STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the risk factors for sacroiliac joint pain (SIJP) after lumbar or lumbosacral fusion. SUMMARY OF BACKGROUND DATA: Recently, the sacroiliac joint has gained increased attention as a source of pain after lumbar or lumbosacral fusion. We examined the factors related to the development of SIJP after lumbar or lumbosacral fusion. METHODS: In total, 262 patients who underwent lumbar or lumbosacral fusion from June 2006 to June 2009 were included in this study. All patients who did not show SIJP clinically in the preoperative screening period were considered. Of these patients, 28 newly developed SIJP. We investigated whether development of SIJP after lumbar or lumbosacral fusion is related to the presence of fusion involving the sacrum (floating fusion vs. fixed fusion) and the number of fused segments. RESULTS: The incidence of SIJP was higher with fixed fusion (13.1%) than with floating fusion (10.0%). With regard to the number of fused segments, the incidence of SIJP was 5.8% for one fused segment, 10.0% for two segments, 20.0% for three segments, 22.5% for at least four segments. Thus, the incidence was significantly higher when at least three segments were fused. Logistic regression analysis was performed to determine if the development of SIJP was related to the presence of fusion involving the sacrum or the number of fused segments. The analysis revealed that the number of fused segments was significantly associated with the development of SIJP. CONCLUSION: SIJP is a potential cause of low back pain after lumbar or lumbosacral fusion surgeries. Our study indicated that fusion of multiple segments (at least three) can increase the incidence of SIJP after lumbar or lumbosacral fusion. LEVEL OF EVIDENCE: Level 3.
STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the risk factors for sacroiliac joint pain (SIJP) after lumbar or lumbosacral fusion. SUMMARY OF BACKGROUND DATA: Recently, the sacroiliac joint has gained increased attention as a source of pain after lumbar or lumbosacral fusion. We examined the factors related to the development of SIJP after lumbar or lumbosacral fusion. METHODS: In total, 262 patients who underwent lumbar or lumbosacral fusion from June 2006 to June 2009 were included in this study. All patients who did not show SIJP clinically in the preoperative screening period were considered. Of these patients, 28 newly developed SIJP. We investigated whether development of SIJP after lumbar or lumbosacral fusion is related to the presence of fusion involving the sacrum (floating fusion vs. fixed fusion) and the number of fused segments. RESULTS: The incidence of SIJP was higher with fixed fusion (13.1%) than with floating fusion (10.0%). With regard to the number of fused segments, the incidence of SIJP was 5.8% for one fused segment, 10.0% for two segments, 20.0% for three segments, 22.5% for at least four segments. Thus, the incidence was significantly higher when at least three segments were fused. Logistic regression analysis was performed to determine if the development of SIJP was related to the presence of fusion involving the sacrum or the number of fused segments. The analysis revealed that the number of fused segments was significantly associated with the development of SIJP. CONCLUSION: SIJP is a potential cause of low back pain after lumbar or lumbosacral fusion surgeries. Our study indicated that fusion of multiple segments (at least three) can increase the incidence of SIJP after lumbar or lumbosacral fusion. LEVEL OF EVIDENCE: Level 3.