Femoropatellar pain syndrome (or chondropathia patellae) affects the joint between the femur and the kneecap (kneecap joint) and refers to pain that occurs between the two bones, especially in the lateral area.
When the knee is bent, the kneecap (patella) runs in a groove-shaped plain bearing (fossa intercondylaris), which is adapted to the shape of the kneecap, so that the movement is fluid, painless and as smooth as possible.
Anatomical deviations such as a twisted shin or a pronounced valgic knee position (X-legs) can change the biomechanics of the joint and represent the prerequisite for the development of this pain syndrome.
In this pathology, the kneecap is shifted outwards in terms of its anatomical position and, when moving, comes against the distal epiphysis, that is, against the lower end of the femur, creating considerable friction.
This pain syndrome can be caused by bony abnormalities, trauma or soft tissue retraction/flaccidity; in the latter case, one speaks of hypercompression of the patella.
The gonalgia (knee pain) of patellofemoral syndrome arises as a result of inflammation of the articular cartilage between the two bones, which is particularly voluminous at this point and has a thickness of about 5-6 millimeters.
Of the patients who go to the doctor for knee pain, about 25% suffer from this disease.
Particularly affected are women and athletes, especially runners and jumpers, who strain the joint through repetitive bending movements of the knee.
Various factors can be responsible for this malalignment:
- Internal rotation of the femur or external rotation of the shin.
- Aplasia of the femoral articular knobs (femoral condyles), due to the dislocation of the kneecap (subluxation).
- Dysplasia or hypoplasia of the kneecap.
- Shape deviations of the kneecap.
- Pronated foot.
- Angle “Q” (this is the angle between two imaginary lines: the first leads from the large anterior iliac spine (spina iliaca anterior superior) to the center of the kneecap and the second from the center of the kneecap to the tibial cusp) greater than 10° for males and 15° for females.
- Direct or indirect trauma.
- Hypotrophy of the vastus medialis muscle in contrast to the vastus lateralis
- Retraction of the iliotibial ligament, femoral biceps or outer wing ligament.
What are the symptoms of femoropatellar pain syndrome?
The most important and ever-present symptom is the pain between the kneecap and the femur, especially in the lateral (outer) knee area.
The Syntomes appear:
- when bending;
- when getting up after prolonged sitting;
- the movement can also cause a crunch in the joint.
In some cases, joint effusion may occur, i.e. inflammation of the structures located behind and above the kneecap: bursa, fatty tissue.
The pain may also occur along the thigh or in the back of the knee.
In some patients who do not start treatment immediately, the clinical picture continues to develop into stiffness and joint restrictions, as well as hypotrophy of the quadriceps.
There are no symptoms of rest.
How is the clinical examination of femoropatellar pain syndrome performed?
The diagnosis can only be made by a specialist after examining the medical history and palpating the painful knee to locate the painful stitches.
Differential diagnosis is made by exclusion of Springer’s knee (tendinitis of the patellar tendon) and chondropathia-chondromalacia.
The exact examination of the knee during the flexion movement could reveal a lateral displacement of the kneecap.
The healthy leg is compared with the aching leg to determine any differences; this when standing (i.e. in an orthostatic position) and when walking.
Then the doctor will perform the compression test, i.e. he presses on the kneecap while bending the fully stretched leg as far as possible; the test is positive if there is crunching joint noise or pain, which could indicate cartilage wear.
If the symptoms occur when bending or stretching the thigh quadriceps, it may be patellofemoral pain syndrome; in case of doubt, the specialist can prescribe lateral X-rays, whereby the leg is taken in different angular positions attracted to the thigh, or a magnetic resonance, which would also show any existing cartilage reductions.
What can be done? Which treatment is suitable?
In severe cases with patellar luxation or malalignment of the kneecap due to bony deviations, surgical intervention may be necessary; if, on the other hand, the external run of the kneecap is only caused by an imbalance of the tendons and muscles, conservative treatment with physiotherapy and a training program is carried out in the gym.
The treatment recommended by the specialist is personally tailored to the patient depending on the pain and exercise options for muscle strengthening.
