[Congenital dysplasia and dislocation of the hip: proven and new procedures in diagnostics and therapy]

The effect of the design of the orthosis on the axial load transmission of two flexion abduction orthoses used in treating congenital hip dysplasia

Background

With an incidence of 2-4% in all newborns, developmental dysplasia of the hip, DDH, represents the most frequent congenital disorder of the skeletal system in Germany. The therapy options are deduced with the help of a sonography. The conservative therapy approach includes the application of flexion abduction orthoses, which lead to a development of the child's hip through abduction and flexion angle. The overall structure of the orthoses puts a strain on the axial skeleton of the children. The following work is intended to clarify what role the design of the orthoses plays in this respect.

Methods

Inclusion criterion for the study was fully developed newborns without an indication of skeletal malformations with Type I hip joints according to Graf verified by ultrasound. A total of 19 newborns were recruited and included in the period 3/2013-01/2015. Two types of orthoses used in treating developmental dysplasia of the hip (Tübinger splint, Otto Bock; hip flexion abduction orthosis (Superior orthosis) according to Mittelmeier-Graf, AIDAMED e.K (Kreuz et al., 2012; Mittelmeier et al., 1998; Schmitz et al., 1999), constructions differ, were used. Force was measured with the help of three force sensors, which were even able to be integrated into these without changing the design of the orthosis. In this closed system, force transmission was measured for the duration of a fixed period of two minutes.

Findings

The greatest axial force development (overall force) is in the Tübinger splint with an average force of 15.1 N (min. 0.59 N, max. 53.09 N, mean 15.1, SD 2.46). 4.09 N (min. 0.96 N, max. 20.99 N, mean 4.09, SD 0.65) resulted in the Superior orthosis. Significant correlations between body weight and resulting axial traction - on average during the entire measurement period and in movement - can be taken from the statistical analysis regarding the Tübinger splint. Such a correlation cannot be depicted for the Superior orthosis.

Interpretation

The analysis of the load transmission of the examined flexion and abduction orthoses reveals differences between the models. The construct of the orthoses in itself appears to play a significant role. Long-term effects of orthosis therapy on a child's axial skeleton have not been studied to date. Furthermore, it seems reasonable to expand the test series to orthoses, the design of which is configured in a similar matter compared to the examined aids.

Conclusion

This study proves that the orthotic design has an influence on the infant's axial load.

Residual dysplasia of the hip after successful ultrasound-monitored treatment: how does an infant's hip evolve?

Despite that normal values for the hip joint are reached at the end of ultrasound-monitored-treatment, the development of the acetabulum can be compromised during the growth phase. The acetabular index (AI) measured on a pelvic radiograph has been proven to be a reliable parameter. The aim of this study is to gain a better understanding of the dynamics of once-treated, residually dysplastic hips. This should be achieved by radiographically following these hips up to a milestone-examination at the end of preschool age. A total of 120 hips of consecutive 60 infants were included in this examination, each presenting with a residual developmental dysplasia of the hips (DDH) after successful ultrasound-monitored harness treatment. Radiographic follow-up was assessed retrospectively around 18 months, 3 years and 6 years of age, and the AI was measured. The age-dependent Tönnis classification was applied. The hips were assigned normal, mildly or severely dysplastic. Dependent t -test for paired samples indicated a highly significant improvement of the AI-values, including from the first to the second and from the second to the third follow-up. The percentage distribution into the Tönnis classification changed remarkably: in the first follow-up, 36 of the 120 hips were evaluated 'severely dysplastic', in the third follow-up only 1. On the other hand, three hips underwent acetabuloplasty. Even after normal values have been achieved at the end of ultrasound-monitored treatment, there remains a risk of residual dysplasia of the hips. Particularly, when the first radiographic examination shows nonphysiological findings, further close-meshed follow-up is recommended. Level of evidence: retrospective study of therapeutic outcome, consecutive patients, level II.

