The following essays are extracts of monthly articles written for the Syracuse Track Club newsletter by Dr. Dan Wnorowski.
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What is Runner’s Knee? (Part 1 of 2)
The phrase “runner’s knee” (RK) is really a generic name for a variety of conditions that cause pain in and about the knee in runners. Unfortunately, that’s about the only thing these conditions have in common, except for their cause, chiefly overuse. Typically, what is most commonly called RK is pain in the region of the kneecap, or in the front of the knee, what we call “anterior” knee pain. The second most common location of pain called RK is on the lateral (outside) side of the knee.
Other symptoms are usually rare, except for stiffness. Any condition which, in addition to pain, causes swelling, or such mechanical symptoms as locking, catching, or real giveaway or instability should not be called RK. In essence, typical RK is not likely to progress to real damage if ignored, or if running continues, hence the distinction.
Pain in the front of the knee can, in itself, stem from a host of causes, such as tendinitis of the quadriceps and patellar tendons which attach to the top and bottom of the kneecap, respectively. This may follow aggressive hill training or racing, increase in mileage, or perhaps from running on the same side of a road with considerable camber (tilt) of the road surface. A pronated, or flat foot, can also contribute to tendinitis via the torque conversion function of the ankle and subtalar joints of the foot. When the foot flattens during the stance phase, the lower leg rotates, and this can produce twisting forces on the knee structures.
Other causes of pain in the front of the knee include pain directly originating from the kneecap. A complete discussion of kneecap problems is far beyond the scope of this article. However, pain from the cap can generally be divided into: pain from surface cartilage problems, pain from malalignment or instability of the kneecap, and pain from the neighboring soft tissues. The actual source of the pain is a moot point, as long as there is no swelling.
Pain in the front of the knee is one of the most common problems seen in the orthopedic office, in runners and non-runners alike. Usually, we try to manage these problems in similar fashion, beginning with cutting back on intensity, and perhaps mileage, avoiding hills, changing roadsides or going alternate directions on a track, increasing stretching, working on quadriceps strengthening exercises, icing knees after workouts, taking medications, and using a knee sleeve. A word about exercises- sole of the foot quad resistance strengthening routines are favored over front of the shin types, as the latter may aggravate the symptoms by increasing pressure behind the cap.
More next time.
What is Runner’s Knee? (Part 2 of 2)
Last time the discussion focused on one type of runner’s knee (RK), that arising in the front (anterior) portion of the knee. Another common type of overuse knee pain is on the outside, or lateral, aspect of the knee. Several tendons may be the primary culprits, but far and away the most common is the iliotibial band. This very long tendon originates at the pelvis, just above the hip joint, as a small fist-sized muscle. The tendon is sheet-like, stretches over the lateral hip (trochanter of the femur- thigh bone), and continues all the way down the thigh to the top of the tibia (leg bone), just below the knee joint.
The problem that usually causes the inflammation, tendonitis, is a small prominence on the femur (thigh bone) just above the knee joint. When the knee bends back and forth, the iliotibial band must slide back and forth over this bump on the outside of the knee. Although this is a normal phenomenon, excessive tightness of this tendon can cause inflammation of the iliotibial band. The runner may feel pain or notice swelling and tightness at this location. The pain is worse during single leg stance, and at 45 degrees of knee flexion (bend). Generalized swelling within the knee joint is not seen, though localized swelling may be noticed..
Contributing factors include inadequate flexibility, hip muscle weakness, excessive pronation, leg-length difference, worn shoes, and running on the same side of the road or in the same direction on a track (especially a banked track). Interestingly, bicyclists are also prone to this condition. The medical term is “iliotibial band friction syndrome” (ITBFS). Although acute (recent onset) ITBFS will often respond to the usual conservative measures of treatment, well-established or chronic tendonitis can be very difficult to eradicate. Therefore, aggressive early treatment is desirable.
Like most other overuse injuries that plague runners, treatment predictably includes modified activity, vigorous stretching, icing, medication, etc. One should examine their training regimen for training errors, such as the technical problems mentioned above. Worn shoes must be discarded. Try avoiding cambered surfaces, such as the same side of the road, or running in the same direction on a track. Stretches that focus on the lateral hip, thigh and knee are very useful and effective. Post-running icing, applied directly to the symptomatic outside of the knee for ten or fifteen minutes after a run can help quiet the inflammatory pain, swelling, and stiffness. If the tendonitis becomes entrenched and chronic, it may be difficult to continue running while expecting the condition to resolve. However, the vast majority of these problems will resolve with the assistance of these measures without injections or surgery.
Dan Wnorowski, M.D.
Tendinitis of the Knee
The knee is an amazing joint. It is uniquely designed to help propel our bodies, cushion shock transmitted up and down the leg, and act as a powerful lever with the largest muscles in our bodies. Specialized components include robust ligaments, tough meniscus cartilage, and undulating smooth gliding joint surfaces. Essential to proper knee function are well-conditioned muscles, which not only include the quadriceps, the hamstrings, and adductors of the thigh, but also the gastrocsoleus complex of the calf.
