[Relationship between alterations of spine-pelvic sagittal parameters and clinical outcomes after oblique lumbar interbody fusion].

OBJECTIVE

To investigate the relationship between spine-pelvic sagittal parameters and clinical efficacy before and after oblique lumbar interbody fusion(OLIF).

METHODS

A retrospective analysis of clinical data of 65 patients with lumbar degenerative diseases treated with OLIF were performed from July 2017 to July 2018. There were 26 males and 39 females aged from 33 to 79 years old with an average of (62.72±10.23) years old. Oswestry Disability Index (ODI) and visual analogue scale (VAS) before and at the latest follow up were evaluated. Disc height (DH) and spine- pelvic sagittal parameters of the surgical segment were measured before and at the latest follow- up, including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS) and lumbar lordosis (LL). According to the difference of PI-LL, it was judged whether PI and LL match and the patients were grouped, PI-LL ranged from -9° to 9° was set as matching group, and PI-LL less than -9° or larger than 9° was set as mismatching group. The spine-pelvic sagittal parameters were analyzed before and at the latest follow-up of OLIF in patients with lumbar degenerative diseases, and the correlation between changes and clinical efficacy was compared.

RESULTS

All patients were followed up from 8 to 20 months with an average of (14.20±3.68) months. Operation time was (91.54±25.97) min, intraoperative blood loss was (48.15±10.14) ml, and the hospitalization time ranged from 6 to 19 days with an average of (9.28± 2.50) days. Totally 84 surgical levels, 46 patients were single segment and 19 patients were double segments. VAS and ODI score were improved from (4.88±0.99) point, (67.60±13.73) % preoperatively to (2.85±1.30) points, (30.57±6.48) % at the latest follow-up. There were significant differences in VAS and ODI scores between before and at the latest follow-up. The sagittal parameters of LL, PT, SS, PI, PI -LL and the surgical level DH were (42.80 ±16.35)° , (23.22 ±10.91)° , (26.95 ± 13.30)°, (50.22±14.51)°, (7.53±16.13) °, (0.91±0.29) cm preoperatively and improved to the latest follow-up (49.95± 12.82) °, (17.94±9.24) °, (33.71±12.66) °, (51.65±10.26) °, (1.68±17.00) °, (1.20±0.40) cm;there were statistical differences in LL, PT, SS, PI-LL, DH before operation and at the latest follow up, while no difference in PI. LL of preoperative PI-LL in matched group was (48.76±11.09)° , and (38.00±18.37)° in PI-LL mismatch group, there was difference between two groups. There were no differences in VAS, ODI, PT, SS, PI and DH between two groups. At the latest follow-up, ODI between PI-LL matched group and PI-LL mismatched group were (29.40±5.93)% and (32.86±7.02)% respectively, and had difference in ODI between two groups;while there were no significant differences in VAS, LL, PT, SS, PI, and DH. Pearson correlation analysis showed preoperative PT-LL was positively correlated with VAS;PT was positively correlated with ODI at the latest follow-up.

CONCLUSION

OLIF has a good surgical effect on lumbar degenerative diseases, and could change spine-pelvic sagittal parameters of patient to a certain extent, and further restoring the balance of the sagittal plane of lumbar spine.