The extreme lateral approach has been successfully proposed for treating DDD in the thoracolumbar spine, but the indications are still controversial and the literature lacks consistent and long-term clinical results [24]. Although few studies have reported outcomes specifically for DDD patient cohorts following XLIF, the minimal invasiveness of the surgical approach with careful patient selection and preoperative evaluation of both radiographic and clinical symptoms seem to be determinant factors for obtaining the best results.

In Marchi et al.’s series of 22 patients treated with XLIF, the fusion rate was 93 % with 70 % improvement in back pain and 53 % improvement in ODI. Patients in this series also experienced short operative times (average 72 min), low mean blood loss (50 mL), and short length of stay (1 day) [21]. Berjano et al. reported on the preliminary clinical results of a series of 97 patients, 80 % of whom were classified as having DDD. In their study, clinical improvement was reported to be 61.3 %, leg pain improved 64 %, and ODI improved 55 %. Only a few complications were described, such as L4 transient weakness that resolved in 1 month and transient crural or tight hypoesthesia in 11 patients [22].

Interestingly, Khajavi et al. compared their results for patients undergoing XLIF for DDD with an adjunct minimally invasive posterior approach to results obtained by Gassman et al. with patients undergoing standard open surgery for DDD. Patients treated with XLIF had improved clinical outcomes at the last follow-up (24 months postoperative), 46 % for ODI, 65 % for low back pain, 55 % for leg pain, and 45 % for the physical component of SF-36. Furthermore, at the 24-month follow-up, the scores for patients who underwent XLIF were favorable to the scores of patients who underwent standard posterior open surgery, with the exception of ODI [8, 25, 26].