OBJECTIVE: This study aimed to compare short-term outcomes between nano-hydroxyapatite/polyamide 66 (n-HA/PA66) cage and polyetheretherketone (PEEK) cage in sclerotic Modic changes (MCs) following transforaminal lumbar interbody fusion and explore the effects of these cages on postoperative sclerotic MCs. METHODS: We retrospectively screened 1076 patients from September 2012 to September 2024 identifying 134 patients (154 levels) with sclerotic MCs after transforaminal lumbar interbody fusion. Patients were divided into the n-HA/PA66 group and the PEEK group. The incidence, timing, location of sclerotic MCs, clinical and radiological outcomes were compared between the 2 groups. RESULTS: The incidence of sclerotic MCs was 9.9% (66/669) in the n-HA/PA66 group and 16.7% (68/407) in the PEEK group (P <
0.002). Visual analog scale and Oswestry Disability Index scores were comparable between the 2 groups. Both the n-HA/PA66 and PEEK groups demonstrated similar fusion rates at 3 and 6 months after operation and at the final follow-up. At the final follow-up, the mean cage union ratios exposed to the upper and lower endplates of the n-HA/PA66 group on the coronal and sagittal plane were significantly larger than those of the PEEK group (all P <
0.002). However, there were no significant differences between the 2 groups in intervertebral space height, lumbar lordosis, and segmental lordosis. CONCLUSIONS: The incidence of postoperative sclerotic MCs in the n-HA/PA66 cage was significantly lower than that in the PEEK, which may be attributed to the better fusion status of the n-HA/PA66 cage. These results indicate that the n-HA/PA66 cage is a good biomimetic cage and may be beneficial for postoperative sclerotic MCs.