacement surgery.

The primary goal during surgery to replace a joint is to properly position the prosthetic joint with a perfect fit, proper alignment, with restoration of joint function.

In fact, the longevity and function of joint replacements has been shown to be related to how well the surgery is performed. It cannot be understated how important this factor is in determining the success of joint replacement. I often hear patients focusing on variables such as the type or brand of implant, when in actually, the most important variable is probably how well the implant is placed in the body. A great implant will not overcome poor surgical technique. Robots can help to control the insertion of joint replacements in the body.

In hip and knee replacement, robots have been used to help guide appropriate bone cuts to accommodate the implanted joint. Robots can also be used to help navigate the anatomy to ensure proper alignmentof an implanted joint.

Success of Robotic Surgery

There have been studies to investigate the success of robotic surgery.

Most of the research is sponsored by the companies investigating the new technology, so there are questions about the quality of some of these studies.

The general theme of the research has shown that robotic surgery may help improve the consistency with which surgeons implant joint replacements. However, there is no research that clearly demonstrates an improvement in how long joint replacements last or how well they function. Most advocates of robotic applications in orthopedic surgery are basing their recommendations on theoretical benefits rather than on actual data.

Problems With Robots

As stated, robotic surgery is a rapidly growing area of surgery, but there is much left to be learned. Robotic surgery is very expensive, and with little demonstrated benefit, many question if this is an appropriate expense.

I use the robot for selected patients including partial knee replacements, and patients who have a deformity requiring a hip replacement.

Is antibiotic necessary prior to dental work after joint replacement?

The use of an antibiotic pill prior to dental work has been thought to lower this risk. In 2013, The American Academy of Orthopaedic Surgeons and The American Dental Association worked together to create guidelines for this situation. The work group reviewed the available published data to try and synthesize recommendations for patients and practitioners. Unfortunately, there is not a large amount of quality data.

The work group was unable to recommend for or against the use of topical oral anti-microbials in patients with prosthetic joint implants or other orthopaedic implants undergoing dental procedures. The work group recommended that patients with prosthetic joint implants or other orthopaedic implants maintain appropriate oral hygiene.

Many factors should be considered when you are making this decision, such as the type of procedure being performed, the presence or absence of an active infection in the mouth, and your tolerance of antibiotics.

With the lack of a definitive answer on this question, I strongly recommend the routine use of antibiotics prior to any dental work for all my patients.

1. Watters, W III, Rethman, MP, Hanson, NB, et al: AAOS-ADA Clinical Practice Guideline Summary: Prevention of Orthopaedic Implant Infection in Patients Undergoing Dental Procedures. Journal of the American Academy of Orthopedic Surgeons. March 2013; 21:180-189.; doi:10.5435/JAAOS-21-03-180

When is it safe to travel after your joint replacement?

A commonly asked question by those seeking a joint replacement is how soon can I fly after the surgery?

I generally recommend as soon as you are comfortable with sitting down, you can fly. Usually, three to four weeks is the minimum time. If the surgery was done within the last 6 weeks, I recommend blood thinner treatment for the prevention of blood clots. Recent surgery is a risk factor for blood clots as is prolonged sitting, and dehydration; make sure to drink water on your flight. For flights longer than 4 hours in duration, I recommend getting out of your seat and moving around the aircraft every few hours. Compression stockings can help prevent swelling in your legs and decrease the risk of blood clots. Taking aspirin before and after a long flight may also decrease this risk. However, if you have had a prior blood clot, have a family history of blood clots, are taking birth control pills or hormone replacement medications, have had recent surgery or have cancer, you may be at much higher risk. Sometimes prescription anticoagulants are recommended for individuals at high risk of blood clots.

After a joint replacement, most patients want to know if there joint replacement will set off airport security metal detectors? Belt buckles, key chains and smartphones may set off sensitive metal detectors at airport security checkpoints. Many commonly used orthopaedic implants may also set off the metal detectors. Over 90% of implanted total hip arthroplasty (THA) and total knee arthroplasty (TKA) devices will set off airport metal detectors. Many THA and TKA implants now include ceramic and plastic materials in addition to metal, and the metal will still likely cause an alarm. A card from your surgeon is no longer needed for identification of these type of implants.

