Reduction therapy in developmental dysplasia of the hip (DDH) is initialized in the newborn period. Harness treatment is continued until normal ultrasound-values are reached. Above the age of one year the assessment of DDH relies mainly on interpretation of plain radiographs of the pelvis. In order to rule out residual dysplasia after ultrasound controlled treatment radiological control is advised to the time children start walking. The purpose of this study is to evaluate the early radiological outcome after ultrasound controlled treatment of DDH and to examine whether there is a correlation between the initial severitiy of DDH, measured by ultrasound, and the severity of residual DDH on the radiograph at the time of the first follow-up.

A. p. pelvic radiographs of 90 children (72 girls, 18 boys, 180 hips) with DDH (29 unilateral, 61 bilateral) were reviewed retrospectively. To the beginning of the ultrasound surveilled therapy (mean age 7,2 weeks) the morphologic findings were staged according to the Graf classification. Ultrasound surveilled abduction treatment was continued until normal ultrasound findings were reached. To the time children started walking (mean age 14,8 months) an a. p. radiograph of the pelvis was performed. The acetabular index (AI) was measured and classified according to the normal values of the hip joint described by Tönnis. The initial ultrasound findings expressed by the Graf classification were compared with the AI in the radiographic follow-up and Tönnis’ normal values.

To simplify matters the 180 Graf-classified hips were distributed into 4 categories: Graf Ia/b=category 1, Graf IIa-D=category 2, Graf IIIa/b=category 3, Graf IV=category 4. The initially normal contralateral hips in ultrasound (n=29, category 1) presented in 37,9% a normal AI, in 41,4% with a mild dysplasia (between 1SD and 2SD) and in 20,7% with a severe dysplasia (beyond 2SD). The Graf type IIa-D hips (n=81, category 2) presented in 37% a normal AI, 32,1% showed a mild dysplasia and 30,9% a severe dysplasia. The Graf type III a/b hips (n=60, category 3) showed 35%, 30% and 35%, Graf type IV hips (n=10, category 4) 60%, 30% and 10%, respectively.

The mean AI in all four categories differed only marginally.

In our setting of patients different conclusions can be drawn:

Even after successful ultrasound guided therapy with a sonographically normal hip at the time bracing is finished there is a risk for residual dysplasia. Therefore radiological follow-up of every once treated hip is necessary.

Introduction: There is rather broad consent that mildly slipped capital femoral epiphyses (SCFE) should be treated by in situ fixation with wires or dynamic screws. There is recent evidence, however, that even mild slips lead to early damage of the acetabular labrum and cartilage by abutment of a prominent femoral metaphysis. It is therefore proposed that treatment of mildly slipped capital femoral epiphyses should not only prevent further slipping of the epiphysis, but also address potential femoro-acetabular impingement (FAI) by restoring the anatomy of the proximal femur. To find proof for this newly proposed therapeutical approach, we reviewed all patients treated in our department ten to twenty years ago for unilateral slipped capital femoral epiphysis by in situ fixation without restoration of the anatomy of the proximal femur.

Methods: From forty-four patients treated between October 1984 and December 1995, twenty-eight could be contacted and eighteen reviewed. Development of FAI was documented by clinical examination (range of motion, “impingement provocation test”) and radiological evaluation (AP radiographs of the pelvis and lateral cross-table radiographs of both hips). Statistical analysis was performed with paired t test and Wilcoxon matched-pairs signed-ranks test in case of numerical data, and Fisher’s Exact Test and Chi-squared Test for Independence in case of ordinal data. The level of significance was set at p < 0.05.

Results: Comparing involved to non-involved hips, mean internal rotation and abduction differed significantly (15° ± 7.9° vs. 21° ± 7.9° (p < 0.01) and 37° ± 7.7° vs. 42° ± 6.7° (p < 0.01), respectively), but the “impingement provocation test” was found positive in only four vs. six hips (p = 0.71). Radiological examination showed significantly difference with respect to waisting of the femoral neck (p < 0.01) and bony appositions at the femoral head neck junction (p < 0.01). No regular waisting was found in all involved hips, whereas it was present in nine non-involved hips. A distinctly reduced or absent waisting was seen in twelve of the involved hips but in only four of the non-involved hips. Bony appositions were found in fourteen of the involved hips, but in only four of the non-involved hips. Furthermore the angle α according to Nötzli et al. (2002) showed a significant difference in its mean on AP radiographs (84° ± 10° vs. 60° ± 15°, p < 0.01), not so, however, in lateral cross-table radiographs (50° ± 8° vs. 48° ± 11°, p = 0.3).

Conclusion: From a clinical point of view, in situ fixation may be sufficient in treating mildly SCFE, whereas radiological data suggest that restoration of the anatomy of the head-neck junction of the proximal femur might be sensible to prevent or delay FAI and thus development of osteoarthritis of the respective hip joint.

Conventional treatment of mild slipped capital femoral epiphysis consists of fixation in situ with wires or screws. Recent contributions to the literature suggest that even a mild slip may lead to early damage of the acetabular labrum and adjacent cartilage by abutment of a prominent femoral metaphysis. It has been suggested that the appropriate treatment in mild slipped capital femoral epiphysis should not only prevent further slipping of the epiphysis, but also address potential femoroacetabular impingement by restoring the anatomy of the proximal femur.

Between October 1984 and December 1995 we treated 16 patients for unilateral mild slipped capital femoral epiphysis by fixation in situ with Kirschner wires. In this study we have reviewed these patients for clinical and radiological evidence of femoroacetabular impingement. There was little clinical indication of impingement but radiological evaluation assessing the femoral head-neck ratio and measuring the Nötzli α angle on the anteroposterior and cross-table radiographs showed significant alterations in the proximal femur. None of the affected hips had a normal head-neck ratio and the mean α angle was 86° (55° to 99°) and 55° (40° to 94°) on the anteroposterior and lateral cross-table radiographs, respectively.

While our clinical data favours conventional treatment, our radiological findings are in support of restoring the anatomy of the proximal femur to avoid or delay the development of femoroacetabular impingement following mild slipped capital femoral epiphysis.