Fig. 1

Flowchart of patient selection and follow-up. Abbreviations: TLIF, transforaminal lumbar interbody fusion; BMI, Body mass index; CCI, Charlson comorbidity index; HCG, Hand grip strength; ASA, American Society of Anesthesiologists; JOA, Japanese Orthopaedic Association; EQ-5D-3L, EuroQol 5-Dimensions 3-Level version