Because of the known tendency for early redislocation following open reduction, we developed surgical methods for shortening the ligamentum teres to improve immediate postoperative stability when performing medial approach open reduction (MAOR) for the management of developmental dysplasia of the hip. Between 2004 and 2014, 32 patients with dysplasia of the hip were managed by MAOR with partial excision and plication of ligamentum teres. The patients were followed up for an average of 6.9 years. At the final follow-up, clinical outcomes achieved were categorized as excellent and good in 39 (39/40; 97.5%) hips. At the latest follow-up, 97.5% (39 hips) were classified as good or excellent on the basis of the Severin classification (Severin grade 1 or 2). In conclusion, this series of MAOR, in which ligamentum teres partial excision and plication was utilized, we found stable reduction in all hips. On the basis of these positive results, we recommend this method for children treated with MAOR. Level of evidence: Level IV: case series.