OBJECTIVES: 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 (TLIF) 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 TLIF. Patients were divided into n-HA/PA66 group and PEEK group. The incidence, timing, location of sclerotic MCs, clinical and radiological outcomes, were compared between the two 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). VAS and ODI scores were comparable between the two groups. Both n-HA/PA66 and PEEK group demonstrated similar fusion rates at three and six 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 two groups in IH, LL, and SL. 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 n-HA/PA66 cage is a good biomimetic cage and may be beneficial for postoperative sclerotic MCs.