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D Tönnis

Publications and source records attributed to D Tönnis.

At least 37 records · Page 2Linked to original sources
PubMed1979

[Predetermination of arthrosis, pain and limitation of movement in congenital hip dysplasia (author's transl)].

The purpose of this investigation was to find out, whether the onset of pain, arthrosis and decrease in mobility in different degrees of joint deformation is predictable for the indication of corrective surgery. When the correlation between of the onset of pain and arthrosis on one side and different measurements of joint deformation was tested, it turned out, that there is a significant correlation. If different age groups are built, however, we observe, that this correlation is given mainly in the youngest age group, where the most extreme dysplasias are found. In slight and moderately severe dysplasias the onset of pain can be found in all age groups. Arthrosis is following pain several years later. For this reason corrective surgery in slight and moderately severe dysplasias cna be postponed until the onset of pain. Borderline values, above or below of which the onset of pain is to be expected until the age of about 35 years, are given in tab. 5.1. In these cases early surgery seems indicated.

Adolescent↗
PubMed1979

[A modified sledge prosthesis for placing on the cortical bone surface (author's transl)].

A new sledge prosthesis is described here. The height of the femoral component as well as of the tibial plateau are diminished in comparison to other models. It seems more safe to place this type of prosthesis on the cortical bone surface than into the spongiosa parts where loosening is more probable. The stems of both components have been designed accordingly. The technique of operation and the indication are described in detail.

Humans↗
PubMed1978

[The inguinal incision for the open reduction of congenital hip dislocation (author's transl)].

Operative reductions of congenital hip dislocation are sometimes difficult when lateral incisions are used since the medial part of the acetabulum and the lower limbus are difficult to visualize. In the Ludloff technique this part of the acetabulum is seen excellent, but not the lateral part. High dislocations with inverted limbus are difficult to reduce and only with partial excision of the limbus. An inguinal incision beginning lateral at the spina ilica ventralis offers the best view and can be used for all different degrees of dislocation and age groups. The technique is described, the advantages and the rate of avascular necrosis compared with other incisions. Femoral osteotomies and acetabular or pelvic osteotomies should not be done at the same time because of a higher percantage of avascular necrosis. In high dislocaitons shortening osteotomies should not be done in the intertrochanteric region but deeper in the shaft to avoid additional disturbances of the vascular system of the proximal femur.

Femur Head Necrosis↗
PubMed1977

[Indication and efficiency of different operations in congenital hip dislocation (author's transl)].

The efficiency of different operations for congenital hip dysplasia is discussed here. Up to the age of 6 years Salters osteotomy and the acetabuloplasty of Lance in a modified form will achieve similar results. In cases with an acetabular index higher than 35 degrees acetabuloplasty is more effective. After our own experience acetabuloplasty can be used in all age groups where there is no congruency between acetabulum and femoral head. In congruent cases Salters osteotomy can be used up to 14 years combined with varus-osteotomy if dysplasia is of moderate degree. Chiaris osteotomy should be reserved for extreme cases, where other methods will not succeed.

Acetabulum↗
PubMed1977

[New results of a modified acetabuloplasty after Lance combined with detorsion-varus-osteotomy (author's transl)].

The results of 254 Lance-acetabuloplasties in a modified technique combined withe detorsion-varus-osteotomy have been analysed. The children were operated upon in the years 1970-1974. Regarding the acetabulum the results were as follow: 1. In children between 1 and 6 years a normal acetabular index (as compared with the Normal Values of Tönnis and Brunken) was achieved in 78.3%, a slightly dysplastic index in 14.8%. In 6.6% a severe dysplasia remained. 2. In children between 6 and 10 years a normal acetabular index was found in 59.4%, a slightly dysplastic index in 24.3% and an index as classifies severe dysplasia in 16.2%. 3. In children older than 10 years and adults in 38.3% a normal Hip Value (Busse et al., Brückl et al.) was achieved, in 19.4% the value classifies a slight dysplasia, in 41.6% a severe dysplasia. These results show, that acetabuloplasty in the technique used here is a very effective method, especially in the first 6 years of life. But even in the older age groups significant improvement has been achieved. There for the indication of different operative techniques should be discussed again.

Acetabulum↗
PubMed1976

[Evaluation of loosening of different total hip models and neck lengths (author's transl)].

