Olympic Disappointment – Griffin Blows a Gasket

Blake Griffin is not in London with the US Olympic Basketball team. Unfortunately he tore his meniscus during a team practice. He will need surgery and should be ready for the NBA season.

The knee is the largest and most complex joint in the human body. It has been likened to a biologic transmission. In a car, a transmission is designed to accept and transfer loads between the engine and the wheel. The knee accept loads from the femur, the longest bone in the body, and transfer the load down to the lower leg and foot. I think of the menisci as a gasket in the knee.

A gasket seals the surfaces between two incongruent surfaces. Often, a gasket makes a joint watertight. This is similar to what the meniscus does. The femur and the tibia – the two bones that meet at the knee joint do not fit together like a ball and socket. Instead, they slide and rotate on each other letting us bend our knee. To help control and cushion this articulation, the inside (medial) and outside (lateral) menisci serve as gaskets.

Meniscus tears are very common and occur in all ages. Not all meniscus tears are alike. They can result from overuse, acute trauma (such as with an ACL injury), or with congenital structural abnormalities. The most common meniscus tears are “acute on chronic” injuries. Specifically, someone develops wear and tear in their meniscus (knee gasket), and then it fails with a sudden movement.

Meniscus injuries are common in all sports. A large percentage of professional athletes will need meniscus surgery at some point in their career. In most cases, surgery involves “trimming” the damaged meniscus fragment and athletes can return to sports at 3-6 weeks. Often, surgery is not season ending. However, some variations of meniscus tears can require longer recoveries. In addition, when the meniscus has be repaired, or sewed back together, 3 months are often required before an athlete can run on the knee.

Though common, meniscus tears are serious. We expect athletes to return to competition without untold effects on performance after meniscus surgery. However, after meniscus surgery, some of the knee gasket is usually removed and this often results in less cushioning in the knee. This can have an effect on the duration of an athlete’s career. Indeed, in a recent study in the NFL, players who had meniscus surgery had, on average, shorter careers than those that did not have meniscus issues.

Good luck to Blake for a speedy recovery and good luck to all our Olympians!!

For a video describing meniscus injuries, view below:

Posted in arthritis prevention, basketball and meniscus, Blake Griffin, knee injury, olympic | Tagged , , , , , , | Leave a comment

If Your Knees Could Speak…

If your knees could speak, what would they tell you?

Here are ten issues I think your knees would discuss with you.

Memo from your knees:
I am the largest and most complex joint in the human body. The knee has been likened to a biologic transmission. In a car, a transmission is designed to accept and transfer loads between the engine and the wheels. The knee accepts loads from the lever arm of the femur, the longest bone in the body, and transfers the load down to the lower leg and foot. Knees typically work well and can last an entire lifetime. However, they are prone to injury and can wear out over time (20% of knees develop arthritis during the course of a lifetime). Here is some advice from your knees on how to keep your “knee transmission” running strong.

1. “Keep me moving”
Blood does not flow to the bearing surface of the knee (the cartilage or the inner portions of the meniscus). Instead, the cartilage and meniscus is bathed in joint fluid that provides nutrients to it. This joint fluid is like transmission fluid and is pumped throughout the joint by moving the knee. Without motion, the cartilage and meniscus is starved of its nutrition as the joint fluid does not circulate. Therefore, keep your knee moving – take walks, bike rides, hikes, etc.

2. “Understand the loads you are putting on me.”
Different activities impart very different loads across the knee. You should know the following chart:
Cycling = 1.2 times body weight across the knee
Walking = 3-5 times body weight across the knee
Stair Climbing = 5-7 times body weight across the knee
Running = 15 times body weight across the knee
When you go running, the magnitude of load you are subjecting your knee to is 10-15x more than when you go cycling. When your knee hurts, go spinning or swimming and don’t pound your knees into the pavement on a jog.

