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Deformities of Joints and Soft Tissues

Joint Deformities

Joint deformities are often difficult to treat. They may be congenital or acquired (ie, after a traumatic injury). Acquired deformities may increase during residual growth.

A complete evaluation is required for joint and ligament lesions, both clinically and often by arthrography or an arthro-CT scan.

Joint deformations may involve either the full joint, inducing a bad joint position, or involve part of the joint surfaces.

SOF TISSUE LESIONS

Muscles and tendons can be abnormal or present lesions.Evaluation of tendinous retractions and natural remodelling of these tissues is important to check possibility of adapatation of the body to a surgical correction of joints, bone or ligaments. Evaluaiton can be clinical, but also with machines (isokinetic testing machines for muscls, KTM or MRI for ligaments, etc.).

Nerves should also be evaluated. In specific conditions (e.g. dwarfism or attached spine cord), during a lengthening, nerves can be moderately flexible and react a lot at light stretching, with irritation and transitory or final paralysis, complete or incomplete. EMG evaluation can be performed when needed.

Vaisseaux condition deformities and corrections potential. In some diseases, soe vessels may be missing, which decreases vascular supply, increasing risks in case of correciotn of deformities.

Hip

A lesion in the cotyle or socket part of the hip joint is generally a deformity due to decreased bone formation ("dysplasia"). The cotyle is oblong instead of spherically shaped, often with a double cavity pattern.
At the femoral level, a varus hip, retroversion (backwards tilt), or other associated lesion (eg, congenital short femur) can occur. Femoral head deformity can present as a double contour, as in Legg-Perthes disease.

Bone deformities

Picture (left): The right hip (left image) is in varus over 90° with a 90° retroversion, which is a very large deformity. Please note the other hip which is normal.

 

At the hip, growth plate orientation plays a major role in ensuring normal bone formation and growth of the femoral neck. In the figure above, note that at the top part of the left femoral neck (at right in figure) the orientation of the growth plate (transparent line crossing the neck) is almost horizontal. At the right hip (at left in figure), the growth plate is more than 90° off normal orientation.

As discussed previously, the growth plate is organized with cells arranged in columns that are vertically loaded from top to bottom. On the right side of the patient (see above figure), the cells and columns are loaded perpendicularly, (ie, 90° from the normal position). This creates a shear stress on the growth plate. Surgery is mandatory to reorient the femoral neck, allowing it to heal and the growth plate to work. At the middle of the right femoral neck, ossification (or calcium deposit) did not progress correctly due to a failure of the two vascular supplies to join. At the base of the neck (close to the shaft) an oblique dark line can be seen, which is in fact a rupture of the bone between the neck and the shaft (pseudoarthrosis). Abnormal shear stress in varus of the femoral neck participates in the rupture of the bone, where healing has not occur correctly.

Treatment consists of reorienting the growth plate so that it can establish a normal growth condition and be stimulated to recover part of the original discrepancy.

Bone deformity

Blade plate correction resulted in a better hip orientation. The femoral retroversion is fully corrected, but full bone fusion, even obtained at the mid-neck, was not possibl at mid-shaft. This correction allowed growth plate stimulation, resulting in a decreased discrepancy between both femora.

 

Knee

Bone/joint support

Some anomalies result from growth defect of the joint surfaces and their bone supports. Hypoplasia, or decreased development, of one of the condyles can result in varus or valgus, depending on the involved condyle.
Some surgical techniques aim at correcting hypoplasia of one condyle ; for example, an intercondylar femoral osteotomy lowers the lateral condyle.
The anterior part of the femur condyle can be hypoplastic ; for instance, at the lateral condyle. This induces a defect of the femoral trochlea that can "open", resulting in dislocation of the knee cap (patella) ; that is, it slides to the outside of the leg when the knee is extended.
Longitudinal bone development is associated with bone torsion. When evaluating altered alignment, it is important to take into account each parameter. For example, a large knee varum with too high a femoral torsion can be associated with a hyperplastic inward rolling of the lateral condyle. This results in closing of the angle between the two joint surfaces of the condyle grove and of the patellar surfaces.