The percentage of aseptic loosening of different types of total hip prostheses in 771 cases has been evaluated. The time of follow-up ranged between 1/2 and 6 years. In prostheses of the Charnley-Müller type of loosening was 7.8% in the Charnley-Müller-Weller type with a 2-year shorter follow-up it was 2.4%. No loosening was found during the last 2 1/2 years when the prosthesis of Beck was used, which has an increased femoral shaft-neck angle and a longer stem. When a longer neck was used, the loosening averaged 5.6%. In cases of normal neck-length it was 3.6%. From the biomechanical standpoint it seems preferable to use prostheses with an increased shaft-neck angle. Comparing the rates of loosening as reported in the literature it appears that prostheses where the femur is displaced medially (by a small femoral head or increased shaft-neck angle) show a very low rate of loosening. Models with metal sockets (McKee-Farrar and Weber-Huggler) seem to have a higher rate of loosening than models with polyethylene sockets.

Biomechanical Phenomena↗
PubMed1976

[Statistical analysis of congenital hip dysplasia is not possible in the first months of life! (author's transl)].

The question whether congenital hip dysplasia can be defined statistically has been raised again by Kristen, Dorda and Zweymüller. These authors believe that a definition is possible by statistical methods. Compiling a normal material for statistical evaluation, however, needs a clinical separation of normal and dysplastic joints before. And this--in our opinion--is not possible during the first half year of life. The only possible way is a long-term follow-up. In our own investigation children with higher acetabular indices have been followed up to 5 years and more. Only by this clinical evaluation is it possible to say which joints have developed normally and which have not. This is a clinical diagnosis of hip dysplasia, not a statistical.

Age Factors↗
PubMed1976

Normal values of the hip joint for the evaluation of X-rays in children and adults.

X-ray measurements of the hip joints of children, with special reference to the acetabular index, suggest that the upper standard deviation of normal comprises the borderline to a critical zone where extreme values of normal and pathologic hips were found together. Above the double standard deviation only severe dysplasias were present. Investigations of the shaft-neck angle and the degree of anteversion including the wide standard deviation demonstrate that it is very difficult to determine where these angles become pathologic. It is more important to look for the relationship between femoral head and acetabulum. A new measurement--the Hip Value is based on measurements of the Idelberg- Frank angle, the Wiberg angle and MZ-distance of decentralization. By statistical methods, normal and pathological joints can be separated as follows: in adult Hip Values, between 6 and 15 indicate a normal joint form; values between 16 and 21 indicate a slight deformation and values of 22 and above are indications of a severe deformation, in children in the normal range the Hip Value reaches 14; values of 15 and up are pathological.

Acetabulum↗
PubMed1976

An evaluation of conservative and operative methods in the treatment of congenital hip dislocation.

An evaluation of different methods of closed reduction of dislocated hips during different periods of time shows that manual reduction and fixation in Lorenz position account for a high rate of avascular necrosis. Even with functional and slow reduction by Pavlik harness and overhead extension, there is still a certain percentage of femoral capital necrosis. The fetal position recommended by Fettweis and Salter seems to reduce the incidence of necrosis. Acetabuloplasty combined with detorsion-varus-ostcotomy provides the means of normalizing a hip joint with a greater degree of success than most other methods.

Acetabulum↗
PubMed1975

[The influence of surgically introduced muscle tension on the function of total hip prostheses (author's transl)].

The functional results of total hip prosthesis are influenced significantly by the tension given to the glutaeus medium muscle at operation. Low tension may result in a limp (positive Trendelenburg sign), high tension may decrease movement. In 206 cases of total hip replacement the Trendelenburg sign (grades from 0-3), the movement (in grades 0-4) and a grade of extension (distance or prosthetic femoral head and plastic acetabulum in cm at maximal extension after resection of the capsule) have been evaluated. In 191 hip joints not operated before the Trendelenburg sign was negativ before operation in only 31%, after operation it was negativ in 73%. The evaluation of the partial correlation coefficient showed a definite relation between Trendelenburg sign and the grade of extension. The higher the extensibility of the hip joint the more pronounced the Trendelenburg sign. In 71% of 191 cases the movement was increased after total hip replacement. With increased extensibility, the movement becomes better. However it is also related to the movement before operation. The optimal muscular tension and movement of the hip joint can be expected at an extension grade of 1.5-2.0 cm (distance between the prosthetic femoral head and the plastic acetabulum at maximal extension during operation).

Aged↗