Every runner has an instinctive understanding of the need for adequate muscle strength. This is especially true with regard to the quadriceps muscles. “Quadriceps” means four heads, which refers to the four separate origins, or upper attachments, of this powerful group of muscles. The quads act chiefly to extend (straighten) the knee, but are also secondary hip flexors (benders). They act to produce knee extension via a “chain” of structures distally including the quad tendon, patella (kneecap), and patellar tendon (or ligament). During quadriceps contractions with climbing and running, forces equal to many times body weight are produced as tension within the tendons, and as compressive forces behind the patella. These areas are usually the “weak link” in the chain, and often complain the loudest during periods of injury or overuse.
Patella problems are numerous and varied, and are beyond the scope of this discussion. However, irritations or inflammations of the quadriceps and/or the patella tendons are also extremely common conditions in runners. In this context, they will cause pain immediately above or below the patella, accompanied by tenderness, and in some cases swelling may be seen. Tendinitis at these sites most often follows a sudden increase in mileage, or change in training routine, such as hill running, or speed work. For the cross-trainers, jumping or twisting sports, hiking downhill, or bicycling with hill climbing in excessively high gear (big front chain ring) may also contribute.
It is infinitely easier to treat and cure this problem with aggressive, early intervention. Once the tendinitis becomes entrenched (chronic), i.e.- greater than six to eight weeks, it is much more difficult to eradicate. Early management includes attempts to “put out the fire” using ice, anti-inflammatory medications, and relative rest, avoiding provocative activities, such as those mentioned above. Gentle knee bends, squats, and quad and hamstring stretches may provide enhanced flexibility. A knee sleeve may provide relief.
A word about strengthening. When pain is present in the front of the knee, such as with these tendinitis problems, or with patella problems, efforts to strengthen the quads are usually beneficial. However, strengthening via knee extensions, i.e.- pushing off with the front of the lower leg, will often only make matters worse. It is much better to try to strengthen the quads by using straight leg lifts with weights, or with the sole of the foot, such as with the leg press, bicycle, stair stepper, rower, etc.
Caution! Avoid steroid injections in and around the patella and quadriceps tendons! Surgery for this problem is seldom necessary, usually a last resort when all else has failed for the frustrated, incapacitated runner.
Dan Wnorowski, M.D.
Patella Pain in Runners
Knee problems seem to be increasing in incidence in the population in general. This is possibly the result of increased exposure to injury through increased activity and risk taking behaviors, and perhaps more importantly, improvements in diagnostic skills of treating practitioners, especially orthopedic surgeons. Although one of the stated goals of managed care is the limitation of costs of care by limiting access to specialists, this runs counter to the trend of enhanced diagnosis. It stands to reason that a specialist who treats knees for a living, will have a superior ability to recognize and differentiate various knee problems relative to the general orthopedist who sees a variety of problems involving all parts of the musculoskeletal system, or especially relative to a primary care provider who has more limited orthopedic training and may see only a few orthopedic problems in an average day.
This concept is important with regard to patella pain. The cookie-sized, kneecap can produce pain for a multitude of reasons. These include wear and tear, and overuse of the surface cartilage (chondromalacia), and malalignment and instability of the patella within the saddle-shaped groove on the end of the thigh bone (femoral trochlea). Quadriceps muscle weakness or lack of development, and tendinitis of the attaching quadriceps and patella tendons above and below the patella,can also cause pain in front of the knee. Congenital problems, such as a two-part (bipartite) patella, and internal abnormalities, such as synovial folds (plicae) can also produce pain in front of the knee. It is very easy to call all patella pain: “patellofemoral syndrome”, and make little or no effort to get at the very root of the problem. Although the initial treatment for much of these problems may be similar, ultimate treatment for those that do not respond to initial interventions, and prognosis, can be vastly different. Furthermore, efficient treatment is of course, dependent upon efficient diagnosis.
Apart from the contributors noted above, probably the most common cause of patella pain in runners is overuse, generically: “too much, too soon, too fast.” Increases in speed or hill running, running the same direction on a circular track, or on the same side of a cambered road, all may contribute. Running downhill places great stress on the patella and its cartilage, as well as the tendons attached above and below the bone. This is because of the quadriceps develops tension as the knee flexes with each step, in order to decelerate the body. This mechanism is analogous to letting a fish run out on a taut line, while keeping tension on the line. The muscle is contracting while stretching out, or lengthening; called “eccentric” contraction. This is usually associated with much muscle soreness afterward. The more typical pattern of muscle work is shortening with tension: “concentric contraction”.
Reasonable things to try as initial interventions include avoidance of hills, quad stretches, anti-inflammatory medications and ice, and use of a knee sleeve. Regarding quad strengthening exercises, although they are usually of great benefit to those dealing with patella pain, how they are done can make or break the outcome. Doing knee extension type strengthening, i.e.- pushing off with the front of the shin, applies substantial loads to the retropatellar surface, which can actually make the pain and underlying problem worse. Safer means of strengthening all have in common the use of the sole of the foot for application of force to the leg, so-called “closed-chain” exercises, such as cycling, stair climbing, rowing machines, leg press, etc. These types of exercises result in less force behind the patella, and hence, typically less pain.
Most patella problems respond, in time to conservative measures. Occasionally however, surgery may be required to restore performance to the knee extensor mechanism. In this situation, it is imperative to know exactly and precisely the cause of the problem, as procedures for malalignment, instability, chondromalacia, plica, etc., are very different. It is rare to operate for chronic tendinitis, but sometimes no options exist other than abandoning running.
Happy and healthy running!
Dan Wnorowski, M.D.
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