Introduction :- Patients had mini invasive posterior osteosynthesis at thoracolumbar fracture posttraumatic, have more quick psychological good outcome and also pain score , comparing the patients had traditional open posterior osteosynthesis up to first 3 days post op , most of patient done both the Mini invasive posterior osteosynthesis(MIPOS) and traditional open posterior osteosynthesis (TOPOS) had good outcome but the time frame and pain duration more immediate recovery for MIPOS patients . Methods: - Our study was retrospectively comparative study. Reviews the medical records of the 22 patient was operated in CHU ibn sina university hospital at Rabat, from time frame 2020 – up to 2024 , for 4 years ,files those was admitted at department for clinical and radiological diagnosed ,and operated for short segment posterior osteosynthesis. Results: - the mean age of the 22 patients in our study of MIPOS vs. TOPOS is 38 years, at range of the age (17-63), The female gander was 10 out of 22 patient 45 %, and 12 of them was male 55%, patient had co-morbid was 8/22 =36.36% at different types of co-morbid, Psychiatric 3 patient, Asthmatic, Tuberculosis, Smoker, Hypertension, obstetric , 14 cases had lumbalgia , 5 dorsalgia , and 3 paraplegic , it postop the main result was the MIPOS patient had less hospital stay and pain relived quick compering the TOPOS which its little longer duration of hospital and pain relief take time longer. Conclusion:-the surgical outcome of the patient had mini invasive posterior osteosynthesis posttraumatic thoracolumbar, its quick and fast respond for VAS, reducing Hospital duration, instead of the open procedure little longer, and VAS its delay resolve post op.