If you or a family member has a metal implant, he or she should inform a Transportation Security Officer before screening begins. Passengers can use TSA’s notification card to communicate discreetly with security officers; however, showing this card or other medical documentation will not exempt a passenger from additional screening.

Many patients now prefer to be screened by imaging technology (X-ray Machine) to reduce the likelihood of a pat-down being necessary. If a pat-down is selected by the TSA, it will be helpful to wear clothes that allow you to easily reveal your surgical scar.

Does PRP injection decrease pain in knee osteoarthritis?

Several treatments for osteoarthritis exist, including exercise, weight control, bracing, nonsteroidal anti-inflammatories, Tylenol, cortisone shots and viscosupplementation, a procedure that involves injecting a gel-like substance into the knee to supplement the natural lubricant in the joint. A new treatment that is being studied by a small number of doctors is PRP injections. PRP, which is produced from a patient’s own blood, delivers a high concentration of growth factors to arthritic cartilage that can potentially enhance healing.

PRP involves taking a person’s own blood, spinning it in a centrifuge which concentrates the platelets, and injecting the blood back into the patient’s knee. The concentrated blood rich in platelets activates growth factors and stem cells to help repair tissue, calming arthritic symptoms, and decreasing inflammation.

In the study, patients with early osteoarthritis had an injection of PRP, and then monitored for one year. Fifteen patients underwent clinical assessments at baseline, one week, and one, three, six, and 12 months. At these time points, clinicians used validated tools to assess overall knee pain, stiffness and function, as well as a patient’s ability to perform various activities of daily living. At baseline and then one year after the PRP injection, physicians also evaluated the knee cartilage with magnetic resonance imaging (MRI), something that has not previously been done by researchers in other PRP studies. The radiologists reading the MRIs did not know whether the examination was performed before or after the PRP treatment.

Previous studies have shown that patients with osteoarthritis can lose roughly five percent of knee cartilage per year, the investigators of this research found that a large majority of patients in their study had no further cartilage loss. Treatment with PRP was also useful in improving pain, stiffness and function.

I have found that a majority of my patients are able to get instant pain relief that lasts for up to 1 year or longer. They are able to perform activities like golf, biking, and running which was not possible prior to the PRP injections. I recommend biologics to patients who have tried other modalities including therapy, oral medications, and viscosupplementation and are not ready to have a knee replacement.

Reference: Halpern B.Clinical and MRI outcomes after Platelet-Rich Plasma Treatment for Knee Osteoarthritis. Clin J Sport Med.2013 May;23(3):238-9.

How long will my knee replacement last?

The good news is that studies show that common types of knee replacements can last more than 20 years. One recent study on long-term outcomes of a commonly used knee replacement found the implant to still be functioning in 96% of patients 20 years after being implanted.

It should be remembered that while some patients may have knee replacements that last several decades, other patients may require a repeat knee replacement just a handful of years after their surgery. Revision knee replacement (a second knee replacement) is a major undertaking, that often has less successful results than an initial knee replacement. On a bright note, a recent report found that only about 2% of knee replacement surgeries required a second surgery within five years of the initial knee replacement.

Factors Affecting Longevity of Knee Replacements

Many studies have been done to determine how long a knee replacement will last. With hundreds of different types of knee replacements, and countless different types of patients, there is no rule to how long a knee replacement will last in a particular individual.

Implant manufacturers are constantly striving to create a “better” implant that will last longer. Some of these implants have only been used for a handful of years, and determining whether or not they will last longer is a question only time can answer.

Some of the factors that seem to influence thelongevity of knee replacement implants include:

Age of the Patient Younger patients require a knee replacement to last much longer. On top of that, younger patients tend to be more active. Therefore, patients who have knee replacement in their 50s or younger can usually expect to require a revision knee replacement in their lifetime.

Patient Activities Some activities may not be appropriate for patients with a knee replacement. While these activities may not be painful or difficult, they may be placing excessive stress on the knee replacement, causing the parts to wear out more quickly.