3. “Lighten my load”
Now that you understand how loading affects a knee, it is critical that you do not put excessive loads on your knees. The best way to unload your knee is to stay slim. Body weight matters and every pound on you is magnified at the level of the knee. For every pound you weigh, your knee feels it as 3-5 pounds when you walk and as 15 pounds when you run!! Think about it – if you lose 10lbs, you reduce your knee’s load by about 50 pounds when you walk and by 150 pounds when you run. That has an enormous effect on how long your knee will last.

4. “Share my load”
The muscles around the knee are the motor that drives the knee transmission but also absorb energy and dampen the load that your knee has to transfer. In fact, during normal walking, the muscles around the knee actually absorb more energy than they generate! As such, keep the hamstrings, quadriceps, and lower leg muscles strong – they take load off of the knee and protect it.

5. “Listen to me”
Your knee can’t speak but it can tell you when something is wrong. Your knee will alert you by swelling, hurting, locking, and buckling. It does this to try to tell you something. Please do not “play through” these things and go see a doctor.

6. “Keep me flexible”
Your knee is most efficient when it has a full range of motion. Stretch often to keep your knee limber and fresh. When it loses motion, your knee will have difficulty regaining it and will often lose progressively more motion over time.

7. “Get me fixed”
If your knee does break down, it needs to be fixed. Because it is the most complex joint in the body, your knee often does not respond well to injury. It doesn’t perform well when its ligaments are destroyed and they often need to be replaced or to be protected as they heal. Your knee’s menisci are prone to injury and either trimming or repair is often needed. This maintenance can often preserve its function.

8. “Respect me as I age”
We can’t reverse the aging process. As your knee get older, its cartilage and menisci become stiffer and less pliable. It has less capacity to transmit high loads and am more susceptible to injury. As your knee get older, you need to make sure you take better care of it – keep it moving to keep it lubricated, stay slim and build muscle to unload it, and incorporate low impact activities into your lifestyle.

9. “Pills, Shots, and Physical Therapy when I break down”
20% of the US population develops knee arthritis. We don’t know why this happens but it is almost part of the human condition. While the arthritic process is not reversible, anti-inflammatory pills such as NSAIDs (ibuprofen, Naprosyn) can reduce inflammation and ease pain. Steroid shots are often effective at reducing pain and viscosupplementation (gel) shots (such as synvisc, orthovisc, etc) can help lubricate the joint (like adding new transmission fluid). Physical therapy often helps by improving muscle function to unload your knee. Weight loss is often the most effective way to help a damaged knee and can relieve 40% of knee pain.

10. “They can rebuild me”
Sometimes a knee breaks down, and pills, shots, and physical therapy are no longer effective at keeping the knee transmission functioning. Excellent operations to rebuild the transmission are now available such as partial and total knee replacement. Although these rebuilt knee transmissions have less capacity than factory “original” knees that you were born with, they can provide excellent pain relief and restoration of function. Newer techniques such as robotic knee resurfacing provide durable pain relief and rapid return to activity.

Posted in arthritis prevention, Knee Arthritis, knee injury, Partial knee replacement, Robotic Knee Resurfacing, TKR, total knee replacement, UKR, Uncategorized, Unicondylar knee replacement | Tagged , , , , , | Leave a comment

Robotics and Experience: a Winning Combination

“Why do you use a robot in the OR?” I am commonly asked this question when I discuss the robotic knee resurfacing (partial knee replacement) procedure. My answer: I want to get it right the first time.

A problem with partial knee replacement is that it is technically demanding, and prone to surgeon error. Rather than making perpendicular cuts to remove the entire ends of the knee (as we do in total knee replacement), the surgeon has to preserve the inner ligaments (ACL and PCL) as well as the dimensions of the native knee in partial knee replacement. Technical error is a major source of failure in partial knee replacement. There are two main solutions to this problem: robotics and surgeon experience.