Treatment of unstable hips with the Tübingen splint in early postnatal period: radiological mid-term results of 75 hips with mean follow-up of 5.5 years

PURPOSE

For treatment of unstable hips, the Tübingen splint is a treatment option. After the initial treatment, regular radiological follow-up examinations are recommended but there is a lack of long-term outcome studies. Therefore, the further development of unstable hips treated with the Tübingen splint were evaluated.

METHODS

From 2004 to 2015 116 patients with 161 unstable hips treated with the Tübingen splint were evaluated. Inclusion criteria were: 1) successfully treated unstable hip (type D, III and IV); 2) pelvic radiographs at the age of one to ≤ two, two to ≤ four and four to ≤ eight years. The acetabular index (ACI) of all and the centre-edge angle (CEA) of the third radiograph were measured and classified according to the Tönnis classification.

RESULTS

A total of 53 patients with 75 unstable hips (type D 34 (45.3%), III 33 (44.0%), IV 8 (10.7%)) were included. In comparison of the first, second and third radiograph, an increase of normal findings was seen in 31 (41.3%) to 53 (70.7%) and 60 (80.0%) hips, respectively. However, a decrease of slightly dysplastic hips from 31 (41.3%) to 19 (25.3%) and 14 (18.7%) respectively and severely dysplastic hips from 13 (17.3%) to three (4.0%) and one (1.3%) hip respectively was detected. In comparison of first to second radiograph, 32 hips improved and five hips deteriorated and of second to third radiograph 16 hips improved and six hips deteriorated. The Tönnis classification of ACI compared with CEA showed no significant differences (p = 0.442).

CONCLUSION

This study shows a good development of unstable hips treated with the Tübingen splint with mean follow-up 5.5 years. Nevertheless, unexpected deteriorations could be identified. The CEA is an alternative to the ACI.

LEVEL OF EVIDENCE

IV.

How to restore rotation center in total hip arthroplasty for developmental dysplasia of the hip by recognizing the pathomorphology of acetabulum and Harris fossa?

PURPOSE

To restore rotation center exactly in total hip arthroplasty (THA) is technically challenging for patients with end-stage osteoarthritis due to developmental dysplasia of the hip (DDH). The technical difficulty is attributable to the complex acetabular changes. In this study, we investigated the pathomorphology of acetabulum and Harris fossa of Crowe types I to IV and discussed the method of restoring rotation center of the hip.

METHODS

This study retrospectively reviewed 56 patients (59 hips) who underwent cementless THA due to end-stage osteoarthritis of DDH. The pathomorphology of acetabulum and Harris fossa was observed during operations. Using the preoperative and postoperative pelvic radiographs, the vertical and the horizontal distances of hip rotation center were measured in order to evaluate the effects of restoring rotation center of the hip.

RESULTS

Adult DDH acetabulum could be classified into four basic pathological types which include the shallow cup shape, the dish shape, the shell shape, and the triangular shape. Adult DDH Harris fossa could be classified into four pathological types, including the crack shape, the closed shape, the triangle shape, and the shallow shape, in accordance with the osteophyte coverage. The vertical and horizontal distances of hip rotation center on the pelvic radiographs before and after operations were as follows: the preoperative vertical distance of hip rotation center was (39.96 ± 5.65) mm, and the postoperative one was (13.83 ± 2.66) mm; the preoperative horizontal distance of hip rotation center was (42.15 ± 6.42) mm, and the postoperative one was (28.12 ± 4.56) mm.

CONCLUSIONS

The acetabulum and Harris fossa can display different pathological types on account of different degrees of dislocation and osteophyte hyperplasia in the end-stage osteoarthritis of adult DDH. The hip rotation center can be accurately restored by locating the acetabular center with Harris fossa and acetabular notch as the marks.

[Acetabuloplasty - The Dega and Pemberton technique]

BACKGROUND

Hip dysplasia is the most common congenital deformity requiring surgical correction osteotomy in order to prevent early onset of secondary hip arthrosis. The shape of the acetabulum can be modified by Dega or Pemberton osteotomy and is indicated for hip dysplasia and luxation with irregularities of the socket for children aged between 2 and 12 when the y‑physis is still open.