Patient Weight The more an individual weighs, the more stress that is placed on the joint replacement implant. Maintaining a normal body weight is critically important when trying to make a joint replacement last. Appropriate exercises can be helpful in maintaining a healthy knee replacement.

Avoiding Complications This may sound obvious, but there are some specific medical conditions that can lead to complications affecting the joint replacement. Patients having invasive medical procedures (including dental work) may require antibiotic treatment to prevent bacteria from getting into the joint replacement. Patients with osteoporosis should ensure they are being adequately treated as a fracture in the bone around a joint replacement can affect the functioning of the implant.

The Latest and Greatest

One temptation of patients and surgeons alike is to be attracted to the newest knee replacement on the market. Undoubtedly, this implant will claim to function better and last longer than other knee replacements. While these newer implants may be better, it is also important to understand they do not have long-term data on how well these implants will function over time. Just because an implant is newer does not necessarily mean it is better.

I always recommend that patients and surgeons try to find an appropriate balance between modern design and not being a ‘test’ patient.

When are you ready to have a hip replacement?

A total hip replacement is a big surgery, and therefore deciding to have the surgery done is a big decision. Here are some signs to look for to help you decide if the time is right, or not right, for hip replacement surgery.

More than 300,000 people have complete hip replacement surgeries in the U.S. every year. About 90% of them feel better and can get back to normal activities months, or even weeks, after surgery.

Here are some signs you’re ready for hip replacement

You have hip/groin pain that keeps you awake, or awakens you, at night.

You have hip pain that limits activities necessary to go about your daily activities (getting up from a chair, climbing stairs,etc.).

It hurts when you walk, when you get in and out of a chair, and when you lean over to put on your shoes. Your hip may even hurt when you’re just sitting or lying down.

You have hip pain that limits activities that give you pleasure (walking for exercise, traveling, shopping, etc.).

You have tried other treatments for a reasonable period of time, and you still have persistent hip pain.

If constant pain affects your daily activities and mood, it may be time for surgery. “It’s when there’s an inability to do the things you want to do.”

Choosing to have a hip replacement is a big decision. As a surgeon I consider many factors including age, overall health, and expectations. As a patient, you need to consider if the surgeon who is performing the surgery is fellowship trained, and has experience performing the surgery with excellent results. I explain the options and benefits of a hip replacement to patients including the type of approach (anterior versus posterior). I also make sure they have the right support structure after surgery, and connect them with patients who have had the surgery before in order to allow them to feel more comfortable with the procedure.

Fast track total hip replacement surgery is effective and safe

Healthy patients who undergo total hip replacement (THR) can be fast tracked to be discharged in two days compared with the standard three to six days, according to a study by researchers at Hospital for Special Surgery (HSS) in New York City. The study could help cut down on hospital-acquired infections, reduce hospital costs and improve patient satisfaction.

The study compared outcomes of patients undergoing THR at HSS. One cohort of 149 patients underwent THR with a fast track protocol. The other cohort of 134 patients underwent THR followed by the hospital’s traditional clinical pathway, which aimed to discharge patients at four days at that time.

Patients in the two cohorts were matched for age, sex, body mass index, and comorbidities. Patients on the fast track protocol had a physical therapy session on the day of their surgery. The main difference was that a patient’s pain medication was discontinued in the fast track cohort postoperative day one (as long as pain was deemed to be under control), whereas in the traditional cohort, pain medication is usually discontinued on day two.

The investigators found that 58 percent of the fast track cohort was discharged within two days of a THR and 73 percent were discharged within three days. The average discharge time was 2.6 days in the fast track cohort and 4.1 in the traditional cohort. Patients were less likely to be discharged rapidly in the fast track cohort, if they had significant post-operative pain, nausea, or dizziness. At one year, there were no differences in complications, readmissions or reoperation in the two cohorts.

This study demonstrates that a two day discharge is safe and feasible for patients undergoing a total hip replacement. I recommend the fast track protocol for select patients.

Fast Track THR: One Hospital Experience with a 2-Day Length of Stay Protocol for Total Hip Replacement. Gulotta LV, Padgett DE, Sculco TP, Urban M, Lyman S, Nestor BJ. HSS J. 2011 Oct; 7(3): 223-228.

