Spine surgeons are becoming increasingly aware of sacral insufficiency fractures as a complication after lumbosacral fusions. We present four patients who suffered from sacral fractures after multi-segmental posterior lumbosacral fusion together with a systematic review of the literature that yielded six papers reporting on 12 cases. Summarizing these 16 cases, the typical patient suffering from this complication is a female, elderly individual [66.4 ± 12.3 (mean ± SD) years of age, 95% confidence interval 57.89–71] undergoing multilevel fusion of 4.9 ± 3.4 (95% CI 3.1–6.8) segments. Due to nonspecific clinical complaints and inconclusive imaging there has been a median delay in diagnosis of 5 (IQR 3–6, range 1–49) weeks after onset of pain. It remains unclear whether this complication is rare or rather under-diagnosed. Fortunately, these fractures are predominantly benign conditions that respond well to conservative management in the majority of cases, depending on location.