Lumbar interbody fusion is the common surgical intervention for lumbar degenerative pathologies. With the advent of the minimally invasive surgical techniques in spine surgery, newer implants have been introduced. Expandable cages were introduced for minimally invasive lumbar interbody fusion. They are inserted in the low-profile state and expanded in the disc space, maintaining intervertebral disc height and foraminal space through narrow corridors. Newer-generation expandable cages allow mediolateral expansion, giving a larger footprint and differential anteroposterior expansion, correcting sagittal balance. Available clinical evidence suggests that expandable cages offer superior early radiographic restoration of disc height and sagittal alignment, particularly in minimally invasive posterior approaches, while long-term fusion rates and patient-reported outcomes remain comparable to static devices. Potential risks, including subsidence, endplate injury, and increased implant cost, are also examined. Expandable cage technology continues to evolve alongside advances in surgical technique and biomaterials, and its role in contemporary spine surgery is likely to expand further with ongoing refinement and long-term outcome data.