Changes in Paraspinal Muscles after PLIF versus Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion (PE-TLIF) in Patients with Lumbar Spinal Stenosis: A One-Year Prospective Study

Background: Compared to PLIF, the advantages of PE-TLIF are its greater preservation of the posterior components of the lumbar spine and its reduction of damage to the paraspinal muscles. However, the full extent of postoperative paraspinal muscle changes after damage by PE-TLIF has remained largely unknown. This is the first study to compare the changes in paraspinal muscles between PLIF and PE-TLIF directly using CT and clinical effects. Methods This study included 52 patients with lumbar spinal stenosis who were treated at Beijing Chaoyang Hospital between January, 2020 and January, 2021. Among them, 22 patients received PLIF, and 30 received PE-TLIF. Outcome metrics including the ODI, VAS-LBP, and VAS-LP at pre-surgery and 1-week, 6-months, and 12-months post-surgery were used to evaluate the clinical effects of both procedures. Additionally, radiographic metrics including the MF FCSA, FI rate, and muscle density were used to evaluate changes in patients’ MF muscles. Results The PE-TLIF group has better performance on the VAS-back pain scale at the 1-day follow-up (PE-TLIF: 3.25 vs. PLIF: 4.32, P = 0.003) and 1-week follow-up (PE-TLIF: 2.53 vs. PLIF: 3.61, P༜0.001). At 6 months after surgery, there was no statistical difference in MF FCAS, FI rate, or CT density between the PLIF and PE-TLIF groups. There was also no statistically significant atrophy of the MF FCSA in both groups at the last (12-month) follow-up (PE-TLIF: 506.5 (488.0,535.0) mm2; PLIF: 512.0 (485.3,564.5) mm2, P༞0.05). At the 12-month follow-up, the FI rate in the MF muscles in the PLIF group was higher than that in the PE-TLIF group (PE-TLIF: 3.0 (2.8,3.0); PLIF:3.0 (3.0,4.0), P༜0.05), and the same result was also observed in CT density (PE-TLIF: 34.2 (31.8,36.9) Hu; PLIF: 30.5 (28.5,32.1) Hu, P < 0.05). Conclusion PE-TLIF can achieve satisfactory clinical results. After 12 months post-surgery, we observed no excess MF atrophy in the PE-TLIF group compared to the PLIF group, and the FI rate and muscle density of the MF in the PE-TLIF group were better than those in the PLIF group.