DocZon -> Re: Knee problem (October 29, 2003 8:54:00 PM)
A high riding patella is also called patella alta and is associated with pain and recurrent dislocations. Taping techniques can be helpful and I agree that you should seek out a good PT or a chiropractor who deels with sports injuries. I posted some chiropractic articles and some research abstracts which you may find interesting. Hope it helps.
Winchester Hospital Chiropractic Dept.
Patella alta and recurrent dislocation of the patella.
Toronto General Hospital, University of Toronto, Ontario, Canada.
Clin-Orthop [m. 1992 Jan. (274). P 265-9.
Fifteen knees were treated with a surgical technique designed for
recurrent patellar dislocations when associated with patella alta. The
average number of patellar dislocations preoperatively was 12, and the
determination of patella alta was made using the technique described by
Insall and Salvati, which is a ratio of the length of the patellar tendon
to the longest diagonal length of the patella. The normal value for this
ratio is 1.02 plus or minus 20%. The average preoperative ratio in this
study was 1.58 (range, 1.2-2.1), which changed to 1.08 (range, 0.99-1.14)
by the time of follow-up examination. The surgical technique used
involves transposing the patellar tendon insertion distally without any
medialization or recessing and allows for good bone contact for healing,
secure fixation, and immediate postoperative motion. There were no
recurrences of patellar dislocation postoperatively and few
complications. Only one patient complained of anterior knee pain in the
follow-up period. This technique is thought to give good results when it
is used specifically for recurrent patellar dislocations associated with
patella alta. Author-abstract.
Patellar Malalignment -- Part II
In the previous article on patellofemoral (PF) problems I alluded to the idea that restoring normal balance to the patella was the main approach to conservative treatment of patellar function. Restoring normal balance to the patella mechanism automatically assumes that we must also take into account not only patellar position and motion but all of the peripheral possibilities that may affect PF mechanics.
Symptomatically, most patients with chronic PF problems complain of knee pain when squatting, climbing and descending stairs, getting up after sitting a while (movie sign), popping, giving way, crepitation, and possible mild parapatellar effusion.
Whether the diagnosis is loose bodies trapped in the PF joint, synovial plica impingement, patellar subluxation, patellar tendinitis, chondromalacia, lateral compression syndrome or patellar malalignment syndrome, to name a few, if the following functional examination and treatment is performed, a clinician should be able to markedly improve most of the PF conditions. The prime purpose of examination is to determine the source of the pain; and while tenderness to palpation may reveal a biomechanical stress, a functional examination is needed to reveal where treatment should be directed. The examination should comprise both a static and dynamic point of view.
A patient should be examined in a standing, sitting, and supine position to ascertain structural deviations.
Standing: Is the pelvis level or oblique? Pelvic obliquity and fixation may affect the hamstrings, quadriceps, and hip joint. An anterior pelvic tilt due to tight hip flexors may be associated with hyperextension of the knees and abnormal knee joint mechanics.1 A posterior pelvic tilt due to hamstring tightness would create excessive stress on the quadriceps. Is there increased internal torsion of the femur (excessive anteversion) causing the patellae to be more medial ("squinting")? Formal retroversion causing laterally pointing patellae? Is there genu valgum (causing an increased Q angle and resulting in abnormal patellar tracking during knee flexion), genu varum (a cause of compensatory subtalar joint pronation), tibial rotation which should be increased internally with pronation and externally with supination, all of which affect PF mechanics? Unfortunately, there is not too much that can be done for structural deformities such as hip coxa valga or vera, femoral rotations or genu valgum and varum. Foot orthotics and stretching of associated tight muscles and strengthening of associated weak muscles might help to compensate. Finally, in the standing position we would check for foot and ankle alignment. Foot pronation is definitely related to PF problems.2 Observing the standing patient from the side might reveal a genu recurvatum which may be associated with general ligamentous laxity or patella alta (high-riding patellae).
