only from an anterior approach. During a posterior discectomy operation in 1940, Cloward noticed a large hole in the remaining annulus fibrosis, and it occurred to him that this void could be filled with a piece of bone. But the patient suffered a pulmonary embolism on the tenth post-operative day, and died. This complication led Cloward to abandon his idea until 1943. Because disk herniation recurred in many cases, Cloward devised to reattempt his posterior interbody fusion procedure, which he did with success. Cloward soon became an expert of the procedure, and began to advocate for its use. In 1945, he presented the technique before the Hawaiian Territorial Medical Association, and at the Annual Meeting of the Harvey Cushing Society (now the American Association of Neurological Surgeons) in 1947. However, at the Harvey Cushing Society meeting, reception to the technique was critical. At the time, neurosurgeons were apprehensive about fusion techniques, which were traditionally an orthopedic method. Moreover, the procedure was very challenging, and was associated with complications. However, as Cloward and later advocates argued, if performed successfully, the PLIF provided better biomechanics and outcomes. Over time, after refining the technique and advocating its merits with publications and lectures, the PLIF became respected. With the help of a few other surgeons, including Paul Lin, the first PLIF Workshop was held at Nazareth Hospital in Philadelphia in 1981 and the first PLIF Symposium was held in Temple Hospital in 1983. By this time, the procedure had garnered many advocates. In later years, when pedicle screw and interbody cage instrumentation became widespread, the PLIF became the most popular method of lumbar fusion. When Cloward published his last paper on PLIF in 1985, he reported a successful fusion rate of over 92%. Cloward was the first to perform PLIF, both unsuccessfully and successfully and the first to publish a large patient series. Anterior Cervical Discectomy and Fusion (ACDF) Other than the PLIF, Cloward is well known as being an innovator in the anterior approach to cervical fusion. In the mid 1950s, techniques for anterior approach to cervical fusions were developed by four groups simultaneously; Carl Badgley, Leroy Abbott and Robert Bailey at the University of Michigan, by Robert Robinson and George Smith at Johns Hopkins University, by Albert Dereymaeker and Joseph Mulier in France and by Cloward in Honolulu. None were aware of the work of the others at the time. Bailey, Badgely