pathology: patellar dysplasia

yogabook / pathology / patellar dysplasia

Definition

Patellar dysplasia is usually congenital, rarely traumatic, and can be categorised into types according to Wiberg (sources do not specify a single type):

  1. normal patella
  2. Hypoplasia of the medial and hyperplasia of the lateral facet, as if the retropatellar fin were shifted slightly to the lateral, possibly with a clearly incongruent medial facet, which absorbs less force due to less surface area
  3. Significantly reduced and convex medial facet with only low force absorption on a very small area
  4. Hunter’s hat-patella: the patella is displaced to the side or the medial aspect of the patella is essentially missing altogether

In patellar dysplasia, the femoral condyles can also be altered, sometimes in such a way that guidance is largely preserved, sometimes in such a way that it is further impaired. In addition to the Wiberg types, there is also the flat patella, which is characterised by a strongly flattened fin.

Patellar dysplasia can be asymptomatic, but can also cause retropatellar pain, especially after weight bearing. The knee joint may feel unstable and limited mobility is possible. It is not uncommon for audible and palpable crepitation to occur or pain that occurs at rest and improves after movement. Swelling and tenderness are possible. Depending on the type, patellar luxation, chondropathia patellae or the development of retropatellar arthrosis is possible or probable. The diagnosis is confirmed by X-ray or MRI. Conservative treatment involves moderating the load and building up the strength of the relevant muscles, including examination for muscular dysbalances. In patellar dislocation, the vastus medialis of the quadriceps is particularly important, as patellar dislocations almost always occur laterally. An insufficiently pulling vastus medialis clearly favours the occurrence, as does a missing retinaculum patellae transversale mediale.
If necessary, orthoses or a surgical intervention are required in which the ligaments are tightened or a lateral release is performed to create stability. Replacement of the patella with an artificial one is also possible. Sport may be possible, but must take the circumstances into account. Often heavy leg-related weight training, rowing, martial arts are not possible, sometimes running, rehabilitative strength training with weights or machines are indicated.

Cause

  1. Genetic
  2. Developmental disorders of the patella due to various influences such as incorrect traction of the musculature, muscular imbalances during growth
  3. traumatic
  4. hormonal influences during growth
  5. Overuse

Predisposing

Diagnosis

  1. X-ray
  2. MRI for precise clarification of the cartilage, ligaments and muscles (injuries?)
  3. Clinical testing, medical history
  4. Running analysis, EMG if necessary

Symptoms

  1. Retropatellar pain on exertion: pulling or cutting, possibly radiating towards the lower leg or thigh. Further flexion under load is the most painful due to the high contact pressure. Downhill or down stairs is also clearly painful
  2. Possibly rest pain, which improves with movement
  3. crepitations
  4. Restriction of movement
  5. Possibly swelling that impairs mobility in the knee joint
  6. Sensitivity to pressure

Complications

  1. Patellar dislocation
  2. Chondropathia patellae
  3. Retropatellar arthrosis
  4. After initial dislocation, damage to the movement apparatus due to asymmetric avoidance behaviour

Therapy

  1. Elimination of muscular imbalances and a strength deficit of the vastus medialis, possibly also isolated EMS training
  2. Rest, elevation, counting, NSAIDs if necessary
  3. Orthosis/brace
  4. Sitting without a widely bent knee
  5. Strengthening and balancing sports (strength training, cycling, swimming), yoga
  6. For significant dysplasia: repositioning osteotomy
  7. For significant dysplasia: patellar plasty

Asana practice and movement therapy

In the case of patellar dysplasia, it must first be determined what type it is and whether there is an additional positional anomaly of the tuberosity of the tibia. If this is further lateral than physiological, this means an additional dislocation risk for the patella. The tendency to patellar dysplasia appears to be inherited, but is not equally pronounced in all family members. Not in all cases can a sufficiently high degree of safety against patellar dislocation be guaranteed purely conservatively. If, for example, the medial half of the patella is missing, the attachment of the vastus medialis is thus so adversely altered, that not only is the risk of patellar dislocation significantly increased, but there is also a massive risk of retropatellar damage (retropatellar arthrosis or chondropathia patellae). A trochlea that is too shallow or a retropatellar fin that is not pronounced enough can also impair the guidance of the patella to such an extent that only a bony realignment provides sufficient safety. For the case to be treated conservatively, the tone of the vastus medialis must almost always be increased to such an extent that sufficient traction of the patella towards the medial is guaranteed in all situations. With its lower fibre course, which runs at an angle of up to 45° to the longitudinal axis of the leg, this muscle is by far the most important muscular component in the guidance of the patella. To make matters worse, some people lack a medial transverse retinaculum patellae, whose action must then be taken over by the vastus medialis. As it is part of the quadriceps, it can only be trained through the stretching movement in the knee joint, but all three other parts are always trained as well. The vastus medialis is trained relatively most in the area of the last 20 degrees or so before extension of the knee joint, which can be done statically, i.e. isometrically, or dynamically. This means that all postures in which the knee joint has to be stretched against the pull of the iliopsoas are suitable, such as in the first hip opening or the first warrior position the case for example.

Bilateral or unilateral squats performed with little flexion are also suitable, as is the leg extension machine under similar conditions. Hypertonicity of the rectus femoris is also a significant risk factor, as it mainly pulls mediolaterally on the caudal patellar pole. Due to the biaticularity of this muscle, activities and postures are conceivable that increase the tonus of the rectus femoris more than that of the other three knee extensors. Postures such as supta virasana, ardha supta krouncasana and quadriceps stretch 1 or quadriceps stretch 2 on the wall are very effective here.