Spinal Disorders: Fundamentals of Diagnosis and Treatment Part 58. Spinal disorders are among the most common medical conditions with significant impact on health related quality of life, use of health care resources and socio-economic costs. Spinal surgery is still one of the fastest growing areas in clinical medicine. | Degenerative Lumbar Spondylosis Chapter 20 559 Non-instrumented Spinal Fusion Lumbar arthrodesis can be achieved by three approaches. The most commonly used technique is posterolateral fusion PLF which comprises a bone grafting of the posterior elements. As an alternative the bone grafting can be performed after disc excision and endplate decancellation interbody fusion by a posterior approach posterior lumbar interbody fusion PLIF or the anterior approach anterior lumbar interbody fusion ALIF . The so-called combined or 360 degree fusion is the combination of both techniques. Posterolateral Fusion Posterolateral fusion was first described by Watkins in 1953 270 and remains the gold standard for spinal fusion. The technique consisted of a decortication of the transverse spinous processes pars interarticularis and facet joints with application of a large corticocancellous iliac bone block. This method has been modified by Truchly and Thompson 255 who used multiple thin iliac bone strips as graft material instead of a single corticocancellous bone block because of frequent graft dislocation 255 . In 1972 Stauffer and Coventry 245 presented the technique still used today by most surgeons which consisted of a single midline approach Fig. 3 . However the bilateral approach had a revival some years later when Wiltse et al. 278 suggested an anatomic muscle splitting approach which was modified by Fraser 118 . Posterolateral fusion remains the fusion gold standard a Figure 3. Surgical technique of posterolateral fusion b Careful preparation of the fusion bed is important and consists of a decortication of the transverse process and facet joints and isthmus b placement of autologous corticocancellous bone chips over the facet joints and transverse processes. 560 Section Degenerative Disorders Non-instrumented posterolateral fusion remains the benchmark for comparison of fusion techniques PLIF increases fusion rate Stand-alone ALIF has not been successful Boos and Webb 24 .