Introduction Lumbar fusion in elderly patients is increasingly common. This study prospectively investigated the clinical and radiological outcome of osteoporotic patients [70 years with degenerative lumbar instability treated with fusion using a new cannulated, cemented, pedicle screw instrumentation augmented with PMMA. Materials and Methods The surgical protocols, patient records, densitometry, imaging studies, and pre-and postoperative patient-reported outcome questionnaires of 23 patients (mean age, 77 years) with a follow-up of 20-49 months were reviewed. All patients underwent postoperative 3D CT scan control to assess cement leakage and instrumentation position. Serial radiological controls were analyzed for secondary complications, i.e., adjacent fractures, hardware mobilization and radiological evidence of fusion. Results Pain and function improved at 6 months and were maintained at the final follow-up. No clinical complications secondary to PMMA leakage developed. No clinical or radiological cases of non-union were observed with a mean of 1.8 levels fused. No fractures occurred in adjacent segments. There were four cases of adjacent disc disease. Three deep infections required surgical revision without removal of material and one superficial infection, all with complete remission. ConclusionThis new instrumentation for degenerative lumbar disease in elderly patients is safe and effective.