Abstract:[Objective] To investigate the clinical outcomes of lumbar decompression in the treatment of lumbo-knee syndrome. [Methods] A retrospective study was done on 35 patients who received lumbar decompression for lumbo-knee syndrome from October 2021 to January 2023. The clinical and imaging documents were evaluated. [Results] All patients had lumbar decompression performed successfully, with no cerebrospinal fluid leakage, allergic reaction, gastrointestinal discomfort and other complications. All of them were followed up for an average of (5.2±1.6) months. With time went from the point preoperatively to those 1 week, 1 month and 3 months postoperatively, the VAS score for lower limb radiation pain [(6.2±1.0), (2.4±0.7), (1.1±0.7), (0.5±0.7), P＜0.001], the VAS score for pain around the knee [(5.1±1.1), (2.1±1.1), (1.2±0.7), (0.9±0.9), P＜0.001], WOMAC score [(51.1 ±9.5), (31.5±6.6), (16.9±.0), (10.3±3.7), P＜0.001] significantly decreased, while the JOA score [(9.2±2.1), (21.3±1.8), (23.5±1.7), (24.6±1.9), P＜0.001] and Lysholm score [(55.8± 9.8), (72.3±7.3), (77.9±6.2), (85.3± 3.9), P＜0.001] significantly increased. In terms of imaging, the spinal canal area was significantly increased at 3 months after surgery compared with that before surgery [(151.9±37.2) mm2 , (180.3±34.9) mm2 , P=0.002]. [Conclusion] After lumbar decompression for lumbo-knee syndrome, the radiative pain of lower limbs and pain around the knee are significantly reduced, while the function of the lumbar spine and knee, as well as spinal canal area are significantly improved.