The goals of therapy include relieving pain and inflammation, regaining knee functions, correctly aligning the kneecap, targeted muscle strengthening and, in athletes, resuming sporting activities.
In the acute phase, the protection of the leg is important, which includes a break from training and the avoidance of pain-inducing movements; Cold treatment and relieving leg rest can be used as a supplement for a few days.
The doctor may prescribe a bandage that holds the kneecap centered in its plain bearing, or recommend a tape bandage (such as McConnell) whose ability to hold the kneecap in axis is not holistically recognized.
Orthopedic insoles are useful for almost all complaints of the lower extremities, because they correct the hyperpronation of the ankle and give support to the sole of the foot in normal and hollow feet.
After 2-3 days, physical therapies are recommended to relieve pain and inflammation; the best results are shown by magnetotherapy and Tecar®.
If the patient cannot bend the knee because of all the pain, therapies to maintain the tone and trophics of the muscles, which act on the hip joint and ankle as well as on the entire healthy leg, are important.
Kinesio taping for patellofemoral pain syndrome
Effect: stabilizing. Shape: an “I” stripe. Length: 15 cm. Bend the knee slightly at 20-30°; anchor the centre of the band to the outer edge of the kneecap; guide the ends of the ligaments with 25-50% tension above and below the kneecap towards the inside of the knee.
As soon as the patient is able to do so, a program is started to stretch and strengthen the muscles, especially the vastus medialis muscle in its transverse component (VMO activation).
After a thorough warm-up, the three-headed calf muscle (gastrocnemius and soleus) is stretched because retraction of this muscle would maintain foot pronation and thus worsen the clinical picture.
If foot pronation is the cause of patellofemoral pain syndrome, the orthopedist will prescribe an orthosis or appropriate footwear.
In addition, stretching exercises of the ischiocrural muscles, the thigh ligament tensioner (tensor fasciae latae) and the iliotibial ligament are important.
Patient or physiotherapist also stretch the outer ligament and lateral wing ligament, which “pull” the kneecap from its anatomical fit; the kneecaps are kept pressed inwards.
Muscle strengthening is probably the most important part of the treatment because an imbalance between the individual quadriceps muscle heads is the main cause of laterization of the kneecap.
In order to selectively strengthen the medial vastus muscle without tensing the lateral vastus muscle, the exercises must be performed in a certain way.
First of all, the knee must be bent only slightly, the flexion movement must be within 0°-30°; in addition, the adductors (approach) of the thigh must be tensed at the same time, because in this way the vastus lateralis relaxes.
At the first stage of rehabilitation, the muscles should be tensed in a closed kinetic chain (with foot in a fixed position) in a slightly bent leg posture, that is, in isometric operation, the back leaning against the wall or a gymnastics ball, holding for 20-30 seconds.
You can start immediately with the leg press and mini squats, whereby the heels must always be closer together than the tips of the feet.
The strengthening of the muscles is done by many repetitions with only light load, I usually recommend 20 repetitions.
In order for the adductors to remain tense during the exercise, I advise holding a ball pressed between the knees.
In the second phase, exercises can be introduced in open kinetic chain, so the feet can move freely during the execution; here, too, the legs are only slightly bent, the adductors tense at the same time and the tips of the feet turned outwards.
A typical exercise for the Fintnesshalle is the leg extension with weights or an elastic band, which has the advantage that it makes the last part of the movement more difficult.
Some authors recommend bending the upper body forward to exclude the straight femoral muscle (rectus femoris muscle) and using the medial vastus even more selectively; I personally do not recommend this in order not to cause or intensify back pain.
Some orthopaedists recommend exercise therapy exercises of a proprioceptive nature on seesaw boards to strengthen the vastus medialis.
First of all, it is difficult to establish a period of time that is universally valid, because each patient reacts differently to therapy. If surgery was not necessary, it will take about two months for the pain to subside and competitions to resume, but further work must be done on the muscle-tendon and ligament structures to avoid relapses.
A return to everyday activities with little or no pain, if there have been no joint restrictions, will take two weeks, during which a targeted physiotherapy exercise program will be carried out.
If the patient cannot bend the leg even up to 90°, more time will be needed.