Dr. Chêneau, inspired by Abbot, fabricated the original Chêneau Brace in 1979. The Chêneau brace is commonly used for the treatment of scoliosis and thoracic hypokyphosis in many European countries such as Spain, France, and Germany as well as other countries like Israel and Russia. However, it is not commonly prescribed in North America and the UK. The brace is commonly known as el corse de Cheneau, Wood, G, Master by thesis, 2003. The brace is fabricated in polypropylene and has an anterior opening with Velcro straps for fastening. The Chêneau brace is defined as a thermoplastic brace modelled on a hyper-corrected positive plaster mould of the patient. The general correction principle is that of detorsion and sagittal plane normalisation, which would correct the coronal and transversal planes, resulting in some elongation of the spine, without any significant distraction force, (Rigo, 1999a).
The objectives of the Chêneau brace are to obtain a three-dimensional correction of the scoliotic deformity, with emphasis not only on the coronal and transverse planes, but also on the sagittal plane (Matthiass and Heine, 1984; Syndikus et al., 1988; Giorgi et al., 1996; Losito et al., 1996; Kotwicki et al., 1999).
The deformation of the scoliotic body consist of (Chêneau 1996a, 1996b):
1. Convexities-concavities.
2. Sagittal configuration deformity.
3. Rotation of the pelvis and shoulders
4. Lateral displacement.
1. The paired convexities and concavities: in an oblique plane the brace reduces the convexities and transfers tissues from the convex humps in the direction of the concave flat areas. All abnormal protrusions with respect to the normal physiological shape must be submitted to pressure.
2. Sagittal configuration deformity: often, abnormal thoracic kyphosis and lumbar lordosis is presented in the scoliotic patient.
3. Torsion of the pelvis and rotation of the shoulders: the brace must produce a detorsion of the pelvis and derotation of the shoulders.
4. The lateral displacement: in a transverse plane the brace establishes a balance of the shoulders and thorax over the sacrum.
Chêneau (1990) provided a number system to indicate pressure and expansion zones on the Chêneau brace. This number system facilitates the identification of important zones on the Chêneau brace, plaster of Paris cast and the patient's body (figure 3.16a and b). The system lists number 1 through number 43, however some numbers are missing as the evolution of the brace has made them obsolete. The number system is used in all different types of classifications of scoliosis and curves, hence it is not limited to only one type of curve. However, not all the numbers in this number system are utilised in all cases. This is because sometimes a particular number may not be utilised as its corresponding function is not required.
Additionally, the location of the numbers often change from being on the right side of the brace to the left side and vice versa, as each scoliosis case is treated independently. As a result, the locations of these numbers are often determined by the direction of the curve convexity. Therefore the brace design is different for each individual case. The basic location of the pressure and expansion zones using the Chêneau brace number system and their corresponding functions are indicated below.
1: The location of the pressure zone 1 is on the convex side of the thoracic or thoracolumbar curve on the dorsal aspect of the brace. The function of this pressure is for the correction of the thoracic or thoracolumbar curve in the coronal plane and rotation of the vertebral column in the transverse plane.
1: The location of pressure zone 1´ is on the convex side of the lumbar curve on the dorsal aspect of the brace. This pressure zone is extended to the posterior midline in the case of lumbar hypolordosis, which is for the correction of the deformity in the sagittal plane.
2: The location of the pressure zone 2 is on the convex side of the lumbar curve on the dorsal aspect of the brace. The function of this pressure is for the correction the lumbar curve in the coronal plane and if present, correction of the lumbar hypolordosis deformity in the sagittal plane.
3: The pressure zone 3 applies a counterforce to the axilla that works on the opposite side to zone 1, which is for the correction of the thoracic and thoracolumbar curve in the coronal plane. Also, in the case of an unbalanced trunk over the pelvis, this force pushes the trunk to the midline of the body, placing it over the pelvis. When retropulsion of the shoulder is present, this force lifts the lower shoulder superiorly.
3': The location of pressure zone 3' is at the same level as 3´, but it is more posteriorly placed to move the retropulsion shoulder ventrally in the sagittal plane.
4: The location of pressure zone 4 is on the ventral aspect of the trunk. This force is placed adjacent to the pressure zone 1. The function of these forces is to work together to reduce the large diameter of the oval shaped thorax, which facilitates the derotation of the thoracic region in the transverse plane.
5: The location of expansion zone 5 is beside the thoracic and thoracolumbar curve and pressure zone 1. The function of this expansion zone is to provide a room or space for the expansion of the trunk, which allows respiratory movement, and permits small voluntary and involuntary movements as well as the patient’s growth. This provides an active mechanism of correction in the direction of derotation and rekyphosis,
5´: The location of this expansion zone is on the concave side of the thoracic curve and is opposite to pressure zone 1. The function of this expansion zone is to provide a room or space for the expansion of the trunk, which corrects the thoracic curve in the coronal plane.
