Radiographic alignment outcomes after the single-position prone transpsoas approach: a multi-institutional retrospective review of 363 cases

OBJECTIVE The aim of this paper was to evaluate the changes in radiographic spinopelvic parameters in a large cohort of patients undergoing the prone transpsoas approach to the lumbar spine. METHODS A multicenter retrospective observational cohort study was performed for all patients who underwent lateral lumber interbody fusion via the single-position prone transpsoas (PTP) approach. Spinopelvic parameters from preoperative and first upright postoperative radiographs were collected, including lumbar lordosis (LL), pelvic incidence (PI), and pelvic tilt (PT). Functional indices (visual analog scale score), and patient-reported outcomes (Oswestry Disability Index) were also recorded from pre- and postoperative appointments. RESULTS Of the 363 patients who successfully underwent the procedure, LL after fusion was 50.0 degrees compared with 45.6 degrees preoperatively (p < 0.001). The pelvic incidence-lumbar lordosis mismatch (PI-LL) was 10.5 degrees preoperatively versus 2.9 degrees postoperatively (p < 0.001). PT did not significantly change (0.2 degrees +/- 10.7 degrees, p > 0.05). CONCLUSIONS The PTP approach allows significant gain in lordotic augmentation, which was associated with good functional results at follow-up.