Sitting: Do the patellae point towards the ceiling (alta) instead of straight ahead, or do they appear to be displaced inferiorly (baja)? Patella alta means that the patella is not protected by the higher lateral femoral sulcus and may be more prone to lateral subluxation. Patella baja ad alta does not allow normal patella contact and is subject to poor stability and function. Patella tracking should be observed as the patient flexes and extends the knee. Look for abrupt patellar deviation (covered in previous article) and popping. Abnormal patella tracking may refer to recurrent subluxation, chondromalacia, excessive lateral patella stress, plica syndrome or a chondral or osteochondral defect. Your treatment of these conditions will be based on the functional findings found during the examination. The vastus medialis obliquus (VMO), an extension of the vastus medialis which inserts into the patella, should be observed to see if it is dysplastic or atrophied. Atrophy will reveal a large superomedial patella dimple as the sitting patient extends the knee 45 degrees. The lower the VMO inserts on the medial patella the more stability it provides.
Supine: Structural or static evaluation in the supine position would include measurement of the Q angle. If the quadriceps angle is abnormal and is due to structural or functional abnormalities, such as genu valgus, VMO atrophy, etc., the angle is considered pertinent. An abnormal Q angle by itself is not necessarily diagnostic.3 One can observe the amount of effusion which obliterates the patella outline in an acute severe injury or a mild effusion in chronic patellar involvement. The patient's knee can be flexed about 30 degrees on the examiner's knee, and the examiner can displace the patella both medially and laterally to determine the degree of retinacular laxity, pain, and apprehension. Usually the patient will express pain, apprehension and excessive movement on medial to lateral stress if subluxation or dislocation is present. There is often tightness on lateral to medial patellar stress. Failure of the patella to displace medially more than one centimeter represents a tight lateral retinaculum which may require lateral to medial stretching as a treatment. In this supine position, orthopedic tests can be performed which help to localize the problem to the PF joint such as the patellar inhibition test. In this test, with the knee flexed five to ten degrees, the patient contracts the quadriceps while the examiner exerts fingertip pressure on the superior patellar pole. Keeping the knee flexed prevents pinching of the suprapatellar pouch which would cause a false positive.4 Crepitation and pain may occur while the patella is compressed during flexion between 30 and 60 degrees. If pain occurs, the examiner shifts the patellar medially to see whether the patient is relieved during grinding; this indicates tight lateral parapatellar tissue.3
The next phase of the PF examination relates to the dynamics of the lower extremity. Related muscles must be tested for tightness which may inhibit normal PF function. Hamstrings: (causes quadriceps to increase stress on PF joint during knee extensor) patient is supine with hip flexed 90 degrees and examiner attempts to straighten the leg; quadriceps: (tightness increases PF joint reaction forces) stretch while patient is prone to see how far the heel reaches to buttock; tensor fascia lata and iliotibial band: use Ober's test;3 gastrocnemius: (increases subtalar pronation) dorsiflex foot with knee extended; test for tight hip flexors by having supine patient with thigh extended and knee hanging off the end of the table. Patient then flexes opposite knee to chest to keep low back flat on the table. If the extended thigh lifts off the table the hip flexors are tight; if the thigh remains on the table and the knee extends, the the rectus femoris is shortened.
Muscle strength should also be tested since muscle imbalance may have an effect on PF joint mechanics. Beckman et al.1 state that the medical hip rotators are often found stronger than the lateral hip rotators, resulting in increased femoral rotation and affect normal tracking of the PF articulation, especially when the knee is near extension.
A dynamic evaluation of the lower extremity could prove to be invaluable. Observing the patient descending stairs or performing single-leg squats might show increased genu valgus due to increased medial femoral rotation and adduction of the femur due to weak abductors and external rotators (posterior gluteus medius and piriformis). When the patient descends the stairs observe the flexing weightbearing knee to see if valgus occurs causing increased stress on the medial retinaculum. The patient's gait should be observed with respect to femoral rotation, position of the patella and foot, and ankle pronation and supination.
