Interbody fusion does not influence development of lumbar compensatory mechanisms 10 year after lumbar fusion

Kristian Høy*, Kamilla My Thanh Lê Truong, Mads Henriksen, Thomas Borbjerg Andersen

*Corresponding author for this work

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review


Background: Restoration of lumbar lordosis in lumbar spine surgery is thought to be associated with better postoperative outcomes. Various inter- body fusion techniques can theoretical help to change and correct sagittal balance. Pelvic plays a central role in sagittal balance. The Three key pelvic parameters are pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). The last 2 can change due to compensatory mechanism. Decrease in SS is posed to increase risk of adjacent segment degeneration (ASD)
Aim: To assess radiographic signs of degenerative changes and compensatory mechanisms after lumbar fusion at 10 year follow-up and their relation to outcome comparing posterolateral instrumented fusion (PLF) to Transforaminal interbody lumbar fusion (TLIF) in a RCT
Materials and Methods: 100 pat. enrolled in a RCT between TLIF and PLF had standing lumbar radiographs analyzed with respect to olisthesis, lordotic angle at adjacent level (AL) and differences in SS. SS was determined by PI = PT + SS. Clinical outcome was measured by Owestry disability index (ODI) and SF-36 Physical Function (PF), Bodily pain (BP) and Physical Component Summary(PCS). Data was analyzed using STATA
Results: There was no difference in development of olisthesis at the (AL) between the two groups at 10 year follow-up (p=0.43). Lordotic angle of the adjacent disc decreased with 5 or more degrees in 6 patients in the TLIF group and 3 in the PLF group. Three pats in the TLIF group and 4 in the PLF group had an increase in lordotic angle at the adjacent disc, the remainders were unchanged (p=0.58). Five pat. in the TLIF group and 7 in the PLF groups had a decrease in SS of 5 degrees or more (p=0.51).There was no difference in ODI score nor PF, BS & PCS at 10 year follow-up between those who developed changes in adjacent disc angle and those who remained unchanged (p=0.49, p=0.20, p=0.94 p=0.65). The same held true for changes in SS (p=0.46, p=0.49, p=0.39, p= 0.58)
Interpretation / Conclusion: No difference between the two fusion methods with respect to degenerative changes visible on radiographs at 10 years follow-up. Signs suggesting development in compensatory mechanisms (SS) was not associated with poorer clinical outcome
Original languageEnglish
Publication date2021
Publication statusPublished - 2021
EventDanish Orthopedic Society Annual Meeting - Hotel Scandic Falkoner, Frederiksberg, Denmark
Duration: 18 Nov 202120 Nov 2021


ConferenceDanish Orthopedic Society Annual Meeting
LocationHotel Scandic Falkoner
Internet address

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