METHOD

We will describe indication, contra-indication, preoperative planning as well as details of the Pemberton technique. In addition, we will provide practical advice based on our long-standing experience.

RESULTS

We present long-term results from the literature and also from our department. In addition, we will explain and critically discuss our own experiences and the risks and complications of surgical techniques. Good long-term results are reported for acetabuloplasties and Salter osteotomy which are preferred for surgical treatment of hip dysplasia in early life. Advantages and disadvantages of both surgical techniques will be compared in the discussion section.

CONCLUSION

Dega and Pemberton acetabuloplasty shows good long-term results regarding prevention of a secondary coxarthrosis. However, correct indication is crucial since this surgical technique is more difficult compared to Salter osteotomy but is also associated with a higher correction potential and a lower complication rate.

[Modified PemberSal osteotomy technique with lyophilized human allograft]

OBJECTIVE

PemberSal osteotomy to improve femoral head coverage by rotating the acetabular roof ventrally and laterally.

INDICATIONS

Insufficient coverage of the femoral head, and can be combined with other surgical procedures such as femoral intertrochanteric varus-derotation osteotomy and open reduction for developmental dysplasia and dislocation of the hip or to improve sphericity and containment in Legg-Calvé-Perthes disease. This specific acetabuloplasty can only be performed in patients with an open epiphyseal growth-plate.

CONTRAINDICATIONS

Increased bleeding tendency (e.g., inherited or iatrogenic); elevated anesthetic risk such as in cerebral palsy, arthrogryposis multiplex congenital, trisomies; syndromes require explicit interdisciplinary clarification to reduce perioperative risks; infections as in other elective surgeries; diseases/deformities making postoperative spica casting impossible or impractical (e.g., deformities of spinal cord or urogenital system, hernias requiring treatment); closed epiphyseal plate requires complex three-dimensional corrections of the acetabular roof (e.g., triple/periacetabular osteotomy).

SURGICAL TECHNIQUE

Osteotomy from the iliac bone to the posterior ilioischial arm of the epiphyseal growth-plate cartilage; controlled fracture of the cancellous bone without breaking the medial cortex of the iliac bone for ventrocaudal rotation of the acetabular roof. To refill and stabilize the osteotomy site, an allogenic bone-wedge is interponated and secured by a resorbable screw or kirschner wire. This method also allows more complex reconstructions of the acetabular roof, e.g., by including the pseudo-cup in a modified Rejholec technique.

POSTOPERATIVE MANAGEMENT

A spica cast is applied to immobilize the hip for 6 weeks. Afterwards physiotherapy can be performed under weight-bearing as tolerated. Radiographic check-ups every 6 months.

[Tönnis and Kalchschmidt triple pelvic osteotomy]

BACKGROUND

The Tönnis and Kalchschmidt triple pelvic osteotomy (TPO) has been performed at the Klinikum Dortmund for more than 30 years. In more than 5000 cases the TPO has proven its potential to deal with even severe dysplastic hips. TPO can be easily combined with other hip procedures as intertrochanteric osteotomies and even impingement treatment can easily be done. As an elaborate technique TPO respects the growth plates and can therefore also be used for treating Legg-Calve-Perthes disease.

PROCEDURE

In most cases only conventional X‑rays are needed for proving the indication. Further imaging like MRI or CT-scans are only needed in certain cases. In addition EOS® is becoming an increasingly useful tool in planning and performing the surgery. For adequate movement of the acetabulum, three clearly defined osteotomies are needed. Current osteosynthesis methods provide an enhanced stability due to a novel technique of screw fixation. This is in line with the general trends towards short hospitalization and early mobilization.

THERAPY

A successful treatment requires not only experience in performing the surgical technique, but furthermore an experienced team, including care, physical examination and also pain management. The surgeon should be aware that he is performing highly elective surgery and complications or a poor outcome can significantly reduce the quality of life of the mainly young patients.