Bone deformity Bone deformities

Pictures above: Genu varum with femoral torsion (quadruple torsion syndrome) of 40° and lateral condyles without hypoplasia, or even with hyperplasia (angle between the 2 joint surfaces at 110°, for a normal angle close to 140°).

Sometimes, in femoral hypertorsion (or more likely in femoral retroversion) and with genu varum, there is a relative hypoplasia of the lateral condyle, or opening of the angle between the 2 joint surfaces. This induces the risk of patellar dislocation or subluxation, in which the patella will slide and move around the lateral femoral condyle.
Often, bone alterations occur as a result of soft-tissue lesions ; for example, hypoplasia of the vastus medialis of the quadriceps (the portion of the muscle above the knee and internal to it).
A thorough evaluation of the anatomical and functional abnormalities involved in axis misalignment allows surgery to be customized for bone and soft-tissue correction.

LIGAMENTS

Cruciate ligaments of the knee (anterior, or ACL, and posterior, or PCL) may be absent from birth. In such cases, knee is unstable. This does not mean playing sports should be avoided, but a gradual degradation of the knee is induced during growth, and those with this condition are at risk of degenerative arthritis in adulthood. Initially, range of motion may be normal, but be decreased by the end of growth period. The unstable knee will have a tendency to "slide" (like a soap bar across the floor), resulting in a flattening of the inferior part of femoral condyles and in a modified shape of the tibial plateau with a posterior neo-joint.
In young children, joint surfaces are cartilaginous and can be rather easily remodeled or modified. However, absence of cruciate ligaments prevents the knee from remodeling spherically around the ligament hinges. When growing cartilage at the joint is replaced by adult bone, remodeling of the joint surface and its supports are no longer possible.
In congenital deficiency of cruciate ligaments, a ligament replacement (ligamentoplasty) is advisable, preferably in young children. It can be performed arthroscopically (without creating lesions of the growth plate) or by a direct surgical approach.

Bone deformity Bone deformity

Pictures above: Patient presenting with a congenital deficiency of both cruciate ligaments (left) with respect ot the normal contralateral knee (right).

Bone deformity Bone deformity Bone deformity

Pictures above: Lateral X-rays of a knee with no cruciate ligaments, without (left) and with (middle) traction on the tibia, and of the positioning of the ligament to implant (right).

Ligament reconstruction at the knee can use adult arthroscopic surgical techniques. Ligaments cross growth plates, carrying out risks of growth disturbances in young patients. Even if used in the USA (Baltimore, Florida, etc.,) they present non negligible risks.

Techniques leaving ligaments in the joint space, used 30 or 40 years ago are not taking into account rotatory centers of joint and can bring overloading of joints and degenerative diseases. They are not adviseable in children.

Dr Guichet designed a specific technique without failures of previous techniques, with a perfect centering of ligaments in the rotatory centers of joints and passed through the bone without crossing the growth plates. Dr. Guichet offers his unique know-how for solving problems of patients.

Bone deformity Bone deformity

Pictures above: Patient presenting with a congenital deficiency of both cruciate ligaments. Stability test in flexion and "drawer" of the knees. Note the lateral view of a knee with no ligament (ACL) without (left) and with (right) traction on the tibia, showing full knee instability.

Bone deformity Bone deformities

Result after 4 year,s with the lateral view of the knee without (left) and with (right) traction on the tibia, showing a perfect knee stability.

Ankles

In various diseases, the ankles are not stable. For example, in longitudinal deficiency of the fibula, the fibula is hypoplastic, or partially or totally absent (fibular hemimelia), and the lateral malleolus, which provides lateral stability to the ankle, is deficient, resulting in deviation of the outside of the ankle. The joint surface at the foot to tibia interface (tibial-talus) becomes rounded in the frontal plane and loses its linearity.