Five functional tests leading to PF involvement are: a probable abnormal patellar tracking; patellar pain on resisted knee extension; pain on patellar inhibition test; retropatellar or popliteal fossa pain on knee-squat test; and pain or apprehension on medial to lateral, or lateral to medial displacement test.3
Joint play (assessory motion) of the patellar should be checked. Finally, based on the work of McConnell5 the position of the patella should be determined. Is the patella centered or is it closer to the lateral or medial condyle? Is the patella tilted medially, laterally, superiorly or inferiorly? Is the patellar inferior pole rotated internally or externally? In the treatment of PF conditions, it helps to tape the patella in its most neutral position to reduce PF pain and help prevent patellar malalignment during exercise.
The taping procedure and exercise protocol will be explained in the next article.
Beckman, M.; Craig, R.; Lehman, R.C. "Rehabilitation of patellofemoral dysfunction in the athletes." Clin in Sports Med 1989; (8)4: 841-860.
Tiberio, D. "The effect of excessive subtalar joint pronation on patellofemoral mechanics: a theoretical model." J. Orth & Sports Phys Ther 1987; (9)4: 160-165.
Hammer, W.I. Functional Examination and Treatment by Manual Methods: The Extremities. Gaithersburg, Maryland; Aspen 1991.
Souza, T. "Treatment of common knee disorders, part II, specific conditions." Chirop Sports Med 1990; (4)4: 119-128.
McConnell, J. "The management of chondromalacia patella: a long-term solution." Aust J. Phys 1986; 31: 214-223.
Warren I. Hammer, M.S., D.C., D.A.B.C.O.
Dr. Hammer will conduct his next soft tissue seminar on April 6-7 in Chicago, Illinois. You may call 1-800-327-2289 to register.
Dr. Hammer's new book, Functional Soft Tissue Examination and Treatment by Manual Methods: The Extremities, is now available. Please see the Preferred Reading and Viewing list on page xx to order your copy.
Patellar Malalignment, Part III
In this article on patellofemoral (PF) problems we will deal with the rationale of treatment based on our static and functional examination described in part I and II. The main purpose of the PF examination was to determine if the patellofemoral dysfunction was localized to the structure (abnormal femoral sulcus and patella contours determined by x-ray, abnormal patella height due to length of patella tendon causing alta or baja, genu valgum or varum) or secondary dysfunction due to peripheral problems such as atrophy or tightness of the tissues that insert into the patellar: vastus medialis obliquus (VMO), iliotibial band, vastus lateralis, tightness of the retinaculum or abnormalities originating from the hip to the feet. Mann1 states that an intensive conservative six- month treatment program should be attempted before surgical intervention.
All of the biomechanical insults found on the examination discussed in the previous article require treatment if possible. It was stated that structural problems such as excessive genu valgum or femoral anteversion could only be treated from a compensatory point of view such as stretching or strengthening involved muscles or using orthotics. Correcting the flexibility of muscles such as the hamstrings, quadriceps, tensae fascia lata, gastrocnemius, hip abductors, medial and lateral hip rotators were mentioned.
Probably, the most significant muscle relating to patellar function is the VMO. As previously stated, the sole function of this muscle is to act as a medial stabilizer to the patella. There is normally more of a tendency for increased lateral knee forces on the patella. There is a normal valgus Q angle in which the pull of the quadriceps on the patella is directed slightly lateral. The knee normally has a more prominent lateral condyle to help the patella resist these lateral forces.
There should be a dynamic balance between the medial and lateral forces that stabilizes the patella throughout its range of motion. The EMG activity between the vastus lateralis and VMO are almost equal, especially in the last 30 degrees of extension,3 although it has been found in patients with PF problems that the vastus lateralis fires before the VMO. The end extension range is probably the range where the knee requires most control by quadriceps contraction,4 because during the last 20 degrees of extension the patella cannot depend on receiving the complete stabilization of the femoral sulcus. It is at this range that the quadriceps are performing their chief function as an eccentric decelerator. It is apparent that weakness of the VMO or tightness of the lateral retinacula will have an adverse effect on patella tracking. Abnormal tracking creates increased chondral changes. The VMO due to its location will be the first to show atrophy; it is also indicative of general quadriceps weakness, not only isolated VMO weakness.5 If found to be weak or atrophied (see previous article), just strengthening this muscle often relieves many PF problems.