Hyaluronic injections may delay time to arthroplasty in elderly patients with knee OA

Results of a new retrospective observational study showed patients with knee osteoarthritis who were treated with intra-articular hyaluronic acid had a longer time to knee arthroplasty compared with patients who did not receive the injections.

Using the 5% sample of Part B Medicare data between 2007 and 2012, researchers identified 23,008 patients with knee osteoarthritis (OA) who underwent knee arthroplasty (KA). Hyaluronic acid (HA) injections were received by 17,007 of the patients prior to arthroplasty. Investigators stratified patients according to whether they received bioengineered high-molecular weight (HMW) or medium-molecular weight (MMW) HA, or non-bioengineered HMW or low- molecular weight (LMW) HA.

Patients who received HA had a delay to knee arthroplasty by 7.1 months after adjustments for potential confounding factors and propensity scores. Compared with patients who did not receive HA injections, investigators found patients who received bioengineered HMW HA had the longest time to arthroplasty compared with patients who received other formulations, and LMW non-biologic HA was associated with the shortest time to arthroplasty. Other formulations had similar lengths of time to arthroplasty.

I always give the option of hyaluronic acid injection to my patients with knee osteoarthritis. I have found that a majority of my patients are able to get pain relief of up to 1 year from these injections.


Ong K, et al. Paper #310. Presented at: American College of Rheumatology Annual Meeting; Nov. 7-11, 2015; San Francisco.

Does osteoarthritis of hip or knee impair driving capability?

Depending on the location of osteoarthritis, a patient’s driving capability can be impaired and can show significantly increased total braking distance, according to recently published results.

German researchers equipped a car cabin with pressure sensors on the accelerator and brake pedals to measure reaction time (RT), movement time (MT), total brake response time (TBRT) and maximum brake force under realistic spatial constraints. Patients with osteoarthritis of the knee or hip were compared to a healthy control group.

Study results showed the control group recorded a median TBRT of 488 milliseconds and no participant in the control group exceeded a median TBRT of 600 milliseconds. While osteoarthritis (OA) of the left hip did not impair driving ability, researchers found OA of the right hip or knee significantly prolonged the patient’s braking performance. However, OA of the left knee prolonged RT and MT to the same degree as OA of the contralateral side, according to the study results.

I recommend that my patients with advanced OA of right hip, and in advanced stages of OA of the right or left knee, reconsider driving if possible.

Am I too young for a hip replacement?

Hip replacement surgery has long been used to treat hip arthritis in elderly patients. However, concerns arise when a patient in his 40s, 50s, or younger, has severe arthrtis that is not relieved with non-operative treatments. Once reserved for elderly patients, hip replacement surgery is now becoming more common in the younger, active population.

How Young is Too Young?

No one can definitively answer this question, but what we do know is that the benefits of performing hip replacement surgery in younger patients may outweigh the risks of surgery. The benefits are primarily pain reduction, quality of life, and maintaining proper fitness. The primary problem in performing hip replacement surgery in the young patient is the concern of wearing out the implant. Developments in manufacturing have sought to reduce the magnitude of this problem, but it is a concern. Furthermore, the amount of wear to a hip replacement is related to the activity level of the patient. As you might expect, the usual activities of the average 30 year old are different from the average 80 year old. Therefore, I always recommend young patients with joint replacements to be cautious.

What Are the Results of Hip Replacement in Young Patients?

The results of hip replacement in patients younger than 50 years of age is not as good as it is in older patients. However, these studies show that almost 90% of implants are still functioning 10 years after surgery, and more than 60% are still working after 15 years. We know that the younger age you have a hip replacement, the more likely it is to wear out quickly. What we do not know is how newer implants may affect the longevity of a hip replacement. Most studies to date looking at how long hip implants last are evaluating traditional metal and plastic replacements. Newer implants made of all metal, or ceramic have shown better results in laboratory testing.

I always advise my younger patients to be cautious of their activity level, and the possibility of a second surgery sometime in their life.