6: The location of expansion zone 6 is on the posterior aspect of the hemipelvis that is in anteversion. This provides a space for the derotation the hemipelvis.
7: The location of expansion zone 7 is on the ventral aspect and is adjacent to pressure zone 3. The function is to provide a large space for the correction of the rotation and hypokyphosis of the thoracic region.
12: The location of pressure zone 12 is in the subclavicular region of the lower shoulder, which is positioned in retropulsion. The function is to facilitate control of the retropulsion shoulder in the sagittal plane.
13: The location of expansion zone 13 is outside the dorsal superior trimline of the brace above expansion zone 5. Its function is to provide an expansion zone for the correction of the thorax.
17: The location of expansion zone 17 is on the dorsal aspect of the brace next to expansion zone and window 5´ . Its function is to provide an expansion zone for the correction of the thoracic or thoracolumbar curve.
18: The location of expansion zone 18 is on the dorsal aspect of the brace above expansion zone and window 5´ . Its function is to provide an expansion zone for the correction of the thoracic or thoracolumbar curve.
19: The location of expansion zone 19 is on the breast that is tilted to the high side. The function is to provide a large space for the correction of rotation and hypokyphosis of the thoracic region.
21: The location of pressure zone 21 is on the ventral aspect between pressure zone 4 and pressure zone 2. The function is to connect pressure zone 4 and pressure zone 2. This provides a smooth connection of the pressure zones and forces from the body to the brace, also this gives a more cosmetic appearance.
23: The location of this expansion zone 23 is on the concave side of the lumbar curve and is opposite to pressure zone 2. The function of this expansion zone is to provide a room or space for the expansion of the trunk, which corrects the lumbar curve in the coronal plane.
24: The location of expansion zone 24 is on the dorsal aspect of the brace above expansion zone and window 5´ and ventral to expansion zone 18. Its function is to provide an expansion zone for the correction of the thoracic or thoracolumbar curve
26: The location of expansion zone 26 is outside the dorsal superior trimline of the brace above pressure zone 1. Its function is to provide an expansion zone for the correction of the thorax.
27: The location of expansion zone 27 is on the concave side of the thoracic or thoracolumbar curve, just above pressure zone 3 on the shoulder, which is in the position of retropulsion. The function of this zone is to provide an expansion zone for the shoulder in retropulsion.
30: The location of pressure zone 30 is applied to the greater trochanter on the low side of the pelvic tilt. The function of this force is to work with pressure zone 2, which provide counterforces to pressure zone 41 to move the pelvis upward from its tilted position.
33: The location of expansion zone 33 is on the dorsal inferior aspect of the brace, which is in retroversion. The function is to allow space for the derotation of the hemipelvis, which is in retroversion in the sagittal plane.
34: The location of the pressure zone 34 is on the dorsal inferior aspect of the brace, which is in anteversion, at the level of the gluteus maximus. The function of this force is to derotate the hemipelvis, which is in retroversion in the sagittal plane.
35: The location of expansion zone 35 is on the low side of the pelvic tilt, positioned on the ventral inferior aspect of the brace. This is above pressure zone 30 at the level of the iliac crest. The function is to provide room or space for the derotation of the hemipelvis in retroversion by allowing it to move upward.
36: The location of expansion zone 36 is on the ventral side of the body, in which the hemipelvis is in anteversion, below pressure zone 37. The function is to allow space for the derotation of the hemipelvis, which is in anteversion in the sagittal plane.
37: The location of the pressure zone 37 is along the waistline going downward towards the ASIS (anterior superior iliac spine) on the side of the body that has the hemipelvis in anteversion. The function of this pressure zone is to derotate the anteversion position of the hemipelvis in the sagittal plane.
38: The location of the pressure zone 38 is above the symphysis pubis on the same side of the body that has the hemipelvis in retroversion. The function of this force is to derotate the retroversion position of the pelvis.
39: The location of the pressure zone 39 is on the ventral aspect of the brace and is below pressure zone 40. The function of this force is to reduce the distance of the oval thorax, this corrects the hypokyphosis in the sagittal plane by causing flexion of the thoracic vertebral column.
40: The location of the pressure zone 40 is on the ventral aspect of the brace and is adjacent to the pressure zone 1, which is on the convex side of the thoracic or thoracolumbar curve. The function of this force is to reduce the distance of the oval thorax, this corrects the hypokyphosis in the sagittal plane by causing flexion of the thoracic vertebral column.
41: The location of the pressure zone 41 is in the iliac fossa, on the lateral aspect of the hemipelvis, which is on the high side of the pelvic tilt. The function of this force is to work with pressure zone 30 and pressure zone 2 to provide a 3-point pressure system that lifts the low contralateral hemipelvis.
43: The location of the pressure zone 43 is underneath the lower positioned breast, which lifts it to the level of the contralateral breast. In the case of a male patient, this zone is designed the same way as the female patient, however it would not have to be as large. The function of this zone is to balance the lower positioned breast with the contralateral side.