Before discussing the exercise procedures regarding the PF area, it is important to understand the effect of compression forces on the patella (patellofemoral joint reaction force) at different ranges of knee motion. There are two sources of patellofemoral compression. One is due to the forces exerted by the quadriceps and the other is the force exerted by increasing the acuteness of the knee angle between the patellar tendon force and the quadriceps tendon force.6 Both of these forces are increased with knee flexion of 90 degrees. As the angle of flexion increases the force increases. Therefore most of the exercises recommended for PF problems are never performed near the 90 degree knee flexion position.
Henry7 feels that excessive progressive resistance exercises with the knees more than 45 degrees of knee flexion can produce retinaculitis or tendinitis. The usual exercises are straight leg raises, short arc terminal knee extension (patient sitting with pillow under the knee and extending from 20 to 0 degrees), and isometric quadriceps setting (patient contracts knee muscle holding knee in as straightened position as possible). A specific exercise for the VMO is a diagonal straight leg raise with the patient sitting on a table with thigh and leg flat (outstretched). The extremity should be positioned slightly lateral to the midline and the foot should be externally rotated. The patient lifts the straight laterally rotated extremity up and across the midline as if the knee were going towards the opposite shoulder. Besides strengthening the medial quadriceps, the hips flexors, adductors, and hip rotators are also exercised. Eventually weights can be added.
Hanten and Shane8 show that the VMO can be selectively strengthened by performing hip adduction exercises alone since the VMO originates off the tendon of the adductor magnus and somewhat off the tendon of the adductor longus muscle. They feel that a "strong VMO originating from weak adductors would serve only to draw the adductor tendons toward the patella, having no effect in reducing the lateral malalignment."8 Patients can be given a home exercise for the VMO. With the leg extended the patient pushes the patella laterally while attempting to contract the medial quadriceps. Patients can also push and hold the patella in a lateral to medial position to stretch the lateral retinaculum.
It has been found that the rectus femoris shows greater EMG activity during straight leg raises than during quadricep sets while the vastus medialis, gluteus medius, and biceps femoris showed greater activity during quadricep sets than during straight leg raises.9 Quadriceps setting generates 40 percent more EMG activity in the VMO than during straight leg raises (SLR). Reilly and Marten10 feel that compression of the patella on the femur normally occurs with the load coming from above and most exercises are performed with the load distal to the knee. Hughston11 feels that the extensor mechanism is used as an extensor of the femur on the fixed tibia so that increasing the extensor strength by extending the tibia on the fixed femur is not functional. He feels that climbing hills is probably one the best exercises (providing knee flexion does not go past 50 degrees). With distal loading of the foot for quadriceps strengthening from flexion to extension, maximum forces with free weight are between 60 and 20 degrees,9 a range that is not recommended.
Beckman et al.,12 feel that all of the above exercises which are of the open kinetic chain type are not as functional as the closed kinetic (weight bearing type). They therefore recommend lunges (dueling position), stair downs (walking down stair exercises stressing the weight bearing knee) and partial squats (bilateral and unilateral), all of the above never flexing the knee more than 50 degrees flexion. Palpate the patella for crepitus when the patient does partial squatting so that the exercise is only performed in the noncrepitus range. Partial squat exercises are important during the first 10 to 30 degrees of flexion when the quadriceps are working at their chief function of deceleration. The patella should also be evaluated and treated for loss of joint play.
In any acute PF problem it is important to reduce swelling before initiating strengthening type exercise because a swollen knee reflexly inhibits quadriceps contraction, causing atrophy and weakness.13 Attempting quadriceps strengthening when there is effusion and pain is a waste of time and effort. PF rehabilitation protocol by Brunet and Stewart14 includes isometric quad sets of 50 per hour, followed by straight leg raises (SLRs), eight sets of 10 lifts three times per day. The SLR are done with the noninvolved knee flexed to 90 degrees with foot next to outstretched involved knee. Patient contracts the knee muscles and raises involved leg up parallel with the uninvolved thigh. Patient holds for three seconds, lowers leg and rests for three seconds. Patient rests for one minute after each set of ten lifts. As soon as leg lifts become easy, free weights are added from one to fifteen pounds and added as soon as patients state that they are no longer fatigued.
