[Long-term results of Imhäuser osteotomy for chronic slipped femoral head epiphysiolysis].

BACKGROUND

The treatment of slipped capital femoral epiphysis (SCFE) has produced in its complexity a great deal of discussion. One well-established method of operative treatment is the corrective intertrochanteric osteotomy according to Imhäuser. This study presents the clinical and radiological long-term results and the biomechanical impacts of this invasive intervention.

PATIENTS AND METHODS

A total of 28 patients with chronic SCFE with slip angles between 30° and 60° were treated by Imhäuser osteotomy at an average age of 13.7 years (SD± 2.2 years, range 9-19 years) and were reexamined after an average period of 24 years (SD± 6.7 years, range 12-32 years).

RESULTS

The results of the biomechanical analyses indicated an increase of force affecting the articulating joint postoperative compared to preoperative, even though the pressure on the joint decreased. This can be interpreted as a result of the enlargement of the articulating joint surface. Of the patients 17 achieved an excellent Harris hip score, 8 a good and 3 a satisfying result in the clinical assessment. There were significant differences in the degree of arthrosis between the side with and the side without osteotomy. Out of 27 cases 10 showed a decrease in the degree of arthrosis of the side with osteotomy whereas 3 cases showed an increase. In 14 cases no difference was measured.

CONCLUSIONS

Despite the valgisation the Imhäuser osteotomy relieves the hip joint thus probably counteracting degenerative alterations even though being unable to fully prevent this progress. The good biomechanical, clinical and radiological results support indications for Imhäuser osteotomy for slip angles between 30° and 60°.