Acetabular dysplasia represents the most common aetiology for secondary ost
eoarthritis of the hip joint in Japan. On radiographs progress of the disea
se can be classified in four stages (I to IV). Labral lesions are common ac
companying findings in acetabular dysplasia, representing an important prog
nostic factor. Therefore we routinely use conventional arthrography to clas
sify labral lesions in three types (normal, torn and detached). From 1978 t
o 1983 a modified Chiari osteotomy of the pelvis (dome osteotomy) was perfo
rmed in 64 hip joints without arthrotomy. The preoperative radiography show
ed labral lesions in 66%. After an average follow-up of 4 years, 43 of the
44 patients with a normal or torn labrum showed excellent or good results.
On contrast, 50% of the 20 patients with a detached labrum showed fair and
poor results only. From 1984 to 1989 an arthrotomy was combined with dome o
steotomy in 29 hip joints and labral lesions had to be resected in 16 cases
. The results were generally good in patients with arthrosis grade I and II
, but in stage III they were only fair. Thus, the success of labral surgery
can only be achieved in early stages of dysplasia. Based on our findings d
ome osteotomy combined with arthrotomy and labral surgery can be recommende
d in patients with labral lesions and hip dysplasia grade I and II.