I have pioneered the use of robotics for partial knee replacement (I call the procedure robotic knee resurfacing) because robotics affords a level of precision and reproducibility that cannot be achieved with manual techniques. I have shown that implant positioning is 3x more accurate and less variable with robotic techniques compared to manual tools and that alignment can be controlled with robotic resurfacing(1,2). My colleague in England, Justin Cobb, demonstrated in a prospective randomized trial that robotic partial knee resurfacing achieved accurate placement of the implant 100% of the time compared to only 40% with manual techniques(3). With robotics, I can reliably get it right the first time.

Another major factor in determining surgical outcome after partial knee replacement is surgeon experience. Medical evidence has long shown that the more you do something, the better you get. This is particularly the case for partial knee replacement. In a recent study looking at partial knee replacement, it was found that high volume surgeons had a revision rate of less than 1% over 5 years. Surgeons who performed 8-12 partial knee replacements per year had a revision rate of 5% while surgeons who performed less than 8 partial knees/year had a revision rate of 6-8% over 5 years(4). Low volume surgeons had a revision rate 6-8x that of high volume surgeons!! I currently perform 150-200 partial knee replacements per year, which is the most of any surgeon in the greater New York area.

Finally, the hospital setting matters. For example, a study out of Sweden demonstrated that there was a direct association between the number of partial knee replacements performed in the hospital and the revision rate. In this study, the greater the surgical volume of partial knee replacements performed, the lower the rate of revision(5). Surgical volume is one reason to choose Hospital for Special Surgery. No hospital in the world performs more joint replacement surgeries than HSS. We are truly experts at what we do. Because Hospital for Special Surgery is devoted exclusively to orthopedics, every one of our scientists, nurses, and therapists is a specialist in this field and aligned to provide the best possible care.

Coupling robotics with my extensive surgeon experience in the world-class environment of the Hospital for Special Surgery is a winning combination.

1.Mustafa Citak; Eduardo M Suero; Musa Citak, MD; Nicholas J Dunbar; Scott A Banks; Andrew D Pearle. Unicompartmental knee arthroplasty: Is robotic technology more accurate than conventional technique? CAOS International 2010
2.Eduardo M. Suero, Mustafa Citak, Innocent U. Njoku, Andrew D. Pearle. Does the type of tibial component affect mechanical alignment in unicompartmental knee replacement? CAOS International 2010
3.Cobb, J.; Henckel, J.; Gomes, P.; Harris, S.; Jakopec, M.; Rodriguez, F.; Barrett, A.; and Davies, B.: Hands-on robotic unicompartmental knee replacement: a prospective, randomised controlled study of the acrobot system. J Bone Joint Surg Br 2006.
4.Tregonning R, Rothwell A, Hobbs T, Harnett N. Early Failure of the Oxford Phase 3 Cemented Medial Uni-Compartmental Knee Arthroplasty: An Audit of the NZ Joint Registry over Six Years. J Bone Joint Surg Br 2009
5.Robertsson O, Knutson K, Lewold S, Lidgren L. The routine of surgical management reduces failure after unicondylar knee arthroplasty. J Bone Joint Surg Br 2001

Posted in Hospital for Special Surgery, Knee Arthritis, knee injury, Partial knee replacement, Robotic Knee Resurfacing, UKR, Unicondylar knee replacement | Tagged , , , | Leave a comment

From the Mick to Mariano Rivera: The Evolution of ACL Treatment in Baseball

Legend has it that Mickey Mantle tore his anterior cruciate ligament (ACL) as a rookie in the 1951 World Series when he tripped over a drain cover in Yankee Stadium.  He went on to play 17 years, win 3 MVPs, hit 523 homers and steal 145 bases without a functioning ACL.  However, his knee was bandaged and iced down before and after nearly every game.  Imagine the Mick’s career numbers if he had a good knee.

Last week, Mariano Rivera tore his ACL while shagging balls before a game.  Please find my discussion on Rivera’s injury on NBC Nightly News with Chuck Scarborough below.

While the Mick and Mo both tore their ACLs chasing fly balls, ACL injuries are relatively rare in baseball.  I have been a team doctor for the NY Mets for over 7 years; we have perhaps 1 or 2 ACL injuries per year among the 275 or so players in entire Mets system (compared this to the 4-5 ACL injuries per year on a 53 player NFL roster).

