ABOUT KEVIN STONE M.D., Founder of The Stone Clinic

Dr. Stone is an orthopaedic surgeon in San Francisco California who specializes in sports medicine with a special interest in knee injuries and knee surgery.

Dr. Stone is a physician for the Lawrence Pech Dance Company, Alonzo King's Lines Ballet, Smuin Ballet, and Marin Ballet. He has served as a physician for the U.S. Ski Team, U.S. Pro Ski Tour, The Old Blues Rugby Club, the United States Olympic Training Center.

He was educated at Harvard College and earned his M.D. at the University of North Carolina at Chapel Hill. He trained in Internal Medicine at Harvard's Beth Israel Hospital, General Surgery at the Stanford University Medical Center, and Orthopaedic Surgery at the Harvard University Combined Orthopaedic Residency Program in Boston. Dr. Stone's training also includes a Knee Surgery and Sports Medicine Fellowship and a visiting Research Fellowship at the Hospital for Special Surgery in New York.

He received the Albert Trillat Young Investigator's Award from the International Society of the Knee, the Cabaud Award from the American Orthopaedic Society for Sports Medicine, the Resident's Essay Award from the Arthroscopy Association of North America, and has more than 40 U.S. patents for his work since 1989. He has been the principle investigator on two N.I.H. grants. Dr. Stone is regularly sought out as an expert for publications ranging from The Wall Street Journal and Newsweek to Men's Journal and Elle Magazine. He has also contributed to a variety of segments for television shows such as ESPN's "Treating Athletes in the New Millennium," The Discovery Channel, and FOX News' special segments on alternative treatments for knees, as well as others. He is the author of numerous scientific articles and is often asked to share his research and teach new surgical procedures internationally at leading forums and symposia. He has lectured around the world as an expert in cartilage and meniscal growth, replacement, and repair.

Dr. Stone is the co-founder of ReGen Biologics, Inc., a medical device company that produced the first collagen scaffold for meniscus regeneration; founder and CEO of CrossCart, Inc., a medical device company that removes the antigens from pig tissues to make pig ligaments, bone, and cartilage available for human use; and founder and CEO of Joint Juice, Inc., a glucosamine-enriched beverage company.

About Knee Injuries and Avoiding Knee Replacement

by Kevin R. Stone, M.D.; The Stone Clinic and The Stone Foundation, with Special Interest in Advanced Research and Techniques for Knee Surgery

For a person who engages in athletic activities, or for active seniors, sports injuries or injuries to the knee that interfere with daily function can be crippling. The very words either sends vivid memories of a previous injury, or anxiety about "what-if?". People who are fortunate enough not to have a lot of experience with knee injuries are not familiar with a lot of the more common ones. This article seeks to help answer some of the questions of; once an injury has been sustained, what can be done for it, short-term and long-term?.

In our orthopaedic practice, some of the more common injuries that we see are in the knee. With the knee being extremely weak in terms of its bony arrangement, most of its stability is gained through ligaments (which connect bone to bone) and tendons (connect muscle to bone). Its two primary motions are flexion and extension, but there is a little movement into rotation and to a lesser degree some lateral (sideways) motions. It is also because of this design that the knee is so vulnerable to injury. Once the knee has been subjected to stresses greater than what it was designed to, injury can occur. This also explains why activities that require a lot of quick turning and twisting have such a higher incidence of knee injury.

One of the more common knee injuries is a sprain of one or more of the stabilizing ligaments. A sprain is stretching a ligament further than it can tolerate and subsequently causing varying degrees of tear. This usually happens as a result of a planted foot and either a twist, a hyperextension, and/or an outside force directed at the knee with the foot planted. Pain is usually immediate and there will be some feelings of apprehension or an inability to bear weight on that leg.

One of the more commonly injured ligaments is the Anterior Cruciate Ligament ( or ACL). This is considered the key "guide wire" in the knee joint and is crucial for guiding the tibia bone in a normal path along the end of the femur bone. Often the person remembers hearing a 'pop' as the injury occurs and there are instant feelings of instability or giving-way.

The other three major ligaments of the knee joint that are more commonly injured are: the medial collateral ligament (MCL) which prevents the knee from moving medially, the lateral collateral ligament (LCL) which prevents lateral movement, and the posterior cruciate ligament (PCL) which criss-crosses with the ACL and prevents backwards movement of the tibia on the femur. As mentioned above, sprains to any of these ligaments illicits symptoms which are similar with respect to feelings of instability, apprehension or inability to bear weight, and immediate pain.

Initial care and treatment of sprains to the knee joint consists of ice for 20 minutes every 1-2 hours, elevation above the level of the heart to reduce swelling, crutch-use so as to not exacerbate the injury, and immediate follow-up with an orthopaedic surgeon for an accurate diagnosis. Because of the relatively poor blood supply to the ligaments of the knee, they are unable to repair themselves like muscles or tendons. They do, however, lay down collagen-based scar tissue which needs to be used regularly in order for it to form strong tissue. Early, protected weight bearing is emphasized as well as prescribed range of motion and strengthening exercises.

Another area in the knee joint where injuries are commonly sustained is to the cartilage of the knee. There are two major kinds of cartilage in the knee: articular and meniscus. Articular cartilage covers the end of the tibia (shin) and the femur (thigh) and acts as a shock absorber and bone protector. The menisci are two disc shaped wedges which float between the tibia and femur and act as stabilizers as well as shock absorbers.

Injury to the meniscus is more common than to the soft articular surfaces and typically results as a result of a twist or torque to the knee. Pain and feelings of catching or "locking" are common and are the result of the torn menisci flipping in and out of the joint space--much like trying to close a door with a marble in the door jam. Pain, swelling and apprehension with walking will typically resolve within a week or two, but sensations of locking, buckling or giving out will be much more apparent as activity level increases. Because of the poor vascularity to the menisci, they are unable to repair themselves and typically need surgical intervention to repair or take out the torn piece. Depending on the work that is done, return to activity takes anywhere from a few weeks to a few months.

So, what can be done to prevent such injuries from occurring? Research clearly shows that getting on a good strength and flexibility program can reduce the risk of injury. The stronger and more agile you are makes you more responsive to avoid vulnerable situations. A good weight-training and stretching program that focuses on the major muscle groups three days per week is usually sufficient. Other examples would be step-aerobics, a stretch cord resistance program, and yoga classes.

The better conditioned you are aerobically also aids in preventing injuries sustained as a result of fatigue. Cardiovascular training in the form of cycling, running, swimming, or stair machines improves endurance. This translates into the ability to play that extra set of tennis or take those last few runs skiing.

Another tip to aid in prevention of injuries is to train and perform activities with a partner or group. There is no better way to get feedback on faulty mechanics or poor technique than if someone is able to critique you. Maybe your golf swing needs more back rotation and follow through. Or perhaps you rotate your hips and knees too much when you are cycling. A good training partner would jump at the chance to volunteer tips knowing that they will receive the same.

The most difficult of all injury prevention techniques is self-discipline--knowing when enough is enough. A significant number of injuries are sustained near the end of an activity when fatigue begins to set in and balance becomes compromised. Next time, consider listening to that voice in your head that says: "I am feeling a little fatigued. Do I really need to play that last game of hoops?".

You may contact us to arrange individual medical consultation or care with San Francisco knee surgeon Kevin Stone MD.