Posterior rotational intertrochanteric osteotomy of the femur in children and adolescents

We describe a method of intertrochanteric osteotomy with posterior rotation of the femoral head and neck. We analysed 45 hips in 44 children and adolescents aged from six to 18 years with residual dysplasia after conservative (35) and operative (10) treatment of developmental dysplasia of the hip complicated by avascular necrosis of the femoral head. In ten, femoral osteotomy was combined with a variety of pelvic procedures.
Thirty-seven hips (36 patients) were available for follow-up at a mean of 4 years 5 months (2 to 15 years). Excellent results were obtained in nine, good in 17, fair in seven and poor in four.
The prevention and treatment of early osteoarthritis after conservative and operative treatment for developmental dysplasia of the hip (DDH) remain a problem. An important cause of incongruity of the hip is deformity of the femoral head and neck caused by avascular necrosis. The use of femoral rotational osteotomy has been reported for the treatment of avascular necrosis in adults' and for Perthes' disease in children. We review our experience of this technique in children and adolescents with residual hip dysplasia after treatment for DDH.


 

Patients and Methods
Between 1970 and 1997 we performed 73 rotational osteo¬tomies for various hip conditions in children and adoles-cents aged between 3 and 18 years. Of these, we were able to review 44 patients (45 hips) who underwent surgical treatment for residual deformity of the hip after con¬servative (35) and surgical (10) treatment for DDH. The mean age of the patients at the time of operation was 11 years and 2 months (6 to 18 years); nine were less than ten years old.
The earliest clinical symptoms of tiredness and limp appeared at the age of six to eight years. All patients older than ten years complained of pain in the hip after prolonged walking. The Trendelenburg test was positive in 19. Limb-length discrepancy ranged from 0.5 to 3.5 cm. The range of flexion was between 90° and 120°; abduction and rotation were more severely restricted.
Radiological examination and CT revealed various multiplanar deformities of the femoral head and neck, as a result of segmental damage to the head and growth plate. The severity of the deformity was assessed according to the quotients described by Heyman and Herndon.3
The femoral head was usually flattened and broadened (coxa plana) and the joint surface irregular. The mean preoperative epiphyseal quotient was 52 (28 to 89).5 The value of the neck-diaphyseal and epiphyseal-diaphyseal angles varied within a range of 10° to 20°. Epiphyseal ante version, rarely retroversion, reached 50° in some cases. When medial physeal damage had occurred we observed medial angulation of the femoral head and neck and the lower border of the neck was short and concave. The mean neck-shaft angle in these patients (30 hips) was 106° (70 to 120).
In the remaining cases we observed lateral physeal dam¬age and lateral displacement of the femoral head. In the most severe, the femoral head seemed to be 'sitting on top of the femoral neck. This deformity was clearly shown on the radiograph taken in the Lauenstein position. As a result there was subluxation or decentralisation of the femoral head in the acetabulum. The measured distance between the femoral head and medial wall of the lower quarter of the acetabulum was at least doubled. Most of these hips had a neck-shaft angle of 125° to 150°.
Premature closure of the growth plate led to marked shortening of the femoral neck with an epiphyseal-neck quotient on the affected side of 47 to 50. This was asso¬ciated with shortening of the limb and relative overgrowth of the greater trochanter. In 36 hips we noted gradual upward migration of the greater trochanter, measured by the articulotrochanteric distance which was zero or had a negative value in 24 hips.

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