The ACL is a ligament in the center of the knee that provides stability during cutting sports.  The video below shows the dynamics of the ACL as the knee is brought through a range of motion.

Modern day treatment of ACL injuries involves replacement (reconstruction) of the ligament.  Recent studies have demonstrated that only 60-80% of NFL players return to the NFL after ACL reconstruction (and their fantasy football numbers drop by about one third after surgery!); in the NBA, approximately 80% of players return to professional basketball after the surgery.  Fortunately, baseball does not require the constant pivoting and cutting seen in football, basketball, and soccer.  As such, the outlook for baseball players who wish to return to sports after ACL reconstruction is particularly good.

ACL surgery remains a “season ending injury” which typically requires 6-9 months prior to return to sporting activities.  The long term outlook for Rivera is good and we all wish him the best for a speedy return to pitching.

For more information on the ACL tears, and my practice, visit www.andrewpearle.com, or call my office at 212-774-2878.

Posted in ACL and baseball, ACL injury, Anterior Cruciate Ligament, knee injury, Mariano Rivera, Mickey Mantle, New York Yankees, Uncategorized | Tagged , , , , , , , , | Leave a comment

ACL: the “Achilles Heel” of the Knee

One day, two devastating ACL injuries.  Yesterday, Derrick Rose and Iman Shumbert both tore their ACLs in classic fashion.  Incredibly, neither player was really touched when their knees blew out.  Unlike ACL tears that occur in football during a violent collision, Rose and Shumbert tore their ACL in a “non-contact” situation while they were making a move.  It is remarkable that the knee can blow out just with a hard cut or an awkward landing, but unfortunately the ACL is a tragically vulnerable ligament.  Indeed, Rose and Shumbert are not alone – 200,000 of us will tear our ACL this year in the US.

The orthopedic community is working hard to prevent and treat this injury.

For example, I am honored to be a member of the prestigious ACL Study group, an international panel of experts whose sole focus is the research and treatment of ACL injuries.   In February, I spoke at the biennial ACL Study Group meeting, where this team of experts spends an entire week discussing ACL injuries and treatments (and nothing else – this is my idea of a dream week!).  I am deeply humbled to be included in this group, and I am committed to its mission of preventing and treating ACL tears.

The anterior cruciate ligament (or ACL) is located in the center of the knee and provides stability during athletic situations as well as during everyday life.  ACL tears commonly occur playing sports; the ligament is particularly susceptible to injury when playing sports such as basketball, soccer, lacrosse, field hockey, football, and skiing.   However it is also not uncommon for people to tear their ACL under less strenuous situations as well.

I am often asked the following questions related to ACL tears:

How can I prevent them?

While it is not possible to entirely eliminate the risk of ACL tears, athletes may be able to reduce their risk by training programs that enhance balance, power, and agility.  Hospital for Special Surgery has developed an ACL Injury Prevention Program that can be tailored to athletes of all ages and abilities.  Information on this program can be found on the HSS website at: http://www.hss.edu/acl-injury-prevention.asp

How long will it take to fully recover from an ACL tear resulting in surgery?

We have come a long way in ACL surgery and now expect athletes to make a full return to sports after the procedure.  However, the procedure remains a “season ending injury” which typically requires 6-9 months prior to return to sporting activities.

My original research in ACL reconstruction over the past 5 years has resulted in improvements in surgical techniques. For more information on the ACL tears, and my practice, visit www.andrewpearle.com, or call my office at 212-774-2878.

In this video, Dr. Andrew Pearle, an Orthopedic Surgeon at the Hospital for Special Surgery, discusses the symptoms and treatment of ACL injuries.


Posted in ACL injury, Anterior Cruciate Ligament, Derrick Rose, Hospital for Special Surgery, Iman Shumbert, knee injury | Tagged , , , , , , | Leave a comment