Vol.:(0123456789) 1 3 European Spine Journal https://doi.org/10.1007/s00586-020-06604-3 ORIGINAL ARTICLE The correlation of intraoperative distraction of intervertebral disc with the postoperative canal and foramen expansion following oblique lumbar interbody fusion Guang‑Xun Lin 1  · Gang Rui 1  · Sagar Sharma 2  · Akaworn Mahatthanatrakul 3  · Jin‑Sung Kim 2 Received: 10 November 2019 / Revised: 4 August 2020 / Accepted: 10 September 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Purpose To examine the correlation of intraoperative distraction of intervertebral disc with the postoperative central canal and foramen expansion by oblique lumbar interbody fusion (OLIF) with indirect decompression. Methods Patients who underwent OLIF between October 2013 and April 2017 were included. Clinical outcomes included back and leg pain evaluated by visual analog scale (VAS) and Oswestry Disability Index (ODI). Intraoperative radiographic parameters of height ratio [(HR) = disc height/intervertebral body height)] and cage location were evaluated on intraopera- tive fuoroscopic images. Disc height (DH), foraminal height (FH), cross-sectional area of spinal canal (CSAC), and CSA of the foramen (CSAF) were measured. Results A total of 47 patients involving 62 levels were enrolled in this study. Mean follow-up was 43.8 ± 12.0 months. These patients reported an improvement of 61.7% in VAS back, 68.1% in VAS leg, and 46% in ODI (all p < 0.01). Radiographic parameters including HR, DH, FH, CSAC, and CSAF were also signifcantly increased by 32.6%, 48.2%, 21.4%, 44.0%, and 40.1% (left-side CSAF) or 45.4% (right-side CSAF), respectively (p < 0.05). HR increment was correlated with CSA (canal and foramen) increment. Slightly higher improvements of HR, DH, FH, CSAC, and CSAF (both sides) were noted when cage was located at middle rather than anterior (p > 0.05). Conclusions The ligamentotaxis efect of OLIF is capable of supporting indirect decompression of central canal and neural foramina and clinical improvement. HR is a reliable intraoperative assessment method. In addition, intraoperative HR incre- ment was correlated with postoperative neural elements expansion. Keywords Indirect decompression · Minimally invasive spine surgery · Oblique lumbar interbody fusion · Radiographic assessment · Intraoperative Introduction The treatment goal for patients with radiculopathy and/or myelopathy is to have adequate neural decompression. Tra- ditionally, such treatment goal is accomplished by direct decompression via posterior laminectomy and/or forami- notomy with additional instrumented fusion if radiculopathy and/or myelopathy is associated with instability [1, 2]. How- ever, there are many reports of complications related to direct * Jin-Sung Kim mdlukekim@gmail.com Guang-Xun Lin linguangxun@hotmail.com Gang Rui reigang@163.com Sagar Sharma dr.sagarsharma2110@gmail.com Akaworn Mahatthanatrakul akaworn@hotmail.com 1 Department of Orthopedics, The First Afliated Hospital of Xiamen University, Xiamen, People’s Republic of China 2 Department of Neurosurgery, Seoul St. Mary’s Hospital, The Catholic University of Korea, 222 Banpo-daero Seocho-gu, Seoul 06591, Republic of Korea 3 Department of Orthopaedics, Naresuan University Hospital, Phitsanulok, Thailand