Stationary biking could be used passively at first by using the good knee only. Later it can be used progressively by decreasing the seat height or increasing the pedaling force.
To decrease pain during exercise and walking, to increase the surface area of patella contact, to create a more even distribution of load, and to allow the muscles inserting into the patellar to function properly, the patella can be taped into a neutral position. It is necessary to take into consideration patella rotation based on which direction the inferior pole is rotated, lateral or medial tilt, medial or lateral glide towards the condyles, and finally superior and inferior tilting of the opposite poles.12,15. Depending on the abnormal directions, the patella is taped towards the normal position. For a laterally positioned patella, tape from lateral border of patella and pull the tape medially. If the patella is tilted, tape from the middle of the patella and pull the tape (i.e., medially) to lift the lateral border of the patella. Taping also helps to influence the dynamic control of the patella. A Palumbo or Camp brace can also be used to help control the patella position during rehabilitation.
In conclusion, patella malalignment is the chief functional stress underlying may PF problems. A forceful quadriceps contraction on a malaligned patella eventually results in excessive chondral wear. Strobel and Stedfeld16 state that "chondromalacia" should not be used as a diagnosis since it is really a "pathoanatomic and morphologic presentation of the cartilage." They feel that due to the complex nature of many PF problems that the best term would be "femoropatellar pain syndrome."
Mann, R.A. "Biomechanics of the Foot and Ankle." In Mann R (ED): Surgery of the Foot, 5 ed. St. Louis, Mosby 1986.
Hammer, W.I. Functional Soft Tissue Examination and Treatment by Manual Methods: The Extremities. Gaithersburg, Maryland, Aspen 1991.
Reynolds L., Levin, T.A., Mediros, J.M., et al. "EMG Activity of the Vastus Medialis Oblique and the Vastus Lateralis in Their Role in Patellar Alignment." Am J Phys Med 1983; 62:61-70.
Delitto, A., Lehman, R.C. "Rehabilitation of the Athlete with a Knee Injury." Clin in Sports Med 1989; (8) 4:805-840.
Lieb, F.J., Perry J. "Quadriceps Function: An Anatomical and Mechanical Study Using Amputated Limbs." J Bone Joint Surg. 1968; 50A:1535-1548.
Frankel, V.H., Nordin M. Basic Biomechanics of the Musculoskeletal System. Philadelphia, Lea & Febiger 1989.
Henry, J.H. "Conservative Treatment of Patellofemoral Subluxation." Clin in Sports Med 1989; (8) 2:261-278.
Hanten, W.P., Schulthies, S.S. "Exercise Effect on Electomyographic Activity of the Vastus Medialis Oblique and Vastus Lateralis Muscles." Phys Ther 1990; (70) 9:561-565.
Soderberg, G.L., Minor, S.D., Arnold, K., et al. "Electromyographic Analysis of Knee Exercises in Healthy Subjects and In Patients with Knee Pathologies." Phys Ther 1987; 67: 1691-1696.
Reilly D., Martens, M. "Experimental Analysis of Quadriceps Muscle Force and Patellofemoral Joint Reaction Force of Various Activities." Acta Orth Scand 1972; 43:126.
Hughston, J.C. "Patellar Subluxation." Clin Sports Med 1989; 8:153-161.
Beckman M., Craiig, R., Lehman, R.C. "Rehabilitation of Patellofemoral Dysfunction in the Athlete." Clin Sports Med 1989; (8) 4: 841-860.
deAndrade, J.R., Grant, C., Dixon, A.S. "Joint Distension and Reflex Muscle Inhibition in the Knee." J Bone Joint Surga 1965; 47A: 313-322.
Brunet, M.E., Stewart, G.W. "Patellofemoral Rehabilitation." Clin Sports Med 1989; (8) 4:319-329.
Arno, S. The A Angle: A Quantitative Measurement of Patella Alignment and Realignment." JOSPT 1990; (12) 6:237-242.
Strobel, M., Stedtfeld, H.W. Diagnostic Evaluation of the Knee. New York: Springer-Verlag, 1990.
Warren Hammer, M.S., D.C., D.A.B.C.O.