Sixteen patients who underwent 18 modified Colonna capsular arthroplasty for old unreduced DDH1 between 1984 and 1992 were recalled and critically reviewed. The average age at operation was 11.5 years (range, 8.1 to 14.5 years). The average follow-up period was 7 years and 1 month (range, 5 to 13 years). All of the patients had pain or discomfort of the hip and limp. Femoral shortening was combined in all patients, and 13 hips required concurrent pelvic osteotomy (Chiari osteotomy in 5 hips Salter innominate osteotomy in 1 hips and Steel s osteotomy in 2 hips) or slotted shelf augmentation (5 hips) due to small and shallow acetabulum relative to the femoral head. In the remaining 5 hips which had thick medial acetabular wall acetabular reaming alone was performed. At the latest followup, 9 hips showed excellent 5, good; and 4, fair results according to the modified Harris hip score and IOWA hip score. In addition, all patients except one were satisfied with the outcome in terms of regaining hip stability and decrease in pain or discomfort and limp. Radiological evaluation revealed progressive, significant increase in size of the femoral head and sphericity improvement in 12 hips. The sphericity of the femoral head did not improve in other 2 hips. In the remaining 4 hips, in which preoperative femoral head shape was relatively aspherical, the sphericity worsened after affection of ischemic necrosis or osteoarthrosis. Complications included undisplaced femoral neck fracture during physiotherapy in 2, ischemic necrosis in 2, heterotropic ossification in 2, acetabular protrusio due to too much reaming in 3 hips, and residual subluxation requiring additional pelvic surgery in 2 hips, In conclusion, we believe that modified Colonna capsular arthroplasty with femoral shortening is valid, if properly done, in the reconsruction of painful hip with old unreduced DDH in late childhood and adolesence.