Abstract:[Objective] To investigate the clinical efficacy and safety of lumbar decompression in the treatment of lumbar-knee syndrome. [Methods] Thirty-five patients with lumbar-knee syndrome admitted from October 2021 to January 2023 were retrospectively analyzed. The visual analogue scale (VAS) score of lower limb radiation pain and pain around the knee joint, Japanese Orthopaedic Association (JOA) score of lumbar spine, Western Ontario and McMaster University (WOMAC) osteoarthritis index score, and Lysholm score of knee joint were collected and observed before operation and at 1 week, 1 month, and 3 months after operation. The area of spinal canal was measured before operation and 3 months after operation. [Results] All 35 patients were followed up for 3-11 months, with an average follow-up time of (5.200±1.587) months.The postoperative VAS scores of radiating pain in lower limbs[(6.2±1.0),(2.4±0.7),(1.1±0.7),(0.5±0.7),P<0.05], VAS scores of pain around the knee joint[(5.1±1.1),(2.1±1.1),(1.2±0.7),(0.9±0.9), P<0.05], JOA scores[(9.2±2.1),(21.3±1.8),(23.5±1.7),(24.6±1.9),P<0.05], WOMAC scores[(51.1±9.5),(31.5±6.6),(16.9±4.0),(10.3±3.7),P<0.05], and Lysholm scores[(55.8±9.8),(72.3±7.3),(77.9±6.2),(85.3±3.9),P<0.05] and the area of spinal canal [(151.9±37.2),(180.3±34.9),P<0.05] were significantly improved when compared with preoperative scores (P<0.05). [Conclusion] Most of the 35 patients with lumboknee syndrome are mainly middle-aged and elderly women, and the onset segment is concentrated in L3/4. After lumbar decompression surgery, the radiating pain of lower limbs and pain around the knee joint are significantly relieved, and Lumbar and knee joint function and spinal canal area were significantly improved.