Osteoporotic spinal deformities with global sagittal imbalance have devastating effects on patients. However, treatment is difficult and there is a high risk of perioperative medical and mechanical complications. Patients with osteoporotic spinal deformities are not ideal candidates for posterior pedicle subtraction osteotomy; the condition necessitates combined anterior-posterior for corrections of the deformity. We ascertained the complication rates and efficacy of the anterior-posterior surgery and determined the factors influencing the results. To determine complication rates we analyzed a series of patients (n = 32). To evaluate overall results, we analyzed 18 patients with more than 2-years followup. A total of 18 complications occurred in 12 of 32 patients (37.5%) with seven early complications occurring in five patients and 11 delayed complications occurring in seven patients. Three patients needed additional surgery to treat the complications. At 2 years postoperatively, 17 of 18 patients (94%) reported subjective improvement with 54% decrement of Oswestry Disability Index and 70% decrement of the visual analogue scale pain score. The factors associated with clinical improvement was restoration of total lumbopelvic lordosis, C7 plumb, and control of T4-12 thoracic kyphosis. Prevention and aggressive treatment of junctional fractures were important in achieving favorable results.